Zur paramagnetischen Elektronenresonanz metallorganischer Sandwich-Verbindungen, Teil I / The magnetic resonance properties of some sandwich compounds, part i

Abstract

The zero-field splitting and ^-values of manganocene and chromocene have been calculated. The wave functions were obtained by means of a self-consistent charge extended Hiickel method. The calculated values <7|| =2.0034 and g = 2.0033 of manganocene agree fairly well with the experimental results obtained from ESR measurements. The very large computed zero-field splitting D=-0.24 cm -1 explains that there has been observed only one ESR transition though manganocene is in a spin-5/2 state. For chromocene no ESR transition has been found until now. We therefore studied the splitting of the orbitally degenerate ground state by the combined action of spin-orbit coupling and low-symmetry perturbation. The predicted splitting is strongly dependent on the magnitude of the rhombic distortion compared to the spin-orbit interaction. The ^-values are highly anisotropic, with <7||=2.49 and <7^ = 1.97.

The Oligomerization of Phosphinoborane by Titanium Complexes

“…Moreover, EPR investigations15 were carried out for 2 and 3 as solids and in solutions, showing complex spectra with unresolved hyperfine splittings. They are reminiscent of {Cp 2 Ti III } compounds containing phosphanido19 and amidinate substituents23 and are consistent with the density functional (DFT) calculations 24…”

Spectroscopic and magnetic studies of the 3d metallocenes

“…For MnCp2 we thus attribute the broad asymmetric band system between 24 and 34 cm™1 X 103 to the elu -*• e2g and elu -* alg excitations, these both leading to allowed 6Alg -* 6Elu transitions. For the inflection at 24.4 cm™1 X 103, however, the intensity is low for an allowed transition, and it is not certain whether or not this feature should be assigned as the lower 6Alg…”