New pyrazole-3,5-dicarboxylato (pzdc) chromate(III) complexes containing linear tetradentate edda (ethylenediamine-N,N′-diacetate), trdda (trimethylenediamine-N,N′-diacetate), or eddp (ethylenediamine-N,N′-dipropionate) were synthesized and characterized by elemental analyses, column chromatography, 2 H NMR, FAB mass spectra, and X-ray analyses. Crystallographic data for Na[Cr 2 (edda) 2 (µ-pzdc)]·5H 2 O (1) are monoclinic with space group P2 1 /n, a ) 11.73(1) Å, b ) 19.475(6) Å, c ) 13.229(6) Å, ) 111.99(5)°, Z ) 4, and a final R factor of 0.056 based on 4673 reflections. Na[Cr 2 (trdda) 2 (µ-pzdc)]·3H 2 O (2) crystallizes in the orthorhombic space group Fdd2, with a ) 16.576(4) Å, b ) 29.235(6) Å, c ) 12.544(5) Å, Z ) 8, and a final R factor of 0.078 based on 2456 reflections. In both complexes two Cr(III) units were bridged by a pzdc. The complex 1 and 2 has a (symcis)-(unsym-cis) edda and (unsym-cis)-(unsym-cis) trdda geometrical configuration, respectively. Unlike the edda and trdda ligands, the eddp ligand formed mononuclear pzdc complexes, which may correspond to two geometrical isomers of unsym-cis-mer-and fac-[Cr(eddp)(pzdc)] 2- (3 and 4). The differences in the formations of the pzdc Cr(III) complexes with the edda-type ligands were demonstrated to arise from the chelate ring sizes and/or the intramolecular interaction such as hydrogen bond and van der Waals contact between two Cr(III)-edda type units. The hydrogen bond between the edda moieties following stereognostic coordination brings about the novel inert unsym-cis configuration in complex 1.

in HC1 should greatly reduce the stability of the HC1 antihydrogen-bonded complexes with respect to their HF analogues. This change in relative intensities of the vs and avs absorptions can play a key role in the band assignments of these weak complexes since the absorptions are in the same spectral region. Conclusions UF6 and HC1 interact in solid argon to form a well-defined 1:1 hydrogen-bonded complex, UF6-HC1. The band positions of the UF6-HC1 and the FC1-HC1 complexes were very comparable. As the HC1 aggregation increased, a 1:2 complex, UF6-(HC1)2, was observed and characterized by considering the perturbation of the second HC1 submolecule on the 1:1 complex. In contrast, the codeposition of WF6 and MoF6 with HC1 produced hydrogen-bonded 1:1 complexes and antihydrogen-bonded complexes.WF6 and MoF6 displayed little preference between the different structural arrangements. In addition, the HC1 in the hydrogenbonded and the antihydrogen-bonded complexes activated several WF6 and MoF6 modes that are normally infrared-inactive.

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Two novel types of binuclear bis(acetylacetonato)chromium(lll) complexes bridged by imidazole-4,5dicarboxylate, 1,2,3-triazole-4,5-dicarboxylate and pyrazole-3.5-dicarboxylate and a binuclear complex bridged by both pyrazolate and hydroxide ligands were prepared and characterized by elemental analysis and positive-ion fast atom bombardment mass spectrometry. Their spectroscopic and magnetic properties were examined by means of luminescence, 2H NMR and magnetic susceptibility measurements.

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