Synthesis and molecular structures of a novel tetranuclear silver(I) cluster [Ag2(Himdc)(PPh3)2]2 (H3imdc=imidazole-4,5-dicarboxylic acid) and a mononuclear silver(I) complex [Ag(H2imdc)(PPh3)2]

Abstract A novel tetranuclear silver(I) cluster, [Ag 2 (Himdc)(PPh 3 ) 2 ] 2 1 (H 3 imdc = imidazole-4,5-dicarboxylic acid; O ∧ N) was obtained by a reaction of the Ag–O bonding precursor [Ag( R -Hpyrrld)] 2 (H 2 pyrrld = 2-pyrrolidone-5-carboxylic acid), PPh 3 and H 3 imdc. The mononuclear complex, [Ag(H 2 imdc)(PPh 3 ) 2 ] 2 , was also formed by the reactions using increased amounts of PPh 3 . In the solid state, complex 1 was a “bivalve”-like Ag 4 cluster, while complex 2 showed a supramolecular arrangement of the 4-coordinate AgP 2 (N ∧ O) unit via the intermolecular hydrogen bonding interaction.