Racemizing Effect of the Phenyl Substituent of Optically Active Hydrogen 2-Phenyl-2-butyl Phthalate in Methanolytic Reaction1

1953 ◽  
Vol 75 (13) ◽  
pp. 3154-3155 ◽  
Author(s):  
Harold H. Zeiss
Keyword(s):  
Optically Active ◽  
Active Hydrogen ◽  
Phenyl Substituent ◽  
Butyl Phthalate

Optically active hydrogen dimers in crystalline silicon

1997 ◽  
Vol 56 (24) ◽  
pp. R15517-R15520 ◽  
Author(s):  
A. N. Safonov ◽  
E. C. Lightowlers ◽  
G. Davies
Keyword(s):  
Crystalline Silicon ◽  
Optically Active ◽  
Active Hydrogen

Optisch aktive Übergangsmetall-Komplexe, LXIII [1] Asymmetrische Induktion in C5H5Mo(CO)2LX-Diastereomeren-Gleichgewichten / Optically Active Transition Metal Complexes, LXIII [1] Asymmetrie Induction in C5H5Mo(CO)2LX Diastereoisomer Equilibria

1979 ◽  
Vol 34 (10) ◽  
pp. 1418-1423 ◽  
Author(s):  
Henri Brunner ◽  
Isabella Bauer ◽  
Rainer Lukas
Keyword(s):  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Optically Active ◽  
Asymmetric Induction ◽  
Chiral Ligand ◽  
Phenyl Substituent ◽  
H Nmr ◽  
Weak Attraction ◽  
Active Transition ◽  
Very High

Abstract The thioamidato complexes C5H5(CO)2MoSC(R)NCH(CH3) (Ar), derived from acetic acid R = CH3 and benzoic acid R = C6H5, were prepared and characterized. The diastereo-isomers, differing in their 1H NMR spectra, were partly separated by fractional crystallization. After equilibration with respect to the labile Mo configuration the diastereoisomer ratio, a measure for the asymmetric induction from the chiral ligand on the formation of the two Mo configurations at equilibrium, was determined by 1H NMR integration. The asymmetric induction is very high for Ar = o-tolyl [76% (R = C6H3) and 84% (R = C6H5)] compared to Ar = phenyl [48% (R = CH3) and 56% (R = C6H5)] and Ar = m-and p-tolyl [52 and 44% (R = CH3)]. The (CO)3Cr complexed phenyl substituent with only 10% asymmetric induction does not show the β-phenyl effect, a weak attraction between aryl groups in β-position to the metal atom and the MC5H5 moiety.

scholarly journals Optically active hydrogen dimers in silicon

1999 ◽  
Vol 273-274 ◽  
pp. 176-179 ◽  
Author(s):  
B Hourahine ◽  
R Jones ◽  
A.N Safonov ◽  
S Öberg ◽  
P.R Briddon ◽  
...  
Keyword(s):  
Optically Active ◽  
Active Hydrogen

Methanolysis of Optically Active Hydrogen 2,4-Dimethylhexyl-4-phthalate1,2

1953 ◽  
Vol 75 (19) ◽  
pp. 4733-4738 ◽  
Author(s):  
W. von E. Doering ◽  
Harold H. Zeiss
Keyword(s):  
Optically Active ◽  
Active Hydrogen

Optical analysis of ink and other contaminants in process waters

TAPPI Journal ◽  
2012 ◽  
Vol 11 (8) ◽  
pp. 51-58
Author(s):  
ANTTI HAAPALA ◽  
MIKA KÖRKKÖ ◽  
ELISA KOIVURANTA ◽  
JOUKO NIINIMÄKI
Keyword(s):  
Optically Active ◽  
Process Water ◽  
Paper Machine ◽  
Optical Analysis ◽  
Direct Process ◽  
Active Components ◽  
Water Contaminants ◽  
Dependent Measurement ◽  
Measurement Methodology

Analysis methods developed specifically to determine the presence of ink and other optically active components in paper machine white waters or other process effluents are not available. It is generally more interest¬ing to quantify the effect of circulation water contaminants on end products. This study compares optical techniques to quantify the dirt in process water by two methods for test media preparation and measurement: direct process water filtration on a membrane foil and low-grammage sheet formation. The results show that ink content values obtained from various analyses cannot be directly compared because of fundamental issues involving test media preparation and the varied methodologies used to formulate the results, which may be based on different sets of assumptions. The use of brightness, luminosity, and reflectance and the role of scattering measurements as a part of ink content analysis are discussed, along with fine materials retention and measurement media selection. The study concludes with practical tips for case-dependent measurement methodology selection.

Microscopic Structure of Er-Related Optically Active Centers in Si

2003 ◽  
Vol 770 ◽  
Author(s):  
H. Przybylinska ◽  
N. Q. Vinh ◽  
B.A. Andreev ◽  
Z. F. Krasil'nik ◽  
T. Gregorkiewicz
Keyword(s):  
Ground State ◽  
Photoluminescence Spectrum ◽  
Zeeman Effect ◽  
Optically Active ◽  
Single Type ◽  
Active Centers ◽  
Mbe Growth ◽  
Spectral Components ◽  
Er Doped ◽  
Successful Observation

AbstractA successful observation and analysis of the Zeeman effect on the near 1.54 μm photoluminescence spectrum in Er-doped crystalline MBE-grown silicon are reported. A clearly resolved splitting of 5 major spectral components was observed in magnetic fields up to 5.5 T. Based on the analysis of the data the symmetry of the dominant optically active center was conclusively established as orthorhombic I (C2v), with g‼≈18.4 and g⊥≈0 in the ground state. The fact that g⊥≈0 explains why EPR detection of Er-related optically active centers in silicon may be difficult. Preferential generation of a single type of an optically active Er-related center in MBE growth confirmed in this study is essential for photonic applications of Si:Er.

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