Solid state conformational preferences of the {M(μ-XPX)}2 core (X = O, S) in transition metal complexes

The conformational preferences in the {M(μ-XPX)}2 core (X = O, S) in transition metal complexes have been established by statistical methods using torsion angles. When X = O a chair conformation is the most frequent with phosphorus and oxygen atoms in the “seat of the chair”. Quantum chemical calculations reveal that donation from filled lone-pairs at oxygen atoms and electrostatic contributions between P and O atoms are the origin of this preference. When X = S a different chair conformation is the preferred and in this case sulphur and metal atoms are in the “seat of the chair”.