James A. Moreland and Robert J. Doedens
2486 Inorganic Chemistry, Vol. 15, No. 10, 1976 Press, Ithaca, N.Y., 1960, pp 224, 256: CI, 0.99 A; Br, 1.14 A; I, 1.33 ~;P,1.10~;As,1.21~;Cu,1.17~;Ag,1.34~ (29) (a) R. W. G. Wyckoff, "Crystal Structures", Vol. 1, Interscience, New York, N.Y., 1963, pp 110, 186; (b) V. H.-J. Meyer, Acta Crystallogr., 16, 7 8 8 (1963); (c) C. J. Gilrnore, P. A. Tucker, and P. Woodward, J . Chem. Soc. A , 1337 (1971): (d) S. Geller, Science, 157, 310 (1967); (e) S. Geller and M. D. Lind, J . Chem. Phys., 52, 5854 (1970).
(30) L. F. Dahl, E. Rodulfo de Gil, and R. D. Feltham, J . Am. Chem. Soc., 91, 1653 (1969). (31) C . A. Tolman, J . Am. Chem. Soc., 92, 2956 (1970). (32) (a) J. C. Phillips, Reo. Mod. Phys., 42, 317 (1970); (b) A. Navrotsky and J. C. Phillips, Phys. Reu. B, 11, 1583 (1975); (c) J. C. Phillips, J . Eleczrochem. Soc., 123, 934 (1976). (33) J . S. John and A. N. Bloch, Phys. Rec. Lett., 33, 1095 (1974).
Contribution from the Department of Chemistry, University of California, Irvine, California 927 17
Crystal and Molecular Structure of a Ruthenium Complex Containing a Metalated PerfluoroazobenzeneLigand and a Novel 2-(r-Cyclopentadieny1)phenyl Group JAMES A. MORELAND and ROBERT J. DOEDENS*
Received April 2, 1976
AIC60247E
The product of the reaction of decafluoroazobenzene with R U ( C H ~ ) ( P P ~ ~ ) ~ (has ~ - been C ~ Hshown ~ ) by a crystal structure analysis to have an unusual structure. Crystals of (diphenyl(2-(~-cyclopentadienyl)phenyl)phosphine)(nonafluoro(pheny1azo)phenyl-Cz,N')ruthenium are monoclinic, space group P21 /c, with four molecules in a unit cell of dimensions a = 15.650 (14) A, b = 13 338 (11) A, c = 14.741 (11) A, and /3 = 97.38 (3)'. The structure determination was based upon 3092 independent nonzero diffraction maxima with 20 < 45' collected by counter methods. A blocked full-matrix least-squares refinement converged to a final conventional discrepancy factor of 0.046. The molecule contains not only the expected metalated perfluoroazobenzene ligand but also a linkage between the 11-cyclopentadienyl group and one of the phenyl rings of the triphenylphosphine. The resulting C,T chelating configuration causes the substituted cyclopentadienyl ring to be tilted by 13' relative to the ML3 portion of the molecule. The fluorinated azobenzene ligand is bound in a chelating fashion via Ru-C and Ru-N bonds. The free phenyl ring is twisted by 64.6' from from the chelate plane. Bond distances involving this ligand include Ru-N = 2.020 (5) A, Ru-C = 2.013 (6) A, and N-N = 1.310 (7) A.
