Structure-Optical Property Relationships of Porphyrins

1997 ◽  
Vol 479 ◽  
Author(s):  
Weijie Su ◽  
Thomas M. Cooper ◽  
Nansheng Tang ◽  
Doug Krein ◽  
Hao Jiang ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Optical Properties ◽  
Optical Property ◽  
Fluorescence Lifetimes ◽  
Structural Variations ◽  
Reduction Behavior ◽  
Oxidation Reduction ◽  
Optical Applications ◽  
The Relationship

AbstractPorphyrins are attractive compounds for optical applications. We have been investigating the relationship between molecular structure and optical properties of a number of porphyrin compounds. Structural variations explored include insertion of metal ions, extension of conjugation, halogenation and formation of multimers. The characterization of these chromophores includes measurement of UV/Vis, fluorescence and fluorescence lifetimes. Furthermore, we have investigated their nonlinear absorption, refraction, excitation dynamics as well as oxidation/reduction behavior. Based on our observations, clear recommendations can be made for the design of optical limiting chromophores.

The Preparation and Characterization of Novel Nonlinear Optical Active Dye

2013 ◽  
Vol 750-752 ◽  
pp. 899-902
Author(s):  
Lin Feng Li ◽  
Hong Yao Xu
Keyword(s):  
Optical Properties ◽  
Optical Property ◽  
Nonlinear Optical ◽  
Nonlinear Optical Property ◽  
Condensation Reaction ◽  
Nonlinear Optical Properties ◽  
532 Nm ◽  
Triazine Dye

A novel nonlinear optical active triazine dye 2-(4-methyl-4-amino-azobenzene )-4-sodium sulfanilate-6-chloro-1,3,5-triazine was synthesized by condensation reaction and characterized by FTIR, 1HNMR, respectively. Their nonlinear optical properties were investigated using 5 ns pulse at 532 nm, which showed excellent nonlinear optical property.

scholarly journals Synthesis, Mesomorphism and the Optical Properties of Alkyl-deuterated Nematogenic 4-[(2,6-difluorophenyl)ethynyl]biphenyls

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4653
Author(s):  
Jakub Herman ◽  
Piotr Harmata ◽  
Michał Czerwiński ◽  
Olga Strzeżysz ◽  
Marta Pytlarczyk ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Optical Properties ◽  
Liquid Crystalline ◽  
Near Infrared ◽  
Synthesis And Characterization ◽  
Molecular Approach ◽  
Scanning Calorimetry

The synthesis and characterization of new deuterated liquid crystal (LC) compounds based on phenyl tolane core is described in this paper. The work presents an alternative molecular approach to the conventional LC design. Correlations between molecular structure and mesomorphic and optical properties for compounds which are alkyl-hydrogen terminated and alkyl-deuterium, have been drawn. The compounds are characterized by mass spectrometry (electron ionization) analysis and infrared spectroscopy. They show enantiotropic nematic behavior in a broad temperature range, confirmed by a polarizing thermomicroscopy and differential scanning calorimetry. Detailed synthetic procedures are attached. Synthesized compounds show a significantly reduced absorption in the near-infrared (NIR) and medium-wavelength infrared (MWIR) radiation range, and stand as promising components of medium to highly birefringent liquid crystalline mixtures.

scholarly journals Cellulose nanocrystal-based liquid crystal structures and the unique optical characteristics of cellulose nanocrystal films

BioResources ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 2116-2137
Author(s):  
Xiaoyao Wei ◽  
Tao Lin ◽  
Min Duan ◽  
Hengli Du ◽  
Xuefeng Yin
Keyword(s):  
Optical Properties ◽  
Liquid Crystal ◽  
Aqueous Suspension ◽  
Cellulose Nanocrystal ◽  
Cholesteric Phase ◽  
Left Handed ◽  
Nanocrystal Films ◽  
Biological World ◽  
Optical Applications ◽  
The Relationship

Liquid crystals (LC) have been found to have many unique characteristics during the last few decades. The liquid crystal phase is ubiquitous in the biological world, as well as in cellulose and its derivatives. Cellulose nanocrystals (CNC), which can obtain the chiral LC phase in aqueous suspension, have been attracting much attention. The unique size and properties of CNC, such as their light weight, special optical properties, non-toxicity, and biocompatibility, etc., have made them widely applicable in diverse fields. This brief literature review introduces the relationship between the LC phase and CNC. Advantages of CNC as a liquid crystal forming material and the preparation of CNC are discussed. The left-handed cholesteric phase structure and the corresponding unique optical properties of CNC-based LC are described in detail. The CNC-based LC aqueous suspension and three stages of forming LC phase are also described. Then, the main reasons accounting for the brittleness and non-uniformity of pristine CNC-based LC are summarized, as well as ways to overcome these problems. Finally, some optical applications of CNC-based LC films in anti-counterfeiting, colorimetric sensors, and composite devices are considered.

