Inorg. Chem. 1988, 27, 3506-3510
3506
with chloroform/acetone (20:1). Evaporation of the solvent and reAnal. Calcd for C32H60CdC12012P4R~Z ( M , = 1146.2): Cd, 9.81; C1, 6.19; P, 10.81. Found: Cd, 9.94; CI, 5.98; P, 10.64. Calcd for C32crystallization from chloroform/pentane gave 103 mg (0.13 mmol,67%) H&I20,,P4PbRu2 ( M , = 1241.0): C, 30.97; H, 4.87. Found: C, 30.87 of orange-yellow crystals. The compound LRe(CO), is stable in air, soluble in acetone, dichloromethane,chloroform, and THF, and insoluble H, 4.85. [((C6Me,)RUc~P(o)(ocH,)z]2)2M]PF6 ([ML,]PF,, M3+ = AI3+, in saturated hydrocarbon solvents. Fe,'). The compounds were prepared from 5 and AI(N0,),-9H20 or Anal. Calcd for CI9H&1O9P2ReRu( M , = 787.1): C, 28.99; H, 3.84. FeC1,.6H20 in water or water/methanol as described above. An excess Found: C, 28.83; H, 3.79. of NaPF6 was added to precipitate the salts completely. The yield was IR (CH2CI2,v(C0)): 2018 (st), 1889 (st, br) cm-I. 60-80%. The products were recrystallized from chloroform/ether or [(C,jMe6)RUO(P(0 )(OCH,)&Vb(CO),H] (LMO(CO)pH). A 63" acetone/ether to give fine black crystals of [FeL,]PF6 and yellow crystals amount (0.21 mmol) of [Mo(CH,CN),(CO),] as added to a solution of O f [AlL2]PF6. 108 mg (0.21 mmol) of 6 in dichloromethane. The reaction mixture was Anal. Calcd for C,2H,&1C12F6012P5R~2 ( M , = 1205.7): C, 31.88; stirred under nitrogen for 30 min and then filtered. Slow evaporation H, 5.02. Found: C, 32.0; H, 5.26. Calcd for C,2H60C12F6FeO12P,Ru2 of the solvent gave 133 mg (92%) of large yellow to brown air-sensitive ( M , = 1234.6): C, 31.13; H, 4.82. Found: C, 31.13; H, 4.96. crystals. IR (CH2CI2,v(C0)): 2007 (st), 1915 (st), 1884 (m)cm-I. [(C6Me6)Ruc~lP(o)(~H,)2)2RU(C6Me6)lpF6([LRu(C6Mea)lPFs). To a solution of 0.243 mmol of N~[(C,M~,)RUC~(P(~)(~CH,),}~] (5, IH NMR (80 MHz, CDZC12): 6 -4.4 (s, Mo-H). NaL) in methanol/water was added a solution of 0.121 mmol of [(C6Me6)RUcl(P(o)(oCH3)2)2W(Co),H] (LW(CO),H). This com[((C6Me6)RUCI2)2]in methanol. slow addition of a concentrated solution pound was prepared in a manner analogous to that for LMo(CO),H from 108 mg (0.21 mmol) Of [(C6Me6)RuC1(P(0)(OCH,)2)(P(OH)(OCH,),}] of NH4PF6 in water gave a yellow precipitate, which was separated, washed with water, and dried under high vacuum. Recrystallization from (HL) and 101 mg (0.21 mmol) of [W(DMF),(CO),]; yield 159 mg acetone/ether gave orange-red crystals, yield 210 mg (93%). (97%) of large yellow to brown air-sensitive crystals. 'H NMR (80 MHz, CDClp): 6 2.08 (s, 18 H, C6(CH,)&UL). IR (CH2CI,, v(C0)): 1994 (st), 1899 (st), 1872 (sh), 1845 (m)cm-I. Anal. Calcd for C28H48C1F606P3R~2 ( M , = 925.2): C, 36.35; H, 'H NMR (80 MHz, CD2CI,): 6 -3.4 (t, )J(POWH) = 1.3 Hz, satellites with lJ(WH) = 10.4 Hz, W-H). 