Reaction of hydrogen sulfide with dinuclear palladium(I) complexes containing bis(diphenylphosphino)methane (dpm) and conversion of bridged-sulfide derivatives to bridged-sulfoxide species. X-ray crystal structure of the dimetallic sulfoxide Pd2Cl2(.mu.-SO)(.mu.-dpm)2 containing pyramidal sulfur

Mechanistic aspects of the reaction of hydrogen sulfide with dinuclear palladium(I) complexes containing bis(diphenylphosphino)methane and related ligands

“…The D2S (4 mL at 1 atm) was added via a syringe to a CH2C12 solution of l a (25 mg) in a 10 mL Schlenk tube under vacuum at room temperature (RT); the originally orange solution precipitated the k-S product 2a completely after 30 min. The isolated 2a, redissolved in CD2C12, gave a 'H nmr spectrum (2) showing a CH2:phenyl integration ratio of 1:10 and thus no incorporation of deuterium at the methylene groups; consistent with this finding, analysis of the gas phase by low range mass spectroscopy, following removal of D2S and CH2C12 at liquid-N2 temperature, revealed only D2.…”

“…The methylene protons of dpm do have acidic character (2,11) and involvement of the --CH2-groups seemed at least a possibility; however, this is ruled out in that reaction of l a with D2S generates D2 with no accompanying HD or Hz, and the 2a product contains only protonated dpm. In related work (12), the synthesis of Pd2C12(p-PPh2CD2PPh2)2 and its exchange with protoncontaining solvents have been studied; reaction of this complex with H2S correspondingly gives only Hz and the --CD2-p-sulfide product, again showing non-involvement of the methylene protons in the H2S reactions.…”

“…The materials used, synthetic procedures for the ligands and complexes, and instrumentation used for 3 1~ and 'H nmr spectra and UV / vis spectra, have been largely described previously (2). D2S was prepared by the action of 10 mL DCI / D20 solution (Stohler Isotope Chemicals) on 2 g CaS; the resulting gas was bubbled through D20 to remove any sulfur oxide impurities and HCl, and then dried over CaC12.…”

“…Reaction [I] is readily monitored by solution electronic spectroscopy; species such as 1 are reddish-orange with two to three absorption maxima in the 340-590 nm region (2,15,16), while the p-S products (2) are brown and have absorption maxima in the 325-350 and 470-485 nm regions (2,17). Figure 3 shows spectral changes on treating a CH2C12 solution of the bromide l b with H2S at 25°C; rates for the bromide system were followed by observing the decreasing absorption at 428 nm as a function of time, and the observed isosbestic point showed a well-behaved system.…”

Two Routes to Bis(μ-diphenylphosphino)methane Diplatinum Halides Bridged by Sulfur Monoxide

“…This reaction was successful, providing what we believe is the first μ-SO complex of platinum. Related complexes have been made with Pd , and Ni, not through direct SO insertion but by oxidation of a μ-S complex. With that in mind, we carried out a parallel (and superior) synthesis of 3 based on an oxidation reaction, eq 3.…”