SOLID-STATE CHEMISTRY OF [NI(AA)(3)][PDCL4]CENTER-DOT-NH(2)O COMPLEXES (AA = BIPY, PHEN) AND CRYSTAL-STRUCTURES OF CIS-DIAQUA-BIS(PHENANTHROLINE)NICKEL(II) TETRACHLOROZINCATE AND CIS-DICHLOROBIS(BIPYRIDINE)NICKEL(II)

The thermal analysis of the complexes [Ni(phen)(3)][PdCl4]. 3H(2)O and [Ni(bipy)(3)][PdCl4]. 2 1/2H(2)O revealed, after the elimination of t he molecules of water, the reciprocal migration of the ligands between the coordination spheres of the two metal ions. This solid-state reac tion leads to mixtures of two neutral complexes: Ni(AA)(2)Cl-2 and Pd( AA)Cl-2 (AA = phenanthroline or bipyridine). In both cases, the migrat ion was found to be exothermic. The bis-chelated nickel complexes, Ni( AA)(2)Cl-2, were extracted in ethanol and separated from Pd(AA)Cl-2. S ubsequent addition of an hydrochloric acid solution of ZnCl2 to the et hanol solution containing Ni(phen)(2)Cl-2 led to the formation of [Ni( phen)(2)(H2O)(2)][ZnCl4]. H2O which was studied by X-ray diffraction m ethods. The Ni-N bond distances vary from 2.078(3) to 2.089(4) Angstro m, while the cis Ni-O distances are 2.057(3) and 2.073(3) Angstrom. Th e crystal structure of Ni(bipy)(2)Cl-2. 2H(2)O 1/2CH(3)CN was also det ermined. The compound is the cis isomer, with the Ni atom located on 2 -fold axis. The Ni-N bonds distances are 2.084(3) and 2.094(2) Angstro m, while the Ni-Cl bonds distances are 2.428(1) Angstrom. The compound crystallizes with two water molecules situated in the lattice and 1/2 molecule of acetonitrile located on a 2-fold axis. The two crystals a re stabilized by hydrogen bonds involving the water molecules. (C) 199 8 Elsevier Science Ltd. All rights reserved.