Some novel mixed terminal ligand trinuclear oxo-centered complexes of iron and chromium with tri-Me acetate anion as bridging ligand of the types Cr2FeO((CH3)3CCO2)6(C4H8O)(H2O)2]NO3, [Cr2FeO((CH3)3CCO2)6(C5H5N)(H2O)2]NO3 were prepd. The materials isolated have been characterized by elemental analyses, IR spectrometry, UV-Visible spectroscopy and electron impact mass spectrometric data. The IR spectra suggested bridging nature of tri-Me acetate anions along with nasym(Cr2FeO) vibrations in the complexes. EI mass spectrometric data showed ions with masses corresponding to the series [M3O((CH3)3CO2)x]+, x =3,4,5 or 6. Elemental anal. and at. absorption spectroscopy established predicted triangle structure of prepd. complexes. The values of interelectronic repulsion parameter (B) calcd. with using UV-Visible spectra data are found to be below the free ion value for chromium (III) ion (933 cm-1) which indicate a considerable covalent nature of the metal-ligand in Cr-O bond.

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