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.

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.

Two acetylacetonato mononuclear [Cr(acac),(acac),-{(tart),H}]* where tart = C4H2Oe4-, were synthesised and characterized by CD or 2H NMR and/or FA6 mass spectroscopy. The former complex was found to be the first example to contain bidentate tartrato-02,03 bound through the alkoxo and hydroxyl oxygen atoms. The latter complex has a dinuclear structure bridged by two tetradentate tartrato-O',W ligands with a A-A absolute configuration. The stereospecificity or -selectivity and magnetic behaviour were examined in comparison with analogous

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3 should also be planar. This would lead to the formation of quite (20) Our studies on metalloporphyrins indicated that this band was very useful to the characterization of both ruthenium and osmium TPP or substituted-TPP complexes. See also: Groves, J. T.; Ahn, K.-H. Inorg. Chem. 1987, 26, 3831. The "oxidation state marker" bands of 1 and 2 are 1007 and 1019 cm"1, respectively. The bis(amine)ruthenium(II) porphyrins Ru(Por)(NH2R)2 and Ru(Por)(NHR2)2 (see text) show the "oxidation state marker" bands ranging from 998 to 1004 cm"1.