Abstract:

The reaction of 3(5)-phenylpyrazole with CH₂Br₂ under phase transfer catalysis yields (3-phenyl pyrazol-1-y1-5'-phenylpyrazo-1-yl)methane, CH₂(3-PhPz-5'-PhPz) and bis(3-phenylpyrazo-1-yl)methane. Upon treating the isomeric mixture with M(CO)₆ (M=Cr, Mo and W) under UV irradiation at room temperature, (3-phenylpyrazol-1-yl-5'-phenylpyrazo-1-yl)methane tetracarbonylchromium, molybdenum or tungsten complexes is isolated, respectively.The molecular structure of CH₂(3-PhPz-5'-PhPz)W(CO)₄ is determined by X-ray crystallography, which clearly shows that phenyl groups lie in the 3 and 51-positions of pyrazole rings. The compound crystallizes in the monotriclinic space group P2(1)/n, with a=1.7976(7) nm, b=1.3210(5) nm,c=1.8681(7) nm, β=98.293(8)°, V=4.390(3) nm³, Z=8, R=0.0516, Rw=0.0898.

Key words: Poly(pyrazo-1-yl)alkane, Group 6 metal carbonyl complex, X-ray structure