Crystal structure of the axial (orange-yellow) isomer of bis(methyldiphenylphosphine)tetrakis(trifluoroacetato)dimolybdenum

Article abstract of DOI:10.1021/ic00134a008

The X-ray crystal structure of the orange-yellow isomer of Mo₂(O₂CCF₃)₄(PMePh₂) ₂ confirms that it possesses a class I (axial) structure as previously deduced spectroscopically. Accordingly, PMePh₂ is capable of forming both class I and class II (equatorial) adducts with Mo₂(O₂CCF₃)₄. NMR studies show that an equilibrium between the two isomers is established in solution. Crystal data: space group P2₁/c; a = 9.923 (1) ?, b = 22.517 (2) ?, c = 18.735 (3) ?, β = 99.18 (1)°; V= 4132 (2) ?³; Z = 4; R = 4.43%, Rw = 6.63%; Mo-Mo = 2.128 (1)?, Mo-P = 2.988 = 0.024 ?, Mo-Mo-P = 166.15 = 0.16°.