Chlorobis(pentafluoroethyl)phosphane: improved synthesis and molecular structure in the gas phase |
| |
Authors: | Hayes Stuart A Berger Raphael J F Mitzel Norbert W Bader Julia Hoge Berthold |
| |
Institution: | 1. Fakult?t für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie, Universit?t Bielefeld, Universit?tsstra?e 25, 33615 Bielefeld (Germany), Fax: (+49)?521‐106‐6026;2. Fakult?t für Chemie, Anorganische Chemie II, Universit?t Bielefeld, Universit?tsstra?e 25, 33615 Bielefeld (Germany) |
| |
Abstract: | (C2F5)2PCl is now accessible through a significantly improved synthesis protocol starting from the technical product (C2F5)3PF2. (C2F5)3PF2 was reduced in the first step with NaBH4 in a solvent‐free reaction at 120 °C. The product, P(C2F5)3, was treated with an excess of an aqueous sodium hydroxide solution to afford the corresponding phosphinite salt Na+(C2F5)2PO? selectively under liberation of pentafluoroethane. Subsequent chlorination with PhPCl4 resulted in the selective formation of (C2F5)2PCl, which was isolated by fractional condensation in an overall yield of 66 %. The gas electron diffraction (GED) pattern for (C2F5)2PCl was recorded and found to be described by a two‐conformer model. A quantum chemical investigation of the potential‐energy surface revealed the possible existence of many low‐energy conformers, each with a number of low‐frequency vibrational modes and therefore large‐amplitude motions. The conformer calculated to be most stable was also found to be most abundant by GED and comprised 61(5) % of the total. The molecular structure parameters determined by GED were in good agreement with those calculated at the MP2/TZVPP level of theory; the only significant difference was a discrepancy of about 3° in the C‐P‐C angle, which, for the lowest‐energy conformer, was refined to 98.2(4)° and was calculated to be 94.9°. |
| |
Keywords: | density functional calculations gas electron diffraction molecular structures fluorine phosphorus |
本文献已被 PubMed 等数据库收录! |
|