Oxomolybdenum coordination compounds with alkyl-substituted pyridines. Solvothermal syntheses and structural characterization of [Mo10O26(3,5-Lut)(8)]center dot 2(3,5-Lut), [Mo10O26(3-MePy)(8)]center dot(3-MePy), [Mo10O26(3-MePy)(8)] and [Mo12O28(OCH3)(2)Cl-2(3-MePy)(8)]

Reactions of (PyH)(2)[MoCl5]with methanol nd 3,5-lutidine or 3-methylpyridi ne carried out under conditions of solvothermal synthesis at 130 degrees C have resulted in two Mo(V, VI) clusters containing the same molybdenum oxid e framework, [Mo10O26(3,5-Lut)(8)]. 2(3,5-Lut) (3,5-Lut = 3,5-lutidine (C7H 9N)) (i) and [Mo10O26(3-MePy)(8)].(3-MePy) (3-MePy = 3-methylpyridine (C6H7 N)) (ii), and in a novel [Mo12O28(OCH3)(2)Cl-2(3-MePy)(8)] (iv). [Mo10O26(S -MePy)(8)] (iii) was also obtained by oxidizing (NH4)(2)[MoCl5(H2O)] in a m ixture of methanol, 3-methylpyridine and nitromethane. X-ray structural ana lyses revealed Mo2O42+ unit as a common structural motif in both cluster ty pes. In i-iii ten molybdenum atoms are grouped into four Mo-2(V) pairs with Mo-Mo bonds and two Mo(VI) sites. The oxomolybdenum core of iv is composed of six Mo-2(V) pairs connected through oxo and methoxo bridges. (C) 2000 E lsevier Science Ltd. All rights reserved.