The activation parameters for the thermal decomposition of 13 acridinium-substituted 1,2-dioxetanes, bearing an aromatic moiety, were determined and their chemiluminescence emission quantum yields estimated, utilizing in situ photosensitized 1,2-dioxetane generation observation its kinetics, without isolation these highly unstable cyclic peroxides. Decomposition rate constants show linear free-energy correlation electron-withdrawing substituents, with a Hammett reaction constant ρ = 1.3 ±...

In this study, we describe the preparation and evaluation of new fluorescent sensor nanoparticles for ratiometric measurement chloride concentrations. Both a chloride-sensitive dye (lucigenin) reference (sulforhodamine derivative) were incorporated into polyacrylamide via inverse microemulsion polymerization investigated their response to ions in buffered suspension as well living cells. The fluorescence intensity lucigenin reversibly decreased presence due collisional quenching process,...

A statistical terpolymer, containing a 2-(pyridine-2-yl)-1,3-thiazole donor-type system and an acceptor-type [Ru(bpy)2(2-(triazol-4-yl)pyridine)]2+ chromophore as well methyl methacrylate comonomer, was synthesized using the controlled reversible addition–fragmentation chain transfer polymerization (RAFT) approach. Additionally, appropriate donor- copolymers were synthesized, whereas only maximum content of 5 mol % ruthenium(II) could be incorporated into macromolecules caused by its...

Abstract Pentacene and its derivatives are among the most important examples of π‐electron‐rich molecules used in organic field effect transistors. The replacement CH groups by nitrogen atoms opens an elegant way to generate highly electron‐deficient molecules, known as oligoazaacenes. We describe synthesis spectroscopic properties two novel this family, namely zwitterionic quinoidal conjugated forms dihydro‐5,6,7,12,13,14‐hexaazapentacene (fluorubine). outline a powerful strategy tune...

Abstract This work describes the synthesis of five O ‐silyloxy‐1,3‐thiazoles and their use as fast‐response “turn‐on” probes for fluoride ion detection in polar aprotic solvents aqueous cetyltrimethylammonium bromide micellar medium. The fluoride‐triggered deprotection these silyl ethers results ca. 180‐nm shifts fluorescence emission wavelengths. All compounds are suitable ions with a limit DMSO 10 –7 mol L –1 ; derivatives containing 2‐pyridyl moiety thiazole system more efficient than...

Abstract Ruthenium dyes incorporating a 4 H ‐imidazole chromophore as ligand exhibit spectrally broad absorption in the UV/Vis region. Furthermore, they show ability to store two electrons within ligand. These features render them promising molecular systems, for example, inter‐ or intramolecular electron relays. To optimize structures with respect their electron‐storage capability, it is crucial understand impact of structural changes accompanying photoinduced charge transfer electronic...

On the Aminolysis of Bis-Imidoylchlorides Oxalic Acid. Part I. Reaction with Aromatic and Aliphatic Amines The reaction between bis-imidoylchlorides 2 derived from oxalic acid several aromatic aliphatic amines was investigated. While primary need a thermical activation by refluxing, give mainly at room temperature amidines 3 in moderatly up to good yields. Proceeding enantiomeric pure e.g. (R)- or (S)-1-phenethylamine new homochiral 3y 3z C2-symmetry were obtained. Several secondary react...

Abstract The peroxyoxalate reaction is utilized in a wide variety of analytical applications; however, its mechanism still not very well understood, especially with respect to the excitation step, where ‘chemical energy’ transformed into ‘excitation energy’. This base‐catalysed activated oxalic phenyl esters hydrogen peroxide presence highly fluorescent aromatic hydrocarbons low oxidation potentials only known chemiluminescence system for which exists experimental evidence occurrence...

Abstract A series of new dihydrotetraazaanthracenes and one dihydrotetraazatetracene as substances for applications in organoelectronic devices suitable building blocks higher azaacenes was synthesised. The condensation aromatic diamines with dichlorodicyanopyrazine led to these tricyclic/tetracyclic compounds. Syntheses N ‐substituted phenylenediamines were developed enable the introduction multiple functional groups such ester, amino, or nitro on chromophoric system. Relationships between...

Processing of 4-alkoxythiazole sulfonamides<italic>via</italic>the Langmuir–Blodgett technique gave an insight into the influence aggregation on electro-optical properties thin films.

Abstract The bioluminescence reaction of many biological subspecies, most notably fireflies, forms dioxetanone derivatives as high‐energy intermediates. thermal instability dioxetanones complicates understanding the transition from ground state to first excited that leads light emission. Herein, we report mechanism 2‐coumaranones, synthetically accessible strongly chemiluminescent materials mimic reaction. pathways chemiexcitation and photorelaxation are clarified on basis synthetic evidence...

