E.S.R. spectra and hyperfine structure of symmetric trinuclear clusters

Chemical and Physical Properties of Triangular Bridged Metal Complexes

“…Yablokov et al (319) proposed that in the applied magnetic field the two doublets undergo Zeeman splitting to the same extent to produce the correlation diagram shown in Fig. 16. The zero-field splitting is marked as 6, and it can be seen that for a given frequency of observation, there are four transitions at three different field intensities B .…”

“…More specifically directed to ESR, however, are predictions of the anisotropy of the effective g values, and of the nonlinear dependence of transition energies on applied field, due to mixing of Zeeman levels, (315, 207, 261, 139, 16. 70); also, consideration of nuclear hyperfine interaction (261,15,16) and of line widths in terms of spin-lattice relaxation (257).…”

“…Strong bands in the spectrum of Delepine's ion. in the range of 15.000 to 23.000 cm-' are attributed to transitions from various of these orbitals to the one antibonding orbital, and from these energies, the contribution of r bonding to the overall stabilization of the molecule is estimated as roughly 10.000 cm ' (131).…”

“…To a first approximation these can be resolved into vibrations of the planar (or near-planar) MO, units, the central M 3 0 triangle, and the M-L bonds, but coupling effects can also be discerned. The highest frequency and strongest, band15. is generally assigned to the mode vd(M04) (seeFig.…”

Spin-frustrated and nanomagnets with Dzialoshinsky–Moriya exchange. 1. Inelastic neutron scattering and EPR in scalene, isosceles and equilateral trimers

“…These magnetically isolated trimeric S i ¼ 1=2 clusters are the simplest magnetic systems which allow one to investigate the effects of the Dzialoshinsky-Moriya [8,9] (DM) exchange H DM ¼ P G ij ½S i  S j and distortions, the spin-frustration, spin chirality, spin reorientation and quantum magnetization. For the equilateral (EQ) Cu 3 (II) clusters with large Heisenberg exchange parameters J 0 , the DM exchange results in zero-field splitting (ZFS) 2D 0 DM ¼ jG z j ffiffiffi 3 p of the 2(S = 1/2) ground state (GS), and determines the anisotropy of magnetic and spectroscopic characteristics [6,7,[10][11][12][13][14][15], G z ¼ ðG 12;Z þ G 23;Z þ G 31;Z Þ=3. In the isosceles (IS) clusters with J 13 ¼ J 23 ¼ J -J 12 ¼ J 0 and G z -0; G x;y ¼ 0, the ZFS 2D 0 ¼ p ½ðJ 0 À JÞ 2 þ 3G 2 z of the 2(S = 1/2) set is determined by G z and distortion ðJ 0 À JÞ [6,7].…”