The beta-thiophosphinoyl carbene PhCCH2P(S)Ph-2 (5) has been prepared by irradiation of the corresponding diazo compound. The relative rates for insertion into the OH bond of methanol and for addition to the double bond of 2-methyl-2-butene indicate enhanced nucleophilic properties of the carbene, comparable to those of PhCCH2CH3 The unusual effect of increased nucleophilicity by an electron-withdrawing substituent probably results from hyperconjugative electron donation by the C-P bond, as recently documented for the same group in a carbocation. (C) 1997 Elsevier Science Ltd.
Photothermographic materials containing silver halide sensitized with combination of compounds
申请人:Simpson M. Sharon
公开号:US20060078833A1
公开(公告)日:2006-04-13
Photothermographic materials are designed with increased photospeed by chemical sensitizing the photosensitive silver halide grains with a combination of compounds. A first chemical sensitizer is a specific gold(III)-containing compound and a second chemical sensitizer is a sulfur-containing compound that is a diphenylphosphine sulfide. The molar ratio of the gold (III)-containing compound to the sulfur-containing compound is at least 1:1.