Hu. Steinberger et al., Tris(tert-butyl)phosphine selenide, the missing link in tris(tert-butyl)-phosphine chalcogenide structures tBu(3)P=X (X = O, S, Se, Te), ACT CRYST C, 57, 2001, pp. 323-324
In tris(tert-butyl)phosphine selenide, C12H27PSe, all the methyl ligands ar
e disordered over two sites in the ratio 70/30. The molecule displays cryst
allographic C-3 symmetry. The bond angles at the P atom are distorted tetra
hedral [CD P-C 110.02 (5)degrees and Se=P-C 108.91 (5)degrees]. The P-C and
P=Se bond lengths are 1.908 (1) and 2.1326 (6) Angstrom, respectively. A c
omparison of the structural data of the complete series of tris(tert-butyl)
phosphine chalcogenides ((Bu3PO)-Bu-t, (Bu3PS)-Bu-t, (Bu3PSe)-Bu-t and (Bu3
PTe)-Bu-t) with the corresponding data of other phosphine chalcogenides sub
stituted by smaller organic groups shows the great influence of the bulky t
ert-butyl ligands.