-
Introduction The ortho metalation of azobenzene, first reported about 10 years ago,' has proven to be the prototype of an extensive and important series of chemical reaction^.^-^ These reactions typically involve formation of a metal-carbon u bond to an aromatic ring, with the displaced hydrogen atom either being eliminated or remaining bound to the metal atom. It is generally believed that the metalation of azobenzene proceeds by a pathway involving initial metal coordination of the azo group, followed by intramolecular attack upon the aromatic ring remote from the bound nitrogen atom.2 Studies of the metalation of substituted azobenzenes by PdC142- strongly suggested an electrophilic mechanism for the intramolecular metalation process in this c a ~ e . ~However, ,~ it has been suggested that under other circumstances (e.g., electron-rich metal atoms, azobenzenes with electron-withdrawing substituents) metalation could occur by a nucleophilic pathways7 This hypothesis has found support in studies of the metalation reaction of 3-monofluoroazobenzene with CH3Mn(CO)s, where the predominant product is the isomer which would be favored by a nucleophilic mechanism.6 In view of these results, the reactions of polyfluorinated azobenzenes, which should be susceptible to nucleophilic attack, with various transition metal systems have been i n v e ~ t i g a t e din ~ ,order ~ to determine whether metalation can occur by fluorine abstraction from these ligands. From the reaction of R u ( C H ~ ) ( P P ~ ~ ) ~ ( with ~ - Cdecafluoroazo~H~) benzene, a product was obtained whose 19FN M R spectrum was that expected of a metalated C ~ F S N ~ ligand C ~ F but ~ whose 'H NMR spectrum suggested that substitution had also occurred on the cyclopentadienyl ring.9 We now report results of a crystal structure analysis of this product, which confirms the proposed metalated structure and demonstrates that an unusual type of linkage has been formed between the cyclopentadienyl group and one of the phenyl rings of the triphenylphosphine ligand. These results have previously ap-
Table I Formula Fw a
b c P
A. Crystal Data RuC3,F,H,,N2P V 769.57 Z 15.650 (14)A d(obsd) 13.338 (11) A d(ca1cd) 14.741 (11) A Space group AM0 K 4 97.38 (3)"
E. Experimental Parameters Radiation Mo K a , h(Kor,) Scan range 0.709 30 A, 3.0-mil Nb filter Temp 23°C Background Receiving 5 X 5 mm, 29 cm counting aperture from crystal Takeoff 2.1" 26 (max) angle Data collected Scan rate l.O"/min in 28 Data with Fo2 > 3o(Fo2)
3051.5 A3 4 1.70 (5) g/cm3 1.68 g/cm3 P2,/c 6.5 cm-' -0.65 + 0.60" in 28 from Ka,, Peak 20-s fixed counts at each end of scan 45" 4135 3092
peared in preliminary form.1°
Experimental Section Data Collection and Reduction. A suitably crystalline sample of the title compound was supplied by Dr. M. I. Bruce. Preliminary precession photographs showed monoclinic symmetry with systematic absences (h01, I # 2n; OkO, k # 2n) uniquely defining space group P21/c. Cell parameters were obtained by least-squares refinement of the setting angles of 13 reflections which had been accurately centered on a Picker four-circle x-ray diffractometer.ll Owing to the solubility of the crystals in many solvents and to the limited amount of sample available, only an approximate value of the observed density could be determined by flotation methods. Crystal data are tabulated in part A of Table I. Intensity data were collected from a dark green thin platelet of dimensions 0.09 X 0.23 X 0.38 mm mounted approximately along the crystallographic b axis. Bounding planes belonged to the (loo), (OlO), (OOl),and (110) forms. Narrow-source, open-counter w scans through several reflections displayed an average full width at half-
