scholarly journals Microwave Assisted Reactions of Fluorescent Pyrrolodiazine Building Blocks

Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3760
Author(s):  
Costel Moldoveanu ◽  
Dorina Amariucai-Mantu ◽  
Violeta Mangalagiu ◽  
Vasilichia Antoci ◽  
Dan Maftei ◽  
...  
Keyword(s):  
Spectral Properties ◽  
Building Blocks ◽  
Biological Molecules ◽  
Quantum Yields ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate ◽  
Microwave Assisted ◽  
Subsequent Step ◽  
Blue Emitters ◽  
Mw Irradiation

We report here the synthesis and optical spectral properties of several new pyrrolodiazine derivatives. The luminescent heterocycles were synthesized by 1,3-dipolar cycloaddition reactions between N-alkylated pyridazine and methylpropiolate or dimethyl acetylenedicarboxylate (DMAD). The pyrrolopyridazine derivatives are blue emitters with moderate quantum yields (around 25%) in the case of pyrrolopyridazines and negligible yet measurable emission for pyrrolophthalazines. In a subsequent step towards including the pyrrolodiazine moiety, given its spectral properties in various macromolecular frameworks such as biological molecules, a subset of the synthetized compounds has been subjected to α-bromination. A selective and efficient way for α-bromination in heterogeneous catalysis of pyrrolodiazine derivatives under microwave (MW) irradiation is presented. We report substantially higher yields under MW irradiation, whereas the solvent amounts required are at least five-fold less compared to classical heating.

scholarly journals Fluorescent Azasteroids through Ultrasound Assisted Cycloaddition Reactions

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 5098
Author(s):  
Costel Moldoveanu ◽  
Ionel Mangalagiu ◽  
Gheorghita Zbancioc
Keyword(s):  
Carbonyl Group ◽  
Fluorescence Intensity ◽  
Spectral Properties ◽  
Probable Mechanism ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Dimethyl Acetylenedicarboxylate ◽  
Fluorescent Properties ◽  
Blue Emitters ◽  
Ultrasound Assisted

We report here the synthesis and optical spectral properties of several new azasteroid derivatives. The formation of these compounds was explained based on the most probable mechanism. The luminescent heterocycles were synthesized by 1,3-dipolar cycloaddition reactions between benzo[f]quinoline and methylpropiolate or dimethyl acetylenedicarboxylate (DMAD). A selective and efficient way for [3+2]-dipolar cycloaddition of benzo[f]quinolinium ylides under ultrasound (US) irradiation (20 kHz processing frequency) is presented. We report substantially higher yields under US irradiation, whereas the solvent amounts required are at least three-fold less compared to classical heating. The azasteroid derivatives are blue emitters with λmax of fluorescence around 430–450 nm. A certain influence of the azasteroid substituents concerning absorption and fluorescent properties was observed. Compounds anchored with a bulky pivaloyl group or without a C=O carbonyl group have shown increased fluorescence intensity.

Photodynamically active phthalocyanine building blocks for click chemistry

2011 ◽  
Vol 15 (09n10) ◽  
pp. 1062-1069 ◽  
Author(s):  
Veronika Novakova ◽  
Kamil Kopecky ◽  
Miroslav Miletin ◽  
Jana Ivincova ◽  
Petr Zimcik
Keyword(s):  
Photodynamic Therapy ◽  
Singlet Oxygen ◽  
Click Chemistry ◽  
Building Blocks ◽  
Quantum Yields ◽  
Dipolar Cycloaddition ◽  
Chromatographic Technique ◽  
Simple Modification ◽  
Fluorescence Quantum Yields ◽  
Zinc Phthalocyanines

Synthesis of symmetrical and unsymmetrical zinc phthalocyanines from two different precursors 4,5-bis(tert-butylsulfanyl)phthalonitrile (A) and N-(3-azidopropyl)-2,3-dicyanoquinoxaline-6-carboxamide (B) is described. Congeners of AAAA, AAAB, ABAB and AABB type were isolated by a chromatographic technique, however, the congener of BBBB type had to be prepared in a separate reaction. The adjacent and opposite isomers were also separated and fully characterized. Isolated phthalocyanines contained different number of azide groups, a substrate for highly efficient Cu(I) -catalyzed azide-alkyne 1,3-dipolar cycloaddition ("click chemistry"). All phthalocyanines absorbed strongly (ε over 150 000 M-1.cm-1) over 700 nm. Their singlet oxygen quantum yields were determined in DMF and ranged from 0.63 to 0.79, fluorescence quantum yields in DMF were considerably lower in the range 0.03–0.06. All these properties make them suitable building blocks for a simple modification and a synthesis of phthalocyanines with better tuned properties for photodynamic therapy.

scholarly journals Microwave-Assisted Preparation of Luminescent Inorganic Materials: A Fast Route to Light Conversion and Storage Phosphors

