Dinitrogen Reduction and Functionalization by a Siloxide Supported Thulium‐Potassium Complex for the Formation of Ammonia or Hydrazine Derivatives
R. A. Keerthi Shivaraam, Thayalan Rajeshkumar, Rosario Scopelliti, Ivica Živković, Laurent Maron, Marinella Mazzanti
Abstract
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.