THE SYNTHESIS AND STRUCTURE OF BIS(1,4,7-TRITHIACYCLODECANE)RUTHENIUM(II) PERCHLORATE - THE MESO DIASTEREOISOMER

The synthesis of the Ru(II) crown thioether complex, bis(1,4,7-trithia cyclodecane)ruthenium(II) perchlorate, [Ru(10S3)(2)](ClO4)(2), and a s tudy of its properties utilizing single crystal X-ray diffraction, ele ctronic spectroscopy, C-13 NMR spectroscopy and cyclic voltammetry is reported, The crystal structure shows the two 10S3 ligands are arrange d in a trans or anti fashion around the ruthenium(II) center in nearly octahedral fashion to yield the meso stereoisomer. C-13 NMR spectrosc opy demonstrates that this stereoisomer is also the predominant one ob served in solution, in contrast to the Co(lII) and Fe(II) complexes, T he electronic absorption spectrum is similar to other previously obser ved hexakis (thioether)ruthenium(II) complexes with d-d transitions at 346 and 297 nm. The electrochemical behavior is also similar to relat ed Ru(II) complexes and shows a single quasi-reversible oxidation wave at +1.37 V versus Fc/Fc(+). Crystal data for [Ru(10S3)(2)](ClO4)(2): C14H28Cl2O8RuS6; monoclinic, space group P2(1)/c; a=7.391(2), b=9.480( 2), c=17.351(3) Angstrom; beta=97.10(2)degrees, V=1206.4(5) Angstrom(3 ); Z=2; R=0.0521; D=1.896 g cm(-3); 3211 reflections measured. The pro perties of the complex are compared with the congeneric Fe complex.