5.23. Found: C, 36.28; H, 5.35. "C NMR (67.9 MHz, CDCI,): 6 16.0 (q, IJ(CH) = 104 Hz, CCH,), [(C~M~~)RUCI(P(O)(OCH,)~J~R~(CJM~S)~PF~ ([LRb(CsMes)lPF6) 51.3 (q, 'J(CH) = 146 Hz, OCH,), 51.7 (q, 'J(CH) = 146 Hz, OCH,), and [(C6Me6)R~CI(P(O)(OCH,)2)2Ru(~-CH,C6H4CH(CH~)2)1PF6 104.9 (s, CCH,), 218.4 (d, ,J(CWH) = 16.0 Hz, satellites with 'J([LRu(p-Cy"e)]PF6). The compounds were prepared as described for (Is3WC) = 154 Hz, C a ) . [LRU(C6Me6)]PF6from [((C,Me5)RhC1,)2]and [(@-cymene)R~Cl,)~] in 80-90% yield. [LRh(CSMe5)]PF6was characterized as follows. Acknowledgment. Support of this research by the Minister fur 'H NMR (80 MHz, CDCI,): 6 1.62 (s, 15 H, C,(CH,),). Wissenschaft und Forschung des Landes Nordrhein-Westfalen Anal. Calcd for C26H&lF606P,RhRu ( M , 900.0): C, 34.70; H, is gratefully acknowledged. We thank B. Engels, P. Dharmawan, 5.04. Found: C, 34.64; H, 5.11. and T. Schmitz for skillful experimental assistance. W e are [LRu@-cymene)]PF6 was characterized as follows. 'H NMR (80 MHz, CDCI,): 6 1.34 (d, ,J(HCCH) = 6.8 Hz, 6 H, indebted to Bayer AG, Leverkusen, FRG, for a gift of trimethyl CH(CH,),), 2.23 (s, 3 H, C&CH,), 2.85 (sept, )J(HCCH) = 6.8 Hz, phosphite and dimethyl phosphonate and to Degussa AG, 1 H, CH(CH,)2), 5.40 (m,4 H, C6H4). Frankfurt, FRG, for a loan of RhCl3-aq and RuC13-aq. W.K. Anal. Cdcd for C26H~C1F606P~RU2 ( M , 897.1): C, 34.81; H, 4.94. thanks the Fonds der Chemischen Industrie for the continuous Found: C, 34.63; H, 5.14. support of his work. [(c6Me6)Ruc1(P(o)(OCH,)2)2Re(CO),] (LRe(CO),). A 79" Note Added in Proof. The perchlorate salt of [(C6Me6)RuCI(Pamount (0.19 mmol) of [ReBr(CO),] and 101 mg (0.19 mmol) of com(OCH,),),]+ and compound 1 have recently been prepared in a similar plex 6 (HL) in 30 mL of chloroform were heated to reflux under a way: Rojas, A.; Scotti, M.; Valderrama, M. Bol. Soc. Chil. Quim. 1988, nitrogen atmosphere for 24 h. The solution was concentrated and 33. 103. chromatographed on a short silica column. A yellow band was eluted
Contribution from the Departments of Chemistry, University of Minnesota-Duluth, Duluth, Minnesota 558 12, and University of Delaware, Newark, Delaware 19716
Reactions of Arenediazonium Salts with Hexacarbonyldicobalt Derivatives. Synthesis of Cationic N-Aryldiazadicobaltatetrahedranesand Crystal and Molecular Structure of [CO2(CO)4(h-Ph2PCH2PPh2)(P - N ~ C ~ H ~ - ~ - C H ~ ) ] [ S ~ F ~ ] Richard E. DeBlois,la Arnold L. Rheingold,*>lband Deborah E. Samkoff*Ja Received December 29, 1987
C~~(CO),(p-CO)~(p-dppm) (dppm = bis(dipheny1phosphino)methane) reacts with a variety of arenediazonium salts in dichloromethane at temperatures well below ambient to produce a series of novel N-aryldiazadicobaltatetrahedranecations as their [BFd-], [PF6-], and [SbFc] salts. The spectroscopic characterizations of these new compounds are discussed, and the structure of [ C O ~ ( C O ) ~ ( ~ - N ~ C ~ H ~ - ~ [SbF6] - C Hhas ~ )been ( M -determined ~ ~ ~ ~ ) by ] single-crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Pbca, with unit cell dimensions a = 22.488 (5) A, b = 19.459 (4) A, c = 18.002 (4) A, V = 7877 (3) A,, and Z = 8. The structure refined to R(F) = 5.40%. It is an isolobal analogue of tetrahedrane; the distorted tetrahedral Co2N2core contains a 1.342 (12) A N-N bond (midway between a single and a double bond) and a Co-Co distance of 2.440 (2) A. Introduction Since the first report more than 20 years ago,2 reactions of arenediazonium ions with nucleophilic transition-metal compounds (1) (a) University of Minnesota-Duluth.
(b) University of Delaware. (2) King, R. B.; Bisnette, M. B. Inorg. Chem. 1966, 5, 300-306.
