Syntheses, structures and luminescence of a series of coordination polymers constructed with 4-substituted 1,2,4-triazole and biscarboxylate co-ligands†
Abstract
Eight coordination polymers {[Cd3(btpm)2(1,4-bdc)3]·6H2O}n (1), {[Cd2(btpm)(mip)2(H2O)]·1.25H2O}n (2), {[Cd2(btpm)(nip)2(H2O)]·H2O}n (3), {[Cd4(btpm)3(H0.5suc)2(suc)2Cl(H2O)2]·9H2O}n (4), {[Cd2(btpm)(glu)2(H2O)2]·5H2O}n (5), {[Cd2(btpm)(mbda)2(H2O)]·3H2O}n (6), {[Zn(btpm)(1,4-bdc)](1,4-H2bdc)}n (7), {[Zn(btpm)(adc)]·3H2O}n (8) (btpm = bis(4-(1,2,4-triazol-4-yl)phenyl)methane, 1,4-bdc = 1,4-benzenedicarboxylate, mip = 5-methyl-isophthalate, nip = 5-nitro-isophthalate, suc = succinate, glu = glutarate, mbda = 1,3-benzenediacetate, adc = 1,3-adamantanedicarboxylate) were hydrothermally synthesized. 1 shows an unusual 8-connected three-dimensional network based on Cd3(COO)2 trimer clusters. 2 exhibits an unusual (3,7)-connected three-dimensional network based on Cd2(COO) dimers. 3 presents a (3,4,5)-connected 3D network. 4 shows the 6-connected three-dimensional pcu net based on Cd4Cl tetranuclear clusters. 5 exhibits a 2-fold interpenetrating three-dimensional pcu network based on Cd2(COO)2 dimers. 6 presents an unusual 2D network based on nanotube-like [Cd2(mbda)2] chains. 7 shows the intriguing 2D → 3D polythreaded network based on a special 2D (6,3) network, with six Zn(II) atoms at six corners and four 1,4-bdc and two double btpm at six edges. 8 exhibits an undulated 2D (4,4) network. 1–8 show structural diversity based on mono-metal, bi-, tri- and tetra-nuclear metal clusters. The coordination polymers can be tuned with different biscarboxylates and metal cations based on the semi-rigid 4-substituted 1,2,4-triazole ligand btpm. The luminescence and thermal stability were investigated.