Heteronuclear W(Mo)CuS complexes of dialkyldithiocarbamate. Syntheses of (Et4N)2[MCu3S4(dtcR2)3] and structures of (Et4N)2[MCu3S4(dtcC5H10)3]· DMF (M = W or Mo)

Compounds (Et4N)2[MCu3S4(dtcR2)3] (M=W (1) or Mo (2); R2  C5H10 (a), Et2 (b) or C4H8 (c) were synthesized by the reaction of (Et4N)2MS4 and CuCl in the presence of NadtcR2 in DMF. The crystal and molecular structures of 1a·DMF and 2a·DMF were determined from X-ray diffraction data. The compounds are isomorphous and crystallize in the triclinic space group P 1 with unit cell parameters for 1a(2a)·DMF: a=12.047(0) (12.053(2)), b= 17.620(3) (17.650(5)), c=14.514(1) (14.533(4)) A; α=100.83(9) (100.43(3)), β=115.41(3) (115.47(2)), γ=79.49(8) (79.78(2))°; V=2715.9 (2727.8) A3, Z=2 (2), and Dx=1.611 (1.497) g/cm3. The final R values converged to 0.048 and 0.067 for M=W and Mo respectively. [p ]The four metal atoms MCu3 are coplanar with the central tetrahedron of MS4 preserved. Each Cu(I) ion is coordinated to two inorganic S atoms from MS4 and two organic S atoms from one dtcC5H10 ligand in a distorted tetrahedral geometry. Infrared spectra showed two stretching vibrations at 430–442 cm− for μ3-SM and 455–463 cm−1 for μ2-SM. The compounds are diamagnetic and show reversible one-electron oxidation-reduction at E1/2 = 0.55 V (2a).