Structural Diversities and Fluorescent and Photocatalytic Properties of a Series of Cu^II Coordination Polymers Constructed from Flexible Bis-pyridyl-bis-amide Ligands with Different Spacer Lengths and Different Aromatic Carboxylates

Thirteen new Cu II coordination polymers, namely, [Cu(3-dppa)(1,3,5-HBTC)] ( 1 ), [Cu(3-dpha)(1,3,5-HBTC)(H 2 O)]·H 2 O ( 2 ), [Cu 3 (3-dpsea)(1,3,5-BTC) 2 (H 2 O) 5 ]·4H 2 O ( 3 ), [Cu(3-dpba)(1,2-BDC)]·H 2 O ( 4 ), [Cu(3-dpha)(1,2-BDC)] ( 5 ), [Cu(3-dpsea)(1,2-BDC)]·H 2 O ( 6 ), [Cu 2 (3-dpyp)(1,3-BDC) 2 (H 2 O) 4 ]·3H 2 O ( 7 ), [Cu(3-dppa)(1,3-BDC)(H 2 O)]·2H 2 O ( 8 ), [Cu(3-dppia)(1,3-BDC)(H 2 O) 2 ]·2H 2 O ( 9 ), [Cu 2 (3-dpsea) 2 (1,3-BDC) 2 (H 2 O) 2 ]·7H 2 O ( 10 ), [Cu(3-dpba)(1,4-NDC)]·3H 2 O ( 11 ), [Cu(3-dpyh)(1,4-NDC)(H 2 O)]·3H 2 O ( 12 ), [Cu(3-dpyh) 0.5 (1,4-NDC)]·H 2 O ( 13 ), have been purposefully synthesized under hydrothermal conditions [3-dppa = N, N ′-di(3-pyridyl)propanediamide, 3-dpba = N, N ′-di(3-pyridyl)butanediamide, 3-dpha = N, N ′-di(3-pyridyl)hexanedioicdiamide, 3-dppia = N, N ′-di(3-pyridyl)pimelicdiamide, 3-dpsea = N, N ′-di(3-pyridyl)sebacicdiamide, 3-dpyp = N, N ′-di(3-pyridinecarboxamide)-1,3-propane, 3-dpyh = N, N ′-di(3-pyridinecarboxamide)-1,6-hexane, 1,3,5-H 3 BTC = 1,3,5-benzenetricarboxylic acid, 1,2-H 2 BDC = 1,2-benzenedicarboxylic acid, 1,3-H 2 BDC = 1,3-benzenedicarboxylic acid and 1,4-H 2 NDC = 1,4-naphthalenedicarboxylic acid]. Complexes 1 – 3 based on the same auxiliary ligand show various structures. Complex 1 features a one-dimensional (1D) ∞-like double-chain structure, which consists of a [Cu-1,3,5-HBTC] n chain and [Cu-3-dppa] n meso -helical chain. Complex 2 possesses a (2,4) undulated honeycomb (hcb) net. Complex 3 is a 3-fold interpenetrating three-dimensional (3D) framework, which shows trinodal (2,3,3)-connected topology with the Schläfli symbol of (10·12 2 ) 2 (10 3 ) 2 (12). Complexes 4 – 6 with 1,2-BDC as secondary ligand exhibit different two-dimensional (2D) layer structures. Complex 4 exhibits a 2D (2,4)-connected (4·12 4 ·14)(4) net. Complexes 5 and 6 have similar structures and show 2D networks with undulated sql topology. For complexes 7 – 10 based on 1,3-BDC secondary ligand, complex 7 shows a 1D zigzag chain, while complexes 8 – 10 have similar wave-like 2D structures. When 1,4-NDC was used as the auxiliary ligand, complex 11 is a 2D puckered (4,4) network, complex 12 reveals a 4-connected topology with the point symbol of (4 4 ·6 2 ), while complex 13 exhibits a 3-fold interpenetrating 3D α-Po framework. The structural diversity indicates that the bis-pyridyl-bis-amide ligands with different spacers and the aromatic polycarboxylates play important roles in tuning the dimensionalities and structures of the title complexes. The fluorescent and photocatalytic properties for 1 – 13 have also been investigated in detail.