Fixation and functionalization of molecular nitrogen have been of great interest in chemistry for several decades because N2 has a high potential to convert into an N1 source. Since the development of Schrock’s catalyst, various transition metal complexes have been reported for activating or functionalizing N2 catalytically. Despite extensive studies of transition metal dinitrogen complexes, transition metal complexes with multi oxygen-based ligands have been less studied for N2 activation. Herein, we present a titanium dinitrogen complex [{(tBuATP)TiIV}2(μ–η1:η1:η2:η2-N2K2)(OEt)K] (H3(tBUATP) = tris(4,6-di-tert-butyl-2-hydroxybenzyl)amine) supported by an amino triphenolate (ATP) ligand for the first time. The complex was characterized by resonance Raman, IR, UV-VIS, and NMR spectroscopy, and single-crystal X-ray diffraction analysis. Most interestingly, the titanium N2 complex shows asymmetric geometries of titanium ions (TBP-Oh) with bridging nitrogen possibly to minimize a steric demand at metal centers. Finally, N2 ligand was converted into ammonia in the presence of the titanium N2 complex with an excess amount of PCy3HI and KC8 with 154% yield (per Ti ion).

Activation of dinitrogen by a titanium complex with an amino triphenolate ligand lead by geometry shift

ACS Spring Meeting 2021

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