Some s- and d-metal complexes with 2,4-bis(hydroxyimino)-6-methylcyclohexane-1,3,5–trionate anion

Nguen Dinh Do, Olga Kovalchukova, Svetlana Strashnova, Paul Strashnov

Peoples' Friendship University of Russia

Email: okovalchukova@mail.ru

Abstract:

Sodium 2,4-bis(hydroxyimino)-6-methylcyclohexane-1,3,5-trionate was obtained by the reaction of nitrosation of methylfloroglucinol [1], and its crystal structure is described in [2]. Here we report the synthesis and some physico chemical investigations of complex compounds of some s- and d-metals with the 2,4-bis(hydroxyimino)-6-methylcyclohexane-1,3,5-trionate anion. The complexes were isolated from ethanolic neutral solutions and their structure was determined by chemical analysis, IR and UV VIS spectra and thermal analysis. The crystal structure of BaH₂L∙10H₂O was determined by X Ray analysis on single crystals. The NBO calculations of the charges on atoms showed that there is almost no overlapping of the molecular orbitals of Ba²⁺  and the ligand. This correlates with  the position of the absorption bands of C=O stretching vibrations in the IR spectrum of the complex (no shift comparing with the “free” anion). From the other hand, the   C=O   absorption bands in the complexes of transition metals are shifted to lower frequencies which indicate strong interaction of lone electron pairs of oxygen with the empty orbitals of metal ions. Thermal analysis indicates that the water molecules of the hydrated complexes are both of the coordinate and lattice nature.

Keywords: sodium 2,4-bis(hydroxyimino)-6-methylcyclohexane-1,3,5-trionate, X-ray, IR, UV-VIS spectroscopy, thermal analysis

References:

1.   O. V. Kovalchukova, S. A. Shevelev, A. H. Shakhnes, K.K. Kobrakov, A. I. Alafinov, O. V. Volyansky and P. V. Strashnov, “Some physico-chemical properties of products of chemical transformation of 2,4,6-trinitrotoluene, Proceedings of the 14th Seminar on New Trends in Research of Energetic Materials. Part I. Pardubice University, Pardubice, 2011, pp. 264-268.

2.   Olga Kovalchukova, Nguyen Dinh Do, Adam Stash, Vitaly  Bel’sky, Paul Strashnov, Andrew Alafinov, Oleg Volyansky, Svetlana Strashnova, and Konstantin Kobrakov. Crystal and molecular structure, and spectral characteristics of sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide.  Crystal Structure  Theory  and  Applications,  2012, 3  (in  press).