Stereochemistry of two dicyclopentadienylmolybdenum complexes. Molecular structure of DI-η 5-cyclopentadienyl- N-(α,α′-dimethylmethoxy)pyrazolatomolybdenum(IV) hexafluorophosphate and DI-η 5-cyclopentadienylbispyrazolatomolybdenum(IV)

Abstract

Crystals of di-η 5-cyclopentadienyl- N-(α,α′-dimethylmethoxy)pyrazolatomolybdenum(IV) hexafluorophosphate, [Mo(η 5-C 5H 5) 2(N 2C 3H 3C(CH 3) 2O)](PF 6), 1, are monoclinic space group P2 1/ n with a 12.943(2) Å, b 10.895(2) Å, c 13.623(2) Å, β 105.22(1)° and Z = 4. Crystals of di-η 5-cyclopentadienylbispyrazolatomolybdenum(IV), [Mo(η 5-C 5H 5) 2(N 2C 3H 3) 2], 2, are monoclinic space group P2 1/ n with a 8.510(1) Å, b 9.631(1) Å, c 18.264(3) Å, β 102.73(1)° and Z = 4. The structures were solved by Patterson and difference electron density syntheses and refined by least-squares to R 1 of 0.046 for 3791 reflexions for 1 and R 1 of 0.029 for 2109 reflexions for 2. The structure of compound 1 consists of discrete cations with an approximate C 2υ symmetry at the molybdenum atom and PF 6 − anions. The molybdenum atom is at an average distance of 1.995 Å from the cyclopentadienyl rings, and the angle between these normals is 128.8°. The MoO and MoN bond lengths are 2.026(2) and 2.123(3) Å, and the OMoN bond angle is 75.4(1)°. The structure of compound 2 consists of discrete molecules with an approximate C s symmetry at the molybdenum. The molybdenum atom lies at an average distance of 1.982 Å from the cyclopentadienyl rings and the angle between the ring normals is 133.2°. The MoN bond lengths are 2.166(3) and 2.157(3) Å and the NMoN bond angle is 83.3(1)°.