Oxidation Reactions of Dithiocarbamate Complexes of Ruthenium(II)

Abstract

The reaction of Ru(Et2dtc)2(DMSO)2 (Et2dtc = N,N-diethyldithiocarbamate; DMSO = dimethyl sulfoxide) with t-BuNC gave trans-Ru(Et2dtc)2(CN-t-Bu)2, 1. Complex 1 crystallizes in the monoclinic space group P21/n with a = 9.753(2) Å, b = 11.583(2) Å, c = 12.974(2) Å, and β = 91.8(2)° for Z = 2. The crystal structure of 1 shows the trans disposition of the two isocyanides; the mean Ru-S and Ru-C distances are 2.409 and 1.977(2) Å, respectively. Treatment of [Ru(diene)Cl2]n with Na(Et2dtc) afforded Ru(Et2dtc)2(diene) (diene = bicyclo[2.2.1]-hepta-2,5-diene (NBD), 2, 1,5-cyclooctadiene (COD), 3). Complex 2 crystallizes in the triclinic space group P1̄ with a = 7.316(1) Å, b = 10.346(1) Å, c = 15.123(2) Å, a = 103.69(2)°, β= 93.54(2)°, and γ = 100.61(2)° for Z = 2. The mean Ru-S and Ru-C distances in 2 are 2.416 and 2.137 Å, respectively. The reaction of cis-Ru(Et2dtc)2(CO)2 with iodine gave the 2:1 molecular iodine complex cis-Ru(Et2dtc)2(CO)2·1/2I2 4, which crystallizes in the monoclinic space group P21/c with a 7.347(2), b = 22.227(2) Å, c = 12.891(2) Å, and β =95.98 (2)° for Z = 4. The mean Ru-S and Ru-C and the I-I distances in complex 4 are 2.427, 1.903, and 2.745(1) Å, respectively. Treatment of Ru(Et2dtc)2(DMSO)2 with I2 gave the linear_Ru(II)-Ru(in)-Ru(III) trimer [Ru3(Et2dtc)6(DMSO)2](I 3)2, 5, which crystallizes in the triclinic space group P1̄ with a = 14.125(3) Å, b = 20.829(6) Å, c = 13.658(3) Å, a = 97.57(2)°, β= 110.01(2)°, and γ = 71.25(2)° for 2=2. The structure of complex 6 can be viewed as consisting of a {Ru2 III(Et2dtc)4}2+ core and a {RuII(Et2dtc)2(DMSO)2} moiety, which are linked together via the two dithiocarbamate sulfurs of the latter. While the two Ru(III) centers are connected by a Ru-Ru single bond (Ru-Ru = 2.826(2) Å), there is no direct interaction between the Ru(III) and Ru(II) centers. Oxidation of Ru(Et2dtc)2L2 (L = PPh3, t-BuNC) by I2 gave the respective [Ru(Et2dtc)2L2]+ cations. The reaction of cis-Ru(Et2dtc)2(PPh3)2 with excess tosyl azide gave the diamagnetic Ru(IV) tetrazene complex Ru(Et2dtc)2(Ts2N4), 7. Complex 7 crystallizes in the triclinic space group P1̄ with a = 10.380(1) Å, b = 11.322-(1) Å, c = 15.310(1) Å, α = 106.84(2)°, β = 106.87(2)°, and γ = 92.63(2)° for Z = 2. The Ru-S and Ru-Nα distances in 7 are 2.385 and 1.98 A, respectively. The formal potentials of the Ru dithiocarbamate complexes were determined by cyclic voltammetry.