Hexanuclear complexes of molybdenum(V) containing [Mo6O12(OCH3)(4)(acac)(3)](-) anion

The novel hexanuclear oxoclusters of the general formula R[Mo6O12(OCH3)(4)( acac)(3)] (1-7), where R = CH3NH3 (1), C5H5NH (2), (CH3)(2)CHNH3 (3), (CH3) (3)CNH3 (4), C5H11NH (5), (C2H5)(3)NH (6), and C6H5NC11H13O2 (7) have been obtained by the reactions of the binuclear oxomolybdenum(V) complex [Mo2O3( acac)(4)] (acac = acetylacetonate ion) with a variety of alkyl or aryl amin es or corresponding alkyl or aryl ammonium chlorides in methanol. The forma tion of 3,5-diacyl-2,6-dimethyl-1-pheny-1-pyridinium cation in 7 is explain ed by the cyclization via Hantzsch condensation of acetylacetone, formaldeh yde and aniline. The molecular structures of complexes 5, 6 and 7 have been determined by a single-crystal X-ray diffraction study. In all salts the a nion is of hexanuclear nature in which molybdenum atoms are bridged by oxo- oxygen and methoxo-oxygen atoms. Six Mo-octahedra are fused through edges, thus allowing the formation of localized metal-metal bonds between three pa irs of molybdenum atoms. (C) 2000 Elsevier Science Ltd. All rights reserved .