Influence of 3-methyl substitution on the ability of 2-pyrrolidone to form heterometallic polymeric structures; synthesis and X-ray crystal structure of [HgCu(C5H8NO)2(CH3O)(NO3)]2, where C5H8NO is the anion of 3-methyl-2-pyrrolidone

Abstract

Abstract Reaction of Hg(C5H8NO)2 (where C5H8NO is the anion of 3-methyl-2-pyrrolidone) with copper(II) nitrate in methanol yields [HgCu(C5H8NO)2(CH3O)(NO3)]2 which has been characterized by X-ray diffraction. The crystals are triclinic, P 1 , a = 7.041(3), b = 11.343(4), c = 11.427(4) A, α = 69.13(3), β = 76.08(3), γ = 84.17(3)°, V = 828 A3, Z = 1. The structure was refined on 1338 reflections to R = 0.074. The compound has pairs of copper atoms bridged by two methoxide ions. Each copper atom has a square pyramidal coordination geometry formed by five oxygen atoms, two from methoxide ions, one from NO3−, and one from each of two different Hg(C5H8NO)2 units. These last two provide additional bridges between the basal and apical coordination sites of the bridged copper atoms and, in so doing, form 10-membered macrocyclic rings. Adjacent dimers are linked by pairs of Hg⋯O(nitrate) interactions, forming a loosely bound polymeric structure.