Molecular Zirconium Nitride Super Base from a Mononuclear Parent Imide

In this work, we prepared, isolated, and structurally characterized a zirconium complex having a terminally bound imide motif, (PN)(2)Zr ENH (PN- = (N-(2-Pr-i(2)-4-methylpheny1)-2,4,6-trimethylanilide)), along with the zirconium nitride complex {(PN)(2)Zr N[mu(2)-Li(THF)]}(2). (PN)(2)Zr NH was prepared by reduction of trans-(PN)(2)Zr(N-3)(2) with KC8. Isotopic labeling and spectroscopic studies were conducted using the respective N-15 enriched isotopologues, whereas solid-state structural studies confirmed some of the shortest Zr N distances known to date (Zr NH, 1.830(3) angstrom; Zr N-, 1.822(2) angstrom). It was found that the nitride in {(PN)(2)Zr N[mu(2)-Li(THF)]}(2) is super basic and in the range of -36 to -43 pK(b) units. Computational studies have been applied to probe the bonding and structure for this new class of zirconium-nitrogen multiple bonds.