2798 Inorganic Chemistry, Vol. 15, No. 11, 1976 hydrogen atoms, and a listing of the observed and calculated structure amplitudes (56 pages). Ordering information is given on any current masthead page.
References and Notes (1) Part 1: L. D. Brown and J. A. Ibers, Inorg. Chem., preceding paper
in this issue. (2) I. D. Brown and J. D. Dunitz, Acta Crystallogr., 14, 480 (1961). (3) J. E. O’Connor, G. A. Janusonis, and E. R. Corey, Chem. Commun., 445 (1968). (4) M. Corbett and B. F. Hoskins, Chem. Commun., 1602 (1968). (5) M. Corbett, B. F. Hoskins, N. J. McLeod, and B. P. O’Day, Aust. J . Chem., 28, 2377 (1975). (6) M. Corbett and B. F. Hoskins, Inorg. Nucl. Chem. Lett., 6, 261 (1970). (7) S. C. De Sanctis, N. V. Pavel, and L. Toniolo, J. Organomet. Chem., 108, 409 (1976). (8) R. T. Kops, A. R. Overbeek, and H. Schenk, Cryst. Struct. Commun., 5, 125 (1976). (9) P. Hendriks, K. Olie, and K. Vrieze, Cryst. Struct. Commun., 4, 61 1 (1975). IO) M. Corbett and B. F. Hoskins. J . Am. Chem. SOC..89. 1530 (1967). ’ l l j M. Corbett and B. F. Hoskins: Aust. J . Chem., 27; 665 (1974). 12) W. R. Krigbaum and B. Rubin, Acta Crystallogr., Sect. B, 29,749 (1973). 13) E. Pfeiffer and K. Olie, Cryst. Struct. Commun., 4, 605 (1975). 14) C. M. Harris, B. F. Hoskins, and R. L. Martin, J . Chem. SOC.,3728 (1959). (15) (a) K. R. Laing, S. D. Robinson, and M. F. Uttley, J. Chem. SOC., Dalton Trans., 1205 (1974); (b) S. D. Robinson and M. F. Uttley, Chem.
Ibers, Yamamoto, et al.
(16) (17)
(18) (19)
Commun., 1315 (1971); (c) S. D. Robinson and M . F. Uttley,J. Chem. Soc., Chem. Commun., 184 (1972). W. H. Knoth, Inorg. Chem.. 12, 38 (1973). A preliminary communication of this structure has appeared: L. D. Brown and J. A. Ibers, J . Am. Chem. SOC.,98, 1597 (1976). R. J. Doedens and J. A. Ibers, Inorg. Chem.. 6, 204 (1967). In addition to various local programs for the CDC 6400 computer,
programs used in this work include local versions of Zalkin’s FORDAP Fourier program, Busing and Levy’s ORFFE function and error program, and the AGNOST absorption program (which includes the CoppensLeiserowitz-Rabinovich logic for Gaussian integration). Our full-matrix least-squares program NUCLS, in its nongroup form, closely resembles the Busing-Levy ORFLS program. The diffractometer was run under the Vanderbilt Disc System as described by P. G. Lenhert, J . Apul. ..
Crystallogr., 8, 568 (i975). (20) D. T. Cromer and J. T. Waber, “International Tables for X-Ray Crystallography”, Vol. IV, Kynoch Press, Birmingham, England, 1974, Table 2.2A. (21) D. T. Cromer and D. Liberman, J . Chem. Phys., 53, 1891 (1970). (22) S. J. La Placa and J. A. Ibers, Acta Crystallogr., 18, 511 (1965). (23) Supplementary material. (24) C. G . Biefeld, H. A. Eick, and R. H. Grubbs, Inorg. Chem., 12, 2166 (1973). (25) S. D. Ittel and J. A. Ibers, Inorg. Chem., 12, 2290 (1973). (26) M. E. Jason and J. A. McGinnety, Inorg. Chem., 14, 3025 (1975), and
references cited therein.
(27) V. F. Gladkova and Yu. D. Kondrashev, Kristallografiya, 17, 33 (1972) [Sou.Phys.-Crystallogr. (Engl. Transl.), 17, 23 (1 972)], and references
cited therein.
Contribution from the Department of Chemistry, Northwestern University, Evanston, Illinois 60201, and the Research Laboratory of Resources Utilization, Tokyo Institute of Technology, 0-okayama, Meguro-ku, Tokyo 152, Japan
Studies on the Reactions of Carbon Dioxide with Transition Metal Complexes. Preparation and Structure of p-Carbonato-pentakis(tripheny1phosphine)dirhodium-Benzene STEPHEN KROGSRUD,la SANSHIRO KOMIYA,lb TAKASHI ITO,lb JAMES A. IBERS,*la and AKIO YAMAMOTO‘lb
Received July 14, 1976
AIC605 114
The rhodium-hydrido complex RhH(PPh3)d (Ph = C&) in toluene reacts with carbon dioxide at room temperature to give, on crystallization from benzene, red crystals of Rh2(C03)(PPh3) j.CgH6, as characterized by diffraction methods. One mole of C 0 2 per mole of the complex is evolved on thermolysis and acidolysis of thecomplex and by treatment with methyl iodide and triphenyl phosphite. The compound crystallizes in space group Cl1-P1with four formula units in the cell. The unit cell has dimensions of a = 22.518 (9) A,b = 28.051 (12) A,c = 12.841 (7) A,cy = 96.12 (3)O, /3 = 97.91 (3)O, y = 92.66 (3)O, and V = 7972 A3. The observed density of 1.39 (1) g ~ m is- in~good agreement with that of 1.38 g ~ m calculated - ~ for four Rh2(CO3)(PPh3)5.C& formula units per cell. There are thus two independent dimeric molecules in the cell. Refinement by full-matrix least-squares methods using 12330 observations for which Fo2 L 3u(FO2)yielded a conventional agreement index of 0.079. Each independent molecule of the compound was found to consist of two Rh atoms, both having square-planar coordination and linked by a planar carbonato ligand. Two oxygen atoms of the carbonate group are coordinated to one Rh atom while the remaining carbonato oxygen atom is bound to the second Rh atom. Triphenylphosphine ligands fill out the four-coordinate geometry of each Rh atom. The bidentate coordination of the carbonato group to the metal atom creates a four-membered ring. The average 0-C-0 angle involved in this ring is 115.9’, a slight decrease from the 120° value found in the free carbonate ion. The 0-Rh-0 angle of the four-membered ring averages 62.6’. No trend in the carbonato group C - 0 bond lengths is evident, the average value being 1.29 A. The 31P(1HJ NMR spectrum of the complex in benzene is compatible with the unsymmetrical binuclear structure consisting of two rhodium(1) nuclei coordinated respectively with two and three triphenylphosphine ligands, as found in the solid state.
Introduction Recently much attention has been focused on the interaction of carbon dioxide with transition metal compounds as a step toward an efficient catalytic system of carbon dioxide fixation. For example, insertions of C 0 2 into metal-hydr~gen,~-~ - c a r b ~ n , ~ --nitrogen,14 l~ and -oxygen15-17 bonds are known as well as the formation of CO2-coordinated complexes.10-12318-23Reactions of carbon dioxide with some rhodium complexes have been reported to produce CO2-coordinated complexes, e.g., Rh2Cl2(C02)(PPh3)5l8 (Ph = C&), Rh2(C02) (CO)2(PPh3)3,l 9 and Rh(OH)(C02)(CO)(PPh3)2.20 Previously, we reported that the reaction of RhH(PPh3)d with carbon dioxide afforded a red crystalline compound, to which,
on the basis of its ir and Raman spectra and chemical behavior, a formula of Rh2H2(C02)(PPh3)6 was a ~ s i g n e d .By ~ x-ray analysis, however, we now show that the compound in question contains not carbon dioxide but the carbonate moiety, as in the earlier case of two other suspected carbon dioxide c ~ m p l e x e s . ~The ~ - ~crystallographic ~ evidence indicates that the compound is in fact Rh2(C03)(PPh3)5.C6H6. The present paper reports the preparation, characterization, and structure of this carbonato complex. Experimental Section All manipulations were carried out under deoxygenated dinitrogen or under a vacuum. Solvents were dried in the usual manner, distilled, and stored under a dinitrogen atmosphere.
