engleski

Synthesis of a series of new molybdenum(V) complexes with beta-hydroxy-beta-enaminones

The complexes with beta'-hydroxy-beta-enaminones containing 4-hydroxy-2-pyrone ring are of interest as models for stuyding the correlation between their steric, electronic and hydrogen bonding effects and possible relevance to biological processes.[1] Also, the enaminone derivatives are good analytical reagents for spectrofluorometric determination of metals.[2] New molybdenum(V) compexes of the general formula [Mo_2O_4L_2D_2] have been prepared by the reaction of [Mo_2O_3(acac)_4] (acac = acetilacetonate ion) with isomeric beta'-hydroxy-beta-enaminones (L) (isomer a: R' = CO_2C_2H_5 and R'' = CH_3; isomer b: R' = CH_3 and R'' = CO_2C_2H_5) containing different substituent at nitrogen atom (R = n-butyl, phenyl, alfa-napthyl, tyramine or o-anisidine All reactions were performed in dry dichlormethane by addition of corresponding donor solvent D (methanol, ethanol, i-propanol). In all complexes ligand L is coordinated to molybdenum in a didentate manner through the deprotonated hydroxyl groups and ketone moieties. The octahedral surroundings around molybdenum are completed by the monodentate solvent molecules D. The complexes were characterized by means of chemical analyses, high-resolution NMR spectroscopy, IR spectroscopy, thermal analyses and some of them by X-ray crystallography. [1] P. Gilli, V. Bertolasi, V. Ferretti, G. Gilli, J. Am. Chem. Soc. 2000, 122, 10405-10417. [2] V. Drevnekar, Z. Štefanac, A. Brbot, Microchem. J. 1976, 21, 402-410.

molybdenum(V) complexes; 4-hydroxy-2-pyrone ring; beta-enaminones

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