Synthesis and crystal structure of [Ni(H2O)(2)(pdc)(4-CNpy)] center dot 2H(2)O (pdc = pyridine-2,6-dicarboxylate, 4-CNpy=4-cyanopyridine)

摘要

A new complex containing two different substituted pyridine ligands, viz. 4-CNpy (4-cyanopyridine) and pdc (pyridine-2,6-dicarboxylate), [Ni(H2O)(2)(pdc)(4-CNpy)] center dot 2H(2)O (1), has been prepared using [Ni(4-CNpy)(2)(H2O)(3)(SO4)] center dot H2O (2) as the starting compound. Crystal data on 1 are: monoclinic, P2(1)/c, a = 11.533(2) angstrom, b = 20.114(4) angstrom, c = 7.306(1) angstrom, beta = 93.777(3)degrees, V = 1,691.1(5) angstrom(3), Z = 2, D-calc. = 1.57 g cm(-3), R-1 = 0.0585, w R-2 = 0.1236 for reflections with I > 4 sigma(F-0) and 268 parameters (R-1 = 0.0859, wR(2) = 0.1336 for all 4,024 reflections). The discrete molecules of the title complex remain hydrogen-bonded to assemble into supramolecular layers interleaved by disordered water molecules. In an attempt to obtain the cationic complex species cis-[Ni(H2O)(4)(4-CNpy)(2)](2+) we have isolated the compound [Ni(H2O)(4)(4-CNpy)(2)] center dot (BPh4)(2) center dot 2(4-CNpy) center dot 4H(2)O (3) by adding NaBPh4 to an aqueous solution of 2. Crystal data on 3 are: monoclinic, P2(1), a = 10.5002(1) angstrom, b = 21.1692(3) angstrom, c = 15.3249(2) angstrom, beta = 95.120(1)degrees, V = 3392.84(7) angstrom(3), Z = 2, D-calc. = 1.231 g cm(-3), R-1 = 0.0453, wR(2) = 0.1217 for reflections with I > 4 sigma (F-0) and 556 parameters (R-1 = 0.0688, wR(2) = 0.1364 for all 9,257 reflections).