A pair of CoII supramolecular isomers based on flexible bis-pyridyl-bis-amide and angular dicarboxylate ligands

Abstract

Thermal reactions of cobalt(II) salts with flexible N,N′-bis(pyrid-3-ylmethyl)adipoamide (L) and angular 4,4′-sulfonyldibenzoic acid (H2SDA) in H2O and CH3OH afforded a pair of supramolecular isomers: [Co2(L)(SDA)2], 1, and [Co2(L)(SDA)2]·CH3OH·H2O, 2. The structure of complex 1 can be simplified as a one-dimensional (1D) looped chain with L ligands penetrating into the middles of squares, forming a new type of self-catenated net with the (42·54)(4)2(5)2 topology, whereas complex 2 displays a 2-fold interpenetrated 2D net with the rare (42·68·8·104)(4)2-2,6L1 topology. While both complexes 1 and 2 display antiferromagnetism with strong spin-orbital coupling, the antiferromagnetism of 2 is accompanied by a cross-over behavior and probably a spin canting phenomenon.