Synthesis and crystal structure of [Cu(4-OOCC6H4CN)2(4-HOOCC6H4CN)(H2O)2]·2(4-HOOCC6H4CN): a hydrogen bonded assembly of the first transition metal complex of 4-cyanobenzoic acid

The first transition metal complex of 4-cyanobenzoic acid, [Cu(4-OOCC6H4CN)2(4-HOOCC6H4CN)(H2O)2]·2(4-HOOCC6H4CN), has been prepared in aqueous medium. X-ray single crystal structure analysis reveals that it is a monometallic complex. Five-coordination Cu(II) ion is approximately in a square based pyramidal environment. Three-dimensional network of this compound is formed through O–H…N, O–H…O, C–H…O and C–H…N hydrogen bonding interactions, yielding a grid framework containing dimers of 4-cyanobenzoic acid with carboxylic dimer synthons locating in the channels.