The reaction between MoCl5 and potassium pyrrole-N-carbodithioate (K(pdc)) in an aqueous solution led to a surprising product with the stoichiometry Mo(pdc)4. Optical spectra and infrared spectra suggested an eight-coordinate, nonoxygenated molybdenum product. A single-crystal structural study on this material recrystallized from CH2Cl2 was carried out, and the eight-coordinate geometry was confirmed. The crystal Mo(pdc)41/2CH2Cl2 crystallizes in the centrosymmetric space group P1 with a = 11.197 (6) Å, b = 11.220 (5) Å, c = 13.165 (7) Å, α = 73.36 (4), β = 67.07 (4), γ = 66.75(4), V = 1382 (1) Å3, and ρ(calcd) = 1.700 g cm-3 for mol wt 707.3 and Z = 2. A unique set of data (h,k,l; 3 < 2θ < 45; Mo Kα) were collected with a Nicolet R3m automated diffractometer using graphite-monochromatized radiation. The structure was solved via a combination of Patterson, Fourier, and least-squares techniques. The final discrepancy indices were RF =3.17% and RwF = 3.26% for the 2822 unique data with F > 6σ(F). The molecule has approximate D2d symmetry with the sulfurs located at the vertices of a D2d dodecahedron. The average Mo-S bond lengths are 2.541 and 2.507 Å for the dodecahedral a and b sites, respectively.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry