Phosphane Chalcogenides and their Metal Complexes. I. Structures of some Diphosphane Monochalcogenides

We report the crystal structures of six diphosphane monochalcogenides [1: 1,2-bis(diphenylphosphano)methane sulfide (dppmS), 2: 1,2-bis(diphenylphosphano)ethane oxide (dppeO), 3: 1,2-bis(diphenylphosphano)ethane sulfide (dppeS), 4: 1,2-bis(diphenylphosphano)benzene sulfide (dppbzS), 5: 1,2-bis(diphenylphosphano)benzene selenide (dppbzSe), 6: 1,8-bis(diphenylphosphano)naphthalene sulfide (dppnS) as its dichloromethane sesquisolvate and monosolvate 6a/6b]. No isotypy is observed for analogous compounds with the same phosphine but different chalcogens. The two independent molecules of 3 are superimposable to a good approximation up to and including the ipso carbons, but the ring orientations are different; 3 differs from 2 mainly by a rotation around the P1–C1 bond. The molecules of 4 and 5 are similar except for the disposition of the rings at P^III. The two molecules of 6 show the distortions typical of 1,8-disubstituted naphthalenes and are closely similar. In the packing of structures 1–3 non-classical hydrogen bonds of the form C–H···E (E = chalcogen) are observed. In a supplement two supposedly new polymorphs of dppmSe₂ are shown to be probably identical to previously known forms.