0020-1669/88/1327-3506$01.50/0
have produced a profusion of neutral, monocationic, and even dicationic aryldiazenyl and aryldiazene derivatives of most of the transition metals3 A rather small subset involves the ArN2 moiety (3) Albertin, G.; Antoniutti, S.; Lanfranchi, M.; Pelizzi, G.; Bordignon, E. Inorg. Chem. 1986, 25, 950-957 and references therein.
0 1988 American Chemical Society
Inorganic Chemistry, Vol. 27, No. 20, 1988 3507
Cationic N-Aryldiazadicobaltatetrahedranes Table I. FABMS and IR (vco) Data for [6][BF4]' molecular high-res FABMS, m / e cation ion! m / e obsd calcd 763.9973 763.9961 6a+ 764 736.9991 737.0015 6bt 737 719.0155 719.0109 6ct 719 733.0243 733.0265 6d+ 733 761.0580 6e+ 761 761.0609 749.0214 749.0202 6fc 749
cm-l 2070, 2051 2068, 2047 2067, 2046 2066,2045 2067, 2045 2066, 2044
vco:
2087, 2086, 2086, 2085, 2085, 2084,
' [6a-fc] = [ C ~ ~ ( c o ) ~ @ - X C ~ H ~ N ~ ) ( d p pXm=) +NO2, ] : 6a; X = F, 6b; X = H, 6c;X CHI, 6d;X = CH(CH3)2,6e, X = OCH3, 6f. bAll spectra also exhibit ions resulting from sequential loss of four CO ligands and Nz.The ions (M - nCO + H)+ are also prominent. 'In CH2C12solution. bound to more than one metal ~ n t e r ;three ~ . ~ structural types have been c h a r a c t e r i ~ e d .In ~ structures 1 and 2, the (neutral) ArN2 Ar
.N'
Table 11. NMR Data for 161IPFnla chem shift, ppm cation 'H NMRb 6a+ 4.92 (Y', 2JpH= 12.1 H z ) ~ 6bt 4.84 ("t", 'JpH = 12.0 H z ) ~ 6c+ 4.80 ("t", 2JpH= 11.9 H z ) ~ 6dt 4.78 (d, HA), 4.72 (d, HE); JAB = 13.4 Hz' 2.40 (s, C6H4CH3) 6et 4.86 (d, HA), 4.79(d, HB); J A B = 13.7 Hz' 3.03 (sept, CH(CH3)2),1.26 (d, CH(CH,),); 3 J = ~7 HZ ~ 6fc 4.75 (d, HA), 4.68 (d, HB); J A B = 13.7 Hz' 3.91 (s, C6HdOCH3)
3'PI'HI NMRc 39.67 39.19 38.90 39.31 38.95 39.29
'In CD2C12 and (CD3)2C0. bPhenyl resonances not listed (see text). cAll spectra also include PFC resonance (-144.4 ppm (sept, 'JpF = 706 Hz)). Resonances for Co-bound P are broadened (fwhm ca. 110 Hz) by 59C0(I = 7/2, 100%). dRecorded without selective ,IP irradiation. 'Recorded with selective irradiation.
Ar
II
/N\ M-M
.
/
I
\
N= N
M-
1
M
2
fragment functions as a 3-electron donor to the dimetal unit. In structure 3,where a metal-metal bond is precluded, the (neutral)
/
Ar
4'
M=N=N M '
3
4
A r N 2 is a 5-electron donor. Structural type 4, in which A r N 2 is a 5-electron donor to a metal-metal-bonded dimetal unit has been unknown hitherto. The diazadimetallatetrahedrane core bears an obvious resemblance to structure 5, numerous examples
R
I
Figure 1. Structure and labeling scheme for the cation of [6d] [SbF,]. Thermal ellipsoids are drawn at the 45% level, and the phenyl rings are drawn with arbitrary radius spheres. [ C O ( C O ) ~ ] ~ A S ~We . * now report the syntheses and characterizations, including a single-crystal X-ray diffraction study, of a series of cations [6+],the first N-aryldiazadicobaltatetrahedrane cations.
