Synthesis and Catalytic Activity of Thorium Nitride Complex from Dinitrogen Reduction.

Metal nitride species are recognized as key intermediates in the conversion of dinitrogen (N) to ammonia (NH). In this work, we report the isolation of a multimetallic nitride-bridged thorium complex () by completely cleaving the N≡N triple bond of N. The complex was synthesized through the reduction of a thorium precursor, {N[CHCHN-PPr]ThCl} () and chromium dichloride (CrCl) using potassium graphite (KC) under an N atmosphere. Isotopic labeling with N confirms that the nitride in complex originates from N. Under ambient conditions, complex exhibits remarkable catalytic activity, converting N to silylamine with yields of up to 9.9 equiv per thorium molecular catalyst. This work not only represents the first isolation of a thorium nitride complex from N reduction but also provides a rare example of N functionalization promoted by an actinide catalyst.