Abstract:The 1-and 2-D coordination polymers [Mn{HB(CzH,N3)3},(H20),1 ' 4H,O (11) and [Ni{H,B(CHN,)2},-(NH3),] (13), respectively, and the chelate 2 H 2 0 (12) were synthesized and structurally characterized. The compounds contain ambidentate poly(azoly1)borato ligands (azolyl = triazolyl or tetrazolyl), which can chelate or bridge metal centers. The metal -ligand structures in 11 -13 difcomplex "i~H2B(CZH,N,),J,(H20~21~ fer from the known coordination modes of the poly(azoly1)borates towards other metal centers. We describe how a change in the metal and/or the conditions of crystallization affects the ligand-field stabilization energy and favors one type of nitrogen donor atom over the other for the poly(triazoly1)borato ligands. The crystal structures of 11 and 12 contain additional water of crystallization; this leads to hydrogen-bonded solvent substructures. In the case of the bis(tetrazoly1)borato ligand the water substructure is shown to function as a "reinforcing bar" that symmetrizes the metal-ligand grid sheet.
found Cul/CuZ-Cl = 2.572(2)/2.328(2), Cul/CuZ-N = 2.585(5)/2.077(4); 2.000(4)/1.979(5); 2.100(5)/2.734(5); 2.005(4)/1.994(4); 2.024(5)/2.369(5). In the 3-D coordination polymer 8 one of the two different Cu centers is chelated by the three endodentate nitrogen donors, while the other Cu center i s coordinated by three exodentate nitrogen atoms. The coordination sphere is completed in both cases by two hydroxo bridges to symmetry-related C u centers. The metalligand connectivity creates infinite channels with helical walls which contain the solvated chloride anions.The results presented here are part of an investigation of the rational assembly of coordination polymers and polynuclear metal complexes containing modifications of the popular poly@.vrazol-$)borate ligands (I) ['], such as hydrotris-and dihydrobis(l,2,4-triazolyflborate (2. 3)[2-41 or dihydrobis(telrazoly1)borale (4)[ips1. The additional donor atoms in 2-4 extend the molecular coordination "chemistry" of 1 to the dimension of the solid state by thc bridging action of the ligand and/or by the formation of hydrogen bonds with water of crystallization as an important elcment of the crystal architecture. Depending on the metal, the poly(triazoly1)borate ligands 2 and 3 were found to be able to function either as chelate ligands or as bridges between metal center~I~,~I. We demonstrate here that five or even all six nitrogen donor atoms o f the hydrotris-(trialzoly1)borate ligand 2 can cngage in metal coordination to give a polynuclear complex, schcinatically shown in 5, as part of a twoor three-dimensional framework, with additional interesting features. The crystal engineering of materials coinposed of inifinite two-and three-dimensional frameworks is an area of intense researchLh].When the labile homoleptic cobalt chelate complex 6[2a,31 is treated with CuClz in water a ligand exchange takes place to give cobalt-free copper compounds of 2 as products. The exact nature of the product depends on the reaction and work-up conditions as outlined in Scheme 1. A slow reaction at elevated temperature yields light blue needle-shaped crystals (7) with a borate ligand-tocopper-to-chlorine ratio of 1 : 1 : 1 directly from the reaction mixture. In contrast. a fast reaction gives a blue precipitate of yet unknown composition (but diffcrent from 7) which was recrystallized from Compounds 7 and 8 cxist as two-and three-dimcnsional coordination polymers, respectively, with two different copper enters each. according to single-crystal X-ray analyses. In 7 the CuC1N5 polyhedra of both copper ions arc approximately tctragonally elongated octahedra, as expccted due to vibronic Jahn-Teller coupling, and the polyhedra are formed by three endodentate and two exodentate nitrogen atoms from the triazolyl rings and a chlorine atom (Figure 1). Two of the triazolyl rings on each borate ligand bridge CuCl2[6l.
Abstract. The phenomena of hydrogen/water solubility in YBa2Cu307_ 5 and BaCeO 3 undoped and doped by Y and Nd are considered. New experimental data as well as recently published data have been accumulated to discuss the chemical state of protons, taking into account the fairly strong interaction of the protons with the electron subsystem. Phase transformation of the studied oxides induced by hydrogen/water intercalation were revealed by the investigations of thermal effects, Xray diffraction, Raman spectroscopy, inelastic neutron scattering and nuclear quadrupole resonance.
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