Crystal and molecular structure of cis-dichloro(1,4,8,11-tetrathiacyclo-tetradecane)ruthenium(II) dihydrate; a correction to the reported stereochemistry based on infrared spectroscopy

Abstract

The crystal and molecular structure of cis-[RuL¹Cl₂]·2H₂O (L¹= 1,4,8,11-tetrathiacyclotetradecane) has been solved by Patterson and Fourier methods. The crystals are monoclinic, space group C2/c, with a= 10.795(2), b= 17.541(3), c= 9.452(1)Å, β= 100.70(1)°, and Z= 4. Refinement by full-matrix least squares gave R= 0.038 for 2 094 diffractometer observations. This crystallographic determination disproves the previous assignment, based on i.r. spectroscopy, of a trans-configuration to this title complex. The importance of Ru → S π back-bonding in this ruthenium(II) complex is manifested by the much shorter Ru–S bond distances when the sulphur atoms are trans to a chloride than when they are trans to each other. The i.r. spectra of this and some related complexes of L¹ and ruthenium(II) and ruthenium(III) are discussed.