23268-95-3Relevant articles and documents
HOMOLYTIC SUBSTITUTION IN TRIALKYLTIN IODIDES BY PHOTOCHEMICALLY GENERATED IODINE ATOMS. V. Mixed Dimethylalkyltin Iodides, Me2R'SnI.
Ryck, P. H. de,Verdonck, L.,Hooste, H. van,Kelen, G. P. van der
, p. 1033 - 1040 (2007/10/02)
Mixed trialkyltin iodides form EDA complexes with iodine.The λCT data suggest an electron transfer from the iodide lone pairs.Rate constants for the reaction under photochemical conditions are determined by kinetic measurements.The selectivity parameter derived from the rate constants and from mass spectrometric measurements prove the presence of a fragmentation step in the reaction process.
Electron Donor-Acceptor Complexes. 1. Linear Free Energy Correletion of the Charge-Transfer Transition Energy with the Kinetics of Halogenolysis of Alkylmetals
Fukuzumi, S.,Kochl, J.K.
, p. 2246 - 2254 (2007/10/02)
Mulliken charge-transfer theory is used to relate the properties of transient donor-acceptor complexes between alkylmetals and halogens with the kinetics of the accompanying cleavage reaction (halogenolysis).The formulation derives from the charge-transfer transition energy hνCT which is proportional to the second-order rate constant for halogenolysis of a variety of tetraalkyltin compounds in hexane or carbon tetrachloride solutions.The description of the activation process for halogenolysis as an electron transfer in the CT complex, e.g., --> , leads to a linear free energy relationship in which the activation free energy is equal to the driving force for ion pair formation.The latter is equated to the charge-transfer transition energy plus a contribution from the solvation energy, by employing a comparative procedure for the evaluation of alkylmetals.An independent measure of the solvation energy obtained from the gas-phase ionization potentials of alkylmetals and their free energy changes in solution supports the electron-transfer formulation of the activation process.The charge-transfer mechanism is generalized for the halogenolysis of alkylmetals.
Mechanisms of the rupture of the carbon-tin bond by halogens II. Free-radical substitution in solution
Boue, S,Gielen, M,Nasielski, J
, p. 461 - 479 (2008/10/08)
The experiments describes in this paper show that the light-induced bromodemetallation of tetraalkyltins in chlorobenzene is a free radical substitution on tin, followed by a propagation step: {A figure is presented}. The stabilisation of R? by hyperconjugation seems to be an important factor for the reaction, but there is evidence for the influence of the other three substituents of tin and of the nature of the attacking radical on the reaction mechanism. The relation between the strucutre and the reactivity of tetraalkyltins suggests that the carbon-tin bond is only slightly loosened in the transition state; this agrees with the great reactivity of the Br atom.