Synthesis, characterization and reactivity of bis(3-ferrocenylpyrazol-1-yl)methane-tetracarbonylmolybdenum and tungsten

Bis(3-ferrocenylpyrazol-1-yl)methane, CH2(3-FcPz)(2), has been prepared by the reaction of 3 -ferrocenylpyrazole with dibromomethane under phase transfer catalytic conditions. The reaction of CH2(3-FcPz)(2) with M(CO)(6) (M = Mo or W) led to bis(3-ferrocenylpyrazol-1-yl)methanetetracarbonylmolybdenum(0) and tungsten(0) in good yield. Upon treatment of these complexes with I-2, the seven-coordinate Mo(II) and W(II) products were obtained. However, the reaction of these complexes with Br-2 led to decomposition. All new compounds were characterized by IR, H-1 NMR and elemental analyses.