Electron Paramagnetic Resonance Studies of Mn(CN)5NO2− and Cr(CN)5NO3− in Dilute Single Crystals

Abstract

Articles you may be interested inSinglecrystal electron paramagnetic resonance study of triplet excitons in [Fe(mesitylene)We have studied the electron paramagnetic resonance spectra of Mn(CN)oN()2-and Cr(CNhN()2as dilute solutions in single crystals of various diamagnetic hosts. From these measurements, we have obtained the spectroscopic splitting factor tensor and the hyperfine tensors to the central metal atom and nitrosyl nitrogen. In the case of Cr(CNhNOa-, we have also measured the hyperfine tensor to carbon-13 in the equatorial and axial cyanides. We have measured the quadrupole coupling constant to 5iMn in Mn(CN).NOi!-. We have attempted to construct a coherent picture of the electronic structure of the complexes from these data. This attempt has been only partly usccessful, primarily because the spectroscopic splitting factors are much nearer the free spin value than one expects on the basis of the hyperfine data. 11 J. Danon and H. C. Panepucci (personal communication).

An EPR Study on VO2+ and Mn2+ Ions in Some Zeolites

“…The high field side of the spectra for the 3A and 4A zeolites seem to indicate the existence of a strong ligand field and therefore, a low spin state of the Mn 2 + . The components of the g tensor, g = 1.965 and g ± = 2.049 for this state of Mn 2+ in the zeolite of type 3A are close to the values given by Fortman and Hayes [10]. All the measured g 0 and A 0 values and the tensor components for Mn(H 2 0)s + are given in Table 2.…”

To Interpretation of the EPR Parameters of Nitrosyl Complexes of Transition Metal Ions

“…Previous investigations were mainly aimed at elucidating the mechanisms of hyperfine couplings (HFCs) at the nitrosyl N atom [1][2][3]. At the same time, the distinctive features of the behavior of the Zeeman parameters ( g -tensor components) remain poorly studied.…”

“…At the same time, the distinctive features of the behavior of the Zeeman parameters ( g -tensor components) remain poorly studied. For instance, the EPR study revealed an abnormal value of the Zeeman parameter in a static magnetic field perpendicular to the longitudinal axis of the nitrosyl complex: > 2.0023 [1]. For oxo complexes (M is the d 1 ion and L is the ligand), the parameter is anomalous (> 2.0023 [4,5]).…”

“…This anomaly was explained in [1] by the presence in the component g ⊥ of the positive contribution from the admixture of the MO of electrons of the closed shell (characterizing the out-of-plane π -bonds of the metal ion with 14 N ( NO ) ) to the ground-state function because of spin-orbital coupling (SOC). However, such an approach to interpretation of the abnormal value has general qualitative character and cannot be used to consider the causes of the anomaly in detail or elucidate the effect of the covalence of the metal-ligand bond in nitrosyl complexes on the parameter .…”

“…formed for a pentacyanonitrosyl complex of Cr + , [ Cr ( CN ) 5 NO ] 3-, because abundant experimental data are available [1,2].…”