Inorg. Chem. 1988. 27. 1358-1363
1358 Table IV. Selected Bond Distances and Angles for [ ( C ~ M ~ S R ~ ) ~ ( ~ - P M ~(7) ~)Z(~-T~)I (a) Bond Distances (A) Rh(2)-P(1) Rh(l)-Rh(2) 3.423 (1) Rh(1)-CNT(1)“ 1.878 (1 1 ) Rh(2)-P(2) Rh(2)-CNT(2) P(1)-C(l) 1.886 (11) Rh(1)-Te P(l)-C(2) 2.667 (1) Rh(2)-Te P(2)-C(3) 2.665 (1) Rh( 1)-P( 1) P(2)-C(4) 2.288 (3) Rh( 1)-P(2) 2.290 (3) P(l)-*P(2)
Rh(1)-Te-Rh(2) Rh(l)-P(l)-Rh(2) Rh(l)-P(2)-Rh(2) CNT(1)-Rh(1)-Te CNT(1)-Rh(1)-P(1) CNT(1)-Rh(1)-P(2) T e R h ( 1)-P( 1) Te-Rh( 1)-P(2) P( 1)-Rh( 1)-P(2)
2.295 (3) 2.284 (2) 1.838 (12) 1.831 (12) 1.846 (10) 1.823 (11) 2.725 (4)
(b) Bond Angles (deg) 79.91 (6) CNT(2)-Rh(2)-Te 96.6 (1) CNT(2)-Rh(2)-P(l) 96.9 (1) CNT(2)-Rh(2)-P(2) 131.4 (1) Te-Rh(2)-P(1) 139.1 (2) Te-Rh(2)-P(2) 136.3 (2) P(I)-Rh(2)-P(2) 75.2 (1) C(1)-P(1)-C(2) 75.3 (1) C(3)-P(2)-C(4) 73.1 (1)
(c) Dihedral Angles (deg)* [P( l)-Rh(l)-P(2)]-[P( 1)-Rh(2)-P(2)] [Rh( I)-P(l)-Rh(P)]-[Rh(l)-P(2)-Rh(2)] [Rh( 1)-P( l)-Rh(Z)]-[Rh( l)-TeRh(Z)] [Rh( l)-P(2)-Rh(2)-[Rh( l)-Te-Rh(Z)]
11: yield 105 mg (34%); mp 250 OC dec. Anal. Calcd for C,oH4804P2Rh2:C, 48.66; H, 6.53; Rh, 27.79. Found: C, 48.86; H, 6.59; Rh, 27.45. The mass spectra of 11 is almost identical with that of 10. ‘H NMR (C6D6): 6 3.70 (S, 6 H, COzMe), 2.26 (vt, N = 11.8 Hz, 6 H, PCH,), 2.10 (d, JRh-H = 0.3 HZ, 15 H, CSMe5),1.96 (dt, Jp-“ = 2.3 HZ, JRh-H = 0.4 HZ, 15 H, C5Me5), 1.40 (Vt, N = 7.0 Hz, 6 H, PCHJ. ” P NMR (C6D6): 6 -2.99 (dd, JRh-p = 158.3 Hz, J ~ h - p= 2.7 HZ). ”C NMR (C6D6): 6 173.40 (Vt, N = 17.2 HZ, COZMe),96.77 (S, = 4.5 Hz, C5MeS),50.47 (s, OCH,), 38.06 (dvt, C5Me5),92.18 (d, N = 69.6, J R h X = 14.6 HZ, CCO,Me), 22.81 (dvt, N = 60.9, J R ~=X 12.1 Hz, PCH,), 21.60 (s, PCH,), 11.50 (s, C5(CH3)5), 10.80 (s, C5( W ) S ) .