A Ruthenium-Perfluoroazobenzene Complex
Inorganic Chemistry, Vol. 15, No. 10, 1976 2487
Table 11. Positional, Thermal, and Groupc Parameters for Ru(C,F,N,C,F,)(Ph,PC,“,) X
Ru P N1 N2
-0.220 -0.244 -0.307 -0.318 c1 -0.168 c2 -0.086 c3 -0.061 c4 -0.118 c5 -0.199 C6 -0.224 c7 -0.407 C8 -0.469 c9 -0.555 c 1 0 -0.579 c11 -0.520 c 1 2 -0.434 F1 -0.026 F2 0.019 F3 -0.090 F4 -0.255 F5 -0.447 F6 -0.612 -0.663 F7 F8 -0.544 F9 -0.379 C13 -0.104 C14 -0.135 C 15 -0.217 C16 -0.238 C17 -0.168
77 ( 3 P 92 (10) 7 (3) 0 (3) 0 (4) 2 (4) 8 (4) 2 (5) 9 (4) 5 (4) 0 (4) 2 (5) 4 (5) 6 (5) 4 (6) 6 (4) 3 (2) 2 (3) l(3) 9 (3) 0 (3) 7 (3) 4 (3) 6 (3) 4 (3) 7 (4) 8 (5) 5 (6) 6 (5) 4 (4)
Y
z
0.054 92 (3) -0.025 52 (11) 0.243 5 (4) 0.155 2 (4) 0.174 3 (4) 0.191 3 (5) 0.279 2 (5) 0.357 2 (5) 0.346 6 (4) 0.255 9 (4) 0.139 6 (5) 0.141 2 (5) 0.129 7 (6) 0.115 2 (6) 0.1 16 8 (6) 0.129 0 (5) 0.117 8 (3) 0.291 5 (3) 0.445 3 (3) 0.422 6 (3) 0.153 4 (3) 0.128 9 (5) 0.105 l ( 4 ) 0.109 4 (4) 0.135 5 (4) -0.019 5 (5) 0.043 9 (5) 0.009 3 (6) -0.076 5 (5) -0.092 2 (5)
d.223 30 (3) 0.354 37 (11) 0.257 l ( 3 ) 0.218 3 (4j 0.292 9 (4) 0.337 7 (4) 0.379 0 (4) 0.376 9 (4) 0.337 7 (5) 0.296 2 (4) 0.185 0 (5) 0.242 l ( 6 ) 0.209 9 (8) 0.119 9 (8) 0.062 2 (6) 0.093 5 (6) 0.343 2 (3) 0.421 l ( 3 ) 0.416 8 (3) 0.338 l ( 3 ) 0.331 8 (3) 0.270 3 (5) 0.089 2 (4) -0.029 0 (4) 0.032 0 (3) 0.187 3 (4) 0.114 5 (5) 0.077 7 (5) 0.125 8 (5) 0.196 2 (4)
PI1
37.2 (3)b 36.7 (8)
PZZ
P33
42.3 (4)
38.2 (31 42.1 igj
47 (4)
54 (4)
PI2
013
Yo 20 6 deg e , deg p , deg -0.157 58 (18) -0.239 78 (22) 0.338 47 (20) -156.55 (16) 169.10 (12) -104.39 (15) -0.437 96 (20) -0.093 73 (22) 0.378 40 (22) 107.17 (16) -167.84 (12) -88.02 (18) -0.167 18 (19) 0.094 46 (21) 0.533 69 (19) -35.79 (17) -134.02 (15) -177.87 (18) a Numbers in parentheses in all tables and in the text are estimated standard deviations in the least significant figures. The form of the anisotropic thermal ellipsoid is exp[-@,, k Z + p z z k Z+ p J 2 + 2p,,kk + 2p,,kl+ 2pz,kl)]. Tabulated p values are X lo., The coordinates x o ,y o , and z o are the fractional coordinates of the origin of the group coordinate system (taken at the midpoint of the ring); the angles @, e , and p are the orientation angles defined by R. J. Doedens in “Crystallographic Computing”, F. R. Ahmed, Ed., Munksgaard, Copenhagen, 1970, pp 198-200. Group Ring 1 Ring 2 Ring 3
XO
maximum of 0.15’, indicative of a satisfactorily low mosaic spread. Intensity data were collected on a Picker automatic diffractometer by use of procedures previously described.I2 Experimental parameters specific to this data set are summarized in part B of Table I. No reflections required attenuation to bring their peak intensities within the linear range of the counting system. Four standard reflections, chosen from widely different regions of reciprocal space, were monitored every 100 reflections throughout the data collection. The intensities of these reflections varied less than f 3 % and showed no systematic