Dinitrogen Reduction and Functionalization by a Siloxide Supported Thulium‐Potassium Complex for the Formation of Ammonia or Hydrazine Derivatives

Abstract The dinitrogen (N 2 ) chemistry of lanthanides remains less developed compared to the d‐block metals and lanthanide‐promoted N 2 functionalization chemistry in well‐defined lanthanide complexes remains elusive. Here we report the synthesis and characterization (SQUID, EPR, DFT, X‐Ray) of the siloxide supported heterobimetallic (Tm/K) complexes [{KTm(OSi(O t Bu) 3 ) 3 } 2 ( μ ‐ η 2 : η 2 ‐N 2 )] ( 1 ) and [K 3 {Tm(OSi(O t Bu) 3 ) 3 } 2 ( μ ‐ η 2 : η 2 ‐N 2 )] ( 2 ). Complex 2 provides a rare example of a metal complex of the triply reduced N 2 3− radical. The structure of 2 differs from the few previously reported N 2 3− complexes as it presents two Tm and three K cations binding the N 2 3− radical, facilitating N 2 functionalization. Notably, the K 3 Tm 2 ‐bound N 2 3− moiety reacts with excess H + to form NH 4 Cl in 18 % yield, and with MeOTf at room temperature to yield the dimethyl hydrazido complex [K 2 {Tm(OSi(O t Bu) 3 ) 3 } 2 ( μ ‐(CH 3 )NN(CH 3 ))] ( 3 ). Protonolysis of 3 yields MeHN−NMeH ⋅ 2HCl in 18 % yield.