REACTION OF POLY(PYRAZOL-1-YL)METHANE TETRACARBONYLMOLYBDENUM (TUNGSTEN) WITH RSNCL3 (R = PH, CL) - X-RAY CRYSTAL-STRUCTURE OF CH2(3,5-ME(2)PZ)(2)W(CL)(CO)(3)(SNCL3) (PZ-PYRAZOLYL)

Bis(pyrazolyl)methane can be synthesized by the reaction of pyrazole w ith dibromomethane in phase transfer catalytic conditions. It reacts w ith M(CO)(6) (M = Mo, W) to give bis(pyrazolyl)methane tetracarbonylmo lybdenum(0) and tungsten(0) complexes in good yield. Upon treatment of these complexes with RSnCl3 (R = Ph, Cl), the seven-coordinate Mo(II) and W(II) products were obtained. The molecular structure of CH2(3,5- Me(2)Pz)(2)W(Cl)(CO)(3)(SnCl3) determined by X-ray crystallography sho wed that the six-membered W-N-N-C-N-N metallacycle was in a boat form. (C) 1998 Elsevier Science Ltd. All rights reserved.