Made available courtesy of Elsevier: http://www.elsevier.com/ ***Reprinted with permission. No further reproduction is authorized without written permission from Elsevier. This version of the document is not the version of record. Figures and/or pictures may be missing from this format of the document.*** Summary: The hydrosilylation of 1-pentyne by triethylsilane has been investigated using rhodium catalysts, formed by displacement of cyclooctene from dichlorotetrakis(cyclooctene)dirhodium(I) by various molar ratios of phosphines. The results are interpreted in terms of isomerization of an intermediate vinylrhodium complex.