Structure of Rh2(C03)(PPh j)sC6& Infrared spectra were recorded on Hitachi EPI-G3 and 295 spectrometers using KBr pellets prepared under an inert atmosphere. 3IP(lH) N M R spectra were measured by Mr. Y. NakamuraIb on a JEOL PS-100 spectrometer operating in a Fourier-transform mode and its signals are referred to triphenylphosphine (downfield positive) as an external standard. Microanalyses for carbon and hydrogen were carried out by Mr. T. Saitolb using a Yanagimoto C H N Type MT-2 Autocorder and for phosphorus and rhodium by Mr. K. Mizubayashi.lb Analysis of the gases evolved in various chemical treatments was carried out by gas chromatography after collecting gases fractionally using a Toepler pump, by which the volumes of gases were also measured. Hydridotetrakis(triphenylphosphine)rhodium(I) was prepared either from RhC1(PPh3)326 or directly from R h C 1 ~ 3 H 2 0by~ the ~ methods previously reported. Hydridotris(triphenyIphosphine)rhodium( I) was prepared according to the literature method.26
Preparation of k-Carbonato-pentakis(tripheny1phosphine)dirhodium-Benzene. Carbon dioxide was bubbled into a suspension of RhH(PPh3)4 (1.00 g, 0.87 mmol) in toluene (20 ml) for 10-15 days. I t was necessary to keep the temperature of the system below 20 OC throughout the reaction. The initial yellow suspension changed gradually to a brownish orange suspension, and the reaction was continued until the yellow precipitate of RhH(PPh3)4 disappeared completely. After the reaction, 20 ml of hexane was added to complete the precipitation of a pale orange powder, which was washed several times with hexane and dried in vacuo. The orange powdery crude product thus obtained weighed 0.60 g (83%). Crystallization of the crude product from a mixture of benzene and diethyl ether gave red crystals of Rh2(C03)(PPh3)&H6. Anal. Calcd for C97H8103P5Rh2: C, 70.4; H, 4.9; P, 9.4; Rh, 12.4. Found: C, 71.2; H, 5.3; P, 9.4; Rh, 11.9. Benzene of crystallization was detected in a yield of 0.0652 mmol on treatment of the crystals (103.2 mg, 0.0623 mmol) with triphenyl phosphite (ca. 1 ml) a t room temperature for 1 day.
Reactions of p-Carbonato-pentakis(tripheny1phosphine)dirhodium-Solvent. (i) Acidolysis. Treatment of Rhz(CO3)(PPh3)&H6 (120 mg, 0.0726 mmol) with ca. 1.5 ml of concentrated sulfuric acid in vacuo at room temperature released 0.063 mmol of carbon dioxide. (E)Thermolysis. Thermolysis of Rh2(CO3)(PPh3)&6H6 (124 mg, 0.0749 mmol) a t 220 OC in vacuo released 0.069 mmol of carbon dioxide. (iii) Reaction with Methyl Iodide. The reaction of Rhz(CO3)(PPh3)yC6&, (1 14 mg, 0.0678 mmol) with ca. 2 ml of methyl iodide in vacuo a t room temperature liberated methane (0.076 mmol) and carbon dioxide (0.067 mmol) as analyzed by gas chromatography and mass spectrometry. (iv) Reaction with Triphenyl Phosphite. An unpurified sample of R ~ ~ ( C O ~ ) ( P P ~ ~ ) ~ *(122 C~H mg, S C0.0730 H ~ mmol) reacting with ca. 2 ml of P(OPh)3 afforded carbon dioxide (0.063 mmol) and toluene (0.065 mmol) which were identified by gas chromatography and mass spectrometry.
X-Ray data Collection Weissenberg and precession photographs of a crystal of what proved to be Rh2(C03)(PPh3)s.C6H6 yielded approximate cell dimensions and indicated that the crystal belonged to the triclinic system. Subsequent calculations have shown the space group to be Ctl-Pi. The crystal chosen for data collection was sealed in a glass capillary. Thi! crystal exhibited eight faces of the forms (OlO), (1lo), (1lo), and ( 101). Its dimensions along the principal crystallographic axes are 0.18, 0.098, and 0.55 mm. With the use of a Picker four-circle diffractometer and Cu Ka1 radiation (X 1.540 56 A) 15 high-order reflections were hand centered. The least-squares refinement of the setting angles led to lattice constants at 22 O C of a = 22.518 (9) A, b = 28.051 (12) A, c = 12.841 (7) A, a = 96.12 (3)O, p = 97.91 (3)O, y = 92.66 (3)O, and V = 7972 A3. Ultimately, four molecules of the title compound and four benzene molecules were found to be contained in the unit cell (Pcalcd = 1.38 g/cm3, pobsd = 1.39 (1) g/cm3). Data were collected by the 8-28 scan technique using nickel-filtered Cu K a radiation. Scans of 0.9O were made above and below the Kal and Ka2 peaks, respectively, at a rate of 2O/min. Ten-second stationary-crystal, stationary-counter background measurements were obtained at each end of the 28 scan range. Copper foil attenuators were automatically placed in the path of the diffracted beam when its intensity exceeded about 7000 counts/s. In the range 3.5O < 28
Inorganic Chemistry, Vol. 15, No. 11, 1976 2799
Figure 1. View of the coordination about the rhodium atoms. The thermal ellipsoids are drawn at the 50% probabiltiy level.
C 98.0°, 16 576 reflections (Ah,hk,-l) were recorded. Six standard reflections were measured after every 100 reflections. The standard reflections uniformly decreased in intensity by approximately 11% during the course of data collection. A correction for this decomposition was made. The data were processed as previously described.28.29 Those 12 330 unique reflections which obeyed the condition Fo2 2 3.(FO2) were used in subsequent calculations.
Solution and Refinement of the Structure A three-dimensional Patterson synthesis30 revealed the coordinates of the eight Rh atoms in the unit cell. Because of the unusually large number of potential independent variables, the structure was initially refined by successive Fourier syntheses. During this process, temperature factors were assigned arbitrarily constant values. Standard atomic scattering factors were used with the inclusion of anomalous terms for the R h atoms.31 Several successive Fourier syntheses resulted in the location of all nonhydrogen atoms and an unweighted agreement index of 0.20.32 Prior to starting least-squares refinement of the model, the intensity data were corrected for absorption ( p = 47.8 cm-l, Cu Ka). Transmission factors varied between 0.43 and 0.67. The function minimized during full-matrix least-squares refinement was Cw(lFol - lFc1)2. The phenyl rings and solvate benzene molecules were treated as rigid groups with D6h symmetry and C-C bond lengths of 1.392 A. An overall temperature factor was used for each group. Nongroup atoms were assigned individual isotropic temperature factors, with the exception of the Rh atoms, whose thermal vibration was treated anisotropically. Hydrogen atoms were not included in the final refinement. The final values for the weighted and unweighted agreement indices are 0.102 and 0.079, r e s p e ~ t i v e l y ,for ~ ~ the 333 variables and 12 330 data. Certainly, relaxation of the rigid-group approximation or assignment of individual temperature factors to the group atoms would have improved the agreement indices. The resulting slight increase in precision, however, would not have been justified by the greatly increased computing expense. The presence of two independent Rh2(C03)(PPh3)5.C6H6 units in the cell raises the question of undetected symmetry in the cell. Certainly the cell reduction did not suggest any hidden symmetry. Also, analysis of the absorption-corrected data sorted on the scattering angle failed to reveal reflections of similar intensity and 28 values. Examination of the refined atom positions inidicates that the two independent molecules are related roughly by a 21 axis. The maximum electron density of the final difference Fourier map of 0.80 e/A3 was located in the vicinity of phenyl ring R152. This peak height is about 2Wo of a typical carbon atom peak. Examination of Cw(lFol for various classes of reflections based on Miller indices, IFol, and setting angles shows no unusual trends. Atomic positional and thermal parameters along with their standard deviations are given in Table I. Tables I1 and 111 list derived positions for the phenyl ring carbon atoms and parameters for the rigid groups. Selected bond distances and angles are tabulated in Table IV. A table giving the final values for the observed and calculated structure amplitudes is available.33 In these tables and elsewhere each atom is uniquely named according to the following systematic numbering scheme. Nongroup atoms are designated by the chemical symbol for the atom plus one or two numbers: the first indicates of which independent molecule the atom is a part; the second number (if present) refers to the numbering scheme in Figure 1. Names for phosphine phenyl groups consist of the letter "R' followed by three numbers. The first number refers to either molecule one or two, the second refers to the phosphorus atom to which the ring is attached, and the third refers to the number of the ring on the phosphine. Names for the carbon atoms are composed of the identifier for the ring of which they are a part, plus
2800 Inorganic Chemistry, Vol. 1.5, No. I I , 1976
Ibers, Yamamoto, et al.
Table I. Positional and Thermal Parameters for the Nongroup Atoms of Rh2(C0,)(P(C,H,),),C6H6 A
?!E I...
e..
RH1111
-0.1169514l
RHll2) RHIZII
i
..I...
*.
....*:.
R
1 1 . 1 . ...I
C....f*
C ..
1 . + . * r . * i .
B l l O R 8.A
..I..
-0.24997(4)
0.17725(31 0.03523131
-0.28280171 -0.1665617)
12.70(23) 12~72122l
0.38326(41
0.3067813)
-0.30496171
14.51 ( 2 4 )
0.4415013)
-0.3768118)
PI111
0.2461714) -0~102501141
0.14177112l
-0.449631261
14.34124) 2.7117)
Pll2)
-0~02101114l
PI131 Pli4l
-0.15980114~ -0.20613114)
0.19656112) 0.23352111) -0~0048811ll
-0.22477126l -0.176531251 -0.06239125)
2.6217) 3.16171 2.7917)
PI151
-0.33735115)
-0.00642112l
-0.21200127l
RHILZ)
PI211
0.38620114l
PI221
0.48002114) 0.35188115) 0.29849115) 0.15535115) -0.204013) -0.2725131 -0+1813(3) 0.2937131
PI231
PI241
PI251 O l l l l OllZ)
01131 0121)
0122) 0123) Clll
0.2213141 0.316313) -0.2185151 0.2788161
.........,.** GI21
0.30997(12) 0.29827112l
-0.12226126l
-0.30734126)
2.951 71 2,96171 2.9717)
0.27449112) 0.51400112)
-0.48043127) -0.38626127)
3.17(71 3.26(7)
0.47142112)
-0.424401271
3.3317)
0.143491271
-0.315416)
2.95(17)
0.08781(261
-0.288416)
3.21(161
0.08806 I271
-0.2029 ( 6 1
2.901161
0.32653l23l
-0,3066 ( 6 )
3. 06117)
0.576591291 0.403041281 0.107014l 0.3672(51
-0.3478161
3.811181 3.23117)
-0.3350161
-0.268119)
2.63(24)
-0.3289110l
3,471271
2
822 e...
