Optical Properties of Poly[(3-Pentyl-5-Oxyazobenzene) Thiophene]

1995 ◽  
Vol 413 ◽  
Author(s):  
S. Luzzati ◽  
W. Viera ◽  
M. Catellani
Keyword(s):  
Optical Properties ◽  
Raman Scattering ◽  
Steric Hindrance ◽  
Uv Light ◽  
Electron Delocalization ◽  
Side Chain ◽  
Ir Absorption ◽  
Spectral Features ◽  
Photoinduced Absorption ◽  
Azo Chromophore

ABSTRACTWe report a study of the optical and photoexcitation properties of a new polyalkylthiophene:poly[(3-pentyl-5-oxoazobenzene)thiophene]. UV-Vis absorption and emission, IR absorption, Raman scattering, indicate that the steric hindrance of the side chain induces some rotational disorder of the backbone but the π electron delocalization is not substantially differing from other polyalkylthiophenes. Long lived photoexcitations have been characterized by photoinduced absorption. The spectral features are intrinsic to the polyconjugated thiophene chain, even when the backbone and the azo chromophore are both photoexcited by UV light.

METABOLISM OF 17α-HYDROXYPROGESTERONE-4-14C-17α-CAPROATE BY HOMOGENATES OF RAT LIVER AND HUMAN PLACENTA

1961 ◽  
Vol 36 (4) ◽  
pp. 511-519 ◽  
Author(s):  
Margaret Wiener ◽  
Charles I. Lupa ◽  
E. Jürgen Plotz
Keyword(s):  
Rat Liver ◽  
Human Placenta ◽  
Steric Hindrance ◽  
Placental Tissue ◽  
Caproic Acid ◽  
Major Product ◽  
Side Chain ◽  
Anaerobic Conditions ◽  
Prolonged Action ◽  
Long Acting

ABSTRACT 17α-hydroxyprogesterone-4-14C-17α-caproate (HPC), a long-acting progestational agent, was incubated with homogenates of rat liver and human placenta. The rat liver was found to reduce Ring A of HPC under anaerobic conditions to form allopregnane-3β,17α-diol-20-one-17α-caproate and pregnane-3β,17α-diol-20-one-17α-caproate, the allopregnane isomer being the major product. The caproic acid ester was neither removed nor altered during the incubation. Placental tissue did not attack HPC under conditions where the 20-ketone of progesterone was reduced. It is postulated that this absence of attack on the side chain is due to steric hindrance from the caproate ester, and that this may account for the prolonged action of HPC.

scholarly journals Formation of Carbon Quantum Dots via Hydrothermal Carbonization: Investigate the Effect of Precursors

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 986
Author(s):  
Md Rifat Hasan ◽  
Nepu Saha ◽  
Thomas Quaid ◽  
M. Toufiq Reza
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Microcrystalline Cellulose ◽  
Uv Light ◽  
Synthesis Method ◽  
Hydrothermal Carbonization ◽  
Carbon Quantum Dots ◽  
Medical Diagnostics ◽  
Particle Size Range ◽  
Wide Range

Carbon quantum dots (CQDs) are nanomaterials with a particle size range of 2 to 10 nm. CQDs have a wide range of applications such as medical diagnostics, bio-imaging, biosensors, coatings, solar cells, and photocatalysis. Although the effect of various experimental parameters, such as the synthesis method, reaction time, etc., have been investigated, the effect of different feedstocks on CQDs has not been studied yet. In this study, CQDs were synthesized from hydroxymethylfurfural, furfural, and microcrystalline cellulose via hydrothermal carbonization at 220 °C for 30 min of residence time. The produced CQDs showed green luminescence behavior under the short-wavelength UV light. Furthermore, the optical properties of CQDs were investigated using ultraviolet-visible spectroscopy and emission spectrophotometer, while the morphology and chemical bonds of CQDs were investigated using transmission electron microscopy and Fourier-transform infrared spectroscopy, respectively. Results showed that all CQDs produced from various precursors have absorption and emission properties but these optical properties are highly dependent on the type of precursor. For instance, the mean particle sizes were 6.36 ± 0.54, 5.35 ± 0.56, and 3.94 ± 0.60 nm for the synthesized CQDs from microcrystalline cellulose, hydroxymethylfurfural, and furfural, respectively, which appeared to have similar trends in emission intensities. In addition, the synthesized CQDs experienced different functionality (e.g., C=O, O-H, C-O) resulting in different absorption behavior.

Amino acid-templated zinc phosphites: low-dimensional structures, fluorescence, and nonlinear optical properties

2021 ◽  
Author(s):  
Yumei Mao ◽  
Xuehua Dong ◽  
Yuandan Deng ◽  
Jing Li ◽  
Ling Huang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Amino Acid ◽  
Nonlinear Optical ◽  
Uv Light ◽  
Nonlinear Optical Properties ◽  
Light Irradiation ◽  
Blue Fluorescence ◽  
Structure Directing Agent ◽  
Uv Light Irradiation ◽  
Low Dimensional

Two new zinc phosphites were prepared using the amino acid alanine as structure-directing agent. They have tubular and ladder-like structures exhibiting blue fluorescence upon UV light irradiation. Notably, the tubular...

Pyridine-based poly(aryleneethynylene)s: a study on anionic side chain density and their influence on optical properties and metallochromicity

RSC Advances ◽  
2015 ◽  
Vol 5 (116) ◽  
pp. 96189-96193 ◽  
Author(s):  
Markus Bender ◽  
Kai Seehafer ◽  
Marlene Findt ◽  
Uwe H. F. Bunz
Keyword(s):  
Optical Properties ◽  
Water Soluble ◽  
Side Chain ◽  
Phenylene Ethynylene ◽  
Alternating Copolymers

We report the Pd-catalyzed synthesis of six new water soluble, alternating poly(p-phenylene-ethynylene-p-pyridinylene-ethynylene) (abcb-alternating) copolymers and one poly(p-pyridinyleneethynylene).

scholarly journals IR ABSORPTION AND RAMAN SCATTERING OF WATER IN PHOSPHATE GLASSES: SIMILARITY AND DIFFERENCES

2002 ◽  
Vol 13 (0) ◽  
pp. 235-238
Author(s):  
TATIANA SMIRNOVA ◽  
VAVIK TER-NERSESYANTS ◽  
MARINA PESTRIKOVA
Keyword(s):  
Raman Scattering ◽  
Phosphate Glasses ◽  
Ir Absorption

High pressure studies of Ni3[(C2H5N5)6(H2O)6](NO3)6·1.5H2O by Raman scattering, IR absorption, and synchrotron X-ray diffraction

RSC Advances ◽  
2016 ◽  
Vol 6 (69) ◽  
pp. 65031-65037 ◽  
Author(s):  
Junru Jiang ◽  
Jianguo Zhang ◽  
Peifen Zhu ◽  
Jianfu Li ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
Molecular Structure ◽  
High Pressure ◽  
Raman Scattering ◽  
Ir Absorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure Studies

Molecular structure (a) and packing diagram (b) of 1. The green, grey, blue, red, and white spheres denote Ni, C, N, O, and H atoms, respectively.

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