摘要:

Excitation spectra of the self-trapped exciton luminescence bands and those of photo-induced absorption bands of halogen-bridged mixed-valence metal complexes have been measured. The excitation spectra of luminescence bands begin to decrease from energies smaller than the peak energies of the charge transfer exciton absorption bands. The excitation spectra of photo-induced absorption bands begin to rise from the same energies. These show the competition between the self-trapped excitons and the photo-induced defect states in their generation processes.

ISSN:1058-725X    

DOI:10.1080/10587259208028769

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

1H NMR spin-lattice relaxation timeT1of the above complex in the solid state was measured from 100 K to room temperature. The presence of paramagnetic PtIIIsites trapped in the 1-D chains was observed at low temperatures.T1was shortened upon heating, and the observedT1data were well explained by the model that the trapped unpaired electrons are thermally excited and diffuse along the chain. The observed spin motion is attributable to the neutral soliton by referring to the data of ESR and the electrical conductivity.

ISSN:1058-725X    

DOI:10.1080/10587259208028770

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An one-dimensional two-channel model in the molecular conductor cobalt-rich nickel phthalocyanine iodide is presented. In the model, the localized-d-electron spins on the metal spine couple ferromagnetic ally the itinerant-π-electron spins on the macro cycle. The energy bands, the charge and spin densities, and the optical-abs option spectrum of the one-dimensional dπcoupled system are computed with aid of the periodic-boundary condition in the mean-field approximation. The optical-absorption spectrum shows the peaks of the π and d electrons. It turns out that the origin of the π-band gap is the dπ-ferromagnetic-exchange coupling in the cobalt-rich nickel phthalocyanine iodide.

ISSN:1058-725X    

DOI:10.1080/10587259208028771

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

We report on a spectroscopic study on (anti) ferroelectricity in organic mixed-stack charge transfer complex TMB-TCNQ. This compound has two polytypes, both of which undergo contrasting phase transitions. The transition of the monoclinic crystal is interpreted in terms of neutral-ionic phase transition, while the tricllnic form undergoes a lattice dimeri-zation driven by an electrostatic mechanism of ferroelectricity.

ISSN:1058-725X    

DOI:10.1080/10587259208028772

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Sulfates in one-dimensional halogen-bridged mixed-valence platinum complexes were synthesized in order to elucidate contributions of hydrogen bonds between in-plane ligand amines and counter ions to the mixed-valence state. Their intervalence charge-transfer bands measured by using the single crystals and their structures determined by single crystal X-ray diffraction analyses show that the energy difference of dz2 orbitals between the PtIIand the PtIVbecomes larger with decreasing linkages between the Pt units by the hydrogen bonds, comparing with perchlorates and hydrogensulfates.

ISSN:1058-725X    

DOI:10.1080/10587259208028773

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Polarized reflection, electrical conductivity, magnetic susceptibility measurements and X-ray crystal structure predetermination have been carried out on one- dimensional iodo-bridged binuclear metal dithioacetato complexes, M2(dta)4I (M=Pt and Ni; dta=CH3CS2−) in order to elucidate their electronic property. The chain structure consists of -M2-5+-M2,5+-I-M2-5+-M2-5+- with no Peierls distortion, and two metal atoms in binuclear moieties are bridged by four dithioacetato ligands to give a cage structure. The magnetic behavior of these compounds revealed very strong anti ferromagnetic coupling between electronic spins (S=1/2) localized on the M-M dimers. They show semi conducting behavior with high conductivities and small activation energies compared with those of the MX compounds. From these results, it may be concluded that the compounds are one-dimensional Mott-Hubbard insulators, in contrast to Peierls insulators of R4[Pt2(pop)4X].nH20 complexes (…M2+-M2+…X-M3+-M3+-X‥).

ISSN:1058-725X    

DOI:10.1080/10587259208028774

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

From the stepwise consideration of proton-electron transfer (PET) phenomena, we developed two reasonable molecular design strategies to construct new molecular systems. As a preliminary investigation, we report the design and construction of the extended conjugated quinhydrones, the donor and acceptor substituted benzoquinones, and new component molecules, focusing on the understanding of the correlation of the properties between molecules and the solid state. Selected solid state properties of an extended conjugated quinhydrones were also presented.

ISSN:1058-725X    

DOI:10.1080/10587259208028775

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In order to discuss the effect of dynamic modulation caused by hydrogen-bonded system on the conduction property, two Ni(dmit)2salts were prepared. In morpholinium salts a remarkable structural modulation was observed on the hydrogen-bonded Ni(dmit)2molecules. In the crystal of hydrated lithium salts, the hydrogen-bonded cation system is incorporated in a cylindrical channel constructed by corrugatedly stacked Ni(dmit)2columns, and a distinct hysteresis was observed on the temperature dependence of conductivity.

ISSN:1058-725X    

DOI:10.1080/10587259208028776

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Infrared absorbance (IR) spectra and Raman scattering spectra were measured as a function of pressure for molecular crystals of several 1,3-diketones, which are composed of hydrogen-bonded π -molecular chains. An unconventional proton-related band is commonly observed in the IR spectra around 1800-2000cm−1in these compounds. We ascribed the observed band to proton vibration localized aroundkink-(orantikink-) solitons. The intensity of the band rapidly increases with application of hydrostatic pressure, suggesting increase in number of the solitons-like defects of the molecular chains via deformation of the double-well type proton potential.

ISSN:1058-725X    

DOI:10.1080/10587259208028777

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The structural and optical studies on the proton transfer in various charge transfer complexes of N-salicylideneaniline derivatives are presented. The OH-N hydrogen-bond structure has been found to be variable by adjustment of the intermolecular interactions.

ISSN:1058-725X    

DOI:10.1080/10587259208028778

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor