Syntheses, structures and luminescence of six 5-(3-pyridylmethoxy)isophthalate coordination polymers

Abstract

Six coordination polymers based on 5-(3-pyridylmethoxy)isophthalic acid (H2L), namely [Zn2L2]n (1), [Zn2L2(1,3-bix)]n (2), [CdL(1,3-bix)]n·2nH2O (3), [CdL(azpy)0.5(H2O)]n (4), [CdL(btx)0.5]n (5), and [CdL(btmb)]n·2nH2O (6) (1,3-bix=1,3-bis(imidazol-1-ylmethyl)benzene, azpy=4,4′-azobispyridine, btx=1,4-bis(1,2,4-triazol-1-ylmethyl)benzene, btmb=4,4′-bis(1,2,4-triazol-1-ylmethyl)biphenyl), have been synthesized and characterized by elemental analyses, IR spectra, PXRD, thermogravimetry and X-ray structural analysis. Complex 1 is a 3D coordination polymer, simplified as a 4-nodal (4,4,5,5)-connected topology net with point symbol {43.63}{43.62.8}{44.65.8}{44.64.82}. Complex 2 is a 3D coordination polymer, simplified as a crs-d topology net with point symbol {6;82}{62;83;10}. Complex 3 is a 2D coordination polymer with a 2-nodal (3,5)-connected topology net. Complex 4 exhibits a 2D double-layered network with a 2-nodal (3,4)-connected topology net, assembled by two parallel [CdL]n layers pillared by azpy spacer. Complex 5 is a 3D coordination polymer, simplified as a 2-nodal (3,8)-connected topology net with point symbol {43}2{46.618.84}. Complex 6 shows a 2D double-layered network with a 2-nodal (3,5)-connected topology net, constructed from wave-like [CdL]n network pillared by btmb spacer. 5-(3-Pyridylmethoxy)isophthalate exhibits five types of coordination modes. Anhydrous or dehydrated substances of 1–6 were thermally stable to 300–400°C. These Zn(II)/Cd(II) complexes emit blue luminescence originating from ligand-centered emission.