Dimolybdenum complexes with mixed formamidinate ligands

A series of dimolybdenum complexes containing mixed formamidinate ligand are discussed. The reactions of trans-Mo2(O2CCH3)2(o-DMophF)2 [o-HDMophF=N,N′-di(2-methoxyphenyl)formamidine] with N,N′-di(2-pyridyl)formamidine (HDpyF), N,N′-di(2-pyrimidyl)formamidine (HDpmF) and N,N′-di(6-methyl-2-pyridyl)formamidine (HDMepyF), in refluxing CH2Cl2 afforded the complexes, trans-Mo2(O2CCH3)(DpyF)(o-DMophF)2 (1), trans-Mo2(O2CCH3)(DpmF)(o-DMophF)2 (2), and trans-Mo2(O2CCH3)(DMepyF)(o-DMophF)2 (3), respectively. The o-DMophF− and DMepyF− ligands in these complexes adopt the s-cis, s-trans conformation, resulting in Mo–O short distances [2.889 (3) and 2.861(2) Å for 1; 2.880(3) and 3.024(4) Å for 2], while the DpyF− ligand adopts the s-cis, s-trans conformation, resulting in a Mo–N [3.208(4) Å] and a Mo–H [2.90 (3) Å] short distances. The reactions of trans-Mo2(O2CCH3)2(o-DMophF)2 with HDMepyF in CH3CN gave complexes 3, trans-Mo2(O2CCH3)(DMepyF)2(o-DMophF) (4), and trans-Mo2(DMepyF)2(o-DMophF)2 (5). The o-DMophF− ligands in 4 and 5 adopt the s-cis, s-cis conformation while DMepyF− assumes an s-cis, s-trans conformation. Complexes 1–5 are the first dimolybdenum complexes containing mixed formamidinate ligands.