Mono- and disubstitution reactions of gyroscope like complexes derived from Cl-Pt-Cl rotators within cage like dibridgehead diphosphine ligands

Reaction of the gyroscope like complex trans-Pt(Cl)(2)(P((CH2)(14))(3)P) (trans-1c) and p-tolSeSiMe(3) (3.8 equiv, 85 degrees C, melt) gives the disubstitution product trans-1;t(Se-p-tol)(2)(P((CH2)(14))(3)P) (trans-3c, 63%) and CISiMe3. Attempts to access a monochloride complex via monosubstitution were unsuccessful. However, when trans-Pt(Ph)(2)(P((CH2)n)(3)P) (trans-2; n = c/14, e/18) and HCI (1.0 equiv; generated from CH3COCl and excess CH3OH) are reacted, the monochloride complexes trans-Pt(Cl)(Ph)(P((CH2)(n))(3)P) (trans-4c,e, 93-96%) are obtained. These feature dipolar rotators, a common design element in approaches to molecular gyroscopes. The crystal structures of trans-3c and trans-4c are determined, and the radii of the rotators and other geometrical features analyzed, especially with regard to the facility of PtL2 rotation. (C) 2016 Elsevier B.V. All rights reserved.