Crystallographic and NMR studies on species intermediate between haloalkoxyphosphoranes and alkoxyphosphonium halides

✍ Scribed by Yohsuke Yamamoto; Kumiko Nakao; Takeshi Hashimoto; Shiro Matsukawa; Naoyuki Suzukawa; Satoshi Kojima; Kin-ya Akiba

• Book ID: 102234562
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 286 KB
• Volume: 22
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/hc.20717

✦ Synopsis

Abstract

A series of the monocyclic organophosphorus compounds ([o‐OC(CH~3~)~2~C~6~H~4~]PPh(CH~2~ Ph)X) bearing a halogen (X = F, Cl, and Br) or a tetrafluoroborate (X = BF~4~) were synthesized. The solid‐state structures of the bromide, the tetrafluoroborate, and an analogous fluoride ([o‐OC(CF~3~)~2~C~6~H~4~]PPh(CH~2~ Ph)F) were determined by single crystal X‐ray crystallography. The geometry of the fluoride was almost an ideal trigonal bipyramid (TBP). On the other hand, the bromide and tetrafluoroborate were essentially phosphonium salts with phosphorane character to some extent for the former. In CD~3~ CN, the bromide, the chloride, and the tetrafluoroborate were found to exist as phosphonium salts. However, it was suggested that in CDCl~3~, the bromide and the chloride have structures rapidly equilibrating or averaged between the phosphorane and the phosphonium forms. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:523–530, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20717