Chemical nitrogen fixation by using molybdenum and tungsten complexes

Dinitrogen complex cis-[W(N-2)(2)(PMe2Ph)(4)] reacts with an excess of acid ic dihydrogen complexes such as trans-[RuCl(eta (2)-H-2)(dppe)(2)]BF4 (dppe = 1, 2-bis(diphenylphosphino)ethane) at 55 degreesC under 1 arm of H-2 to form ammonia in moderate yield. The reaction is presumed to proceed through nucleophilic attack of the remote nitrogen of the coordinated dinitrogen o n the dihydrogen ligand. The coordinated dinitrogen is also protonated by t reatment with hydrosulfido-bridged dinuclear complexes such as [Cp*Ir(mu -S H)(3)IrCp*]Cl (Cp* = eta (5)-C5Me5) to afford ammonia. On the other hand, t he synthetic cycle for the formation of pyrrole and N-aminopyrrole from din itrogen and 2,5-dimethoxytetrahydrofuran has been established starting from dinitrogen complexes of the type trans-[M(N-2)(2)(dppe)(2)] (M = Mo, W).