Synthesis, characterization and X-ray structure of three types of triply crotonate-bridged heterometallic zinc(II)–lanthanide(III) complexes

Abstract

Three types of carboxylate-bridged heterometallic zinc(II)–lanthanide(III) compounds [C 9H 7N·H][ZnSm(crot) 3(C 9H 7N)(NO 3) 3]·H 2O ( 1) (crot=O 2CCHCH 2Me), [Zn 2Dy(crot) 6(C 9H 7N) 2(NO 3)]·C 9H 7N ( 2), [Zn 2Y(crot) 6(C 9H 7N) 2(NO 3)] ( 3) and [Zn 2Yb 2(crot) 8(C 9H 7N) 2(NO 3) 2] ( 4) have been synthesized and structurally characterized by IR spectra and X-ray crystallography. Complex 1 is composed of protonated quinoline cations, triply crotonate-bridged dimeric ZnSm anions and lattice water molecules. Complexes 2 and 3 have a similar quasi-linear trinuclear ZnLnZn structure, in which the central lanthanide ion and two terminal zinc ions are bridged by two sets of three equivalent bidentate crotonate ligands. Complex 4 consists of two triply crotonate-bridged dinuclear [ZnYb(crot) 4(C 9H 7N)(NO 3)(H 2O)] subunits, being linked together by two tridentate carboxylate groups via the two ytterbium ions. Magnetic measurements for complex 4 show that there is a weak antiferromagnetic intramolecular Yb⋯Yb interaction.