....
8.101151
833 312 +...*.*.**...*...***...*..~******.~,*..~...~..~*..
813
-1.02(14) -1.99(141
5.2131
3 - 1 4 115)
48.0 ( 8 I
0.12114l
6.6(31
3.85(261
9.98(161
€3.318)
0.03115)
4.4131
6.84129)
lJ.01114)
7.7(3)
023
47.7(71 44.8(71
'
2.361261 5.211251
~ . ~ t C . . . . ~ . ~ . ~ . . ~ ~ . . ~ ~ ~ ~ . . . . . . . ~ . . . . . ~ ~ ~ ~ . ~ . ~ ~ ~ ~ . . . ~ * ~ * * . . ~ ~ * * . . . . ~ . . * ~ . * . . ~ ~ . . ~ * ~ ~ ~ . ~ ~ ~ . * ~ . ~ * ~ ~ . . ~ ~ . * ~ . . . ~ ~ . ~ ~ . . ~ . . ~
Estimated standard deviations in the least significant figure(s) are given in parentheses in this and all subsequent tables. The form of the anisotropic thermal ellipsoid is exp[-(B,,h2 + B 2 , k 2 + B J 2 + 2B12hk+ 2B,,hl + 2B2,k1)]. The quantities given in the table are the thermal coefficients X104. The minimum, intermediate, and maximum values (A) of rms displacement for the anisotropically refined atoms are as follows: R h ( l l ) , 0.155 (2), 0.186 (2), 0.206 (1); Rh (12), 0.152 (2), 0.192 (1),0.215 (1); Rh(21), 0.174 (2), 0.195 (2), 0.203 (1);Rh(22), 0.181 (2), 0.195 (2), 0.232 (1). a
the suffix C ( I ) where I varies from 1 to 6.
characteristic ir bands in the present complex and in the reported C02-coordinated Rh complexes, e g , 1498 (s), 1368 Results and Discussion (s), and 813 (s) cm-l for Rhz(C02)(CO)~(PPh3)3,~~ 1600 (s), Preparation of Rh2(C03)(PPh3)5 and Its Chemical 1355 (s), and 825 (m) cm-' for Rh2(COz)z(C0)2Properties. Passing gaseous carbon dioxide through a yellow (PPh3)3.C6H6,'9 1602 (s), 1351 (s), and 821 (m) cm-' for suspension of the hydridorhodium complex RhH(PPh3)4 in R~(OH)(COZ)(CO)(PP~~)Z~~ and 1630 cm-I for Rh2C12toluene a t about 20 "C for 10-15 days yielded an orange (CW(PPh3)5." diamagnetic compound, which was recrystallized from The following chemical behavior of the carbonato complex benzene-diethyl ether to give red crystals. These crystals have is compatible with the observed binuclear p-carbonato been unambiguously characterized as the carbonato complex structure. Acidolysis of the complex by concentrated sulfuric Rh2(CO3)(PPh3)5.C6H6 (Figure 1) on the basis of the x-ray acid releases only carbon dioxide mole for mole of the starting complex. Half a mole of carbon dioxide per rhodium atom structure determination (see below). Although the reaction is liberated either on thermolysis or on the reaction of the temperature can be raised to ca. 50 OC at an initial stage of the reaction, it is important to keep it below 20 "C subsecomplex with triphenyl phosphite. Treatment of the complex quently or an uncharacterized compound, whose infrared with methyl iodide releases the calculated amount of carbon spectrum possesses strong bands characteristic of tridioxide per mole of the complex together with methane, phenylphosphine oxide, is produced predominantly. The evolution of which may arise from a hydride intermediate reaction rate did not increase on raising the CO2 pressure up produced by ortho metalation of the triphenylphosphine ligand. The complex dissolves in pyridine to give a deep brown soto 50 atm. Existence of a small amount of free triphenylphosphine in the reaction mixture hindered the formation of lution. Heating this solution at 70 "C liberates carbon dioxide the carbonato complex. The reaction was completed in a much and gives an unidentified complex containing pyridine and triphenylphosphine ligands. Heating the toluene solution of shorter period (several days) when RhH(PPh3)3 was employed in place of RhH(PPh3)4. These results suggest that prethe complex at ca. 80 " C also causes decomposition to yield dissociation of triphenylphosphine ligand from RhH(PPh3)d carbon dioxide and some species containing triphenylphosphine is necessary to initiate the reaction. Addition of a small oxide. In some cases, red crystals having an approximate amount of water affected neither the reaction rate nor the yield composition of RhH(PPh3)2(0PPh3)2 were isolated from this of the carbonato complex. system. Anal. Calcd for C64H6102P4Rh: c , 70.6; H , 5.7. Found: C, 70.1; H, 5.2. Ir: u(P=O) 1180, 1120, 720 cm-'; The infrared spectrum of the carbonato complex exhibits v(Rh-H) was not observable. no band from v(Rh-H) but does possess several new bands, probably from the bridging carbonato group, as follows: 1485 31PNMR Study of Rh2(C03)(PPh3)5. The ' H N M R spectrum of the complex shows only phenyl proton signals. A (s), 1460 (vs), 1360 (m), 1350 (m), 820 (w), and 500 (m) thorough examination of the high-field region using a FT mode cm-'. Bands at 1300 (s) and 1660 (m) cm-I were observed in the Raman spectrum of the carbonato complex. These ~ p e c t r o m e t e rdid ~ ~ not show any indication of a signal from vibrational spectral data differ significantly not only from those a possible hydride ligand. reported for a di-pcarbonato complex of molybdenum, The 31P(1H)NMRspectrum of the complex in benzene, as shown in Figure 2, is compatible with the unsymmetrical Mo~(CO~)~(CO)~(PM~~P~)~, in which the carbonato abdimeric structure found in the solid state. A doublet of sorption is observed at 1835 cm-1,23but also from a mononuclear chelate carbonato complex, P t ( C 0 3 ) ( P P h 3 ) ~ . ~ ~ doublets with a chemical shift of 36.3 ppm (downfield from Furthermore, marked differences are observed between the external free PPh3 reference) may be assigned to the
Inorganic Chemistry, Vol. 15, No. 11, 1976 2801
Structure of R ~ ~ ( C O ~ ) ( P P ~ ~ ) S . C ~ H ~
Table 11. Derived Parameters for the RigidGroup Atoms of Rh,(CO,)(P(C,H,),), Molecule 1
!!E.,.+, .I..
'
....".l:l...l.........fC...
5.....I.
.... ..... *..e
0.)
ATOM
I....
* I . . . *
. . 1
RlllCl
-0.147141
0~08461241
-0.492
I71
4.641131
R132C4
-
RlllC2
-0.177141
0.0721 1291
-0.594
161
4.641131
R132C5
RlllC3
-0.20414.)
0.026131
-0.624l51
4.641131
R132C6
RlllC4
-0.202141
-0.PD74124I
-0.551171
4.64 I 1 3 I
R111C5
-0.172141
0.00511291
-0.44916l
RlllCb
-0.145141
0.051 I 3 1
RllZCl
-0.130141
Rll2C2
.......*.... ...5
....
