Title :
Ferromagnetic interactions through end-on azido bridges in a nickel(II) dimer: [Ni2(C15H11N3 )2(H2O)(N3)3]ClO4 .H2O
Author :
Cortés, Roberto ; Lezama, L. ; Rojo, Teófilo ; Urtiaga, M. Karmele ; Arriortua, M. Isabel
Author_Institution :
Dept. de Quimica Inorg., Pais Vasco Univ., Bilbao, Spain
fDate :
11/1/1994 12:00:00 AM
Abstract :
The crystal structure of [Ni2(C15H11 N3)2-(H2O)(N3)3 ]ClO4.H2O, (C15H11N 3)=2,2\´:6\´, 2"-terpyride, has been solved: a=10.179(2), b=10.800(3), c=16.866(6) Å, α=85.54(2), β=78.49(2), γ=72.03(1)°, R=0.055, RW=0.061. It consists of dimeric cations where the two nickel(II) ions are linked through the nitrogen atoms of two azide bridging groups in end-on fashion and ClO 4-anions. Magnetic susceptibility measurements show the existence of ferromagnetic superexchange between the nickel ions. The exchange parameters determined are J=+13.6 cm-1, D=-19.2 cm(-1), Z\´J\´=0.03 cm-1 and g=2.12. Q-band EPR spectrum shows signals at 525 and 1100 mT values. A theoretical study, by using extended Huckel molecular orbital calculations, shows a minimum of the antiferromagnetic component of the exchange parameter for a bridging angle of 115°
Keywords :
EHT calculations; HMO calculations; crystal structure; ferromagnetic materials; magnetic susceptibility; nickel compounds; paramagnetic resonance; superexchange interactions; ClO4-anions; Ni(II) dimer; Q-band EPR spectrum; [Ni2(C15H11N3)2 (H2O)(N3)3]ClO4.H 2O; antiferromagnetic component; bridging angle; crystal structure; dimeric cations; end-on azido bridges; exchange parameters; ferromagnetic interactions; ferromagnetic superexchange; magnetic susceptibility; Atomic measurements; Bridges; Extraterrestrial measurements; Magnetic field measurement; Magnetic susceptibility; Nickel; Nitrogen; Orbital calculations; Paramagnetic resonance; Temperature;
Journal_Title :
Magnetics, IEEE Transactions on
