posted on 2004-02-16, 00:00authored byDaewon Hong, Patrick J. Carroll, Larry G. Sneddon
The new hypho-class carboranes endo-7-[Ph2(H)P]-8-R-hypho-7,8-C2B6H11 (R = H, Me) were
prepared from the reactions of Na+[arachno-4,6-C2B7H12]- and Na+[4-Me-arachno-4,6-C2B7H11]- with Ph2PCl. Single-crystal X-ray crystallographic determinations and DFT/GIAO
computational studies established that while the endo-7-[Ph2(H)P]-8-R-hypho-7,8-C2B6H11
cages (R = H, Me) have frameworks that are consistent with those which have been adopted
by other isoelectronic eight-vertex hypho clusters, the cage carbon having the Ph2(H)P
substituent exhibits a shortened phosphorus−carbon bond, suggesting an ylide-like character.