0.A
E..*..IC.*.-5.* 0.109131
-0.404 ( 7 1
5,471151
-0.299 (41
0~260131
-0.403171
5.471151
-0.258141
0.23811241
-0,334 18)
5.471151
R133Cl
-0.210 (41
0.21214l
-0.087181
6.371 171
4.641131
Rl33C2
-0.19614)
0.172141
-0.037
-0.419151
4.641131
R133C3
-0.232
0.155131
0.03218l
6.37117)
0.1820 1291
-0.54916)
4.59(131
R133C4
-0.zn3141
0.179141
0.051 1 8 1
6.371171
-0.162141
0.2ZlI3I
-0.51415)
4.59113)
R133C5
- 0 , 2 9 7 I41
0.219141
0.000 I91
R112C3
-0.184141
0.25241271
-0.58417)
4.591131
R133C6
-0.261151
0.236111
R112C4
-0~175141
0 - 2 4 6 (31
-0.689161
4.59113)
R141Cl
-0.13751281
0.028131
R112C5
-0.14314)
0~207131
-0.724151
4.591131
RlklC2
-0.089141
0~034131
RllZCb
-0.121141
0.1752 ( 2 7 1
-0.65517)
4.59113)
R141C3
-0.034
R113Cl
-0.0 3 2 I 3 1
-0.500171
R141C4
Rl13C2
-
0.1251 31
0.294 14 I
(51
(91
-0.069181 0~014161
-0.040 I91
6.371171
6.371 171 6.371171 3.981121 3.981121
01054131
0.014161
3.981121
-0.02771281
0.067131
0~123Ibl
3.981121
I SI
0.0 1 7 I 3 1
0.0776 I261
-0.514171
4.19 1121 4.19112l
Rl4lC5
- 0 , 0 7 6 I41
0.06113l
0.177 ( 5 1
3.981121
R113C3
0.03314)
0.06541221
-0.561171
4.191121
R141C6
-0.131131
0.041151
0.123161
3.981 121
R113C4
0.068151
O.lOlI31
-0.59517)
4.191121
Rl42Cl
-0.$75141
-0.0625123l
-0.099 (71
4.391 13)
R113C5
0.054131
0.1488l261
-0.580
4.191121
R142C2
-0.1931bI
-0.085131
-0.201161
4.39 1131
R113Cb
0.00414l
0.1610122l
-0.533171
4.191121
R142C3
-0.174141
-0.13Ol3l
-0,232 ( 5 1
4.391 131
Rl2lCl
-0.00614l
0~211131
-0.078151
4.581131
R142C4
-0.136141
-0.1527lZ3l
-0.160171
4.39 1 1 3 1
RlZlCZ
0.028151
0,25111291
-0.025171
4.58113)
R14ZC5
-0.11714l
-0.130131
- 0 . 0 5 8 I61
4.391131
R121C3
0.03414)
0.259812bI
0.0841 7 1
4.58 I 1 3 1
Rl42C6
-0~137141
-0.085131
-0.028151
R121C4
0.007141
0.228l31
0.142I5l
4.58113)
R143Cl
-0.250141
-0.017131
0.044 I61
4.661131
R121C5
-0.027141
0 , 1 8 7 5 1291
0.090 ( 7 1
4.581131
Rl43C2
-0.25114)
-0.0591129l
0 . 0 9 1 171
4.661131
RltlC6
-0.034141
0~178812bl
-0.020171
4.58113)
R143C3
-0.28814)
-0~06561261
0.167 ( 7 1
4.661131
R122Cl
0.021141
0114141231
-0.243171
4.06112I
R143C4
-0.325141
-0.030131
0 . 1 9 6 161
4.66 I 1 3 1
R122CZ
-0.00901281
0.099131
-0.227171
4m061121
R143C5
-0.325
0.0129 1 2 8 1
0.14917l
4 . 6 6 1 131
R122C3
0.018141
0.0555123l
-0.241171
4.06112l
R143C6
-0.287 (41
0.01941251
0.073171
4.661131
R122C4
0.075141
0.05481251
-0.271171
4.061121
R151Cl
-0.391141
0.026131
-0.155 I 8 1
5.551151
R122C5
0.10521281
0.097I3l
-0.287171
R151C2
-0.454151
0.00591261
-0.157181
5.551151
RlZZCb
0.078141
0~14D7lt3l
-
4 . 061121 4.061121
R151C3
-0.496 I 3 1
0.032141
-0.108181
R123Cl
0.023141
0,244131
-0.276111
4.891151
R151C4
-0.48014)
0.078131
-0.058
R123C2
0.084141
0.255I3l
-0.24016)
4.89113)
R151C5
-0.42315)
0.09811261
-0.05618I
5.551151
Rl23C3
0.11451291
0 . 2 9 0 131
- 0 . 2 8 6 1 71
4.891131
R151C6
-0.181131
0.072141
-0.105181
5.551151
R123C4
0.085141
0.313131
-0.367171
4.891131
R152Cl
-0.368151
-0.020141
-0.355 I 7 1
7.44 I191
R123C5
0.024141
0 . 3 O l I 31
-0.40 3 1 61
4.89113)
Rl52C2
-0.33714)
-0.002141
-0~4301101
7,44119)
171
0'. 2 7 3 I 7 I
141
I81
4.391131
5.551151 5.55 I 1 5 1
Rl23C6
-0~00671291
0. 2 6 6 l 3 l
-0.35717)
4.89113)
Rt52C3
-0.360151
-0.012141
-0.53719)
7.44119)
R131Cl
-0~11615l
0.285131
-0.093181
61441171
R152C4
-0~414151
-0.039141
-0.569 17)
7.44119)
R131C2
-0~122141
0.296141
0.012191
6.441171
R152C5
-0.44514)
-0.057141
-0,494 I10 I
R131C3
-0.091151
0.337141
0.070 I61
6.44 I171
R152C6
-0,42215)
-0~048141
-0.387
19)
7.441191
R131C4
-0.053141
0.366131
0.022181
6.441171
R153Cl
-0.350141
-0.0673126I
-0.174 1 8 1
5.291141
R131C5
-0.047141
0.354141
-0.084191
6.441171
R153C2
-0.332
-0.106141
-0,237 ( 6 1
5.29 I141
R131C6
-0.07815)
0.313141
-0.142161
6.441171
R153C3
-0.33614)
-0.15213)
-0,205171
5.29 1141
R13ZCl
-0.214141
0.266111
-0.265171
5.471151
R153C4
-0,357141
- 0 . 1 5 9 1 I261
-0.lllI8)
5.29 1 1 4 1
Rl32C2
-0.209141
0~31613I
-0.26617l
5.471151
R153C5
-0.374141
-0.120141
-0.048
5.291141
R132C3
-0.250141
0.33731241
-0.335181
5.471151
R153C6
- 0 . 3 7 1 141
-0,074I3l
-0.079 ( 7 1
...
141
..*..........*.,..*.~~'*...*~.*...***...*..*.**.*~**...**.***...***..~~*~**..*..~...~**.**.~....***..*****.~*.*........*..****.
161
7.441 191
5.29 1 141
R I G I O GROUP PARAMETERS
...**.................~.*.*. GROUP
X
A
C
z
I
OEL T A
B
"....*~.****...*...**..*~~.*.*.~~..~.~.*..**.~**..~.~~........*~~...*.~.~..,*.~.*.~~.~.~...~~~...**.*.
EPSILON
ETA
R l l l
-0.174501241
0.03860 I221
-0.5214 ( 5 1
-2.45338119)
-2.05403191
RllZ
-0~152401241
0.21380 ( 2 1 1
-0.6191 ( 5 1
-2.k6344116l
2.21384191
-1~7518111bl
R113
0.01830 ( 2 4 1
0~11320121)
-0.5471141
-0~20106181
3.01277191
-0.59059191
Rl2l
0.000401241
0.21930121l
2.53787191
-3102974191
1.6260319l
Rl22
0.04810 (24)
0.098101201
-0.2568
-1.03551181
2 . 7 7 4 8 4 191
-0.20427110)
R123
0.05390127I
0.27810I211
-0~321615l
2.619121101
-0~601981111
R131
-0.084701291
0.325201251
-0.0351161
-0.986151221
11132
-0.25400 1281
0.28770 1241
-0.3145151
2.65251110l 0~64805111l
%
0.0323151 141
R133
-0.246513)
01195501251
- 0 . 0 184 I 5 1
R141
-0.08260 (251
0e.04760 1 1 8 1
0 a 068414)
R142
- 0 . 1 5 5 4 0 (241
-0.107601201
R143
-0~287701251
- 0 . 0 2 3 1 0 1211
R151
-0.438401291
0.052101241
11152
- 0 . 3 9 1 0 131
-0~02970IZbI
-0.4620
5153
-0,35320 I 2 5 1
-0.11320123l
1.30009111l
Xc.
IC. AN0 I
SILOPI.
2.8 3 9 2 1 I 1 0 I
-1.80132116l
0.1199141
3.06289llll
1~9162312Z) - 0 . 6 0 322 I1 1 1 2.33767llll
-1.97130181
1.249171231
-2.13799191
-0.64574 I 1 7 1
0134622191
3 , 0 9 4 1 6 I91
-0.761591101
-2.967241101
2.553701111
I61
2.158581131
-2.789641131
-1.451191131
- 0 . 1 4 2 1 151
0.878941211
-2.053371101
2 . 4 4 7 7 7 I211
-0.106515l
.......*.....*....**~***.*.~,*.~~~.*.*~~.~.......~..~*..**.*.*.*....~~.~***.*~..**~*~*.* 4
2.O772Ollll
1.558 65 I 2 3 1
-0.129815)
-0.47154119I
".~*~~..*~~....~*....~.~*...*..**.*~****..
PRE THE F R I C T I O N A L COORDINATES OF THE O R I G I N OF THE
AN0 E T A I R P O I P N S I HAVE BEEN OEFINEO P R E V I O U S L I I S , J .
2.242611101
RIGIO
GROUP.
LP PLACA AN0 J.A.
mutually trans Pa phosphorus nuclei which are cis from the oxygen atom of the bridging carbonato group and the Pb ligand. The P b resonance is partly obscured in the slope of the P, signal but a triplet and a part of another triplet, which constitute together a doublet of triplets, are discernible. These signals are best accounted for by assuming the AMX2 spin system in which Pb, Rh ( I = l/2), and Pa nuclei constitute the A, M, and X2 portions, respectively. The other part of the spectrum which shows an apparent doublet of doublets in Figure 2 is from the Rh(PPh3)z portion
B
THE R I G I D GROUP ORIENTATION LNGLES DELTA.
IBERSI
A C T A CRYSTALLOGR..