deviations. The intensity data were processed according to previously described methods.12 The p factor in the expression for the standard deviation of the observed intensities was assigned a value of 0.05. A trial calculation indicated that transmission factors ranged only from 0.92 to 0.97; hence no absorption correction was applied. Solution and Refinement of the Structure. Solution of the structure was achieved by heavy-atom Patterson and difference Fourier methods. Refinement of positional and isotropic thermal parameters for all nonhydrogen atoms, based upon all data with Fo2 2 ~ U ( F ~converged )~, to discrepancy factors R1 = 1llFol - lFcll/xlFol = 0.075 and R2 = [Cw(lFol- IFc1)2/CwlFo12]1/2 = 0.096. The phenyl rings of the triphenylphosphine ligand were treated as rigid groups with the hydrogen atoms included in the groups (C-C = 1.39 A, C-C-C = H-C-C = 120°, C-H = 0.95 A). Further refinement employed anisotropic temperature factors for all nonhydrogen atoms other than the group atoms. Hydrogen atoms for the cyclopentadienyl ring were included as fixed contributions to Fc based upon their “ideal” trigonal positions. The anisotropic refinement was carried out in blocks because of the number of parameters involved. The first block included the scale factor, the metal atom, and the substituted azobenzene ligand. The remaining atoms and groups together with the scale factor and the Ru atom comprised the second block. The blocks were refined alternately and new hydrogen atom positions were calculated for the cyclopentadienyl ring after each pair of cycles. This final refinement
converged to R I= 0.046 and R2 = 0.058, with the largest parameter shift in the last cycle equal to 1 . 3 ~ .The largest peak (1.1 e A-3) on a final difference map at this point was very close to F7 and apparently represented residual motion of that atom not accounted for in the thermal model. Throughout the least-squaresrefinement, the weights of the observed structure amplitudes were taken as w = 4F02/U2(Fo2)and the function minimized was Cw(lFol - lFc1)2. The final standard deviation of an observation of unit weight was 1.5. Calculation of w ( W 2for subsets of the data as a function of uncorrected intensity, observed F , and Bragg angle showed no significant trends, thus confirming that the relative weights were appropriate. Calculation of structure factors for data with Fo2 I 3uF02 revealed 12 reflections with (IFol lFc/)/u(Fo)2 3; only three of these had AF/u > 4. Scattering factors for Ru, P, and F were those of Cromer and Waber,I3 those for C and N were taken from ref 14, and those of Stewart et a1.I5 were employed for H. Structure factor calculations used the Af ’ and Af ” values of CrornerI6 in estimating the real and imaginary parts of anomalous scattering by the Ru and P atoms. Final atomic positional and thermal parameters for the nongroup atoms are listed in Table 11. Positional and thermal parameters for the group and hydrogen atoms are given in Table 111. Intramolecular distances and angles are tabulated in Tables IV and V. The principal root-mean-square amplitudes of thermal motion for the atoms refined anisotropically are listed in Table VI.17 Information concerning selected molecular planes and dihedral angles is given in Table VII. A table of observed and calculated structure factors is available.’’