Absorption, fluorescence, and fluorescence excitation spectra of two substituted [(5-methyl-2-pyridine-2'-yl-1,3-thiazole-4-yl)oxy]acetic acid its methyl ester (2,2'-pyridylthiazoles) are studied at various pH values in aqueous solution. The exhibits pKa(1) = 2.10 ± 0.07 pKa(2) 3.45 0.03, whereas the pKa 1.93 0.03. protonation site is pyridyl-nitrogen. When protonated, cisoid conformer most stable; however, transoid more stable deprotonated form. Fluorescence quantum yields close to unity...

Abstract The synthesis of two new monomers based on 4‐hydroxythiazoles, with a non‐classical chromophore structure similar to the luciferin dye glowworms, is presented. These dyes are functionalized methacrylates and copolymerized methyl methacrylate using RAFT polymerization process. obtained polymers reveal PDI values below 1.2 characterized by NMR spectroscopy, SEC including diode‐array detector, UV‐vis fluorescence spectroscopy. In addition, thin films prepared spin‐coating investigated...

The supramolecular structure essentially determines the properties of organic thin films. Therefore, it is utmost importance to understand influence molecular modifications on formation. In this article, we demonstrate how tune orientations amphiphilic 4-hydroxy thiazole derivatives by means Langmuir-Blodgett (LB) technique and depends length an alkylic spacer between chromophore polar anchor group. characterize their corresponding structures, thermodynamic, absorption, fluorescence...

The optimized one-pot synthesis of 16 new 2-coumaranones containing a carbamate side-chain is described.Furthermore, the quantum yields for base-activated chemiluminescence in presence oxygen was determined all compounds, with maximum 5.9 ± 0.1 x 10 -2 E mol -1 , and application these compounds as substitutes usual bioluminescent chemiluminescent reagents bioassays anticipated.A preliminary mechanistic pathway also suggested, making use recent developments regarding aspects organic...

The reaction of oxalic amidines R1–N=C(NHR2)–C(NHR2)=N–R1 with CH3MgX followed by uptake CO2 results in the formation trimeric carbamato complexes [R1–N=C(NR2–COO)–C(NR2COO)=N–R1]3Mg3(THF)6 (2a: R1 = R2 Ph; 2b: p-tolyl) as thermodynamically stable final products reaction. Their X-ray crystal structures show that three metal centres are a linear arrangement. central magnesium ion is octahedrally surrounded six O-donor atoms μ2-carbamato bridges, while both peripheral ions facially coordinated...

The condensation reaction of N-heteroaromatic nitriles with d,l-mercaptolactic acid results in the formation 4-hydroxythiazoles. products are sparingly soluble most solvents which they display only a weak fluorescence. However, upon derivatization OH-group by etherification, blue emitting luminescence dyes high quantum yields and large stokes shifts were obtained. these thiazoles is affected 2-substituents lies region 410 nm, between 30% 90%. Employing this method, not new fluorophores...

Abstract A series of new 4‐hydroxy‐1,3‐thiazole‐based chromophores bearing different arylamine components (triarylamines, carbazole, and phenothiazine) as electron donors azaheterocycle (pyridine, pyrazine pyrimidine) electron‐acceptor moieties have been synthesized. Elaborate quantum chemical calculations were carried out with two selected compounds to identify the natures HOMO/LUMO transition intramolecular charge‐transfer state. The electrochemical properties investigated: dyes show...

The density functional theory calculations of molecular structure and spectroscopic electronic properties charged states in four triazine-heteroaryl star-shaped compounds are presented. molecules end-capped with different heteroaryl groups, i.e., thiophene (TTT1), furan (TFT2), 3,4-ethylenedioxythienyl (TET3), thiazole (TSNT4), were studied by electrochemical situ ESR/UV-vis-NIR spectroelectrochemical techniques tetrahydrofuran/(TBA)BF(4). monomers created cathodic reduction the stability...

A dye-based polymeric antenna system for energy transfer towards a photoactive Os(<sc>ii</sc>) metal complex is described.

The supramolecular structures and their constituents essentially determine the optoelectronic properties of thin films. introduction amphiphilicity to interface assembly is one established technique control resulting material properties. To yield amphiphilicity, rather hydrophobic chromophores are linked hydrophilic head groups via flexible alkyl chains. In present work, we investigate whether replacement linkers by a phenylene linker, that is, replacing an electrically isolating moiety with...