Reactions of Ph4Se4Br4 with tertiary phosphines. Structural isomerism within a series of R3PSe(Ph)Br compounds

被引:21
作者
School of Chemistry, University of Manchester , PO Box 88, Manchester, M60 1QD, United Kingdom [1 ]
机构
[1] School of Chemistry, University of Manchester (North Campus), Manchester, M60 1QD
来源
Dalton Trans. | 2006年 / 12卷 / 1517-1523期
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D O I
10.1039/b516784a
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学科分类号
摘要
The synthesis and characterisation of Ph4Se4Br 4 (1) directly from the reaction of Ph2Se2 with dibromine is reported. The solid-state structure of 1 consists of four PhSeBr units linked by weak selenium-selenium bonds [3.004(2)-3.051(2) ] into a Se 4 square, and is structurally analogous to the previously reported Ph4Te4I4. The reactions of Ph 4Se4Br4 with a variety of tertiary phosphines have been undertaken, resulting in the formation of compounds of formula R 3PSe(Ph)Br. X-Ray crystallographic analysis of three of the compounds reveals different structural isomers. Ph3PSe(Ph)Br (2) is a charge-transfer (CT) compound [Se-Br 3.0020(8) ], with an essentially linear P-Se-Br bond angle, 172.15(4)°and T-shaped geometry at selenium. Me 3PSe(Ph)Br (5) also contains the selenium atom in a T-shaped geometry, consistent with a CT formulation, although the Se-Br distance of 3.327(3) is considerably longer than observed for 2. In contrast, Cy 3PSe(Ph)Br (6) is an ionic phosphonium salt, [Cy3PSePh]Br with no short Se-Br interactions. Geometry at selenium is bent, as expected for an ionic compound. These results are discussed with reference to the previously reported iodo-compounds Ph3PSe(Ph)I and [(Me2N) 3PSe(Ph)]I. © The Royal Society of Chemistry 2006.
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页码:1517 / 1523
页数:6
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共 56 条
[21]  
Romming C., Acta Chem. Scand., 14, (1960)
[22]  
Blake A.J., Gould R.O., Radek C., Schroder M., J. Chem. Soc., Chem. Commun., (1993)
[23]  
Regelman B., Klinkhammer K.W., Schmidt A., Z. Anorg. Allg. Chem., 623, (1997)
[24]  
Blake A.J., Cristiani F., Devillanova F.A., Garau A., Gilby L.M., Gould R.O., Isaia F., Lippolis V., Parsons S., Radek C., Schroder M., J. Chem. Soc., Dalton Trans., (1997)
[25]  
Blake A.J., Devillanova F.A., Garau A., Gilby L.M., Gould R.O., Isaia F., Lippolis V., Parsons S., Radek C., Schroder M., J. Chem. Soc., Dalton Trans., (1998)
[26]  
Blake A.J., Devillanova F.A., Garau A., Isaia F., Lippolis V., Parsons S., Schroder M., J. Chem. Soc., Dalton Trans., (1999)
[27]  
McCullough J.D., Hamburger G., J. Am. Chem. Soc., 63, (1941)
[28]  
McCullough J.D., Hamburger G., J. Am. Chem. Soc., 64, (1942)
[29]  
McCullough J.D., Marsh R.E., Acta Crystallogr., 3, (1950)
[30]  
McCullough J.D., Inorg. Chem., 3, (1964)