2,6-Dimethoxyphenyl derivatives of sulfur, selenium, and tellurium, such as
Phi EE Phi, Phi(2)E, Phi SeH, [Me Phi(2)E]X (X = MeSO4, ClO4), Phi(2)EO .
xH(2)O, [Phi(2)EOH]ClO4, [Phi(2)EOR]ClO4 (R = Me, Et), Me2SnCl2. 2 Phi(2)EO
(E = S, Se) [Phi = 2,6-(MeO)(2)C6H3; E = S, Se, Te] have been prepared, an
d their properties compared with common phenyl derivatives. The reaction ra
tes of Phi(2)E with dimethyl sulfate and butyl bromide increased in the ord
er E = S < Se < Te, which were compared with those of Ph3M and Phi(3)M, M =
P > As > Sb. These reactivities are parallel with the electrochemical oxid
ation potentials reported for Ph,E and with the first ionization potentials
reported for Ph,M. The rate of Phi(2)Te was faster than that of Ph3P and s
lightly faster than that of Phi(3)Sb. From the reactivity of [Phi(2)E-Me]() salts with nucleophiles, the E+-Me bond strengths were estimated to incre
ase in the order E = Se < S < Te. The reaction rates of Phi(2)EO with dimet
hyl sulfate increased in the order E = S < Se < Te, and the respective rate
of Phi(2)EO was faster than that of Phi(2)E. The origins of these reactivi
ties and bond strengths are discussed. (C) 1999 Elsevier Science S.A. All r
ights reserved.