Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published 1999 | metadata_only
Journal Article

Intra- and inter-molecular exchange on symmetrical hydrazine diradical dications and comparison of the magnetic exchange with ET parameters derived from their optical spectra


The spin alignment in a charged molecular field is important research issue in the molecular magnetism. In order to clarify the interrelation between spin alignment and the charged molecular field, we have investigated intra- and inter-molecular exchanges on some Hydrazine diradical dictations 1–3 shown in Scheme 1 (see texts) by ESR and magnetic susceptibility measurement. The magnetic behavior of the dication salt 1 has been well analyzed using the alternating linear chain models with J_(intra)/k_B = −106 K, J_(inter_/k_B = −49 K and an alternating parameter α=0.46. The magnetic property of 3 has been also fitted to the alternating chain model with J/k_B = −106 K J_(inter)/k_B = −42 K (α=0.40). On the other hand, 2 gives a robust triplet ground state with larger energy separation from other spin states. The energy separation has been estimated to be larger than 300 cm−1 (J_(intra)/k_B > ±190 K) from the temperature dependence of the ESR signal intensity. These findings indicate that the sign of the intramolecular exchange depends on the linking position (m- or p-) of the hydrazine cation group, i.e. the topology of the π orbital network even in the cationic molecular field. The magneto-optical correlation is also discussed based on the intramolecular electron transfer (ET) parameters.

Additional Information

© 1999 Taylor & Francis. This work was financially supported by a Grant-in-Aid for a General Scientific Research (No. 07454191) from the Ministry of Education, Science, Sports, and Culture, Japan and Precursory Research for Embryonic Science and Technology (PEST) from Japan Science and Technology Corporation.

Additional details

August 22, 2023
August 22, 2023