“…As a flexible ligand, bix has often been used in the synthesis of metal-organic frameworks as a linker molecule (Hoskins et al, 1997a;Abrahams et al, 2002;Carculli et al, 2005;Wen et al, 2005;Zhang et al, 2005) and in the construction of hydrogen-bonded supramolecular assemblies as hydrogenbonding acceptors Shen et al, 2004;Aakerö y et al, 2005Aakerö y et al, , 2006Zhang et al, 2007). Recently, as a result of our interest in exploring the selfassembling nature of carboxylic acids with Lewis bases (Meng et al, 2007;Meng, Lin & Li, 2008;Meng, Xiao, Wang & Liu, 2008;Meng, Xiao, Zhang & Zhou, 2008), we have resynthesized the N-containing Lewis base bix by the standard procedure (Hoskins et al, 1997b).…”