Bonding and Activation of N 2 in Molybdenum(0) Complexes Supported by Tripod Ligands with Phospholane End Groups

Tripod ligands with a neopentyl backbone and one ( trpd‐1 pln ), two ( trpd‐2 pln ) or three ( trpd‐3 pln ) phospholane end groups are synthesized and used for the synthesis of MoX 3 (X=Cl, Br, I) complexes supported by these ligands. Na x Hg reduction of [MoBr 3 ( trpd‐3 pln )], in the presence of N 2 and the bidentate coligand dppm leads to the molybdenum(0) mono(dinitrogen) complex [Mo(N 2 )( trpd‐3 pln )(dppm)] with a moderately activated N 2 ligand. An attempt to further increase the activation by using dmpm as coligand leads to a mixture containing desired [Mo(N 2 )( trpd‐3 pln )(dmpm)], but also the bis(dinitrogen) complex [Mo(N 2 ) 2 ( κ 2 ‐ trpd‐3 pln ) 2 ] and the homoleptic complex [Mo( trpd‐3 pln ) 2 ]. Protonation of [Mo(N 2 )( trpd‐3 pln )(dppm)] with [H(OEt 2 ) 2 ][Al{OC(CF 3 ) 3 } 4 ] generates the hydrazido(2‐) complex [Mo(NNH 2 )( trpd‐3 pln )(dppm)][Al{OC(CF 3 ) 3 } 4 ] 2 .