Reaction of R3PSe with I2; crystal structures of Ph3PSeI2, (Me2N)3PSeI2 and (Et2N)3PSeI2, the first crystallographically characterised charge-transfer complexes of tertiary phosphine selenides with diiodine
作者:Stephen M. Godfrey、Sheena L. Jackson、Charles A. McAuliffe、Robin G. Pritchard
DOI:10.1039/a706180c
日期:——
The compounds Ph3PSeI2, (Me2N)3PSeI2 and (Et2N)3PSeI2 have been prepared and characterised by 31P-H} NMR and infrared spectroscopy. Their single crystal structures have also been determined. Interesting variations in d(P–Se) and d(I–I) are noted upon changing R (Ph, Me2N, Et2N). The variation in d(P–Se) for R3PSeI2 compared to the parent tertiary phosphine selenide is also discussed with respect to the degree of retention of phosphorus selenium double-bond character upon co-ordination of I2. The variations in d(P–Se) and d(I–I) are reflected in the infrared and 31P-H} NMR spectra of the R3PSeI2 compounds when compared to R3PSe (R = Ph, Me2N or Et2N). The P–Se–I geometries for all three compounds are bent [Ph3PSeI2, 106.0(1), (Me2N)3PSeI2, 100.4(2) (average); (Et2N)3PSeI2, 106.4(1)°] whereas the Se–I–I linkages are all essentially linear [173.69(6), 174.98(8) (average); 178.04(5)°]. These results are interpreted as a donation of electron density from the selenium atom to the σ*-antibonding orbital of the diiodine.
制备了 Ph3PSeI2、(Me2N)3PSeI2 和 (Et2N)3PSeI2 化合物,并通过 31P-H} NMR 和红外光谱对其进行了表征。核磁共振和红外光谱对其进行了表征。它们的单晶结构也已确定。当改变 R(Ph、Me2N、Et2N)时,d(P-Se)和 d(I-I)会发生有趣的变化。此外,还讨论了 R3PSeI2 的 d(P-Se)与母体叔膦硒化物相比的变化,以及 I2 配位后磷硒双键特性的保留程度。d(P-Se) 和 d(I-I) 的变化反映在 R3 的红外光谱和 31P-H} NMR 光谱中。与 R3PSe(R = Ph、Me2N 或 Et2N)相比,R3PSeI2 化合物的红外光谱和 31P-H} NMR 光谱反映了 d(P-Se) 和 d(I-I) 的变化。所有三种化合物的 P-Se-I 几何结构都是弯曲的[Ph3PSeI2,106.0(1);(Me2N)3PSeI2,100.4(2)(平均值);(Et2N)3PSeI2,106.4(1)°],而 Se-I-I 连接基本上都是线性的[173.69(6),174.98(8)(平均值);178.04(5)°]。这些结果被解释为硒原子向二碘的σ*反键轨道捐赠了电子密度。