SPECTROSCOPIC STUDIES OF EXCHANGE INTERACTIONS IN POLYNUCLEAR TRANSITION METAL COMPLEXES I. [(NH3)5Cr(OH)Cr(NH3)5] Cl5,3H20.

1973 ◽  
Vol 26 (3) ◽  
pp. 505 ◽  
Author(s):  
J Ferguson ◽  
HU Gudel
Keyword(s):  
Absorption Spectrum ◽  
Single Crystals ◽  
Transition Metal Complexes ◽  
Level Scheme ◽  
Exchange Interactions ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Luminescence Spectra ◽  
Weakly Coupled ◽  
Chloride Trihydrate

Large single crystals of ,u-hydroxo-bis[pentaamminechromium(III) chloride trihydrate have been prepared and their spectroscopic properties determined. The analysis of polarized single-crystal luminescence spectra provides an accurate ground electronic level scheme for the weakly coupled chromium ions in the dimeric cluster. The splitting is described by the isotropic Hamiltonian X = JS,.Sb-j(S,.Sb)2 with J = 31.9 cm-1 and j = 0.23 cm-1. The temperature dependence of the polarized absorption spectrum is consistent with this level scheme. The positions of the components of the singly excited (4A2-2E) state have been determined.

SPECTROSCOPIC STUDIES OF EXCHANGE INTERACTIONS IN POLYNUCLEAR TRANSITION METAL COMPLEXES II. [(NH3)5Cr(OH)Cr(NH3)5] Cl5,3H20.

1973 ◽  
Vol 26 (3) ◽  
pp. 513 ◽  
Author(s):  
J Ferguson ◽  
H.U Gudel ◽  
M Puza
Keyword(s):  
Room Temperature ◽  
Energy Levels ◽  
Exchange Interactions ◽  
Structural Disorder ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Stable Form ◽  
Strongly Coupled ◽  
Crystal Forms ◽  
Chloride Monohydrate

Single crystals of phydroxo-bis[pentaamminechromium(III)] chloride monohydrate have been prepared. The spectroscopic properties of these crystals have been measured and two crystal forms have been characterized. The first form is obtained from solutions at 2�C and it changes to the second, stable form, at room temperature. The latter is tetragonal, space group D44-P41212 with a = 16.28 %L, c = 14.84 A, and Z = 8. The spectroscopic properties require two inequivalent sets of dimer units in the unit cell and this result is consistent with the X-ray data. The spectroscopic properties of the first form require four inequivalent sets of dimers and the ground state energy levels of each of these are described by the isotropic Hamiltonian H = JSa . Sb - j(Sa. Sb)2 with the following values: set 1, J = 30.4+/- 0.2, j = 0.32+/-0. 10; set 2, J = 30.4 +/-0.2, j = 0.221 0.10; set 3, J = 31.4 +/-0.2, j = 0-18+/- 0.10; set 4, J = 31-4+/- 0.4, j = 0.0+/- 0.20. High-resolution luminescence excitation spectroscopy shows that sets 1 and 2 are not strongly coupled to sets 3 and 4. The small differences between sets 1 and 2 and between sets 3 and 4 suggest that these differences arise from structural disorder within the two inequivalent sets of the room temperature stable form. Previous differences in the interpretation of the earlier magnetic and

Optical Spectroscopic Studies of a Soluble Fluorene-Based Conjugated Polymer: A Hydrostatic Pressure and Temperature Study

2001 ◽  
Vol 708 ◽  
Author(s):  
S. Guha ◽  
J.D. Rice ◽  
C. M. Martin ◽  
W. Graupner ◽  
M. Chandrasekhar ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Conjugated Polymer ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Phonon Interaction ◽  
Optical Studies ◽  
Strong Electron ◽  
Conjugated Molecules ◽  
Electron Phonon Interaction ◽  
Backbone Conformation

ABSTRACTSpectroscopic properties of conjugated molecules/polymers have varying degrees of sensitivity to backbone conformation. Optical studies are presented as a function of temperature and hydrostatic pressure, using photoluminescence and Raman scattering from two polymers with distinct differences in their backbone conformation, namely, polyfluorene (PF) and ladder type poly(para-phenylene)(m-LPPP). In contrast to the photoluminescence (PL) vibronics in mLPPP, the 0-0 PL vibronic peak in PF shows a red-shift with increasing temperatures. Pressure studies reveal that the PL spectrum of PF red-shifts and broadens with increasing pressures. The phonon lines in PF show an antiresonance effect at higher pressures indicating a strong electron-phonon interaction.

Spectroscopic studies and crystal-field analysis of U3+ ions in RbY2Cl7 single crystals

1997 ◽  
Vol 106 (8) ◽  
pp. 3067-3077 ◽  
Author(s):  
M. Karbowiak ◽  
J. Drozdzynski ◽  
K. M. Murdoch ◽  
N. M. Edelstein ◽  
S. Hubert
Keyword(s):  
Single Crystals ◽  
Crystal Field ◽  
Spectroscopic Studies ◽  
Field Analysis

Growth and spectroscopic properties of rare-earth doped YAl3(BO3)4 single crystals

2003 ◽  
Vol 102-103 ◽  
pp. 395-401 ◽  
Author(s):  
I. Földvári ◽  
E. Beregi ◽  
A. Baraldi ◽  
R. Capelletti ◽  
W. Ryba-Romanowski ◽  
...  
Keyword(s):  
Rare Earth ◽  
Single Crystals ◽  
Spectroscopic Properties ◽  
Rare Earth Doped

Spectroscopic studies on plastocyanin single crystals: a detailed electronic structure determination of the blue copper active site

1981 ◽  
Vol 103 (15) ◽  
pp. 4382-4388 ◽  
Author(s):  
K. W. Penfield ◽  
R. R. Gay ◽  
R. S. Himmelwright ◽  
N. C. Eickman ◽  
V. A. Norris ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Single Crystals ◽  
Structure Determination ◽  
Active Site ◽  
Spectroscopic Studies ◽  
Blue Copper
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