NEW CHELATING PYRIDYL-INDENYL AND QUINOLYL-INDENYL LIGANDS LEADING TOC-1 SYMMETRICAL COMPLEXES OF ZIRCONIUM VIA AMINE ELIMINATION - X-RAY STRUCTURE OF -PYRIDYLMETHYL)(INDENYL)]TRIS(DIMETHYLAMIDO)ZR(IV)

Two new chelating (1-) ligands, based on an indenyl group and either a pendant pyridylmethyl arm or a pendant quinolylmethyl arm were synthe sized. The two Ligands react cleanly with tetrakis(dimethylamido)zirco nium by amine elimination reactions leading to complexes of C-1 symmet ry. The crystal structure of the pyridyl-indenyl zirconium complex 3 w as determined. Compound C21H30N4Zr (3) crystallizes in the orthorhombi c space group Pbca with a = 9.588(1), b = 14.858(12), c = 29.932(7) An gstrom, V = 4264.1 (Angstrom(3)), Z = 8. The structure refinement conv erged to R1 = 0.049 for 2363 F-0>4 sigma(F-0) and wR2 = 0.167 for all 3197 unique data, S = 1.04. The structure shows that the indenyl is bo und in a eta(5) fashion blocking the top of the zirconium atom, and th e pyridine is coordinated in an exceptionally long 2.536(5) Angstrom N -Zr bond, blocking the back of the zirconium atom. (C) 1997 Elsevier S cience S.A.