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2882
Author(s):  
José Miranda de Carvalho ◽  
Cássio Cardoso Santos Pedroso ◽  
Matheus Salgado de Nichile Saula ◽  
Maria Claudia França Cunha Felinto ◽  
Hermi Felinto de Brito
Keyword(s):  
Rapid Heating ◽  
Inorganic Materials ◽  
Rapid Screening ◽  
Conventional Heating ◽  
Quantum Yields ◽  
Microwave Assisted Synthesis ◽  
Volumetric Heating ◽  
White Leds ◽  
Microwave Assisted ◽  
And Storage

Luminescent inorganic materials are used in several technological applications such as light-emitting displays, white LEDs for illumination, bioimaging, and photodynamic therapy. Usually, inorganic phosphors (e.g., complex oxides, silicates) need high temperatures and, in some cases, specific atmospheres to be formed or to obtain a homogeneous composition. Low ionic diffusion and high melting points of the precursors lead to long processing times in these solid-state syntheses with a cost in energy consumption when conventional heating methods are applied. Microwave-assisted synthesis relies on selective, volumetric heating attributed to the electromagnetic radiation interaction with the matter. The microwave heating allows for rapid heating rates and small temperature gradients yielding homogeneous, well-formed materials swiftly. Luminescent inorganic materials can benefit significantly from the microwave-assisted synthesis for high homogeneity, diverse morphology, and rapid screening of different compositions. The rapid screening allows for fast material investigation, whereas the benefits of enhanced homogeneity include improvement in the optical properties such as quantum yields and storage capacity.

scholarly journals Modified Nucleosides, Nucleotides and Nucleic Acids via Click Azide-Alkyne Cycloaddition for Pharmacological Applications

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3100
Author(s):  
Daniela Perrone ◽  
Elena Marchesi ◽  
Lorenzo Preti ◽  
Maria Luisa Navacchia
Keyword(s):  
Cancer Therapy ◽  
Nucleic Acids ◽  
Click Chemistry ◽  
Nucleoside Analogs ◽  
Modified Nucleosides ◽  
Biological Molecules ◽  
Dipolar Cycloaddition ◽  
Virus Diseases ◽  
Reaction Conditions ◽  
Hybrid Compounds

The click azide = alkyne 1,3-dipolar cycloaddition (click chemistry) has become the approach of choice for bioconjugations in medicinal chemistry, providing facile reaction conditions amenable to both small and biological molecules. Many nucleoside analogs are known for their marked impact in cancer therapy and for the treatment of virus diseases and new targeted oligonucleotides have been developed for different purposes. The click chemistry allowing the tolerated union between units with a wide diversity of functional groups represents a robust means of designing new hybrid compounds with an extraordinary diversity of applications. This review provides an overview of the most recent works related to the use of click chemistry methodology in the field of nucleosides, nucleotides and nucleic acids for pharmacological applications.

scholarly journals The Photostability of Novel Boron Hydride Blue Emitters in Solution and Polystyrene Matrix

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 589
Author(s):  
Jakub Ševčík ◽  
Pavel Urbánek ◽  
Barbora Hanulíková ◽  
Tereza Čapková ◽  
Michal Urbánek ◽  
...  
Keyword(s):  
Thin Films ◽  
Photophysical Properties ◽  
Inorganic Compounds ◽  
Solid Polymer ◽  
Organic Polymer ◽  
Quantum Yields ◽  
Boron Hydride ◽  
Polystyrene Matrix ◽  
Blue Emitters ◽  
Solvent Blends

In recent work, the boron hydride anti-B18H22 was announced in the literature as a new laser dye, and, along with several of its derivatives, its solutions are capable of delivering blue luminescence with quantum yields of unity. However, as a dopant in solid polymer films, its luminescent efficiencies reduce dramatically. Clarification of underlying detrimental effects is crucial for any application and, thus, this contribution makes the initial steps in the use of these inorganic compounds in electrooptical devices based on organic polymer thin films. The photoluminescence behavior of the highly luminescent boron hydrides, anti-B18H22 and 3,3′,4,4′-Et4-anti-B18H18, were therefore investigated. The quantum yields of luminescence and photostabilities of both compounds were studied in different solvents and as polymer-solvent blends. The photophysical properties of both boranes are evaluated and discussed in terms of their solvent-solute interactions using photoluminescence (PL) and NMR spectroscopies. The UV degradability of prepared thin films was studied by fluorimetric measurement. The effect of the surrounding atmosphere, dopant concentration and the molecular structure were assessed.

scholarly journals Indenopyrans – synthesis and photoluminescence properties

2016 ◽  
Vol 12 ◽  
pp. 825-834 ◽  
Author(s):  
Andreea Petronela Diac ◽  
Ana-Maria Ţepeş ◽  
Albert Soran ◽  
Ion Grosu ◽  
Anamaria Terec ◽  
...  
Keyword(s):  
Solid State ◽  
Emission Band ◽  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Band Broadening ◽  
Photoluminescence Properties ◽  
Fluorescence Quantum Yields ◽  
Blue Emitters ◽  
Solid State Fluorescence

