52 research outputs found
Proton ENDOR spectra of phenanthrene-TCNB triplet traps in single crystals of naphthalene-TCNB.
No full textThe ENDOR spectra of triplet traps of phenanthrene-TCNB in doped single crystals of naphthalene-TCNB have been recorded and the complete hyperfine tensors of all the protons have been measured. The spin densities on the carbon atoms are obtained from the isotropic as well as from the anisotropic part of the tensors. The spin density distribution on phenanthrene inphenanthrene-TCNB differs from that of the pure phenanthrene in its first excited triplet state, due to a polarizing effect of the acceptor. The CT degree is obtained from the reduction of the total spin density on the donor molecule and it results to be 40%. The structure of the trap is also discussed
ENDOR of the pyrene triplet-state in the charge-transfer crystal naphthalene tetracyanobenzene.
No full textENDOR measurements of the pyrene-TCNB excited triplet state in the CT crystal of naphthalene-TCNB have been performed at 130 K. Proton hyperfine tensors of both the donor and the acceptor molecule have been determined. Isotropic hyperfine coupling constants have served to obtain spin distribution and CT character (16%) of the trap. Experimental hyperfine dipolar tensors of pyrene protons are averaged by motion and are reproduced by a dynamical model in which rotation of ± 16° about the long in-plane axis accompanied with that of ± 5° about the normal to the molecular plane. © 1985
ESR Investigation of Mn Carbonyl Complexes Formed by Reaction of Mn2(CO)10 with Electron Acceptor Molecules.
No full text
Isotropic and anisotropic chlorine hyperfine coupling of dichloro-dicyano benzoquinone anion radical
No full textStructural and spectroscopic characterization of Cu(II) [tetrakis-(3,3-dimethyl-l-butoxycarbonyl)] phthalocyanine thin films deposited by the Langmuir—Blodgett technique
No full textLangmuir-Blodgett (LB) films of Cu(II) [tetrakis(3,3-dimethyl-1-butoxycarbonyl)] phthalocyanine were prepared and characterized by X-ray diffraction, and polarized UV-Vis and electron paramagnetic resonance (EPR) spectroscopies. It was found that the phthalocyanine molecules deposited on quartz and polyethylene terephthalate (pet) are arranged edge-on on the substrate with the normal to the molecular plane that lies close to the plane of the film. Polarized W-Vis spectra of films show in-plane anisotropy in the orientation of molecules for LB films deposited on quartz and on pet. EPR spectra also, assigned to CU2+ interacting species, were detected for the LB films deposited on pet. The spectra show a marked in-plane anisotropy of the Zeeman interaction when the magnetic field lies in the support plane. The analysis of their angular dependence confirms that the plane of the phthalocyanine molecule is almost perpendicular to the film plane and gives evidence that the in-plane orientation anisotropy arises from two different distributions of orientations pinned around two average orientations having an angle of 68 degrees between them
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