18,
EP-
511119651.
of the dinuclear complex. A close examination of the spectrum reveals that this portion is not a doublet of doublets but rather two pairs of doublets. The doublet which appears at the higher field with the greater intensity may be assigned to the P, ligands, which are mutually cis and coupled with the Rh(2) atom. The other doublet labeled Pd in Figure 2 with a 12J(Rh-Pd)l value of 189 Hz varied in its intensity from one sample to the other and is considered to be associated with a yet unidentified species formed by dissociation or partial decomposition of the carbonato complex. Heating the benzene
2802 Inorganic Chemistry, Vol. 15, No. 11, 1976
Ibers, Yamamoto, et al. Molecule 2 plus Solvate Benzene Molecules
Table 111. Derived Parameters for the RigidCroup Atoms of Rh,(CO,)(P(C,H,),),
.........
ATOM
............ ....
..........r..
2
. . . . . .*.X.. . .*
I.: ...*........*.I:
ATOM %!. .*...*.*...~*.*.~.*.*
f..,..
I.......
.....*.e::
2 . . I .
R2llCl
0.378141
0.36771251
- 0.044
4.74 113 I
11233C4
Oa47914l
1.2'18 1 3 I
-3.703161
4.251121
RZllC2
0.370141
0.408131
-0.099151
4.741131
R233C5
0.425141
0.21.7131
-0.731 I 5 1
4.251121
RZllC3
0.364141
0.45241271
-0.Ok5
4.741131
9233C6
0.439141
0.25681201
-1.564 I71
4.251121
R2llC4
0.365141
0.45731251
0.064171
4.741131
R241C1
0 . 2 0 2 15 I
C.568131
- S . 305 171
5 . 9 3 1 151
RZllC5
0.373141
0.417131
0,120 1 5 1
4.74 I 1 3 1
R24lC2
0.257151
C.56101281
-9. 2 1 4 1 8 1
5.931161
RZllCb
0.379141
0.37261271
01066171
4.741131
R24lC3
0.245141
0.h00141
-1.145171
5.931151
R212Cl
0.449ISl
0.206131
5,211141
424lC4
0.257151
0.647131
-1.159 171
5.951161
R212CZ
0.494141
0.31731241
0.022181
5.211141
9241C5
0 . 2 8 2 151
0.55401281
-].?bo
101
5.931161
R212C3
0.543141
0.299131
0.079171
5.21114)
R241C5
0,294141
0.615141
-1. 328 l b l
5.9311bI
R212C4
0.546141
0 a 2 4 9 131
0.070171
5.211141
R242Cl
0 . 3793 1 2 8 1
1,61213l
-1.334171
4.851131
RZlZC5
0.501141
0.21831241
0.019181
5.211121
RZi2CZ
0.413141
0.4Sl131
-1. 795 151
4.851131
R212Cb
0.452141
0.237131
-0,038171
5.211141
92rZC3
0.475141
0.40?111
- 1 . 7 6 4 171
4.851131
R213Cl
0.322141
0.270131
-0.lOt18l
5.871151
P242C4
0 . 5 0 2 5 1281
0.509 1 3 1
-1.272171
4.851131
R213C2
0.296141
0.273131
-0.00817l
5.871151
R242C5
0.458 1 4 1
0.578131
-1,210161
4.85 1 1 3 1
R213C3
0.2C9141
0.242141
0.004161
5.67(15)
9242C5
0 . 4 0 7 141
3.519131
-1.241171
iiAS113I
R213C4
0.22714l
0~206131
-0.078 181
5.871151
rt243Cl
0.337141
0.533131
-0,519151
4.86 I 1 3 1
R213C5
0.252151
0.202131
-0.171 171
5.871151
5243C2
O12F7131
0.511131
-0. 505 1 7 1
4.8L113I
R213C6
0.300141
0 . 2 3 4 141
-0,183161
5.871151
Q243C3
0.274 1 4 I
0+5?1131
-1.706161
40861131
R221Cl
0.530141
0.340131
-0.208161
4.901131
R243C4
0.321141
0.553131
-3.721 151
41*61131
R221C2
0.510131
0.386131
-0.184171
4.901111
R243C5
0.3hll31
0.574 1J
-1.635171
4.86 f 1 3 1
R221C3
0.545141
0.41891251
-0.109171
4.90 I 1 3 1
Q243C6
0. 3 5 4 1 4 1
0.55L131
-3.533 l b l
4,861131
RZZlC4
0.599141
0.406 131
-0.05716)
4~901171
R251Cl
0.127151
0.57E13I
-1.490191
6.61.1171
R221C5
0.619131
0.36iI31
-0.001171
4.901111
Q251C2
0.148151
C.571141
-1.41llbl
6.641171
R22lCb
0.585141
0.32771251
-0.156171
4.901131
Q251C3
0.137151
0.512131
-1.481191
b.Fb1171
R222Cl
0.505141
0.319131
- 0 , 4 2 9 161
4.761131
Q251C4
0.117151
0.638131
- 0 . 5 % 9 191
6 . 6 4 1171
R222C2
0.400121
0.361131
-0.459171
4.761131
R251C5
0.107151
0.553141
-1.547 16 I
6.641171
R222C3
0.49314)
0.37861261
-0.551171
4.761131
3251C6
0.1'.7151
0.522131
-3.598 191
6.64117)
RZZZC4
0.532141
0.35513)
-0.612161
4~761131
Q252Cl
O.lC0141
C, 475 141
-1.319171
5.191151
R222C5
0.556141
0.313131
-0.582171
4.761131
Q252C2
0.114141
0.441t31
-1.253 I81
5,591151
R222C6
0.543141
0.29501261
-0.490171
4.761131
Q252C3
0.07fl151
O.4'-!
131
-1.169 1 7 1
5.t91151
R223Cl
0.509141
0.23841251
-0.295
5.271141
R252C4
0.C36141
C.475141
-3.159 I 7 1
5.691151
R223C2
0.56814)
0.227131
-0.30418I
5.271141
Q252C5
0.01014l
1.51013l
-0.2?7 1 8 1
5 . t 9 1151
R223C3
0.504131
0.180141
-0.299181
5.271141
R252C5
0 . C65151
3.511131
-3.307171
5.691151
R223C4
0.542141
0.1442 1 2 5 l
-0.285181
5.271141
R253C1
0.111(4)
0.424141
-3.517171
4.971141
R223C5
0.403141
0.156 131
-0.276 1 81
9253C2
O+C48r41
0.r23131
- 0 , 5 3 3 171
L.971141
R22336
0.467(31
0.203141
-
5.271141
0.280 1 0 1
5.271141
R253C3
0.01551291
0.387131
-1.5;5
181
4.971141
R231C1
0.310141
0.312131
-0.571171
5.191141
R?53Cr
0. C45141
0.153131
- 0 . 5 ~ 2171
4.57114l
R231C2
0.270141
0.29141241
-0.658181
5.191141
R253C5
0 I l C 0 141
0.355131
- 1 . 6 ~ 6I71
4.571141
R23lC3
0.24714)
0.320131
-0.735161
5.19 1 1 4 1
R253C6
0.141512dl
0.190131
-1.574 181
b.971141
R231C4
0.26414!
0.369 131
-0.724171
5.191141
SNLlCl
0. 1 4 0 I 5 1
3 I 276 1 8 1
9.781251
R231C5
0.303141
0.38901241
-0.636181
5.191141
~
0.110151
1.310 1 1 1 1
9.781251
R231C6
0.32714)
0.351131
-0.560161
5.191141
SNZlC3
-0
406161
3.046141
3.4011131
9.78 1251
R232Cl
0.296141
0.225 131
-0.474 1 81
5.73 115 I
BNZlC4
-0, 353 1 71
?.l11151
5.467 1 8 1
9.78 1251
R232CZ
0.306131
0.177141
-0.488181
5.731151
BYZlC5
-0.310151
0.141151
3.4331111
9.78 1251
R232C3
0.264151
0.1411126l
-0.481181
5 , 7 3 1151
BNZlCb
-0 * 321161
O.lCb(4l
0.33141
9.78 125 I
171
171
-0.037171
I01
~
2
-3.3
74
171
1- 0 .~4 1 62 1 5 1 I
I
R232C4
0.207141
0.154131
-0.460181
5.73(151
BNZZCl
0.1-{4 1 8 1
0.172161
R232C5
0.195131
0.202141
-0,446 1 8 I
5.73 1151
BNZZC2
0 - 1 7 7 1 71
0.167191
-3.008112)
13.5131
R232C6
0.239151
0.23751261
-0.453181
5.73 ( 1 5 1
8 ~ ~ 2 r 30 . 2 1 0 1 9 1
0.407151
-:.0701141
13,5131
R233Cl
0.40214l
0.248131
-0.570161
4.25 1121
8V%2C4
0.210181
0.453161
O.Ol0116l
13.5131
R233C2
0.435141
0. 2 0 9 1 3 1
-0.542151
4,25(121
8NZ2C5
0,157171
c.
01005 I121
13.5131
0.474141
0.18941261
-0.609171
4.251121
eNL2C5
0 . 1 2 4 191
0.41015I
0.117 1141
13.5131
*.*.*..*
R233CS
11060 1161
45 9 191
13.5131
.....*..~ ..........~ ......******.....*...*..............**....**...*.*.....*.**..**...*.**1 .....*.1........ '
R I G I O GROUP PAQAMETERS A X
GROUP
3
2
Y
OELTO
EPSILON
ETA
* . * . . . 1 1 . 1 . . . . . . . . . . . . . . . . . . . . . . .