New indeno[1,2-c]pyran-3-ones bearing different substituents at the pyran moiety were synthesized and their photophysical properties were investigated. In solution all compounds were found to be blue emitters and the trans isomers exhibited significantly higher fluorescence quantum yields (relative to 9,10-diphenylanthracene) as compared to the corresponding cis isomers. The solid-state fluorescence spectra revealed an important red shift of λmax due to intermolecular interactions in the lattice, along with an emission-band broadening, as compared to the solution fluorescence spectra.

scholarly journals Prebiotic Chemical Refugia: Multifaceted Scenario for the Formation of Biomolecules in Primitive Earth

2021 ◽  
Author(s):  
Francisco Prosdocimi ◽  
Savio Torres Farias ◽  
Marco V José
Keyword(s):  
Chemical Elements ◽  
Building Blocks ◽  
Biological Molecules ◽  
Critical Problem ◽  
Primitive Earth ◽  
Prebiotic Chemical ◽  
The Origin Of Life ◽  
Prebiotic Earth ◽  
Stanley Miller ◽  
Periodic Changes

The origin of life was a cosmic event happened on primitive Earth. A critical problem to better understand the origins of life in Earth is to glimpse in which chemical scenarios the basic building blocks of biological molecules could be produced. Classic works in pre-biotic chemistry frequently considered early Earth as a homogeneous atmosphere constituted by chemical elements such as methane (CH4), ammonia (NH3), water (H2O), hydrogen (H2) and hydrogen sulfide (H2S). Under that scenario, Stanley Miller was capable to produce amino acids and solved the question about the origin of proteins. Conversely, the origin of nucleic acids has tricked scientists for decades as nucleotides are complex though necessary molecules to allow the existence of life. Here we review possible chemical scenarios that allowed not only the formation of nucleotides but also other significant biomolecules. We aim to provide a theoretical solution for the origin of biomolecules at specific sites named “Prebiotic Chemical Refugia”. A prebiotic chemical refugium should therefore be understood as a geographic site in prebiotic Earth on which certain chemical elements were accumulated in higher proportion than expected, facilitating the production of basic biomolecules. Plus, this higher proportion should not be understood as static, but dynamic; once the physicochemical conditions of our planet changed periodically. This different concentration of elements, together with geochemical and astronomical changes along days, synodic months and years provided somewhat periodic changes in temperature, pressure, electromagnetic fields, and conditions of humidity; among other features. Recent and classic works suggesting most likely prebiotic refugia on which the main building blocks of biological molecules might be accumulated are reviewed and discussed.

scholarly journals Plasmonic Resonant Nanoantennas Induce Changes in the Shape and the Intensity of Infrared Spectra of Phospholipids

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 62
Author(s):  
Fatima Omeis ◽  
Zahia Boubegtiten-Fezoua ◽  
Ana Filipa Santos Seica ◽  
Romain Bernard ◽  
Muhammad Haseeb Iqbal ◽  
...  
Keyword(s):  
Spectral Properties ◽  
Field Enhancement ◽  
Spectroscopic Studies ◽  
Biological Molecules ◽  
Future Application ◽  
Spectral Signature ◽  
Electric Field Enhancement ◽  
Low Concentrations ◽  
Surface Enhanced ◽  
Different Temperatures

Surface enhanced infrared absorption spectroscopic studies (SEIRAS) as a technique to study biological molecules in extremely low concentrations is greatly evolving. In order to use the technique for identification of the structure and interactions of such biological molecules, it is necessary to identify the effects of the plasmonic electric-field enhancement on the spectral signature. In this study the spectral properties of 1,2-Dipalmitoyl-sn-glycero-3 phosphothioethanol (DPPTE) phospholipid immobilized on gold nanoantennas, specifically designed to enhance the vibrational fingerprints of lipid molecules were studied. An AFM study demonstrates an organization of the DPPTE phospholipid in bilayers on the nanoantenna structure. The spectral data were compared to SEIRAS active gold surfaces based on nanoparticles, plain gold and plain substrate (Si) for different temperatures. The shape of the infrared signals, the peak positions and their relative intensities were found to be sensitive to the type of surface and the presence of an enhancement. The strongest shifts in position and intensity were seen for the nanoantennas, and a smaller effect was seen for the DPPTE immobilized on gold nanoparticles. This information is crucial for interpretation of data obtained for biological molecules measured on such structures, for future application in nanodevices for biologically or medically relevant samples.

Contribution to PNA-RNA Chimera Synthesis: One-Pot Microwave-Assisted Ugi Reaction to Obtain Dimeric Building Blocks

2016 ◽  
Vol 2017 (3) ◽  
pp. 469-475 ◽  
Author(s):  
Reuben Ovadia ◽  
Clémence Mondielli ◽  
Jean-Jacques Vasseur ◽  
Carine Baraguey ◽  
Karine Alvarez
Keyword(s):  
Building Blocks ◽  
Ugi Reaction ◽  
One Pot ◽  
Microwave Assisted
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