The crystal and molecular structures of bromotricarbonyl(phenylbis(3,5-dimethylpyrazolyl)phosphine)rhenium(I) and tricarbonyl(phenylbis(3,5-dimethylpyrazolyl)phosphine)tungsten(0)

Abstract

Crystals of [Re(CO) 3 (P(Me 2 pz) 2 C 6 H 5 )Br] (where Me 2 pz is 3,5-dimethylpyrazolyl) are monoclinic, space group P2 1 /c, with a = 8.964(4), b = 14.441(10), c = 18.156(8) Å, β = 111.32(4)°, and Z = 4. Crystals of W(CO) 3 (P(Me 2 pz) 2 (C 6 H 5 )) are monoclinic, space group P2 1 /c, with a = 12.479(7), b = 10.207(4), c = 16.118(7) Å, β = 98.77(2)°, and Z = 4. In both structures there is irregular octahedral geometry about the metal atom with the carbonyl groups in a fac arrangement. The phenylbis(3,5-dimethylpyrazolyl)phosphine ligand, [P(Me 2 pz) 2 (C 6 H 5 )], is coordinated to the tungsten atom through the two 2N nitrogen atoms of the pyrazolyl rings and to two carbon atoms of the phenyl ring so that the ligand is essentially tridentate. In the rhenium complex this ligand is bidentate with coordination via the 2N nitrogen atoms with a bromine atom occupying the sixth site.