The reaction of tertiary aryl phosphites with diiodine at ambient temperatures; structural characterisation of the tertiary phosphite tetraiodides (PhO)(3)PI4, (4-MeC6H4O)(3)PI4 and (2,4-(Bu2C6H3O)-C-t)(3)PI4

摘要

The reaction of the tertiary phosphites (RO)(3)P (R = Ph, 4-MeC6H4, 4-(BuC6H4)-C-t, 2,4-(Bu2C6H3)-C-t, 2,6-Me2C6H3, 2,4,6-Me3C6H2 or 2-PhC6H4) with one and two mole equivalents of diiodine has been investigated. In all cases the tetra-iodide compounds (RO)(3)PI4 were isolated regardless of the stoichiometry employed. The three compounds (RO)(3)PI4 (R = Ph, 4-MeC6H4 or 2,4-(Bu2C6H3)-C-t) have been crystallographically characterised for comparative purposes and represent the first examples of crystal structures for compounds of this formula. The structural characterisation of these compounds illustrates the structural dependence of (RO)(3)PI4 compounds on R. For (RO)(3)PI4 (R = Ph or 2,4-(Bu2C6H3)-C-t) the compounds exist as discrete molecular species whereas, for R = 4-MeC6H4 the triiodide fragments of discrete molecules link via long-range I-I interactions to form a dimer. Additionally, d(I-I) for the (RO)(3)PI and I-3 fragments is sensitive to R, being 3.227(1) Angstrom for (2,4-(Bu2C6H3O)-C-t)(3)PI4 and 3.3888(7) Angstrom for (PhO)(3)PI4. In contrast to the analogous R3PI4 compounds, which show great variation in delta in their P-31-{H-1} NMR spectra depending on R, the (RO)(3)PI4 compounds described all exhibit quite similar delta values irrespective of R. [References: 13]