The molecular and crystal structure of (PCF3)5

Visual estimates of 2078 reflections obtained from a single crystal at -100 o(?. indicated four molecules of (PCFa) 5 in a unit cell of symmetry P21/n an(t having parameters a =9-87, b =9-78, c = 16.67 A; fl = 103 ° 0'.The sterically distorted P~ ring shows also one short P • • • F interaction of 3"04 ,~.Average distances are P-P = 2-223 +0.007, P-C = 1.91 +0.02 and C-F = 1.35 +0.03 A. The P-P-P angles vary from 94-6 to 107.5 _+ 0.4 °.Values of R =ZI[Fo [ -]I~I[/ZlFo!=0.18 and r = Zwl!Fo] 2 -[],'ci21e/Zw)'4o =0"14 do not include the anisotropic thermal motions of the P5 ring along x anti the torsional oscillations of CF z and the P-C bonds.