Microwave Synthesized Functional Dyes

Microwave chemistry involves the application of microwave radiation to chemical reactions and has played an important role in organic synthesis. Functional dyes are those with hi-tech applications and this chapter attempts to provide an overview of the recent developments in microwave-assisted synthesis of functional dyes. Emphasis has been paid to the microwave-assisted synthesis of dye molecules which are useful in hi-tech applications such as optoelectronics (dye-sensitized solar cells), photochromic materials, liquid crystal displays, newer emissive displays (organic-light emitting devices), electronic materials (organic semiconductors), imaging technologies (electrophotography viz., photocopying and laser printing), biomedical applications (fluorescent sensors and anticancer treatment such as photodynamic therapy). In this chapter, the advantages of microwaves as a source of energy for heating synthesis reactions have been demonstrated. The use of microwaves to functional dyes is a paradigm shift in dye chemistry. Until recently most academic laboratories did not practice this technique in the synthesis of such functional dyes but many reports are being appeared in the journals of high repute.

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Microwave-Assisted Synthesis of an Alternant Poly(fluorene–oxadiazole). Synthesis, Properties, and White Light-Emitting Devices

Polymers ◽

10.3390/polym11101562 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1562

Author(s):

Dumitru Popovici ◽

Andrei Diaconu ◽

Aurelian Rotaru ◽

Luminita Marin

Keyword(s):

Oxidative Polymerization ◽

Polarized Light ◽

Gel Permeation Chromatography ◽

Complete Separation ◽

Microwave Assisted Synthesis ◽

Compact Structure ◽

Light Emitting ◽

Light Emitting Devices ◽

Microwave Assisted ◽

Synthesis Properties

An alternant poly(dihexyl fluorene-co diphenyl oxadiazole) has been synthetized by microwave-assisted oxidative polymerization. The structure has been confirmed by 1H-NMR and FTIR spectroscopies. Gel permeation chromatography indicated high molecular weight and low polydispersity index. DFT calculations suggested a complete separation of HOMO and LUMO orbitals, which were located on fluorene and oxadiazole moiety, respectively. X-ray diffraction, polarized light microscopy, and atomic force microscopy indicated the polymer tendency to stack into a layered morphology with a more compact structure for the films prepared by spin coating. Furthermore, UV-vis and photoluminescence spectroscopies indicated the formation of H-aggregates which played a key role in photoluminescence quenching in solid state. Nevertheless, the good charge mobility gained due to the orbital overlapping in H-aggregates led to excellent electroluminescence, which enabled the development of white OLED devices with outstanding stability.

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Conjugated Polymer Surfaces and Interfaces for Light-Emitting Devices

MRS Bulletin ◽

10.1557/s0883769400033625 ◽

1997 ◽

Vol 22 (6) ◽

pp. 46-51 ◽

Cited By ~ 15

Author(s):

W.R. Salaneck ◽

J.L. Brédas

Keyword(s):

Conjugated Polymers ◽

Photoelectron Spectroscopy ◽

Electronic Materials ◽

Structural Information ◽

Molecular Solids ◽

Chemical Modeling ◽

Polymer Leds ◽

Light Emitting ◽

Light Emitting Devices ◽

Surfaces And Interfaces

Since the discovery of high electrical conductivity in doped polyacetylene in 1977, π-conjugated polymers have emerged as viable semiconducting electronic materials for numerous applications. In the context of polymer electronic devices, one must understand the nature of the polymer surface's electronic structure and the interface with metals. For conjugated polymers, photoelectron spectroscopy—especially in connection with quantum-chemical modeling—provides a maximum amount of both chemical and electronic structural information in one (type of) measurement. Some details of the early stages of interface formation with metals on the surfaces of conjugated polymers and model molecular solids in connection with polymer-based light-emitting devices (LEDs) are outlined. Then a chosen set of issues is summarized in a band structure diagram for a polymer LED, based upon a “clean calcium electrode” on the clean surface of a thin film of poly(p-phenylene vinylene) (PPV). This diagram helps to point out the complexity of the systems involved in polymer LEDs. No such thing as “an ideal metal-on-polymer contact” exists. There is always some chemistry occurring at the interface.

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Molecular materials for micro-electronics

Canadian Journal of Physics ◽

10.1139/p00-033 ◽

2000 ◽

Vol 78 (3) ◽

pp. 231-241 ◽

Cited By ~ 3

Author(s):

M D'Iorio

Keyword(s):

High Performance ◽

Organic Materials ◽

Coming Of Age ◽

Polymeric Materials ◽

Organic Light Emitting Diodes ◽

Light Emitting ◽

Light Emitting Devices ◽

Plastic Electronics ◽

Organic Light ◽

Recent Developments

Molecular organic materials have had an illustrious past but the ability to deposit these as homogeneous thin films has rejuvenated the field and led to organic light-emitting diodes (OLEDs) and the development of an increasing number of high-performance polymers for nonlinear and electronic applications. Whereas the use of organic materials in micro-electronics was restricted to photoresists for patterning purposes, polymeric materials are coming of age as metallic interconnects, flexible substrates, insulators, and semiconductors in all-plastic electronics. The focus of this topical review will be on organic light-emitting devices with a discussion of the most recent developments in electronic devices.PACS Nos.: 85.60Jb, 78.60Fi, 78.55Kz, 78.66Qn, 73.61Ph, 72.80Le

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Microwave-assisted synthesis of high-quality “all-inorganic” CsPbX3 (X = Cl, Br, I) perovskite nanocrystals and their application in light emitting diodes

Journal of Materials Chemistry C ◽

10.1039/c7tc03774k ◽

2017 ◽

Vol 5 (42) ◽

pp. 10947-10954 ◽

Cited By ~ 83

Author(s):

Qi Pan ◽

Huicheng Hu ◽

Yatao Zou ◽

Min Chen ◽

Linzhong Wu ◽

...

