79994-14-2Relevant academic research and scientific papers
Polynuclear coordination and ligand activation. The structure, bonding, and desulfurization of thioformamido ligands about a trinuclear site
Adams, Richard D.,Dawoodi, Zain,Foust, Donald F.,Segmüller, Brigitte E.
, p. 315 - 323 (2008/10/08)
The reactions of H2Os3(CO)10 with the organoisothiocyanates RN=C=S, R = C6H5, C6H4-p-F, C6H4-p-CH3, and CH3, have been investigated. A sequence of products has been isolated and structurally characterized that shows the activation and desulfurization of an organothioformamido ligand about a trinuclear site. The initial products of the reactions are the compounds HOs3[μ-η1SC(H)=NR] (CO)10, Ia-IVa (R = C6H5, C6H4-p-F, C6H4-P-CH3, and CH3). IIa has been characterized by X-ray crystallographic methods. It contains a thioformamido ligand that bridges an edge of the cluster via the sulfur atom. The carbon-sulfur bond distance at 1.782 (12) A? is long while the carbon-nitrogen distance at 1.279 (13) A? is short and similar to a C-N double bond. Under irradiation, Ia-IVa lose 1 mol of CO to form the complexes HOs[μ3-η2-SC-(H)=NR](CO)9, Ib-IVb (R = C6H5, C6H4-p-F, C6H4-p-CH3, and CH3), that contain triply bridging thioformamido ligands in which the sulfur atom bridges two metal atoms and the nitrogen atom is bonded to the third. IIB was characterized by X-ray crystallographic methods. When heated to 125°C, Ib-IVb are transformed into the compounds HOs3(μ3-S)(μ-HC=NR)(CO)9, Ic-IVc, that contain an open cluster of three metal atoms with a triply bridging sulfido ligand and formimidoyl ligand which bridges the open edge of the cluster. IIc was characterized by X-ray crystallographic methods. Ib was found to add 1 mol of P(CH3)2C6H5 to form the complex HOs3[μ-η2-SC(H)=NC6H 5](CO)9[P(CH3)2C6H 5], Id. An X-ray crystallographic analysis showed that it contains a N-phenylthioformamido ligand bridging an edge of the cluster, but unlike Ia-IVa the ligand is coordinated through both the sulfur and nitrogen atoms. The carbon-sulfur distance at 1.69 (1) A? is significantly shorter than that in IIa while the carbon-nitrogen distance at 1.32 (1) A? is longer. The effect of coordination on the bonding in the thioformamido ligand and its influence on the desulfurization reaction is described and discussed.