Results
5
6a,XZN02 6b,X=F 6c,X=H
6d, X'CH3 6e, X =CH(CH3)2
6 f , X-OCH3
of which have been reported,6 as well as to [ C O ( C O ) ~ ] ~ and P~' (a) Deane, M. E.; Lalor, F. J. J. Organomet. Chem. 1974,67, C19c22. (b) Rattray, A. D.; Sutton, D. Inorg. Chim. Acto 1978, 27, L85-L86. (c) Angoletta, M.; Caglio, G. J. Orgonomet. Chem. 1979,182,425-430. (d) Angoletta, M.; Caglio, G. J. Organomet. Chem. 1980,185, 105-109. (a) Churchill, M. R.; Lin, K-K. G. Inorg. Chem. 1975,141133-1138. (b) Einstein, F. W. B.; Sutton, D.; Vogel, P. L. Inorg. Nucl. Chem. Lett. 1976, 12, 671-675. (c) Churchill, M. R.; Wasserman, H. J. Inorg. Chem. 1981, 20, 1580-1584. (d) Samkoff, D. E.; Shapley, J. R.; Churchill, M. R.; Wasserman, H. J. Inorg. Chem. 1984, 23, 397-402. (e) Barrientos-Penna, C. F.; Einstein, F. W. B.; Jones, T.; Sutton, D. Inorg. Chem. 1983, 22, 2614-2617. See, for example: (a) Sly, W. G. J . Am. Chem. SOC.1959,81, 18-20. (b) Bailey, N. A.; Mason, R.J . Chem. SOC.A 1968, 1293-1299. (c) Jack, T. R.; May, C. J.; Powell, J. J. Am. Chem. SOC.1977, 99, 4707-4716. (d) Angoletta, M.; Bellon, P. L.; Demartin, F.; Sansoni, M. J. Organomet. Chem. 1981, 208, C12-Cl4. Campana, C. F.; Vizi-Orosz, A.; Pglyi, G.; Mark& L.; Dahl, L. F. Inorg. Chem. 1979, 18, 3054-3059.
C O ~ ( C O ) ~ ( ~ - C Oreacts ) , (with ~ -arenediazonium ~ ~ ~ ~ ) ~ salts, [p-XC&4N2+] [A-] ( X = NO2, F, H , CH3, CH(CH3)2, OCH,; [A-] = [BF4-], [PF6-], [SbF6-]) a t temperatures below 0 OC to produce salts of the cations [6+] (see Experimental Section). These compounds are moderately air-stable, deep red-purple crystalline solids that dissolve in acetone, dichloromethane, acetonitrile, and, to a smaller extent, tetrahydrofuran, to give air-sensitive solutions. They are insoluble in aromatic and aliphatic hydrocarbons, and they decompose without melting or subliming. Their low-resolution FAB mass spectra exhibit molecular ions and sequential loss of four CO ligands and Nz. High-resolution peak matches on the molecular ions confirm the formulations [Co2(C0)4(N2C6H4X)(dppm)+l(Table 1). Their IR spectra (Table I) are devoid of absorptions in the bridging C O region, and the absorptions in the terminal C O region are 40-50 cm-' to high frequency of those in the IR spectrum of Co,(CO)(p-CO),(pdppm). T h e former also show a small, but systematic, variation with para substituent X. The 31P(lH] NMR spectra (Table 11)of cations [6+] consist of a single resonance each, down to -90 OC. These resonances are rather broad at room temperature (fwhm ca. 110 Hz), but narrow as the probe temperature is lowered (fwhm ca. 35 H z a t (8) Foust, A.; Campana, C. F.; Sinclair, J. D.; Dahl, L. F. Inorg. Chem.
1979, 18, 3047-3054. (9) Lisic, E. C.; Hanson, B. E. Inorg. Chem. 1986, 25, 812-815.
