title: Direct observation of fine structure transitions in a paramagnetic nickel(II) complex using far-infrared magnetic spectroscopy: a new method for studying high-spin transition metal complexes.
abstract: Novel far-infrared (FIR) absorption spectroscopy in conjunction with multiple, fixed external magnetic fields (FIR magnetic spectroscopy, FIRMS) has been used to investigate pseudotetrahedral complexes with the formula M(PPh(3))(2)Cl(2) (M = Ni, Zn; Ph = C(6)H(5)). Crystal structures have been reported for the Ni complex; we report the structure of the Zn complex. Transmission spectra at 5 K of Ni(PPh(3))(2)Cl(2) (S = 1) at zero magnetic field exhibit absorption bands at 11.41, 15.28, and 23.0 cm(-1). The two lower frequency bands show great sensitivity to external magnetic field, and their field dependence is as expected for electron spin transitions allowing precise determination of the following parameters: |D| = 13.35(1) cm(-1), |E| = 1.93(1) cm(-1), g(x,y) = 2.20(1), g(z) = 2.00(1). Corresponding spectra of Zn(PPh(3))(2)Cl(2) (S = 0) exhibit bands only at >20 cm(-1), which show no field dependence. FIRMS is a promising technique for direct investigation of the electronic structure of high-spin transition metal complexes.
authors.affiliation: Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, Stuttgart, D-70550 Germany.
authors.forename: Suriyakan
authors.initials: S
authors.lastname: Vongtragool
authors.forename: Boris
authors.initials: B
authors.lastname: Gorshunov
authors.forename: Martin
authors.initials: M
authors.lastname: Dressel
authors.forename: J
authors.initials: J
authors.lastname: Krzystek
authors.forename: David M
authors.initials: DM
authors.lastname: Eichhorn
authors.forename: Joshua
authors.initials: J
authors.lastname: Telser