Phosphorus pentachloride Crystal structure

Cl 64.24%. SeCI4. Prepd by the action of an excess of chlorine on selenium Berzelius, cited in Meltor s vol X, 898 (1930) by the action of thionyl chloride or phosphorus trichloride on selenium oxychloride and by the action of phosphorus pentachloride on selenium oxide Michael is. Z Chem. [2) 6, 460 (1870) by the action of anhydr selenic acid on acetyl chloride at 0 Lamb, Am, Chem. J. 30,209 (1903). Crystal structure Shoemaker, Abrahams, Acta Cryst. 18,... 

The unsymmetrical diphosphene (167) and its reaction product (168) with sulphur have been described. A corresponding 1,2,3-selenadiphosphirane (169) has been prepared from the very stable bis(2,4,6-tris(trifluoromethyl)phenyl)diphosphene and its X-ray crystal structure determined. Addition of chlorine to a diphosphene has been realised for the first time in the reaction of (170) with phosphorus pentachloride to give (171) cyclization of (171) to (172) followed by substitution of the chlorine atom gave interesting ring-opened compounds, e.g. (173). 

Treatment of/j-t-butylcalix[4]arene with phosphorus pentachloride afforded (179), which underwent ethanolysis to give (180) the crystal structure of (180) was determined <93PS(84)217>. 

The pentachloride (Powell, Clark, and Wells, J, Chem, Soc. 1942, 642) and pentabromide (PoweD and Clark, Nature, 146, 971 [1940]) of phosphorus have been the subject of crystal structure investigations which have shown them to be ionic in the solid state. The ions are PCU and PCl for the chloride and PBr4 and Br for the bromide. This fact does not mean that they are not covalent in the gaseous state, nor does it imply that PFs is not pentacovalent in all three states. The boiling point for the fluoride is far below the boiling points of the chloride and bromide. If the fluoride were ionic, its boiling point would be higher. 

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