Effect of solvent and temperature upon the emission spectra of aromatic amines

Author(s):  
R. S. Davidson ◽  
M. Santhanam
1992 ◽  
Vol 46 (11) ◽  
pp. 1630-1635 ◽  
Author(s):  
Sheryl A. Tucker ◽  
Hardjanti Darmodjo ◽  
William E. Acree ◽  
Maximilian Zander ◽  
Erich C. Meister ◽  
...  

Fluorescence emission spectra are reported for naphth[2′l′8′7′: 4,10,5]anthra[l,9,8cdef]cinnoline, benzo[lmn][3,8]phenanthroline (also called 2,7-diazapyrene), benz[4,10]anthra[l,9,8cdef]cinnoline, naphtho[8,1,2hij]pyreno[9,10,ldef]phthalazine, acenaphtho[l,2b]pyridine, benzo[a]phenazine, indeno[l,2,3ij][2,7]naphthyridine, and indeno-[l,2,3ij]isoquinoline dissolved in organic nonelectrolyte solvents of varying polarity and acidity. Results of these measurements indicate that naphth[2′,1′,8′,7′:4,10,5]anthra[l,9,8cdef]cinnoline exhibits some signs of probe character as evidenced by changing emission intensity ratios; however, numerical values did not vary systematically with solvent polarity. The effect of nitromethane and 1,2,4-trimethoxybenzene as selective quenching agents on both the unprotonated and protonated PANHs was also examined. Nitromethane was found to quench fluorescence emission of roughly two-thirds of the alternant unprotonated PANHs studied to date. Emission intensities of the protonated PANHs remained essentially constant and were not affected by nitromethane. 1,2,4-Trimethoxybenzene, on the other hand, quenched the fluorescence emission of several unprotonated and all protonated PANHs examined.


Author(s):  
Y. Y. Wang ◽  
H. Zhang ◽  
V. P. Dravid ◽  
H. Zhang ◽  
L. D. Marks ◽  
...  

Azuma et al. observed planar defects in a high pressure synthesized infinitelayer compound (i.e. ACuO2 (A=cation)), which exhibits superconductivity at ~110 K. It was proposed that the defects are cation deficient and that the superconductivity in this material is related to the planar defects. In this report, we present quantitative analysis of the planar defects utilizing nanometer probe xray microanalysis, high resolution electron microscopy, and image simulation to determine the chemical composition and atomic structure of the planar defects. We propose an atomic structure model for the planar defects.Infinite-layer samples with the nominal chemical formula, (Sr1-xCax)yCuO2 (x=0.3; y=0.9,1.0,1.1), were prepared using solid state synthesized low pressure forms of (Sr1-xCax)CuO2 with additions of CuO or (Sr1-xCax)2CuO3, followed by a high pressure treatment.Quantitative x-ray microanalysis, with a 1 nm probe, was performed using a cold field emission gun TEM (Hitachi HF-2000) equipped with an Oxford Pentafet thin-window x-ray detector. The probe was positioned on the planar defects, which has a 0.74 nm width, and x-ray emission spectra from the defects were compared with those obtained from vicinity regions.


1997 ◽  
Vol 7 (C2) ◽  
pp. C2-515-C2-516
Author(s):  
H. Agren ◽  
L. G.M. Pettersson ◽  
V. Carravetta ◽  
Y. Luo ◽  
L. Yang ◽  
...  

1995 ◽  
Vol 5 (9) ◽  
pp. 1269-1275 ◽  
Author(s):  
W. Essafi ◽  
F. Lafuma ◽  
C. E. Williams

1980 ◽  
Vol 41 (12) ◽  
pp. 1431-1436 ◽  
Author(s):  
M. Larzillière ◽  
F. Launay ◽  
J.-Y. Roncin

1979 ◽  
Vol 40 (C2) ◽  
pp. C2-417-C2-419
Author(s):  
C. H.W. Jones ◽  
M. Dombsky
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document