Synthesis and characterization of tungsten bis-imido complexes containing bi-dentate pyrrole-amine, pyrrole-imine or ketiminate ligands

Three new imido tungsten derivatives containing bi-dentate pyrrole-amine, pyrrole-imine or ketiminate precursor were synthesized and characterized. Reacting W(NtBu)2(NHtBu)2 with two equiv of C4H3NH(2-CH2NHtBu) and C4H3NH(2-CHNCH2Py) in diethyl ether and toluene generates [W(NtBu)2{C4H3N(2-CH2NHtBu)}2] (1) and [W(NtBu)2{C4H3N(2-CHNCH2Py)}2] (2) in good yield. Similarly, while subjecting two equiv of (ArNCMeCHCMeOH) (Ar = 2-MeOC6H4) with W(NtBu)2(NHtBu)2 in diethyl ether, affords [W(NtBu)2{OCMeCHCMeNAr}2] (3) in high yield. Single crystal X-ray structure reveals that in all three complexes the 6-coordinate W atoms belong to a distorted octahedral environment.