The reactions of iron, cobalt, nickel, and iridium complexes with (CH3C5H4)2V2S4 (1) have been studied, resulting in the preparation of a series of new mixed-metal clusters. Reaction of 1 with Fe(CO)5/Me3NO yields (CH3C5H4)2V2S 4Fe(CO)3 (2) while (CH3C5H4)2V2S 4Fe(NO)2 (3) is obtained from 1 and Fe(CO)2(NO)2. The μ-η2-S2 ligands in 2 and 3 are electrophilic and react with PBu3 or Pt(C2H4)(PPh3)2 to give V2FeS3 or V2FePtS4 clusters, respectively. The compound (CH3C5H4)2V2S 4CoC5H5 can be prepared from 1 and C5H5Co(CO)2 or CpCo(CO)I2 and Zn. The cluster (CH3C5H4)2V2S 4Ir(PPh3)Cl can be prepared from 1 and IrCl(N2)(PPh3)2; 1H NMR studies on this compound show that the vanadium centers are equivalent. [(C5H5)Ni(CO)]2 reacts with 1 to give [(CH3C5H4)2V2S 4]2Ni (4), which can be desulfurized to give [(CH3C5H4)2V2S 3]2Ni. The V4NiS8 cluster also reacts with Pt(C2H4)(PPh3)2 to give V4NiS8Pt and V4NiS8Pt2 derivatives. The compound (CH3C5H4)2V2S 3Fe(NO)2 reacts with CoI(NO)2 and zinc to give (CH3C5H4)VS3FeCo 2(NO)6, an analogue of Roussin's "black salt", Fe4S3(NO)7-. The structures of 2, 2-S, 3, and 4 were determined by X-ray crystallographic techniques. The crystals of 2 were monoclinic, with a = 9.853 (2) Å, b = 15.652 (3) Å, c = 12.821 (3) Å, β = 105.89 (2)°, and Z = 4; the space group was P21/c. Conventional full-matrix least-squares refinement with non-hydrogen atoms anisotropic and hydrogen atoms isotropic gave R = 0.028 and Rw = 0.036 for 2889 reflections having 2θ < 55° and I > 3σ(I). The structure consists of an isosceles triangle of metal atoms capped by two μ3-S moieties, with the V-V edge spanned by a μ-η2-S2 ligand. The V-Fe distances are unusually long, and the V-V distances are unusually short. The crystals of 2-S were monoclinic with a = 10.397 (2) Å, b = 25.504 (7) Å, c = 14.135 (4) Å, β = 106.63 (2)°, and Z = 8; the space group was P21/c. Modified full-matrix least-squares refinement with non-hydrogen atoms anisotropic and fixed hydrogen atoms isotropic gave R = 0.038 and Rw = 0.051 for 8422 reflections having 20 < 55° and I > 3σ(I). The structure is similar to that of 2 but with the V-V edge spanned by a μ-S ligand. The crystals of 3 were monoclinic with a = 10.190 (3) Å, b = 12.680 (5) Å, c = 14.016 (5) Å, β = 103.01 (3)°, and Z = 4; the space group was P21/c. Conventional full-matrix least-squares refinement with the non-hydrogen atoms anisotropic and the hydrogen atoms isotropic gave R = 0.031 and Rw = 0.030 for 5227 reflections having 2θ < 55° and I > 3σ(I). The structure of 3 is very similar to that for 2, except that the iron is coordinated to two nearly linear nitrosyl ligands. The unusual V-Fe bond lengths of 2, 2-S, and 3 are rationalized by V-S(μ-S) and V-S(μ3-S) π interactions, which are competitive with V-Fe bonding. Crystals of the V4Ni cluster 4 were orthorhombic with a = 16.014 (4) Å, b = 14.477 (3) Å, c = 12.990 (3) Å, and Z = 4; the space group was Pbcn. Refinement with the least-squares matrix blocked into random units and with anisotropic non-hydrogen atoms gave R = 0.081 and Rw = 0.081 for 1693 reflections having 2θ < 50° and Fo > 3σ(Fo). The molecule consists of tetrahedral Ni situated on a crystallographic 2-fold axis bound via two μ3-S atoms to each of two [(CH3C5H4)2V2(μ-S 2)] fragments. The V-V distance is 2.484 (2) Å, and the V-Ni distances are 2.813 ± 0.03 Å.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry