A Series of 1D, 2D, and 3D Coordination Polymers Based on Flexible 3-Carboxy-1-Carboxymethyl-2-Oxidopyridinium and Different N-Donor Ligands – Syntheses, Structures, and Luminescent Properties



Twelve new coordination polymers, namely, [Pb(L)] (1), [Mn2(L)2(H2O)] (2), [Mn(L)(H2O)] (3), [Zn3(L)2(H2O)4] (4), [Zn(L)(pbib)0.5]·1.5H2O (5), [Cd(L)(pbib)0.5]·2H2O (6), [Zn(L)(bbtz)0.5]·H2O (7), [Zn(L)(bbmb)0.5] (8), [Co(L)(bbmb)0.5(H2O)] (9), [Zn(L)(biim-6)0.5]·2H2O (10), [Cd(L)(biim-6)0.5]·2H2O (11), and [Cd(L)(biim-4)0.5]·2H2O (12) have been synthesized under hydrothermal conditions [H2L = 3-carboxy-1-carboxymethyl-2-oxidopyridinium, pbib = 1,4-bis(imidazol-1-ylmethyl)benzene, bbtz = 1,4-bis(1H-1,2,4-triazol-1-ylmethyl)benzene, bbmb = 1,1′-(1,4-butanediyl)bis(2-methylbenzimidazole), biim-6 = 1,1′-(1,6-hexanediyl)bis(imidazole), and biim-4 = 1,1′-(1,4-butanediyl)bis(imidazole)]. Compound 1 features 1D double-chain structures, which are further linked by C–H···O hydrogen-bonding interactions to form a 3D supramolecular architecture. Compounds 211 have 2D layer structures. Compound 2 possesses a 2D (42·64) layer. Compound 3 exhibits a 2D undulated 44-squar lattice (sql) sheet. The 2D layers of 2 and 3 are further connected by intermolecular hydrogen-bonding interactions, which lead to 3D supramolecular architectures. The structure of 4 is a 2D (3,4)-connected net with the (42·62·82)(42·6) topology. Compounds 57 have similar structures and show 2D networks with 4-connected 44-sql topologies. Compounds 8 and 9 have similar structures and display (3,4)-connected networks with the (42·6)(42·63·8) topology. Compounds 10 and 11 reveal similar 4-connected 44-sql nets. The 2D layers of 511 are further extended into 3D supramolecular architectures through π–π interactions. Compound 12 has a 3D (65·8) CdSO4-type framework. The thermal stabilities of 112 have been studied by thermogravimetric analysis. The luminescent properties for 48 and 1012 have also been investigated in detail.