-Tri-chlorido-tris-(tetra-hydro-thio-phene-κ)iridium(III): preparation and comparison with other -tri-chlorido-tris-(tetra-hydro-thio-phene-κ)metal complexes.

The title complex, [IrCl(CHS)], was prepared according to a literature method. A suitable crystal was obtained by diffusion of pentane into a di-chloro-methane solution and analyzed by single-crystal X-ray diffraction at 100 K. The title complex is isotypic with -tri-chlorido-tris-(tetra-hydro-thio-phene-κ)rhodium(III). However, the orientation of the tetra-hydro-thio-phene rings is different from an earlier report of -tri-chlorido-tris-(tetra-hydro-thio-phene-κ)iridium(III) deposited in the Cambridge Structural Database. The IrSCl core shows a nearly octa-hedral structure with various bond angles within 1-2° of the perfect 90 or 180° expected for an octa-hedron. The structure of the title compound is compared with the previous iridium complex as well as the rhodium and other octa-hedral metal tris-tetra-hydro-thio-phene compounds previously structurally characterized. DFT calculations were performed, which indicate the isomer is significantly lower in energy than the isomer by 50.1 kJ mol, thereby accounting for all compounds in the CSD being of the geometry. Powder X-ray diffraction of the bulk material showed that the preparation method yielded only the isomorph reported in this communication.