Theoretical Study of Effective Exchange Integrals for Ferromagnetic Phenylenevinylene Polymers with Nitroxddes. Possibilities of Organic Ferro-or Ferri-Magnetic Solids
- 1 March 1996
- journal article
- research article
- Published by Taylor & Francis in Molecular Crystals and Liquid Crystals
- Vol. 279 (1) , 19-28
- https://doi.org/10.1080/10587259608042172
Abstract
Molecular orbital calculations were carried out for pendant-type ferromagnetic phenylenevinylene pligomers with nitroxide groups in order to elucidate variations of the effective exchange integrals with oligomer size, conformational change and spin defects generated in the dehydrogenation process of NOH groups in the precursor oligomers. It was shown that the ferromagnetic effective exchange interactions between the nearest neighbor nitroxides are about 50–80 cm−1, but they decrease with the internal rotation and spin defect. The interchain interactions between the oligomers are antiferromagnetic, and therefore they should be controlled by introduction of spacer group, showing a possibility to obtain the high Tc organic ferrimagnet induced by one-electron transfer between the oligomer and spacer.Keywords
This publication has 12 references indexed in Scilit:
- Ferromagnetic Spin Coupling oftert-Butylnitroxide Diradicals through a Conjugated Oligo(1,2-phenylenevinylene)-CouplerChemistry Letters, 1995
- CASSCF and CASPT2 calculations of hole-doped polycarbenes. Possibilities of organic ferromagnetic conductors and metalsChemical Physics Letters, 1995
- Effective exchange integrals for open-shell species by density functional methodsChemical Physics Letters, 1994
- Poly(phenylenevinylene) Bearing Built-in tert-Butylnitroxide. A Polyradical Ferromagnetically Coupled in the IntrachainChemistry Letters, 1994
- Theoretical Approaches to Molecular Magnetisms: Through-Bond Couplings Between Triplet Carbenes and Related SpeciesMolecular Crystals and Liquid Crystals, 1993
- Semiempirical study of electron exchange interaction in organic high-spin .pi.-systems. Classifying structural effects in organic magnetic moleculesThe Journal of Organic Chemistry, 1991
- Ab Initio Calculations of Effective Exchange Integrals. Possibilities of Superparamagnetic, Mictomagnetic and Amorphous Feromagnetic States for Aggregates of Aromatic Free Radicals and Polymer RadicalsMolecular Crystals and Liquid Crystals Incorporating Nonlinear Optics, 1989
- Density-functional exchange-energy approximation with correct asymptotic behaviorPhysical Review A, 1988
- Development of the Colle-Salvetti correlation-energy formula into a functional of the electron densityPhysical Review B, 1988
- A generalized MO (GMO) approach to unstable molecules with quasi-degenerate electronic states: GMO calculations of intramolecular effective exchange integrals and designing of organic magnetic polymersSynthetic Metals, 1987