scholarly journals The dependence of oxygen sensitivity on the molecular structures of Ir(iii) complexes and their application for photostable and reversible luminescent oxygen sensing

RSC Advances ◽  
2019 ◽  
Vol 9 (27) ◽  
pp. 15370-15380 ◽  
Author(s):  
Yang Xing ◽  
Chengfang Qiao ◽  
Xinmin Li ◽  
Chun Li ◽  
Honghao Wang ◽  
...  
Keyword(s):  
Oxygen Sensing ◽  
Molecular Structures ◽  
Operational Stability ◽  
Oxygen Sensitivity ◽  
Spin Populations

The delocalization of spin populations (DSPs) could be used to describe the dependence of oxygen sensitivity on the molecular structures of Ir(iii) complexes. And excellent operational stability of an Ir(iii) oxygen sensing film is presented.

Comparison study on the influence of the central metal ions in palladium(ii)- and gadolinium(iii)-porphyrins for phosphorescence-based oxygen sensing

2016 ◽  
Vol 4 (40) ◽  
pp. 9581-9587 ◽  
Author(s):  
Lixin Zang ◽  
Huimin Zhao ◽  
Jianyu Hua ◽  
Wenwu Cao ◽  
Feng Qin ◽  
...  
Keyword(s):  
Metal Ions ◽  
Oxygen Sensing ◽  
Oxygen Sensitivity ◽  
Central Metal ◽  
Comparison Study

Gd-porphyrins exhibit longer phosphorescence wavelength and greater oxygen sensitivity as compared to Pd-porphyrins.

Oxygen sensing and OLED applications of di-tert-butyl-dimethylacridinyl disubstituted oxygafluorene exhibiting long-lived deep-blue delayed fluorescence

2020 ◽  
Vol 8 (28) ◽  
pp. 9632-9638
Author(s):  
Dalius Gudeika ◽  
Oleksandr Bezvikonnyi ◽  
Dmytro Volyniuk ◽  
Eigirdas Skuodis ◽  
Pei-Hsi Lee ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Molecular Design ◽  
Oxygen Sensing ◽  
Delayed Fluorescence ◽  
High Oxygen ◽  
Oxygen Sensitivity ◽  
Tert Butyl ◽  
Deep Blue

Optical sensors with high oxygen sensitivity and efficient deep-blue OLEDs with CIEy of 0.08 was developed using the simplicity in molecular design of di-tert-butyl-dimethylacridanyl disubstituted oxygafluorene.

scholarly journals Modulation of Optical Oxygen Sensing Properties of Iridium (III) Complexes By Changing Their Substitution Groups

2021 ◽  
Author(s):  
Merve Zeyrek Ongun ◽  
Murat Şahin ◽  
Sibel Oguzlar ◽  
Tuğçe Akbal Aytan ◽  
Devrim Atilla ◽  
...  
Keyword(s):  
Thin Films ◽  
Ethyl Cellulose ◽  
Oxygen Sensing ◽  
Oxygen Sensitivity ◽  
Ir Absorption ◽  
Decay Kinetics ◽  
Sensing Properties ◽  
H Nmr ◽  
Signal Changes ◽  
Weak Electron

Abstract The series of bis-cyclometalated iridium (III) complexes bearing different substituents (-H, -OCH3, -F, -CH3) at the aryl moiety (Ir-1, Ir-2, Ir-3 and Ir-4) have been synthesized and characterized by MASS and 1H NMR spectrometries, and IR, absorption and emission spectroscopies. The effects of the substituents on their oxygen sensing properties as well as optical properties and decay kinetics have been investigated systematically in tetrahydrofuran (THF) and ethyl cellulose (EC) thin films. The Ir (III) complexes embedded in EC-based thin films showed more advanced sensor dynamics, higher oxygen sensitivity, and superior relative signal changes when compared with their solution phase. The I0/I100 values of Ir-1, Ir-2, Ir-3 and Ir-4 immobilized in EC thin film were calculated as 11.3, 5.2, 7.0 and 25.6 for the concentration range of 0-100% pCO2, respectively. These results show that the weak electron-donating properties of the methyl groups at the aryl moiety improve remarkably the optical oxygen sensing abilities of the Ir (III) complexes.

Significant sensitivity and stability enhancement of tetraphenylporphyrin-based optical oxygen sensing material in presence of perfluorochemicals

2013 ◽  
Vol 17 (06n07) ◽  
pp. 431-439 ◽  
Author(s):  
Sevinc Z. Topal ◽  
Emel Önal ◽  
Kadriye Ertekin ◽  
Ozlem Oter ◽  
Ayşe G. Gürek ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Oxygen Sensing ◽  
Intensity Variation ◽  
Oxygen Sensitivity ◽  
Regeneration Time ◽  
Sensing Material ◽  
Response Range ◽  
Stability Enhancement ◽  
Volmer Constant

