title: A magnetostructural investigation of an abrupt spin transition for 1-phenyl-3-trifluoromethyl-1,4-dihydrobenzo[e][1,2,4]triazin-4-yl.
abstract: 1-Phenyl-3-trifluoromethyl-1,4-dihydrobenzo[e][1,2,4]triazin-4-yl is the first example of a hydrazyl radical that shows a reversible sharp spin transition fully completed within 5(1) K. The nominally first-order transition takes place at ca. 58(2) K and proceeds via subtle changes of intra- and interstack interactions between two similar structural phases. The low-temperature phase (5-60 K) is diamagnetic and has a singlet ground state (2Jexp = -166.8 cm(-1), gsolid = 2.0042, ρ = 0.2%) stemming from a multicenter two-electron interaction. The high-temperature phase (60-300 K) is paramagnetic as a result of noninteracting S = 1/2 spins arising from weakly bound dimers.
authors.affiliation: Department of Chemistry, University of Cyprus , P.O. Box 20537, 1678 Nicosia, Cyprus.
authors.forename: Christos P
authors.initials: CP
authors.lastname: Constantinides
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Berezin
authors.forename: Georgia A
authors.initials: GA
authors.lastname: Zissimou
authors.forename: Maria
authors.initials: M
authors.lastname: Manoli
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Leitus
authors.forename: Michael
authors.initials: M
authors.lastname: Bendikov
authors.forename: Michael R
authors.initials: MR
authors.lastname: Probert
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Rawson
authors.forename: Panayiotis A
authors.initials: PA
authors.lastname: Koutentis