Isolation and characterization of main group and late transition metal complexes using orthometallated imine ligands.

Several late transition metal and main group orthometallated imine complexes were synthesized by utilizing ortholithiated imine precursors. Magnesium, aluminum, zinc, copper(I), and tin(IV) complexes were isolated and characterized. Subsequent reactions with electrophiles such as Ph(2)PCl, MeI and I(2) yielded several functionalized products, including a new iminophosphine ligand and its corresponding copper(I) complex. The coordination modes of the orthometallated imine ligands, as well as the structures of the metal complexes, were studied in the solid state using small molecule X-ray diffraction when possible.

Mono-anionic acetophenone imine ligands: synthesis, ortho-lithiation and first examples of group (V) metal complexes.

A series of niobium and tantalum imido complexes with mono-anionic ortho-metallated acetophenone imine ligands have been prepared and characterized using NMR spectroscopy, mass spectrometry and elemental analysis. These low symmetry complexes are produced with only one or two structural isomers in all cases and display interesting correlations between the steric bulk of the ligands employed and the isomers formed. Crystal structures of several new niobium and tantalum complexes are presented as confirmation of the connectivity in these structural isomers.

Titanium imido complexes utilizing orthometallated derivatized acetophenone and piperonal imine ligands: synthesis, isolation, and characterization.

A series of five ortho-lithiated imines (Li-L(n); n = 1-5) was synthesized via the reaction of an aryl or alkyl acetophenone imine with n-butyllithium. The ortho-lithiated imines were subsequently reacted with Ti(NR)Cl(2)py(3) (R = C(CH(3))(3), 2,6-Me(2)C(6)H(3), 2,6-Et(2)C(6)H(3), or 2,6-(i)Pr(2)C(6)H(3)), yielding complexes of the form (L(n))(2)Ti(NR). Several of the resulting complexes [(L(1))(2)Ti(NC(CH(3))(3)), 1a; (L(3))(2)Ti(N-2,6-Me(2)C(6)H(3)), 3b; and (L(5))(2)Ti(NC(CH(3))(3)), 5a] were structurally characterized using small molecule X-ray diffraction. The C(2) symmetric complexes produced in these reactions displayed a distorted square pyramidal geometry. In each complex the titanium center was located above the square plane of the two coordinated bidentate ligands and the chelating C approximately N ligands were folded away from the metal center. When a less sterically demanding alkylimine was used (L(4)), the resulting complex was isolated as an equilibrium mixture of cis and trans isomers of the empirical formula (L(4))(2)Ti(NC(CH(3))(3))py (cis/trans 4a).