Network topology and property studies for two binodal self-penetrated coordination polymers

Abstract

Two coordination polymers, [Co^IICu^I(m-BDC)(BIPY)_1.5(m-NBZ)]_n (1) and [Co^II₄(BPTC)₂(BBI)₄]_n (2), (where BIPY = 4,4′-bipyridine, BBI = 1,1′-(1,4-butanediyl)bis(imidazole), m-BDC = 1,3-benzenedicarboxylate, m-HNBZ = m-nitrobenzoic acid and H₄BPTC = 3,3′,4,4′-biphenyltetracarboxylic acid), have been obtained under solvo/hydrothermal conditions, which were characterized by single-crystal X-ray diffraction, XRPD, IR, ICP, TGA, and elemental analysis. Both 1 and 2 feature two unusual binodal self-penetrated architectures: 1 presents a 2-D network with (4·6²)₂(4²·6²·8²) topology in terms of the rationalization of T-shaped Cu^I and Co₂ unit as 3- and 4-connected node, respectively; however, compound 2 built up from a flexible long-chain ligand and a polycarboxylate confers a 3-D (6²·8⁴)(6⁴·8²)₂ net based on the definition of square-planar and tetrahedral 4-connected nodes. The magnetic study of 1 was carried out in the temperature range of 5–300 K, showing antiferromagnetic coupling interaction within the dimeric Co₂ unit. In addition, 1 was found to exhibit fluorescence at about 420 nm (λ_ex = 330 nm).