Cu2+- promoted nucleophilic addition of pyrazole to cyano group

Abstract Ligands resulting from copper(II)-promoted in-situ nucleophilic addition of pyrazole (Hpz) to 2-pyrimidinecarbonitrile (pcn), acetonitrile (MeCN) have been utilized in synthesis of clusters under conventional conditions. The addition of Hpz to pcn results in formation one uncommon polynitrogen ligand (1H-pyrazol-1-yl)(pyrimidin-2-yl)methanimine (Hppmi), deprotonation of it giving [ppmi]-, which has been incorporated into a cyclic tetranuclear cluster Cu4(ppmi)2(pz)4(MeOH)2(ClO4)2 (1) , which shows strong antiferromagnetic coupling. Addition of Hpz to MeCN results in formation of 1-(1H-pyrazol-1-yl)ethanimine (pei), which features in a mononuclear complex Cu(pei)2(H2O)(NO3)2 (2).