Enthalpies of formation and charge-transfer bands in the complexes of the sulfides and selenides of tertiary phosphines with iodine and tin tetrachloride

Abstract

1. Thermodynamic parameters (ΔH°, ΔG°, ΔS°) have been determined for the complexing of organophosphorus R1R2R3PX (X=S, Se) donors with I2 and SnCl4. The entropy and enthalpy of these complexing reactions are linearly related in the manner characteristic of electron donor-acceptor complexes. 2. It is shown that the enthalpies of complexing can be correlated with the Kabachnik substituent constants in the R1R2R3PS·I2 and R1R2R3PS·SnCl4 complexes. 3. It has been found that a charge-transfer band appears in the electronic spectrum of each of these complexes, the band maximum shifting toward shorter wavelengths with an increase in the donor ionization potential. © 1979 Plenum Publishing Corporation.