Two New Tetravacant Organometallic Keggin-Type Heteropolyoxomolybdates-Supported Manganese Carbonyl Derivatives.

ABSTRACT: Two novel heteropolyoxomolybdate [XMo?O₃₁]^n- (X = Ge(1) or P(2)) manganese carbonyl derivatives [(CH?)?N]?H?{Mn^II(GeMo?O₃₁)[Mn^I(CO)?]?}?·12H?O (1) and [(CH?)?N]?H?{Mn^II(PMo?O₃₁)[Mn^I(CO)?]?}?·14H?O (2), have been successfully synthesized and characterized in the solid state by single crystal X-ray diffraction, IR and thermogravimetric analysis, and in solution by UV-Vis spectroscopy and electrochemistry. The two polyoxomolybdate-based organometallic compounds 1 and 2 represent rare examples of transition metal sandwich-based polyoxometalate metal carbonyl derivatives (PMCDs), in which the organic-inorganic hybrids are composed of four Mn(CO)?? groups symmetrically occupied the tetravacant sites of dimeric heteropolyoxomolybdate {Mn?(XMo?O₃₁)?}^n- through Mn^I-O-Mo bonds. The carbonyl functionalized Mn atoms are octahedrally coordinated via three ??-oxygens of the [XMo?O₃₁]^n- unit and three carbonyl carbon atoms. Interestingly, 1 and 2 form a psedocuboidal ring Mn(CO)?Mo?O₁₂ with {Mn(CO)?}? occupying the three fold axis of the Mo?O₁₂ octahedral triad. Beside this, the two centrally placed adjacent Mn^II atoms show intramolecular Mn???Mn interactions of 3.11 and 3.16 Å in 1 and 2, respectively. Significant n??* and O···O intermolecular interactions between the orthogonally aligned adjacent carbonyl groups through the overlap of lone-pair electrons on oxygen atoms with the antibonding orbital (?*) of the adjacent carbony carbon atom of the subsequent units in 1 and 2 were observed. The electrochemical properties of the two compounds were also been investigated.

SUBMITTER: Singh V 

PROVIDER: S-EPMC6152162 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature