Heterometallic copper(II)–lead(II), nickel(II)–lead(II) and copper(II)–indium(III) compounds derived from an acyclic double-compartment Schiff base ligand

Abstract

The work in this report deals with the syntheses, characterization and crystal structures of four compounds of composition [NiIILOEt–pn(H2O)2PbIIBr2] (1), [NiIILOEt–pn(H2O)2PbII(NO3)2] (2), [{CuIILOEt–pn(μ-Br)PbII}2(μ-Br)2] (3) and [{CuII(NO3)LOEt–pnInIII(NO3)}2(μ-OH)2] (4), where H2LOEt–pn is N,N′-propanebis(3-ethoxysalicylaldimine). Copper(II)/nickel(II) in these compounds occupies the N(imine)2O(phenoxo)2 compartment, while PbII/InIII occupies the O(phenoxo)2O(ethoxy)2 compartment of the ligand. Compounds 1 and 2 are diphenoxo-bridged dinuclear, whereas two dinuclear units are dimerized in 3 and 4. Copper(II) and indium(III) in the dinuclear unit in 4 are diphenoxo-bridged, while copper(II) and lead(II) in 3 are triply bridged by bis(μ-phenoxo)-μ-bromide moiety. Dimerization takes place by two bridging bromides (that bridge two PbII centers) in 3 and by two bridging hydroxides (that bridge two InIII centers) in 4. Copper(II) in 3 and 4 are distorted square pyramidal, while nickel(II) centers in 1 and 2 are distorted octahedral. All the four oxygen atoms of the O(phenoxo)2O(ethoxy)2 compartment are coordinated to the second metal ion (PbII/InIII) in 1–4. Coordination number of lead(II) is 6, 7 and 8 in 1, 3 and 2, respectively, while indium(III) in 4 is 8-coordinated. Salient features of the compounds are discussed.