Molecular tailoring and prediction of strongly ferromagnetically coupled trimethylenemethane-based nitroxide diradicals.
We have investigated the magnetic properties of four recently synthesized stable TMM-type nitroxide diradicals. Four new diradicals are proposed by tailoring one of the species in such a way that both conjugation and planarity increase. As a remarkable consequence, the intramolecular ferromagnetic exchange interaction was found to be quite high in the proposed radicals. The calculated coupling constants were in the range of +102 to +140 cm-1. The MO and spin density analysis are provided to interpret the exchange interactions. We observed the existence of intramolecular pi-pi-interactions for the species 2. This slightly increased the J value by shortening the length of the spacer between the two spin sources.
Ali
Md Ehesan
ME
Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai 4000076, India.
Roy
Abhishek Singha
AS
Datta
Sambhu N
SN