Assignment and conformational investigation of asymmetric phenylindenylidene ruthenium complexes bearing N,O-bidentate ligands

✍ Scribed by P. M. S. Hendrickx; R. Drozdzak; F. Verpoort; J. C. Martins

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 212 KB
• Volume: 48
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.2599

✦ Synopsis

Abstract

The NMR conformational study of three asymmetric phenylindenylidene ruthenium complexes 4.1–4.3, is presented. Complete ^1^H and ^13^C assignments could be obtained for 4.1–4.3 in benzene solution from multiple 2D homonuclear and heteronuclear NMR techniques. Our NMR analysis shows that each complex exists as a 55:45 mixture of two rotational isomers in slow exchange on the NMR chemical shift timescale. They are shown to be related by a 180° flip of the indenylidene ligand along the RuCR bond. Both rotational isomers can be discriminated by means of NOEs contacts between the various ligands coordinating to the Ru. By matching these stereospecific assignments to the chemical shift, a chemical shift based fingerprint of the isomers that may allow straightforward assignment of future asymmetric phenylindenylidene ruthenium complexes is proposed. Copyright © 2010 John Wiley & Sons, Ltd.