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K Mobius

Publications and source records attributed to K Mobius.

2 recordsLinked to original sources
PubMed1998

Optically detected electron spin echo envelope modulation on a photoexcited triplet state in zero magnetic field-A comparison between the zero-field and high-field limits

Electron spin echo envelope modulation (ESEEM) has been studied at zero and low magnetic fields (B </= 100 G) by means of optically detected magnetic resonance. Qualitative differences of the ESEEM effect for an electronic triplet state (S = 1) under low-field and high-field conditions are observed and discussed. They are related to the different properties of the total spin angular momentum operator S and the hyperfine interaction at zero and high magnetic field. The novel method was applied to the photoexcited triplet state of acridine-d9 in a fluorene-h10 matrix. An analysis of the observed nitrogen quadrupole splitting is done by a quantitative description of the ESEEM effect in zero field. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

High-Frequency/High-field electron spin echo envelope modulation study of nitrogen hyperfine and quadrupole interactions on a disordered powder sample

High-frequency/high-field (95 GHz/3.4 T) electron spin echo envelope modulation (ESEEM) experiments on single crystals and disordered samples of dianisyl-nitroxide (DANO) radicals are reported. At these high microwave frequencies (W-band), the anisotropic g-matrix of the nitroxide radical is resolved in the EPR spectrum. Additionally ESEEM modulations from other than nitrogen nuclei, such as protons, are highly suppressed at these frequencies, because they are too far from the cancellation condition for effective mixing of the nuclear spin functions. Therefore the nitrogen (14N) hyperfine and quadrupole coupling tensors could be determined without ambiguity from powder measurements. The results obtained were checked by ESEEM measurements on single crystals. Advantages and disadvantages of high-field ESEEM on nitrogen couplings are briefly discussed and compared with electron nuclear double resonance (ENDOR) and X-band ESEEM. Copyright 1998 Academic Press.

Journal Article↗