scholarly journals Effect of heteroatoms on the optical properties and enzymatic activity of N-doped carbon dots

RSC Advances ◽  
2021 ◽  
Vol 11 (31) ◽  
pp. 18776-18782
Author(s):  
Ahyun Lee ◽  
Sohee Yun ◽  
Eun Soo Kang ◽  
Jung Wan Kim ◽  
Jeong Ho Park ◽  
...  
Keyword(s):  
Optical Properties ◽  
Enzymatic Activity ◽  
Physicochemical Properties ◽  
Chemical Bonding ◽  
Carbon Dots ◽  
Dopant Content ◽  
Optical Applications ◽  
Doped Carbon Dots ◽  
The Relationship

The characteristics of N-CDs suitable for their optical applications or for use as nanozymes were demonstrated by rationalizing the relationship between the dopant content (e.g., the amount of doped N and types of chemical bonding) and physicochemical properties.

scholarly journals Characterization of Surface Structure and Oxidation/Reduction Behavior of Pd–Pt/Al2O3 Model Catalysts

2016 ◽  
Vol 120 (49) ◽  
pp. 28009-28020 ◽  
Author(s):  
Natalia M. Martin ◽  
Johan Nilsson ◽  
Magnus Skoglundh ◽  
Emma C. Adams ◽  
Xueting Wang ◽  
...  
Keyword(s):  
Surface Structure ◽  
Model Catalysts ◽  
Reduction Behavior ◽  
Oxidation Reduction

Effects of the molecular structure on the second-order nonlinear optical properties of stilbazolium derivative single crystals: a review

2020 ◽  
Vol 8 (47) ◽  
pp. 16668-16690
Author(s):  
Senthil Kannan ◽  
Anand Sekar ◽  
Kalainathan Sivaperuman
Keyword(s):  
Molecular Structure ◽  
Optical Properties ◽  
Single Crystals ◽  
Nonlinear Optical ◽  
Second Order ◽  
Nonlinear Optical Properties ◽  
The Relationship

In this review, we present the relationship between the molecular structure and NLO effects in stilbazolium family single crystals.

Synthesis, growth and characterization of a new acentric 4-[4-(4-dimethylamino-phenyl)buta-1,3-dienyl]-1-methyl pyridinium p-chlorobenzenesulfonate dihydrate crystal for nonlinear optical applications

2018 ◽  
Vol 42 (23) ◽  
pp. 18865-18872 ◽  
Author(s):  
S. John Sundaram ◽  
Jerald V. Ramaclus ◽  
Priya Antony ◽  
M. Jaccob ◽  
P. Sagayaraj
Keyword(s):  
Optical Properties ◽  
Nonlinear Optical ◽  
Nonlinear Optical Properties ◽  
Organic Crystal ◽  
Linear And Nonlinear ◽  
Optical Applications ◽  
Nonlinear Optical Applications

A new organic crystal with a noncentrosymmetric structure is developed, and its structural, thermal, linear and nonlinear optical properties are reported.

scholarly journals The ray transference of a reversed optical system

2008 ◽  
Vol 67 (2) ◽  
Author(s):  
W. F. Harris
Keyword(s):  
Optical Properties ◽  
Optical System ◽  
Complete Characterization ◽  
Reverse Direction ◽  
First Order ◽  
Optical Character ◽  
Relationship Of ◽  
The Relationship ◽  
Explicit Expressions

The optical character of an optical system is changed if the system is reversed.  This is as true of eyes as it is of telescopes.  In vision light traverses the eye from cornea to retina; in ophthalmoscopy the practitioner views the retina via light traversing the eye in the reverse direction.  The purpose of this paper is to determine the relationship of the optical character of the reversed system to that of the system itself. The result is in terms of the ray transference of the system.  Since the ray transference gives a complete characterization of the first-order optics of a system the analysis is complete in this sense as well.  Explicit expressions are also presented for the effect of reversal on the six fundamental first-order optical properties of the system.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Microstructural Characterization of Au-Ge-Ni based ohmic contacts to GaAs/AlGaAs modfet device

1987 ◽  
Vol 45 ◽  
pp. 326-327
Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer
Keyword(s):  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Microstructural Characterization ◽  
Almost Everywhere ◽  
Spacer Layer ◽  
Good Contact ◽  
The Relationship ◽  
Lower Contact

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.

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