Photocatalytic H-Evolution by Homogeneous Molybdenum Sulfide Clusters Supported by Dithiocarbamate Ligands.

Irradiation at 460 nm of [Mo(μ-S)(μ-S)(SCNR)]I ([]I, R = Me; []I, R = Et; []I, R = Bu; []I, R = CHCH) in a mixed aqueous-polar organic medium with [Ru(bipy)] as photosensitizer and EtN as electron donor leads to H evolution. Maximum activity (300 turnovers, 3 h) is found with R = Bu in 1:9 HO:MeCN; diminished activity is attributed to deterioration of [Ru(bipy)]. Monitoring of the photolysis mixture by mass spectrometry suggests transformation of [Mo(μ-S)(μ-S)(SCNR)] to [Mo(μ-S)(μ-S)(SCNR)] via extrusion of sulfur on a time scale of minutes without accumulation of the intermediate [MoS(SCNR)] or [MoS(SCNR)] species.

Crystal structure of tetra-iso-butyl-thiuram di-sulfide.

Tetra-kis(2-methyl-prop-yl)thio-per-oxy-dicarbonic di-amide, or tetra-iso-butyl-thiuram di-sulfide, CHNS, crystallizes in a general position in the triclinic space group -1 but shows pseudo- symmetry about the di-sulfide bond. The C-S-S-C torsion angle [-85.81 (2)°] and the dihedral angle between the two NCS mean planes [85.