130.3 (1) 139.1 (2) 137.2 (2) 75.2 (1) 75.5 (1) 73.0 (1) 99.2 (6) 99.1 (6)
136.7 (3) 127.0 (3) 116.3 (2) 116.7 (2)
“ C N T = centroid of Cp* ring. *String of atoms in brackets represents the atoms of a plane. 6.59; Rh, 27.52. MS (70 eV): m / e 740 (17%; M’), 725 (100%; M+ CH,), 695 (9%; M+ - 3CHp), 373 (3%; Rh(C5Me5),+), 238 (3%; CSMe5Rh+).‘H NMR (C6D6): 6 3.75 (s; 3 H, CO,Me), 3.71 (s; 3 H, C02Me),2.31 (d, Jp-H = 10.5 Hz, 3 H, PCH,), 2.00 (d,br, Jp-H = 2.6 Hz,15 H, CSMe5),1.75 (d, JP-H = 10.5 Hz, 3 H, PCH,), 1.70 (ddd, J F H = 2.9 HZ, J p + 2.1 HZ, JRh-H = 0.4 HZ, 15 H, CSMe5),1.40 (m, 6 H, PCHI). ” P NMR 6 -30.02 (ddd, JRh-p = 128.8 HZ, J ~ h - p= 6.7 HZ, J p - p = 32.8 HZ), -79.84 (ddd, JRh-p = 142.9 HZ, JRh-p = 87.8 Hz, J p - p = 32.8 Hz). ”C NMR (C6D6): 6 172.20 (s, CO,Me), 169.61 (s, CO,Me), 97.39 (s, C5Me5),95.20 (s, CSMes),49.77 (s, OCH,), 49.59 (s,0CH3), 22.48 (s, CC02Me), 22.29 (s, CCo,Me), 14.82 (m, PCH,), 9.97 (s, C5(m3)5), 9.92 (s, C5(cH3)5).
Crystallographic Structural Determination for 7. Crystals of 7 were grown by layering pentane on a toluene solution. All specimens examined showed extensive interpenetrant twinning; a crystal free of twinning effects was obtained from one arm of a much larger formation. Lattice parameters (Table 11) were obtained from the best fit of the angular settings of 25 reflections (23O 5 28 5 30O). The data were corrected for Lp effects, linear decay (-lo%), and absorption (empirical, 256 data, ellipsoidal model). The Te, Rh, and P atoms were obtained by direct methods (SOLV). All nonhydrogen atoms were anisotropically refined, and hydrogen atom contributions were idealized for the (p-PMe,) groups but ignored for the C5Me5groups. Table I11 provides the atomic coordinates and Table IV selected bond distances and angles. SHELXTL software was used for all computations and served as the source for the neutral-atom scattering factors (Nicolet Corp., Madison, WI).
Acknowledgment. We thank the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie for financial support and Degussa A G for generous gifts of chemicals. We also thank U. Neumann and R. Schedl for the elemental analyses, Dr. G. Lange for the mass spectra, and Dr. W . Buchner and C. P. Kneis for NMR measurements. Registry No. 2, 87882-79-9; 3, 87882-82-4; 4, 87882-83-5; 5, 87882-85-7; 6, 87882-84-6; 7, 87882-86-8; 8, 113219-00-4; 9, 11321901-5; 10, 113219-02-6; 11, 113219-03-7; C,(CO,Me),, 762-42-5. Supplementary Material Available: Tables of bond distances and angles, anisotropic thermal parameters, and hydrogen atom coordinates (5 pages); F,/F, tables (21 pages). Ordering information is given on any current masthead page.
Contribution from the Institut fur Anorganische Chemie, Universitat Bern, CH-3000 Bern 9, Switzerland, Laboratorium fur Kristallographie, Universitat Bern, CH-3012 Bern, Switzerland, and Institut de Chimie Mintrale et Analytique, UniversitC de Lausanne, CH-1005 Lausanne, Switzerland
Triaqua(benzene)ruthenium(II) and Triaqua(benzene)osmium(II): Synthesis, Molecular Structure, and Water-Exchange Kinetics Monika Stebler-Rothlisberger,laWolfgang Hummel,Ib Pierre-A. Pittet,If Hans-Beat Burgi,*lb Andreas Ludi,*la and Andri E. Merbach*lc Received September 23. I987 Solid salts of M(?pC6H6)(H2O),’+ (M = Ru, Os) are obtained by reacting [MC1,(q-C6H6)], with Ag+ in aqueous solution or by the reaction of Ru(H2O)?+ with cyclohexadienein ethanol. [ R u ( I I - C ~ H ~ ) ( H , ~crystallizes ) , ] ~ ~ ~ in the orthorhombic space group Pbca with a = 12.892 (2) A, b = 12.441 (1) A, and c = 12.183 (2) 8, ( T = 125 K), and 2 = 8. The structure was refined to 1.9% for 2168 reflections with F, > 3a(F0). The relative arrangement of the benzene ring and the three water molecules is approximately staggered, the torsional angle being 19.2 (4)’. After correction for thermal motion, average distances are Ru-C = 2.164 (4). C-C = 1.419 (5), and Ru-0 = 2.1 17 (11) A. The Ru-center of the benzene plane distance is 1.631 A. Structural results obtained at 295 K agree with those at 125 K. Water-exchange rates at variable temperature and pressure were determined by line width measurements of I7O NMR spectra at 4.7 T. For R U ( ~ - C ~ H , ) ( H ~ and O ) ~0s(a-C6H6)(H20),*+ ~+ the following results are obtained: k(298 K), 11.5 f 3.1 and 11.8 f 2.0 s-I; AH*, 75.9 f 3.8 and 65.5 k 2.2 kJ mol-’; AS*,+29.9 f 10.6 and -4.8 f 6.1 J K-’ mol-’; A P , +1.5 f 0.4 and +2.9 & 0.6 cm3 mol-I. The reaction proceeds via an interchange mechanism (I) where the bond-breaking contribution has only a slightly larger weight than the bond-making one. The kinetic behavior indicates a strong trans-labilizing influence of the aromatic ligand.
Introduction Conventional procedures for the preparation of ruthenium arene complexes use the starting reagent uRuC13.xH,0”. Bis(arene) (1) (a) Institut far Anorganische Chemie, Universitat Bern. (b) Laboratorium fiir Kristallographie, Universitat Bern. (c) UniversitC de Lausanne.
species have been originally obtained by treating ruthenium trichloride with a n MCl$M mixture and the corresponding “e.* A n elegant high-yield preparative route to a variety of Ru-arene complexes starts with the reaction of cyclohexa- 1,3-diene with “RuCl,.xH,O” in ethanol affording t h e dimeric compound (2) Fischer, E. 0.;Bottcher, R. Z . Anorg. Allg. Chem. 1957, 291, 305.
0020-1669/88/1327-1358$01.50/00 1988 American Chemical Society
RU(~-C~H~)(HZO a n)d~ O ~ S+( ~ - C & 6 ) ( H 2 0 ) 3 2 t [RUC12(q6-C6H6)]?.3-5 Prolonged heating of the analogous pcumene species with a n excess of another arene accomplishes complete exchange of the aromatic ligands6 These dimeric species serve as precursors to synthesize a large number of monomeric Ru(I1) complexes with the general stoichiometry Ru(q6-arene)L,L2L3.' Depending on p H and anion concentration, treatment of the uncharged dimer in aqueous solution produces ions such as [$-arene)Ru(p-X),Ru(q6-arene)]+ (X = C1-, OH-, MeO-), Ru(q6-arene)C13-, and the cubane-like [ R u , ( ~ - O H ) ~ ( ~ ~ - a r e n e ) , ] ~ +The . ~ general aqueous solution chemistry of monomeric q6-arene complexes of Ru(I1) and Os(1I) has been summarized by Taube et al., who concluded that the stable species in acidic water occurs as M11(q6-C6H6)(H20)32+.9 In the course of our study of the ruthenium aqua ion, we became interested in the Ru($-arene)(H20)z+ ion because its combination of ligands represents a unique conceptual link between classical coordination chemistry and organoruthenium compounds. Moreover, this arene-aqua species is a convenient and versatile starting reagent in preparative ruthenium chemistry.I0 A variety of substitution products Ru(q6-arene)L32+can be synthesized with L covering a wide range of a-acidity, e.g. M e 2 S 0 , pyridine, (CH,)*S, and CH3CN." N o member of this novel class of compounds, however, has been fully characterized by its molecular structure or its ligand-exchange properties. I t is on this background that we performed a thorough investigation of the Ru(q6-C6H6)(H20)32+ ion encompassing the formation reaction, its crystal and molecular structure, and the water-exchange kinetics in acidic medium as part of a general study concerned with the structure and reactivity of these compounds. The kinetic properties have to be seen in close connection with mechanistic investigation of the water exchange for the hexaaquaruthenium ions.12