Keyword(s):

Light Emitting Diodes ◽

Microwave Assisted Synthesis ◽

High Quality ◽

Light Emitting ◽

Perovskite Nanocrystals ◽

Microwave Assisted

A fast and efficient microwave-assisted strategy is developed to prepare high-quality CsPbX3 nanocrystals with controllable morphologies (nanoplate, nanocube, and nanorod).

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The microwave-assisted syntheses and applications of non-fused single-nitrogen-containing heterocycles

Organic & Biomolecular Chemistry ◽

10.1039/d0ob01779e ◽

2020 ◽

Vol 18 (48) ◽

pp. 9737-9761

Author(s):

Jay Prakash Soni ◽

Krishna Sowjanya Chemitikanti ◽

Swanand Vinayak Joshi ◽

Nagula Shankaraiah

Keyword(s):

Present Review ◽

Microwave Assisted Synthesis ◽

Microwave Assisted ◽

The Past ◽

Recent Developments

The present review emphasizes the scope of and recent developments in the microwave-assisted synthesis of various non-(benzo)fused single-nitrogen-containing heterocycles and related applications in the past decade.

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A Review on Graphene-Based Light Emitting Functional Devices

Molecules ◽

10.3390/molecules25184217 ◽

2020 ◽

Vol 25 (18) ◽

pp. 4217

Author(s):

Muhammad Junaid ◽

M. H. Md Khir ◽

Gunawan Witjaksono ◽

Zaka Ullah ◽

Nelson Tansu ◽

...

Keyword(s):

Thermal Emission ◽

Ultra Wideband ◽

Optical Modulators ◽

Active Materials ◽

Linear Dispersion ◽

Light Emitting ◽

Light Emitting Devices ◽

Theoretical Investigations ◽

Recent Developments ◽

Potential Applications

In recent years, the field of nanophotonics has progressively developed. However, constant demand for the development of new light source still exists at the nanometric scale. Light emissions from graphene-based active materials can provide a leading platform for the development of two dimensional (2-D), flexible, thin, and robust light-emitting sources. The exceptional structure of Dirac’s electrons in graphene, massless fermions, and the linear dispersion relationship with ultra-wideband plasmon and tunable surface polarities allows numerous applications in optoelectronics and plasmonics. In this article, we present a comprehensive review of recent developments in graphene-based light-emitting devices. Light emissions from graphene-based devices have been evaluated with different aspects, such as thermal emission, electroluminescence, and plasmons assisted emission. Theoretical investigations, along with experimental demonstration in the development of graphene-based light-emitting devices, have also been reviewed and discussed. Moreover, the graphene-based light-emitting devices are also addressed from the perspective of future applications, such as optical modulators, optical interconnects, and optical sensing. Finally, this review provides a comprehensive discussion on current technological issues and challenges related to the potential applications of emerging graphene-based light-emitting devices.

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Microwave-assisted synthesis of high thermal stability and colourless polyimides containing pyridine

Royal Society Open Science ◽

10.1098/rsos.190196 ◽

2019 ◽

Vol 6 (6) ◽

pp. 190196 ◽

Cited By ~ 1

Author(s):

Kai Cheng ◽

Jie-pin Hu ◽

Yan-cheng Wu ◽

Chu-qi Shi ◽

Zhi-geng Chen ◽

...

Keyword(s):

Thermal Stability ◽

Synthesis Method ◽

Optical Transmittance ◽

Aromatic Diamine ◽

Microwave Assisted Synthesis ◽

Step Method ◽

Light Emitting ◽

Microwave Assisted ◽

One Step ◽

Biphenyltetracarboxylic Dianhydride

A novel aromatic diamine containing pyridyl side group, 4-pyridine-4,4-bis(3,5-dimethyl-5-aminophenyl)methane (PyDPM), was successfully synthesized via electrophilic substitution reaction. The polyimides (PIs) containing pyridine were obtained via the microwave-assisted one-step polycondensation of the PyDPM with pyromellitic dianhydride (PMDA), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3,3′,4,4′-diphenylether tetracarboxylic dianhydride (ODPA) and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA). Contrarily to the reported similar PIs, these PIs exhibit much higher thermal stability or heat resistance, i.e. high glass transition temperatures ( T g s) in the range of 358–473°C, and the decomposition temperatures at 5% weight loss over 476°C under nitrogen. They can afford flexible and strong films with tensile strength of 82.1–93.3 MPa, elongation at break of 3.7%–15.2%, and Young's modulus of 3.3–3.8 GPa. Furthermore, The PI films exhibit good optical transparency with the cut-off wavelength at 313–366 nm and transmittance higher than 73% at 450 nm. The excellent thermal and optical transmittance can be attributed to synthesis method and the introduction of pyridine rings and ortho-methyl groups. The inherent viscosities of PIs via one-step method were found to be 0.58–1.12 dl g −1 in DMAc, much higher than those via two-step method. These results indicate these PIs could be potential candidates for optical substrates of organic light emitting diodes (OLEDs).

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