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

The work in this report deals with the syntheses, characterization and crystal structures of four compounds of composition [(NiLOEt-pn)-L-II(H2O)(2)(PbBr2)-Br-II] (1), [(NiLOEt-pn)-L-II(H2O)(2)Pb-II(NO3)(2)] (2), [{(CuLOEt-pn)-L-II(mu-Br)Pb-II}(2)(mu-Br)(2)] (3) and [{Cu-II(NO3)(LOEt-pnInIII)(NO3)}(2)(mu-OH)(2)] (4), where H2LOEt-pn is N,N'-propanebis(3-ethoxysalicylaldimine). Copper(II)/nickel(II) in these compounds occupies the N(imine)(2)O(phenoxo)(2) compartment, while Pb-II/In-III occupies the O(phenoxo)(2)O(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(mu-phenoxo)-mu-bromide moiety. Dimerization takes place by two bridging bromides (that bridge two Pb-II centers) in 3 and by two bridging hydroxides (that bridge two In-III 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)(2)O(ethoxy)(2) compartment are coordinated to the second metal ion (Pb-II/In-III) 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. (C) 2015 Elsevier B.V. All rights reserved.