Crystal structures of phosphine-supported (η 5 -cyclo-penta-dien-yl)molybdenum(II) propionyl complexes.

Three cyclo-penta-dienylmolybdenum(II) propionyl complexes featuring tri-aryl-phosphine ligands with different para substituents, namely, dicarbon-yl(η ⁵ -cyclo-penta-dien-yl)propion-yl(tri-phenyl-phosphane-κ P )molybdenum(II), [Mo(C ₅ H ₅ )(C ₃ H ₅ O)(C ₁₈ H ₁₅ P)(CO) ₂ ], ( 1 ), dicarbon-yl(η ⁵ -cyclo-penta-dien-yl)propion-yl[tris-(4-fluoro-phen-yl)phosphane-κ P ]molybdenum(II), [Mo(C ₅ H ₅ )(C ₃ H ₅ O)(C ₁₈ H ₁₂ F ₃ P)(CO) ₂ ], ( 2 ), and dicarbon-yl(η ⁵ -cyclo-penta-dien-yl)propion-yl[tris-(4-meth-oxy-phen-yl)phosphane-κ P ]molybdenum(II) dichloromethane solvate, [Mo(C ₅ H ₅ )(C ₃ H ₅ O)(C ₂₁ H ₂₁ O ₃ P)(CO) ₂ ]·CH ₂ Cl ₂ , ( 3 ), have been prepared from the corresponding ethyl complexes via phosphine-induced migratory insertion. These complexes exhibit four-legged piano-stool geom-etries with mol-ecular structures quite similar to each other and to related acetyl complexes. The extended structures of the three complexes differ somewhat, with the para substituent of the tri-aryl-phosphine of ( 2 ) (fluoro) or ( 3 ) (meth-oxy) engaging in non-classical C-H⋯F or C-H⋯O hydrogen-bonding inter-actions. The structure of ( 3 ) exhibits modest disorder in the position of one Cl atom of the di-chloro-methane solvent, which was modeled with two sites showing approximately equivalent occupancies [0.532 (15) and 0.478 (15)].
(© Whited et al. 2021.)