3508 Inorganic Chemistry, Vol. 27, No. 20, 1988 -60 “C). The chemical shifts are neither greatly nor systematically dependent on X. In addition to resonances in the expected regions for P-Ph and N-Ar protons and for X protons (6d-f), the IH N M R spectra (Table 11) feature P C H 2 P multiplets whose chemical shifts are neither greatly nor systematically dependent on X. These are discussed further below. In part because of the novelty of the structure implied by the spectroscopic data, we undertook a single-crystal X-ray diffraction study Of [6d] [SbF6]. Structure Description [Co2(C0)4(pu-Nz-C6H4cH3)(~-dPPm)l [SbF61 ([a] [SbFd) crystallizes as well-separated ions without significant interionic contacts. The cation structure (Figure 1 ) contains a central distorted tetrahedral CozNz core with a short N-N bond, 1.342 (12) A, a Co-Co distance of 2.440 (2) 8, and average Co-N distances of 1.898 (8) 8, to the substituted N atom and 1.939 (8) 8, to the other N atom. An equivalent description of the Co2N2 core considers it to be a complex of the N = N triple bond to the Co2 moiety. Assignment of a specific coordination geometry to Co is difficult due to the very acute N-Co-N angles, 41.0 ( 3 ) O (average). The dppm ligand bridges the two Co atoms. The N-N distance of 1.342 (12) 8,is considerably longer than (1.20 the N=N double bonds in (p-H)Os,(CO),,(p,q2-N=NPh) (4) (p-H)Os3(CO)lo(p,q1-N=N-p-Tol) (1.238 (18) [Mn(CO)4(p,q1-N=NPh)]z (1.233 (2) A)saCH3N=NCH3 (1.23 A),’’ and FN=NF (1.25 (4) 8,).11 It is somewhat shorter than the distances in compounds such as [(CH3),CCNJZNi(q2PhN=NPh) (1.385 (5) 8,),12 Fe2(Co),(~,q2-CH,N=NCH3) (1.366 (8) Fe2(CO)6(p,qZ-ClzHsN2) (1.399 (8) and Fe2(CO),(p,q2-CSHsNz)(1.404 (9) A),’’ in which the N = N a electrons are necessarily involved in bonding to the metal centers. It is substantially shorter than the 1.45 A distance in hydrazine, which may be taken as representative of a N-N single bond.I6 The N-N distance in our compound is thus consistent with substantial reduction in the N-N bond order, from 3 in the starting diazonium ion to between 1 and 2 in the product. The Co-Co distance is unusually short for Co2E2( E = group 15 element) tetrahedranes. In the Co2As2complex C O ~ ( C O ) ~ [P(C6H5),](p-As2),the c o c o distance is 2.594 (3) A; it is 2.576 (3) 8, in C O ~ ( C ~ ) ~ [ P ( C ~ H ~ )and ~ ] 2.574 ~ ( ~ -(3)A S8,~in) ~ ~ O ~ ( ~ ~ ) , [ P ( C , H ~ ) in ~ ]the ( ~ cubane L - P ~ analogue );~ [co4($C5H5)4P4]the Co-Co distance is 2.504 8, (average).]’ Discussion Solution Structures of [6+] from Spectroscopic Data. The appearance of terminal C O ligand absorptions at frequencies 40-50 cm-’ higher than the corresponding absorptions in c 0 2 ( C O ) ~ ( p CO),(pdppm) is consistent with a single positive charge delocalized over two Co centers.” Further, the small but systematic dependence of vco on X in cations [6+] indicates that information about the electronic characteristics of X is being transmitted through the N-aryl ring and through the N-N moiety to the Co centers and thence to the C O ligands. The presence of a single resonance in the 31P{1HJ NMR spectrum of each cation indicates the presence of a plane of symmetry relating the two dppm phosphorus sites. There is no evidence for fluxional behavior giving this result in the temperature range we examined (-90 to +20 “C). The phosphorus resonances narrow as the probe temperature is lowered; this observation is consistent with their admittedly rather large line widths at room temperature 10) 11)
12) 13) 14) 15) 16) (17) (18)
Boersch, H. Monatsh. Chem. 1935, 65, 311. Bauer, S.H. J . Am. Chem. SOC.1935, 65, 31 1. Dickson, R. S.; Ibers, J. A . J . Am. Chem. SOC.1972, 94, 2988-2993. Doedens, R. J.; Ibers, J. A. Inorg. Chem. 1969, 8, 2709-2714. Doedens, R. J. Inorg. Chem. 1970, 9, 429-436. Little, R. G.;Doedens, R. J. Inorg. Chem. 1972, J J , 1392-1397. Huheey, J E. Inorganic Chemistry, 3rd ed.; Harper & Row: New York, 1983; p A-38. Simon, G. L.; Dah], L. F. J . Am. Chem. SOC.1973, 95, 2175-2183. Nakamoto, K. Infrared and Raman Spectra of Inorganic and Coordinarion Compounds, 4th ed.; Wiley-Interscience: New York, 1986; pp 292-293.
DeBlois et al. Table 111. Crystal, Data Collection, and Refinement Parameters for [MI [SbFd formula Z 8 C36H29C02F6-
N20,P,Sb
fw cryst system space group
969.14
0.20 X 0.31 X 0.43
color temp, K Tmxi T m i n p, cm-l scan method no. of data colld no. of indep data no. of obsd data
purple
orthorhombic Pbca 22.488 (5) 19.459 (4) 18.002 (4) 7877 (3)
a, A b, A c,
D(calcd), g cm-3 1.634 size. mm
A
v,A3
diffractometer radiation wavelength, 8, monochromator scan limits, deg scan speed, deg m i d data collected
Nicolet R3m Mo Ka X = 0.71073
graphite
293 0.260/0.215 16.6
Wyckoff 6052 5486 2747
(5 aFo)
std reflcns
3 stdsl197
f h , +k, + I
decay, %
5.40 6.21 1.22
Aia
