Ag(3) triangle and Ag(4) rectangle supported by deprotonated aminopyrimidyl derivatives and bis(diphenylphosphino)methane

Abstract

Two new coordination compounds [Ag(6)(NHdmpym)(2)(dppm)(4)] (1 center dot 4ClO(4)) and [Ag(4)(NHpym)(2)(dppm)(2)] (2 center dot 2ClO(4)center dot 2DMF) (NH(2)dmpym = 2-amino-4, 6-dimethylpyrimidine, NH(2)pym = 2-aminopyrimidine, dppm = bis(diphenylphosphino)methane, DMF = N, N-dimethylformamide) have been synthesized under the ammoniacal conditions and structurally characterized. In 1 and 2, NH(2)dmpym and NH(2)pym ligands are deprotonated and show rare mu(4)-N(1):N(1):N(2) and mu(3)-N(1):N(2) coordination modes, respectively. The bridging dppm ligand combines the N-donor ligands to give 1 and 2 triangle Ag3 and rectangle Ag(4) cores, respectively. The resulting Ag(3) metallacycle is a scalene triangle with an average Ag center dot center dot center dot Ag distance of 3.1043(9) angstrom. The Ag(4) metallacycle is an irregular rectangle with a shorter and a longer Ag center dot center dot center dot Ag distances of 2.8852(15) and 3.3202(13) angstrom, respectively. The structural variances between 1 and 2 are caused by the ratios of metal and ligands and substituent group effect. In addition, 1 and 2 exhibit blue photoluminescence which may be assigned to ligand-to-metal charge transfer (LMCT) transition. (C) 2011 Elsevier B.V. All rights reserved.