Synthesis, spectroscopy and structures of halogen and sulfur-bridged dinuclear silver(I) complexes with N1-substituted thiophene-2-carbaldehyde thiosemicarbazone
摘要:
The reactions of silver(I) halides (Cl or Br) with thiophene-2-carbalclehyde N-1-methyl thiosemicarbazone (HttscMe) in the presence of Ph3P (1:11 molar ratio) yield halogen-bridged dimers, [Ag-2(mu-X)(2)(eta(1)-S-HttsMe)(2)] (X = Cl, 1; Br, 2). The use of 2,2'-bipyridine in lieu of Ph3P in the reaction of silver(1) chloride with HttscMe yields the sulfur-bridged dimer, [Ag-2(mu-S-HttscMe)(2)(eta(1)-HttsMe)(2)] center dot 2CHCl(3) 3. The substituents have altered the nature of bridge between the two silver atoms. The Ag center dot center dot center dot Ag separation (3.4867(5) angstrom) in coniplex 3 is less than that in the halogen-bridged dimers (3.734(4) angstrom 1: 3.746(5) angstrom 2). Unlike PPh3 the co-ligand 2,2'-bipyridine did not coordinate to the silver center, but was necessary for crystallization in the reaction with the thio-ligand. NMR spectroscopy revealed that the complexes remained unchanged in the solution state (CDCl3). (C) 2009 Elsevier Ltd. All rights reserved.