11211
0.371501231
0.41250 1 2 2 1
0.0113151
-2.977361 181
RE12
0.497501281
0.267801231
0.02Y715I
2.723581lOI
R213
0.274301201
0.23700123l
-0.0896151
11221
0.56460 I 2 7 1
0.373301221
-0.1325
R222
0.518101251
0.33680(21l
-0.5206151
R223
0.525801281
0.19130123l
-0.2898121
R231
0.286601251
0.3402Ol231
-0.6472
151
R232
0.2515 1 3 1
o.im930(251
-0,4572
(51
R233 R24l
0.440801241
0.220101201
-0
0.26920 1261
0.60750 1251
-0.2367151
R242
0.440901271
0~510501211
-0.3027151
I
3.230281201
151
-2.39128191 -2.498371101
1.8332611PI -0
I
527041111
0.725541101
5367141
C.324281111 - 0 , 4 6 8 3 4 1141
0~11000llFl
-2.10594131
1~613371181
2.875141101
2+7C15211Ol
1.94319 1111
3.527931281
-3.09042 [ ? I 2.89017191
2 . ' 4 6 6 8 1 I 10 1
-2.023311101
-?. 8 7 9 1 4 1 1 0 I
-3.147621111
-2.579781lOl
-2,33191 1111
-2.8 5 0 5 3 110 I
2 1 9 t 7 1 6 1111 -1.097251121
2.48512141
2.42960 1 1 1 1 -2.171711101
R243
0.313801261
0.542601201
-0.6197151
-0.97 8 9 0 I 1 0 I
R251
0.127101271
0.567201271
-0.53911bI
2.5956E1211
2.14301 1121
R252
0.07200128l
0.475701231
- 0 . 2 3 8 4 151
0.46687111l
2 . 8 9687 I 1 0 1
2.137C41111
0.078001281
0.38070 1 2 2 1
-0. 6 7 3 4 7 1 1 1 1
R253
-2.67922 191
2.lCZCO1141 0.25626 1 1 5 )
-0.5896 151
-2.005221131
2.79492 I 1 0 I
BNZl
-0.3634 I41
0.1256131
0.3665 1 8 1
-1.041991151
3 . 1 1 5 9 6 1171
BUZZ
0.1671151
0.4126141
0.0389181
.........**........................*.*..~*..*......*...
0 , 7 2 8 0 141
-2.389081191
-1.75434110) -0.9175C
1211
1.12421 I141
-0.3820 1 3 1
~....*..**..***..*******.**........***....**..**.~...*......~*...**.-.*..*..
A Xc.
.Ic, A H 0 .7
SILON,
4RE THE FR4CTION4L COORDINATES OF THE O Q I G I N OF THE
LHO E T I I R A O I A W S I H4YE BEEH OEFINEO PREVIOUSLY1 S . J .
R I G I O GROUP.
L 4 PLACA LNO J.4.
solution at 80 OC caused the complete broadening of the Pa, Pb, and P, signals, whereas the peaks P d and that of free triphenylphosphine oxide (observed at 30.7 ppm), which may
B
THE R I G 1 0 GQOUP OQIENTATION 4NGLES OELTP,
IBERS,
ACTA CQVSTALLOGQ.,
18,
EP-
511119651.
be present in the system as impurity, remained unchanged. Cooling the system caused the reappearance of the Pa, Pb, and P, signals indicating the exchange of the coordinated tri-
Inorganic Chemistry, Vol. 15, No. 11, 1976 2803
Structure of Rh2(CO3)(PPh3)5.C6H6
Table IV. Selected Bond Distances and Angles in Rh,(CO,)(PPh,), Distances. A
pb
Figure 2. "P{'H} C,H, at 25 "C.
Atoms
Molecule 1
Rh(l)-P(l) Rh(l)-P(3) Rh(l)-P(2) Rh(1)-O(1) C-O(l) C-0(2) C-0(3) Rh(2)-P(4) Rh(2)-P(5) Rh(2)-0(2) Rh(2)-0(3)
2.335 (4) 2.309 (4) 2.209 (3) 2.105 (7) 1.295 (12) 1.290 (12) 1.275 (12) 2.199 (3) 2.207 (3) 2.107 (8) 2.138 (7)
Molecule 2 2.330 (4) 2.337 (4) 2.207 (3) 2.113 (7) 1.255 (13) 1.328 (13) 1.299 (13) 2.183 (5) 2.208 (5) 2.126 (8) 2.104 (7)
2'328 (13)' 2.208 (3) 2.109 (7) 1.290 (24)
2'199 (') 2.119 (16)
Angles, deg
J(P,-PJ=LO Hz
NMR spectrum of Rh,(CO,)(PPh,),C,H,
Average
in
Atoms
Molecule 1
Molecule 2
Average
P( 1)-Rh( 1)-P(2) P( 1)-Rh( 1)-P(3) P( 1)-Rh( 1)-0(1) P(2)-Rh( 1)-P(3) P(2)-Rh( 1)-0(1) P(3)-Rh(l)-O( 1) Rh( 1)-0(l)C 0(1)€-0(2) 0(1)-C-0(3) 0(2)-C-0(3) C-O( 2)-Rh( 2) C-O(3)-Rh(2) P(4)-Rh(2)-P(5) P(4)-Rh( 2)-O(2) P(4)-Rh(2)-0(3) P(S)-Rh(2)-0(2) P(S)-Rh(2)-0(3) 0(2)-Rh(2)-0(3)
95.9 (1) 151.0 (1) 86.4 (2) 99.7 (1) 165 .O (2) 84.7 (2) 121.0 (7) 119.4 (10) 123.3 (10) 117.3 (10) 90.8 (7) 89.8 (7) 96.7 (1) 164.2 (2) 102.9 (2) 98.4 (2) 160.4 (2) 62.1 (3)
96.7 (1) 154.4 (1) 85.5 (2) 96.2 (1) 170.8 (2) 85.3 (2) 121.2 (8) 120.9 (11) 124.6 (11) 114.5 (11) 90.4 (7) 92.1 (7) 98.9 (1) 162.5 (2) 99.8 (2) 98.4 (2) 161.1 (2) 63.0 (3)
96.3 (5) 152.7 (24) 86.0 (6) 97.9 (25) 167.9 (41) 85 .O (4) 121.1 (8) 120.1 (11) 123.9 (9) 115.9 (20) 90.6 (7) 90.9 (16) 97.8 (15) 163.3 (12) 101.3 (22) 98.4 (2) 160.8 (5) 62.6 (6)
phenylphosphine ligands with each other at the higher temperature. Prolonged heating of the solution at 80 OC, however, caused a considerable irreversible increase in the intensity of the Pd signals at the expense of the signals Pa, Pb, and P,. The intensity of the signal of free triphenylphosphine oxide did not change significantly throughout this process. Evolution of C 0 2 by heating the benzene solution at 80 "C for several hours was confirmed by gas chromatography. The 31P(1H) N M R spectrum of the carbonato complex in pyridine at room temperature showed only signals of Pd and triphenylphosphine oxide. This may result from the exchange of the triphenylphosphine ligands in pyridine. Heating the pyridine solution to 70 OC caused the evolution of carbon dioxide from the complex. The main features of the 31P(1H) N M R spectrum of the a The number in parentheses is the standard deviation of a single benzene solution of the rhodium complex are in agreement with observation. It is the larger of (1) the quantity estimated from the values averaged on the assumption that they are from the same the unsymmetrical binuclear structure of the rhodium(1)population or (2) the average standard deviation as estimated from carbonato complex in the following aspects. The chemical the inverse matrix. shifts of Pa, Pb, and P, are normal for Rh(1) complexes as values found for the P atom trans to the X atom in the above compared with reported values for RhX(PPh3)3, where X examples. In fact, the nitrate ligand, which is obviously similar stands for halogen.36 The IJ(Rh-P)I coupling constant is known to be sensitive to the nature of the ligand trans to the to the carbonate species, has been shown to cause an even phosphorus nucleus but insensitive to the cis l i g a r ~ d . ~ ~ - ~larger ~ increase in the Rh-P coupling constant of the P atom IJ(Rh-P)I values of 139-142 Hz for mutually trans P ligands trans to it than do halide ligands.39 It is not surprising then to find IJ(Rh-P,)I equal to 198 Hz, slightly larger than the in RhX(PPh3)3 and of 189-194 Hz for the P ligand trans to X have been reported.36 The observed value of IJ(Rh-Pa)I corresponding values in the RhX(PPh3)3 compounds. Although the IJ(RhPb)l value was not measured precisely owing of 154 Hz is therefore reasonable for the trans P ligands here. to partial overlap with the intense Pc signals, it appears to have The P atoms trans to the carbonato group would be expected to have coupling constants with the Rh atom similar to the a value larger than IJ(Rh-Pa)I and close to IJ(Rh-P,)I.
Figure 3. Stereoscopic packing diagram of Rh,(CO,)(PPh,),C,H,. The atom shapes represent 20% probability contours of thermal motion. Hydrogen atoms have been omitted for the sake of clarity. The x axis is horizontal and to the right, t h e y axis is vertical, and the z axis is out of the page.
