Can effective atomic polarizability alphad determine the ionization of 99tc m - diaminedithiol alkylamine radioligand derivatives?

[摘要] Polarizability correlates well with organic ion stabilization in solution and can be defined as a measure of the relative ease of the distortion of the electronic cloud of a dipolar system exposed to an external electric field. The effective atomic polarizability, ad, has a fundamental influence on chemical reactivity in the gas phase and in solution. In terms of chemical reactivity the charge is generated within the molecule as a positive charge due to protonation, ionization or resulting from the attack of a nucleophilic anion. In this paper, lipoidal diaminedithiol (DADT) perfusion radioligands based on 99Tcm and possessing an alkylamine side chain have been used to check the influence of ad on their brain uptake. Some new DADT derivatives, respectively DADT-DIPA (diaminedithiol - diisopropylamine), DADT DIBA (diaminedithiol diisobutylamine), DADT-PR (diaminedithiol - branched pyperidine), have been designed to have high nitrogen alkylamine ad values. In spite of the fact of higher ad values having been correlated to higher brain uptakes, there isn't a clear mechanism able to trap these radioligands into the brain space.

[学科分类] 化学（综合）

[关键词] effective atomic polarizability;99m technetium radioligands;alkylamine ionization.