Emission-based oxygen sensing properties of highly luminescent tetraphenylporphyrin molecules were investigated in polystyrene, ethyl cellulose, poly(1-trimethylsilyl-1-propyne) and poly(isobutylmethacrylate) matrices. The effect of perfluorochemicals (PFCs) on oxygen sensitivity and stability of the sensor materials was also examined. Fluorescence intensity and lifetime measurements of meso-tetraphenylporphyrinato Zn ( II ) (ZnTPP) and meso-tetraphenylporphyrin (H2TPP) materials were performed in the concentration range of 0–100% pO 2. The fluorescence intensity variation of H2TPPvs. oxygen was 86%. H2TPP-based composite also yielded higher Stern–Volmer constant, faster response and regeneration time, excellent long term photostability and larger linear response range with respect to ZnTPP. The detection limit of oxygen for H2TPP was less than 0.5%. When stored in sealed bags protected from sunlight, no decrease in oxygen sensitivity was observed during approximately five months. As far as we know, the gathered utilization of PFCs and H2TPP embedded in polymer matrices was not previously described in literature, and has present amelioration compared to materials already existing.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

Scanning tunneling microscopy (STM) of DNA and RNA

1989 ◽  
Vol 47 ◽  
pp. 34-35
Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans
Keyword(s):  
Molecular Structures ◽  
Inorganic Materials ◽  
Resolving Power ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Form And Function ◽  
Dna And Rna ◽  
Calf Thymus ◽  
And Function ◽  
The Relationship

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).

Molecular architecture and functions of the neuronal cytoskeleton

1990 ◽  
Vol 48 (3) ◽  
pp. 2-3
Author(s):  
Nobutaka Hirokawa
Keyword(s):  
Major Elements ◽  
Molecular Structures ◽  
Organelle Transport ◽  
Molecular Architecture ◽  
Neuronal Morphogenesis ◽  
Microtubule Associated Proteins ◽  
Associated Proteins ◽  
And Function ◽  
Small Clusters

In this symposium I will present our studies about the molecular architecture and function of the cytomatrix of the nerve cells. The nerve cell is a highly polarized cell composed of highly branched dendrites, cell body, and a single long axon along the direction of the impulse propagation. Each part of the neuron takes characteristic shapes for which the cytoskeleton provides the framework. The neuronal cytoskeletons play important roles on neuronal morphogenesis, organelle transport and the synaptic transmission. In the axon neurofilaments (NF) form dense arrays, while microtubules (MT) are arranged as small clusters among the NFs. On the other hand, MTs are distributed uniformly, whereas NFs tend to run solitarily or form small fascicles in the dendrites Quick freeze deep etch electron microscopy revealed various kinds of strands among MTs, NFs and membranous organelles (MO). These structures form major elements of the cytomatrix in the neuron. To investigate molecular nature and function of these filaments first we studied molecular structures of microtubule associated proteins (MAP1A, MAP1B, MAP2, MAP2C and tau), and microtubules reconstituted from MAPs and tubulin in vitro. These MAPs were all fibrous molecules with different length and formed arm like projections from the microtubule surface.

Toxicity of Heparinoids, with Special Reference to the Precipitation of Fibrinogen

1964 ◽  
Vol 12 (01) ◽  
pp. 232-261 ◽  
Author(s):  
S Sasaki ◽  
T Takemoto ◽  
S Oka
Keyword(s):  
Molecular Weight ◽  
Dextran Sulfate ◽  
Anticoagulant Activity ◽  
Molecular Structures ◽  
Severe Reaction ◽  
Clinical Use ◽  
Molecular Weights ◽  
Close Relationship

SummaryTo demonstrate whether the intravascular precipitation of fibrinogen is responsible for the toxicity of heparinoid, the relation between the toxicity of heparinoid in vivo and the precipitation of fibrinogen in vitro was investigated, using dextran sulfate of various molecular weights and various heparinoids.1. There are close relationships between the molecular weight of dextran sulfate, its toxicity, and the quantity of fibrinogen precipitated.2. The close relationship between the toxicity and the precipitation of fibrinogen found for dextran sulfate holds good for other heparinoids regardless of their molecular structures.3. Histological findings suggest strongly that the pathological changes produced with dextran sulfate are caused primarily by the intravascular precipitates with occlusion of the capillaries.From these facts, it is concluded that the precipitates of fibrinogen with heparinoid may be the cause or at least the major cause of the toxicity of heparinoid.4. The most suitable molecular weight of dextran sulfate for clinical use was found to be 5,300 ~ 6,700, from the maximum value of the product (LD50 · Anticoagulant activity). This product (LD50 · Anticoagulant activity) can be employed generally to assess the comparative merits of various heparinoids.5. Clinical use of the dextran sulfate prepared on this basis gave satisfactory results. No severe reaction was observed. However, two delayed reactions, alopecia and thrombocytopenia, were observed. These two reactions seem to come from the cause other than intravascular precipitation.

Factors Affecting Molecular Self-Assembly and Its Mechanism

2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Molecular Engineering ◽  
Molecular Structures ◽  
Polymer Science ◽  
New Approach ◽  
Factors Affecting ◽  
Dna Structures ◽  
Self Assembling ◽  
Wide Range

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.

Sign in / Sign up

Export Citation Format

Share Document