2804 Inorganic Chemistry, Vol, 15, No. 1I, 1976 Table V. Closest Contacts between the Phosphine Hydrogen Atoms and the Conjectured Hydride Positions' Hydride
Phosphine hydrogenb
Distance: A
Rh(l1)Hl Rh(ll)H2
R122H2 R112H2
1.6 1.3
Rh(12)Hl Rh(12)H2
R151H6 R142H2
1.6 2.0
Rh(2 l)H 1 Rh(21)H2
R222H2 R213H6
1.9 1.4
Rh(22)Hl Rh( 2 2)H 2
R241H2 R25 3H6
1.8 1.9
a See text for description of idealized geometry. Hydrogen These disatom RwxyHz is bound to carbon atom RwxyCz. tances may be compared with a value of 2.4 A for the sum of two hydrogen van der Waals radii.jh
Finally, IJ(Rh-P)( values of Rh(1) complexes are known to be larger than those of Rh(II1) by a factor of ca. 1.5, owing to the larger fraction of both s and 7r character of the rhodium bonding orbitals in four-coordinate Rh(1) complexes than in six-coordinate Rh(II1) c ~ m p l e x e s . ~A~similar - ~ ~ decrease in coupling constants is also seen when going from four-coordinate Pt(I1) complexes to six-coordinate Pt(1V) comp l e ~ e s .In~ the ~ present case both IJ(Rh-Pa)I and IJ(Rh-P,)I are in the Rh(1) range, excluding a possible rhodium(II1) dihydride structure (also, see below). Description and Discussion of Structure. Discrete molecules of Rh2(C03)(PPh3) j occupy general positions in the unit cell, as do the solvate benzene molecules. Figure 3 shows a stereoview of the molecular packing in the unit cell. The only unusual nonbonded contacts occur between oxygen atoms and hydrogen atoms on the phenyl rings. Two of the 0-H atom distances are about 2.3 8, and therefore fall in the range expected for weak hydrogen bonds.40 The minimization of nonbonded contacts between the phenyl rings is, however, the most important factor influencing their orientation. The coordination about both rhodium atoms is best described as square planar, although the Rh( 1)41coordination is slightly distorted toward tetrahedral geometry. A square-planar ligand arrangement is, of course, the normal geometry for four-coordinate d8 Rh(1) (see Figure 1). Consideration of steric factors shows that the fifth and sixth coordination positions of the rhodium atoms are not occupied by hydride ligands as might be implied from the original formulation of the c0mpound.j Assuming normal phenyl ring geometry with a C-H bond length of 0.95 A and a Rh-H bond length of 1.65 A, unreasonably short hydrogen-hydrogen contacts are calculated. These contacts are given in Table V. If the orientations of the phenyl rings are ignored, the molecule is seen to contain a mirror plane. This plane contains atoms Rh(l), Rh(2), P(2), P(4), P(5), and the carbonate group atoms (Table VI). The least-squares plane of the Rh(1) coordination sphere makes an angle of 87' with this pseudo mirror plane (Table VI). The Rh-P bond lengths for the phosphine ligands trans to each other are n ~ r m a l . They ~ ~ , range ~ ~ from 2.309 (4) to 2.337 (4) A. For the phosphine groups trans to the oxygen atoms of the carbonate groups, the average Rh-P distance is 2.202 A. This shortening of the Rh-P bond length from the value for the mutually trans phosphine groups to the value for the phosphorus atom trans to an oyxgen atom is also observed in the structure of benzoatotris(tripheny1phosphine)rhodium. l 3 Platinum(I1) compounds also exhibit a similar trend. For example, the Pt-P bond distance in trans-PtCl(CO)(P(C2Hj)3)2+ is 2.34 A.44 This distance however decreases to Rather short Rh-P bond 2.24 8, in ci~-Pt(CO3)(PPh3)2.~~ distances of 2.218 (8) and 2.21 1 (2) 8, are also found for the
Ibers, Yamamoto, et al. Table VI. Least-Squares Planes with Dihedral Angles Atoma
Dev, A
Atom'
Dev, A
Plane l l : b 8 . 8 5 1 ~ - 15.434~ - 9.3932 + 1.059 = O C(1) -0.008 (10) O(12) 0.001 (7) O(11) 0.001 (8) O(13) 0.001 (7) Plane 21: - 3 . 1 7 7 ~+ 5 . 4 8 0 ~+ 12.2542 + 2.901 = 0 C(2) -0.002 (12) O(22) 0.000 (8) O(21) 0.000 (8) O(23) 0.000 (8) Plane 12: - 0 . 7 3 0 ~- 2 3 . 8 0 1 ~+ 7.9182 + 6.429 = 0 Rh(l1) 0.057 (1) -0.410 (3) Plane 22: 1 . 9 8 3 ~+ 2 7 . 6 4 8 ~- 2.8932 - 10.075 = 0 Rh(21) 0.049 (1) -0.398 (3) Plane 13: 1 0 . 2 2 7 ~ -1 5 . 7 9 5 ~ -8.9432 + 1.449 = O Rh(12) 0.004 (1) O(12) -0.146 (8) P( 14) -0.025 (3) 0(13 0.018 (8) P(15) -0.004 (3) Plane 23: 4 . 7 9 0 ~- 5 . 6 2 3 ~ - 12.2072 - 3.263 = 0 Rh(22) 0.000 (1) O(22) -0.075 (8) ~(24) -0.008 (3) O(23) 0.075 (8) P(25) 0.011 (3) Plane 14: 9 . 7 6 0 ~- 1 5 . 4 8 1 ~- 9.1812 + 1.280 = 0 Rh(l1) O(11) -0.037 (8) -0.009 (1) Rh( 12) O(12) -0.091 (8) 0.008 (1) O(13) 0.010 (8) P(12) 0.096 (3) ~(14) -0.083 (3) P(11)" 2.213 P(15) 0.033 (3) P(13)" -2.274 C(1) -0.048 (10) Plane 24: - 1 . 9 3 1 ~ t 4 . 4 3 0 ~+~ 12.3652 + 3.165 = 0 Rh(21) 0.013 (1) O(21) 0.252 (8) Rh(22) 0.013 (1) O(22) 0.105 (8) P(22) -0.241 (3) 0 ~ 3 ) 0.197 (8) P(24) 0.089 (3) P(21)* 2.280 P(25) -0.295 (3) P(23)" -2.239 C(2) 0.187 (12) Dihedral angles, deg
~4
PlaneC
2
3
11
87.3 85.7
4.3 4.2
2.7 3.8
85.6 85.9
86.7 87.5
21 12 22 13 23
1.8 7.7
'The atoms marked with an asterisk were not included in the In the nomenclature for calculations of the least-squares plane. the planes, the first number refers to either molecule 1 or 2 and the second number serves to identify the plane within the molecule. ' Only dihedral angles between planes within the same molecule are tabulated. phosphine group trans to the chlorine atom in RhCl(PPh3)342 and RhCl((C6H ~ ) ~ P C H ~ C H ~ C H = C H respectively. Z)~,~~ These results are consistent with the relatively small trans influence and negligible ir-bonding capabilities of the carbonate group in accordance with 31PN M R spectral results (see above). The phosphorus ligand, however, does have an effect on the Rh-0 bond trans to it. The compounds tetrakis(pacetate)-diaquodirhodium and potassium tris(oxa1ato)rhodite(II1) can be taken as examples where the Rh-0 bond experiences little trans influence. The average Rh-0 bond length is 2.04 A in the former47 and 2.016 A in the latter.48 In contrast is acetatobis(phenylazophenyl-2C,N')rhodium(II), where the oxygen atoms of the acetate group are trans to the labilizing ortho-metalated phenyl rings. There, the R h 4 bond distance lengthens to an average value of 2.230 A.49 The average Rh-0 bond length in the compound reported here of
Inorganic Chemistry, Vol. 15, No. 11, 1976 2805
Structure of Rh2(C03)(PPh3)5GjH6 2.12 A is intermediate in value. Three other compounds, each with a tridentate bridging carbonate group similar to that found here, have previously been structurally ~ h a r a c t e r i z e d . ~ Here, ~ , ~ ~as * ~in~the other structures, the carbonato moiety is essentially planar. Generally, four-membered ring formation causes the carbonato 0-C-0 bond angle to decrease from 120’ to an average of 1 13°.23351-56 The 0(2)-C-0(3) angle reported here of 116’ may represent a decrease from 120’. The average O(2)Rh(2)-O(3) bond angle here of 62.6’ is similar to the 64.0’ angle found in the four-membered ring of the square-planar complex Pt(C03)(PPh3)2.45 In other structures containing a metal-bonded carbonate group, the C-O bond length in the carbonate moiety has ranged from 1.36 (2)57to 1.245 (3) A51 depending on the strength of the various oxygen-metal interactions. Unfortunately, little can be said concerning the carbonato C-0 bond distances here because of deviations in lengths between equivalent atoms in the two independent molecules. However, the average C-0 bond length found here of 1.29 A is virtually identical with that in the free carbonate ion of calcite, 1.294 (4) A.50 Conclusion The red compound produced by the reaction of RhH(PPh3)4 with C02 thus has been characterized as a bridging carbonate complex, Rh2(C03)(PPh3)5.C6H6, on the basis of vibrational and 31P N M R spectra, chemical evidence, and x-ray crystallographic analysis. The problem remains, however, as to how a carbonato complex is formed by the reaction of RhH(PPh3)4 with C 0 2 in a nonaqueous system. There are several conceivable routes to the Rh-CO3 complex: (1) disproportionation of C 0 2 molecules to CO and co32-; (2) reaction of C02 with oxygen introduced into the system as impurity to form co32-;(3) reaction of H2O impurity in the C 0 2 gas. The disproportionation of C 0 2 was postulated by Chatt et al.23 in the formation of a bis(p-carbonate)-molybdenum complex. Yet in the present system the other two possibilities cannot be eliminated: the duration of C 0 2 bubbling into the system is so long that introduction of oxygen and/or water as impurities is unavoidable despite vigorous attempts to remove them from the C 0 2 gas. Attempts to detect the possible products, H2 and/or CO, from the reaction system using a closed system under a normal pressure of COS failed because of the lack of reactivity of RhH(PPh3)4 toward carbon dioxide. Acknowledgment. This work was financially supported by the Asahi Glass Foundation for the Contribution to Industrial Technology and by the U.S. National Science Foundation.