Experimental Section A. Preparations and Crystal Growth. The reaction of solid Ru( H 2 0 ) 6 ( t ~ ~(tos ) 2 = toluenesulf~nate)l~~ with cyclohexadiene (the 1,3or the 1,4-isomer can be used) in EtOH affords orange [Ru($C6H6)(H20),](tos)? All crystals investigated by precession photography turned out, however, to be twins. A systematic search for another counterion lead to SO>-.The corresponding salt is conveniently prepared An acidic aqueous solution (pH 1) of this from dimer is treated with a stoichiometric amount of Ag,S04. Solid AgCl is removed by filtration. The resulting solution is concentrated by rotatory evaporation at 35 OC until the first orange solid separates; this is redissolved by warming to SO OC. Slow cooling to 5 OC produces airstable orange single crystals. Yield: 40%. A further crop can be obtained by repeating the evaporation and cooling. Anal. Calcd for [Ru(C&)(H20)3]S04: RU, 30.7; C, 21.9; H, 3.6; S, 9.7; HzO, 16.4. Found: Ru, 30.2; C, 21.9; H, 3.7; S, 9.8; H20, 16.5. [os(?+'-C6H6)(H20)3](tos)2 is obtained by dissolving [OscI2(q6C6H6)]: in 1 M Htos and adding a stoichiometric amount of Ag(tos). Filtration of AgCl and concentration of the solution by rotatory evaporation produces a yellow powder. Yield: 88%. Anal. Calcd for [Os(c&,)(H@)3](tOS)2: c, 36.1; H, 3.9; s,9.7; H20, 8.1. Found: c, 35.4; H, 4.0; S, 10.0; H20, 7.5. Ru was analyzed spectroph~tometrically;'~ elemental analyses were carried out by CIBA-GEIGY, Basel. B. Crystal Structure Analysis of [Ru(q6-c6H6)(Hzo),~04.Lattice parameters (Table I) were determined at several temperatures by (3) (4) (5) (6)
Winkhaus, G.; Singer, H. J . Organomet. Chem. 1967, 7, 487. Zelonka, R. A,; Baird, M. C. Can. J. Chem. 1972, 50, 3063. Bennett, M. A,; Smith, A. K. J. Chem. Soc. Dalton Trans. 1974, 233. Bennett, M. A.; Matheson, T. W.; Robertson, G. B.; Smith, A. K.; Tucker, P. A. Inorg. Chem. 1980, 19, 1014. (7) Bennett. M. A.: Bruce. M. I.: Matheson. T. W. In ComDrehensiue Organometallic Chemistry; Wilkinson, G:, Ed., Pergamon: Oxford, England, 1982; Vol. 4, pp 796. Gould, R. 0.;Jones, C. L.; Robertson, D. R.; Tocher, D. A.; Stephenson, T. A. J. Organomet. Chem. 1982, 226, 199. Hung, Y.;Kung, W. J.; Taube, H. Inorg. Chem. 1981, 20,457. Bailey, 0. H.;Ludi, A. Inorg. Chem. 1985, 24, 2582. Stebler-Rathlisberger, M.; Ludi, A. Polyhedron 1986, 5 , 1217. Rapaport, I.; Helm, L.; Merbach, A. E.; Bernhard, P.; Ludi, A. Inorg. Chem. 1988, 27,0000. (13) (a) Bemhard, P.; BiJrgi, H.-B.; Hauser, J.; Lehmann, H.; Ludi, A. Inorg. Chem. 1982, 21, 3936. (b) Bernhard, P.; Lehmann, H.; Ludi, A. J. Chem. Soc., Chem. Commun. 1981, 1216. (14) Marshall, E. D.; Rickard, R. R. Anal. Chem. 1950,22,795. Woodhead, J. L.; Fletcher, J. M. J . Chem. SOC.1961, 5039.
Inorganic Chemistry, Vol. 27, No. 8, 1988 1359 Table I. Crystal Data, Intensity Collection, and Refinement Parameters for [Ru(q6-C6H6)(H2O)~]SOa at 295 and 125 K 295 K 125 K Pbca
12.919 (2) 12.501 (2) blA 12.282 (2) CIA VIA3 1983.5 (5) fw 329.3 z 8 D,,,(flotation)/g cm-3 2.19 (2) Dcakdll3 C n r 3 2.198 (1) cryst dimens/" 0.2 x 0.15 x 0.1 linear abs coeff/cm-l 17.6 28 limitsldeg 1-60 hkl 518,517,517 0.8 + 0.4 tan 8 scan widthldeg no. of unique reflcns measd 2901 no. of unique reflcns 2509 with F,,> 3a(F,,) 2.4 R/% Rwl% 3.1 goodness of fit 2.03 final shiftlerror
