Preparation and characterization of binuclear complexes of molybdenum(III) and molybdenum(V) via oxidative decarbonylation. Reactions of LMo(CO)3 (L = 1,5,9-triazacyclododecane) and crystal structure of anti-[L2Mo2O4](ClO4)2.2H2O

The cyclic triamine 1,5,9-triazacyclododecane (L), C/sub 9/H/sub 21/N/sub 3/, reacts with Mo(CO)/sub 6/ in Decalin at 150/sup 0/ to yield yellow, air-stable LMo(CO)/sub 3/ (1). Oxidation of 1 with bromine, nitrous acid (or NOBF/sub 4/), or hydrochloric acid in the presence of O/sub 2/ affords the monomeric complexes (LMo(CO)/sub 3/Br)(Br/sub 3/), (LMo(CO)/sub 2/NO)BF/sub 4/, and LMoCl/sub 3/, respectively. Oxidative decarbonylation of 1 in HClO/sub 4/ with O/sub 2/ gives the two isomers purple anti-(L/sub 2/Mo/sub 2/O/sub 4/)/sub 2/(ClO/sub 4/)/sub 2/ x 2H/sub 2/O and yellow syn-(L/sub 2/Mo/sub 2/O/sub 4/)(ClO/sub 4/)/sub 2/ x H/sub 2/O. Reduction of the former with zinc amalgam in aqueous solution in the presence and absence of coordinating acids (HBF/sub 4/, formic acid, acetic acid, hydrochloric acid) affords diamagnetic, green, dimeric bis(..mu..-hydroxo)-bridged species of molybdenum(III): (L/sub 2/Mo/sub 2/(..mu..-OH)/sub 2/(OH)/sub 2/)I/sub 2/ x 2H/sub 2/O, (L/sub 2/Mo/sub 2/(..mu..-OH)/sub 2/(..mu..-HCOO))I/sub 3/ x 2H/sub 2/O, (L/sub 2/Mo/sub 2/(..mu..-OH)/sub 2/(..mu..-CH/sub 3/CO/sub 2/))I/sub 3/, and (L/sub 2/Mo/sub 2/(..mu..-OH)/sub 2/Cl/sub 2/)(ClO/sub 4/)/sub 2/. Purple anti-(L/sub 2/Mo/sub 2/O/sub 4/)(ClO/sub 4/)/sub 2/ x 2H/sub 2/O crystallizes in the monoclinic space group P2/sub 1//c with a = 8.515 (8) A, b = 11.11 (2) A, c = 16.56 (3) A, ..beta.. = 92.3 (1)/sup 0/, Vmore » = 1565 (1) A/sup 3/, and d/sub calcd/ = 1.77 g/cm/sup 3/ for Z = 2 and M/sub r/ = 833.4. Least-squares refinement of the structure based on 3216 observations led to final discrepancy indices of R = 0.039 and R/sub w/ = 0.045. 21 references, 4 figures, 6 tables.« less