(9) I. S. Kolomnikov, T. S. Lobeeva, V. V. Gorbachevskaya, G. G. Aleksandrov, Y. T. Struchkov, and M. E. Vol’pin, Chem. Commun.,972 (197 1). (10) M. E. Vol’pin and I. S. Kolomnikov, Pure Appl. Chem., 33, 567 (1973). (1 1) A. Miyashita and A. Yamamoto, J. Organomet. Chem.,49, C57 (1973); 113, 187 (1976). (12) T. Ikariya and A. Yamamoto, J . Organomet. Chem., 72, 145 (1974). (13) I. S. Kolomnikov, A. 0. Gusev, T. S. Belopotapova, M. Kh. Grigoryan, T. V. Lysyak, Yu. T. Struchkov, and M. E. Vol’pin, J . Organomet. Chem., 69, C10 (1974). (14) M. H. Chisholm and M. Extine, J . Am. Chem. SOC.,96,6214 (1974); 97, 1623, 5625 (1975). (15) M. Hidai, T. Hikita, and Y. Uchida, Chem. Lett., 521 (1972). (16) E. Chaffee, T. P. Dasgupta, and G. M. Harris, J . Am. Chem. Soc., 95, 4169 (1973). (17) B. R. Flynn and L. Vaska, J . Am. Chem. SOC.,95, 5081 (1973). (18) M. E. Vol’pin, I. S. Kolomnikov, and T. S. Lobeeva, Izv. Akad. Nauk SSSR, Ser. Khim., 2084 (1969). (19) I. S. Kolomnikov, T. S. Belopotapova, T. V. Lysyak, and M. E. Vol’pin, J . Organomet. Chem., 67, C25 (1974). (20) B. R. Flynn and L. Vaska, J:. Chem. Soc., Chem. Commun., 703 (1974). (21) P. W. Jolly, K. Jonas, C. Kruger, and Y.-H. Tsay, J. Organomet. Chem., 33, 109 (1971). (22) M. Aresta, C. F. Nobile, V. G. Albano, E. Forni, and M. Manassero, J . Chem. Soc., Chem. Commun., 636 (1975). (23) J. Chatt, M. Kubota, G. J. Leigh, F. C. March, R. Mason, and D. J. Yarrow, J . Chem. SOC.,Chem. Commun., 1033 (1974). (24) C. J. Nyman, C. E. Wyrnore, and G. Wilkinson, Chem. Commun., 407 (1967). (25) C. J. Nyman, C. E. Wymore, and G. Wilkinson, J . Chem. SOC.A , 561 (1968). (26) K. C. Dewhirst, W. Keim, and C. A. Reilly, Inorg. Chem., 7, 546 (1968). (27) J. J. Levison and S . D. Robinson, J . Chem. SOC.A, 2947 (1970). (28) P. W. R. Corfield, R. J. Doedens, and J. A. Ibers, Inorg. Chem., 6, 197 (1967). (29) R. J. Doedens and J. A. Ibers, Inorg. Chem., 6, 204 (1967). (30) In addition to various local programs for the CDC computer, local versions
Registry No. Rhl(CO)3(PPh3)5.C6H6, 60364-00-3; RhH(PPh3)4, 18284-36-1; 31P,7723-14-0; sulfuric acid, 7664-93-9; methyl iodide, 74-88-4; P(OPh)3, 101-02-0. Supplementary Material Available: Listing of structure amplitudes (84 pages). Ordering information is given on any current masthead page.
(1969). (43) K. W. Muir and J. A. Ibers, Inorg. Chem., 8, 1921 (1969). (44) H. C. Clark, P. W. R. Corfield, K. R. Dixon, and J. A. Ibers, J . Am. Chem. SOC.,89, 3360 (1967). (45) F. Cariati, R. Mason, G. B. Robertson, and R. Ugo, Chem. Commun., 408 (1967). (46) R. R. Ryan, R. Schaeffer, P. Clark, and G.Hartwell, Inora. - Chem.. 14. 3039 (1975). F. A. Cotton, B. G. DeBoer, M. D. LaPrade, J. R. Pipal, and D. A. Ucko, Acta Crystallogr., Sect. B, 21, 1664 (1971). B. C. Dalzell and K. Eriks, J . Am. Chem. Soc., 93, 4298 (1971). R. J. Hoare and 0.S. Mills, J. Chem. SOC.,Dalton Trans., 2138 (1972). R. L. Sass, R. Vidale, and J. Donohue, Acta Crystallogr., 10, 567 (1957). M. H. Meyer, P. Singh, W. E. Hatfield, and D. J. Hodgson, Acta Crystallogr., Sect. E , 28, 1607 (1972). G. Ferguson and D. M. Hawley, Acta Crystallogr.,Sect. E, 30,103 (1974). R. L. Harlow and S . H. Simonsen, Acta Crystallogr. Sect. B, 31, 1313 (1975), and references therein. K. Kaas and A. M. Sorensen, Acta Crystallogr.,Sect. B, 29, 113 (1973). R. J. Geue and M. R. Snow, J . Chem. SOC.A , 2981 (1971). G. A. Barclay and B. F. Hoskins, J. Chem. SOC.,586 (1962). P. C. Healyand A. H. White, J . Chem. Soc., Dalton Trans., 1913 (1972). L. Pauling, “The Nature of the Chemical Bond”, 3d ed,Cornel1 University Press, Ithaca, N.Y., 1960.
References and Notes (a) Northwestern University. (b) Tokyo Institute of Technology. L. S. Pu,A. Yamamoto, and S. Ikeda, J. Am. Chem.Sa., 90,3896 (1968). A. Misono, Y. Uchida, M. Hidai, and T. Kuse, Chem. Commun., 981 (1968).
I. S. Kolomnikov, T. S. Lobeeva, and M. E. Vol’pin, Izv. Akad. Nauk SSSR,Ser. Khim., 19, 2650 (1970). S. Komiya and A. Yamamoto, J . Organomet. Chem., 46, C58 (1972); Bull. Chem. SOC.Jpn., 49, 784 (1976). I. S. Kolomnikov, A. I. Gusev, G. G. Aleksandrov, T. S.Lobeeva, Yu. T. Struchkov, and M. E. Vol’pin, J. Organomet. Chem., 59,349 (1973). V. D. Bianco, S. Doronzo, and M. Rossi, J. Organomet. Chem., 35,337 (1972). U. Zucchini, E. Albizzati, and U. Giannini, J . Organomet. Chem., 26, 357 (1971).
(31)
(32) (33) (34) (35) (36) (37) (38) (39)
of Zalkin’s FORDAP Fourier program, the AGNOST absorption program, and Busing and Levy’s ORFFE function and error program were used. Refinement using our least-squares program, NUCLS, was accomplished on the CDC7600 computer at the Lawrence Berkeley Laboratory. The diffractometer was run under the disk-oriented Vanderbilt system (P. G. Lenhert, J . Appl. Crystallogr., 8, 568 (1975)). D. T. Cromer and J. T. Waber, “International Tables for X-Ray Crystallography”, Vol. 4, Kynoch Press, Birmingham, England, 1974. The unweighted and weighted agreement indices are defined as ~ l i F o l - lF~ll/XlF~l and (Xw(lFol - IFcI)z/CwlFo12)1/z, respectively. Supplementary material. Y. Iwashita and A. Hayata, J . Am. Chem. SOC.,91, 2525 (1969). FT mode ‘H NMR spectra were recorded on JEOL FX-60 spectrometer by courtesy of Mr. K. Kosaka (Japan Electron Optics Laboratory), to whom we are indebted. T. H. Brown and P. J. Green, J . Am. Chem. SOC.,92, 2359 (1970). J. F. Nixon and A. Pidcock, Annu. Rev. NMR Spectrosc., 2,345 (1969). S. 0. Grim and R. A. Ference, Inorg. Chim. Acta, 4, 277 (1970). F. H. Allen, A. Pidcock, and C. R. Waterhouse, J. Chem. SOC.A, 2087
(1970). (40) W. C. Hamilton and J. A. Ibers, “Hydrogen Bonding in Solids”, W. A. Benjamin, New York, N.Y., 1968. (41) In referring to atoms with similar environments in both independent
molecules, the index specifying the molecule number is dropped For example, Rh(1) refers to both Rh(l1) and Rh(21). (42) P. B. Hitchcock, M. McPartlin, and R. Mason, Chem. Commun., 1367
