Synthesis, characterization, and crystal structures of novel single and mixed-metal framework materials assembled from 2-(4-pyridyl)thiazole-4-carboxylic acid with cobalt, cadmium, and vanadium oxide

摘要

Three new coordination polymers containing 2-(4-pyridyl)thiazole-4-carboxylate (pytac) with cobalt, vanadium oxide, or cadmium iodide have been synthesized solvothermally, isolated, and characterized by single-crystal X-ray diffraction and powder X-ray diffraction. [Co_3(pytac)_6] (H_2O)_8 (1), which crystallizes in the space group C2/c (a = 24.1418(8) A,b = 17.5088(6) A, and c = 14.4562(5) A, beta = 96.0390(10) deg), has 1D hex-americ water channels that constitute a 14.4 percent of the unit cell volume. Co_3(pytac)_2(H_2O)_4V_4O_(12) (2), which crystallizes in the space group P1-bar (a = 8.6591(5) A, b = 9.0044(5) A, and c = 10.6495(6) A, alpha = 67.1160(10) deg, beta = 82.6880(10) deg, and gamma = 83.9880(10) deg), is an extension of the former in that it contains Co(H_2O)_4V_4O_(12) in addition to the Co-only 2D layers. [CdI(pytac)(H_2O)] centre dot H_2O (3), which also crystallizes in the space group P1-bar (a = 8.2376(4) A, b = 8.4859(4) A, and c = 11.1261(5) A, alpha = 68.2020(10) deg, beta = 77.5610(10) deg, and gamma = 69.1230(10) deg), exhibits structural characteristics similar to 2, in that both contain 1D chains where the pytac ligand simultaneously engages in three different coordination modes: chelating, single bond coordination, and mu-2 bridging between two metal centers via carboxylate oxygen atoms.