A three-dimensional interpenetrating framework with spacious multi-channels: synthesis and characterisation of a cobalt(II) coordination polymer based on an angular dipyridyl ligand incorporating an amide spacer

Self-assembly of Co(NO3)2 and N,N′-bis(4-pyridylcarbonyl)-4,4′-diaminodiphenyl ether (L), a dipyridyl-based ligand separated by phenyl amide spacer, afforded an interpenetrating Co(II) coordination polymer {[CoL2(NO3)2] · 2(C2H5)2O · (CH3)2SO · H2O}n (1). X-ray analysis of 1 shows that a unique combination of coordination and hydrogen bonds within a framework gives this material a spacious multi-channel structure. Moreover, the crystalline framework of 1 is virtually unchanged after removing the solvent molecules from the channels resulting in a nanoporous structure with estimated free volume of 31.4%.