Description of the Structure and Discussion An overall view of the molecular structure of (diphenyl-
(2-(~-cyclopentadienyl)phenyl)phosphine)(nonafluoro(pheny1azo)phenyl-C?,N’)ruthenium is shown in Figure 1. As suggested on the basis of 19F and ‘H NMR spectra, the
James A. Moreland and Robert J. Doedens
2488 Inorganic Chemistry, Vol. 15, No. 10, 1976
Table IV. Intramolecular Distances (A)
Table 111. Atomic Positions of Group Atoms and Hydrogen Atoms Y
X
-0.1926 -0.1631 -0.1280 -0.1225 -0.1521 -0.1871 -0.1078 -0.0986 -0.1484 -0.2073
(3)' (3) (3) (3) (3) (3) (4) (4) (5) (4)
Ring -0.1458 -0.1687 -0.2627 -0.3338 -0.3109 -0.2169 -0.2783 -0.3980 -0.3595 -0.2013
1
C18 C19 C20 C21 C22 C23 H20' H21 H22 H23
(2) (3) (3) (3) (3) (3) (5) (3) (4) (4)
0.3515 (3) 0.2689 (2) 0.2558 (2) 0.3254 (3) 0.4080 (3) 0.4211 (2) 0.1994 (3) 0.3165 (4) 0.4556 (3) 0.4776 (3)
C24 C25 C26 C27 C28 C29 H25 H26 H27 H28 H29
-0.3542 -0.3797 -0.4634 -0.5217 -0.4963 -0.4125 -0.3399 -0.4808 -0.5789 -0.5361 -0.3951
(2) (3) (3) (2) (3) (3) (4) (4) (3) (3) (4)
Ring -0.0636 -0.0760 -0.1062 -0.1238 -0.1114 -0.0813 -0.0640 -0.1146 -0.1444 -0.1235 -0.0728
2 (3) (4) (4) (4) (4) (3) (6) (6) (6) (6) (5)
0.3699 (3) 0.4563 (2) 0.4647 (3) 0.3869 (3) 0.3005 (3) 0.2921 (2) 0.5095 (3) 0.5237 (3) 0.3926 (5) 0.2473 (3) 0.2331 (2)
(2) (3) (2) (3) (3) (2) (4) (3)
Ring 3 0.0356 (3) 0.0103 (3) 0.0691 (4) 0.1533 (3) 0.1786 (3) 0.1198 (4) -0.0472 (5) 0.0518 (6) 0.1934 (4) 0.2361 (5) 0.1371 (6)
-0.2036 -0.1237 -0.0872 -0.1307 -0.2107 -0.2471 -0.0940 -0.0326 -0.1059 -0.2404 -0.3017
H13 H14 H15 H16
Cyclopentadienyl Hydrogen Atoms -0.0503 -0.0144 0.2440 -0.1067 0.1003 0.0938 -0.2531 0.0391 0.0280 -0.2893 -0.1160 0.1138
(5) (3)
3.43 (1 1) 3.84 (12) 5.77 (17) 6.39 (18) 5.06 (15) 4.46 (14) C
3.99 (12) 5.42 (16) 6.63 (19) 6.61 (19) 5.78 (17) 4.78 (14)
R u C1 Ru-N~ Ru-P RuC13 Ru-Cl4 Ru-Cl5 RuC16 RuC17 Nl-N2 N1-C6 c1c2 C1C6 C2C3 C3C4 C4C5 C5-C6 N2C7 C7C8 C8C9 C9C10 ClOCll
2.013 (6) 2.020 (5) 2.284 (2) 2.195 (6) 2.216 (7) 2.238 (7) 2.262 (6) 2.183 (6) 1.310 (7) 1.365 (8) 1.382 (8) 1.406 (8) 1.353 (9) 1.362 (9) 1.342 (9) 1.388 (8) 1.431 (8) 1.366 (10) 1.380 (10) 1.346 (13) 1.336 (12)
CllC12 C12C7 C2-F1 C3-F2 C4-F3 C5-F4 C8-F5 C9-F6 C10-F7 Cll-F8 C12-F9 C13C14 C14C15 C15C16 C16-CI7 C17C13 C17C19 PC18 PC24 PC30
N1. ,F4 N1. . ,F5 N2. . .F5
Nonboiided Contactsn 2.746 (7) N2. . *F9 2.833 (7) F1. *H13 2.783 (7) F9. . .H15 8
1.371 (11) 1.370 (10) 1.352 (7) 1.347 (7) 1.362 (7) 1.340 (7) 1.334 (8) 1.343 (10) 1.337 (9) 1.352 (9) 1.334 (9) 1.404 (9) 1.401 (10) 1.407 (10) 1.426 (9) 1.409 (9) 1.474 (7) 1.804 (4) 1.826 (4) 1.812 (4)
2.804 (7) 2.483 2.365
'This tabulation includes N. . .F intramolecular contacts
