Synthesis and photophysical properties of a new tetraphenylethylene-o-carborane-based star-shaped molecule

2021 ◽  
Author(s):  
Xiang Li ◽  
Qin Zhou ◽  
Miao Zhu ◽  
Wei Chen ◽  
Beibei Wang ◽  
...  
Keyword(s):  
Solid State ◽  
Quantum Yield ◽  
Photophysical Properties ◽  
The Absolute

A novel TPE-o-carborane-based star-shaped molecule with a triphenylamine core was synthesized. In the solid state, the absolute luminescent quantum yield of this dendrimer can be improved to 62%.

scholarly journals Zn(II) Heteroleptic Halide Complexes with 2-Halopyridines: Features of Halogen Bonding in Solid State

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3393
Author(s):  
Mikhail A. Vershinin ◽  
Marianna I. Rakhmanova ◽  
Alexander S. Novikov ◽  
Maxim N. Sokolov ◽  
Sergey A. Adonin
Keyword(s):  
Solid State ◽  
Quantum Yield ◽  
Crystal Packing ◽  
Halogen Bonding ◽  
Molecular Complexes ◽  
Substituted Pyridines ◽  
Halide Complexes

Reactions between Zn(II) dihalides and 2-halogen-substituted pyridines 2-XPy result in a series of heteroleptic molecular complexes [(2-XPy)2ZnY2] (Y = Cl, X = Cl (1), Br (2), I (3); Y = Br, X = Cl (4), Br (5), I (6), Y = I, X = Cl (7), Br (8), and I (9)). Moreover, 1–7 are isostructural (triclinic), while 8 and 9 are monoclinic. In all cases, halogen bonding plays an important role in formation of crystal packing. Moreover, 1–9 demonstrate luminescence in asolid state; for the best emitting complexes, quantum yield (QY) exceeds 21%.

scholarly journals A Sustainable Biomineralization Approach for the Synthesis of Highly Fluorescent Ultra-Small Pt Nanoclusters

Biosensors ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 128 ◽  
Author(s):  
Rajkamal Balu ◽  
Robert Knott ◽  
Christopher M. Elvin ◽  
Anita J. Hill ◽  
Namita R. Choudhury ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Photoelectron Spectroscopy ◽  
Photophysical Properties ◽  
Conformational Dynamics ◽  
Aqueous Media ◽  
Intrinsically Disordered Protein ◽  
X Ray ◽  
Pt Nanoclusters ◽  
Intrinsically Disordered ◽  
Green Fluorescent

Herein we report the first example of a facile biomineralization process to produce ultra-small-sized highly fluorescent aqueous dispersions of platinum noble metal quantum clusters (Pt-NMQCs) using a multi-stimulus responsive, biomimetic intrinsically disordered protein (IDP), Rec1-resilin. We demonstrate that Rec1-resilin acts concurrently as the host, reducing agent, and stabilizer of the blue-green fluorescent Pt-NMQCs once they are being formed. The photophysical properties, quantum yield, and fluorescence lifetime measurements of the synthesized Pt-NMQCs were examined using UV-Vis and fluorescence spectroscopy. The oxidation state of the Pt-NMQCs was quantitatively analyzed using X-ray photoelectron spectroscopy. Both a small angle X-ray scattering technique and a modeling approach have been attempted to present a detailed understanding of the structure and conformational dynamics of Rec1-resilin as an IDP during the formation of the Pt-NMQCs. It has been demonstrated that the green fluorescent Pt-NMQCs exhibit a high quantum yield of ~7.0% and a lifetime of ~9.5 ns in aqueous media. The change in photoluminescence properties due to the inter-dot interactions between proximal dots and aggregation of the Pt-NMQCs by evaporation was also measured spectroscopically and discussed.

scholarly journals Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

2019 ◽  
Vol 15 ◽  
pp. 2013-2019 ◽  
Author(s):  
Esther Nieland ◽  
Oliver Weingart ◽  
Bernd M Schmidt
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Visible Light ◽  
Half Life ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Halogen Bonding ◽  
Building Blocks ◽  
Partial Overlap

ortho-Fluoroazobenzenes are a remarkable example of bistable photoswitches, addressable by visible light. Symmetrical, highly fluorinated azobenzenes bearing an iodine substituent in para-position were shown to be suitable supramolecular building blocks both in solution and in the solid state in combination with neutral halogen bonding acceptors, such as lutidines. Therefore, we investigate the photochemistry of a series of azobenzene photoswitches. Upon introduction of iodoethynyl groups, the halogen bonding donor properties are significantly strengthened in solution. However, the bathochromic shift of the π→π* band leads to a partial overlap with the n→π* band, making it slightly more difficult to address. The introduction of iodine substituents is furthermore accompanied with a diminishing thermal half-life. A series of three azobenzenes with different halogen bonding donor properties are discussed in relation to their changing photophysical properties, rationalized by DFT calculations.

Effects of electron-withdrawing groups in imidazole-phenanthroline ligands and their influence on the photophysical properties of EuIII complexes for white light-emitting diodes

2017 ◽  
Vol 41 (18) ◽  
pp. 9826-9839 ◽  
Author(s):  
Boddula Rajamouli ◽  
Rachna Devi ◽  
Abhijeet Mohanty ◽  
Venkata Krishnan ◽  
Sivakumar Vaidyanathan
Keyword(s):  
Thin Film ◽  
Quantum Yield ◽  
White Light ◽  
Light Emitting Diode ◽  
Photophysical Properties ◽  
Red Light ◽  
Europium Complexes ◽  
Light Emitting ◽  
White Light Emitting Diodes ◽  
Phenanthroline Ligands

The red light emitting diode (LED) was fabricated by using europium complexes with InGaN LED (395 nm) and shown digital images, corresponding CIE color coordinates (red region) as well as obtained highest quantum yield of the thin film (78.7%).

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 Non-Covalent Binding of Tripeptides-Containing Tryptophan to Polynucleotides and Photochemical Deamination of Modified Tyrosine to Quinone Methide Leading to Covalent Attachment

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4315
Author(s):  
Antonija Erben ◽  
Igor Sviben ◽  
Branka Mihaljević ◽  
Ivo Piantanida ◽  
Nikola Basarić
Keyword(s):  
Quantum Yield ◽  
Photophysical Properties ◽  
Covalent Binding ◽  
Quinone Methide ◽  
Covalent Attachment ◽  
Dna And Rna ◽  
Pair Composition ◽  
Aqueous Solvent ◽  
Fluorometric Study ◽  
Spectral Responses

A series of tripeptides TrpTrpPhe (1), TrpTrpTyr (2), and TrpTrpTyr[CH2N(CH3)2] (3) were synthesized, and their photophysical properties and non-covalent binding to polynucleotides were investigated. Fluorescent Trp residues (quantum yield in aqueous solvent ΦF = 0.03–0.06), allowed for the fluorometric study of non-covalent binding to DNA and RNA. Moreover, high and similar affinities of 2×HCl and 3×HCl to all studied double stranded (ds)-polynucleotides were found (logKa = 6.0–6.8). However, the fluorescence spectral responses were strongly dependent on base pair composition: the GC-containing polynucleotides efficiently quenched Trp emission, at variance to AT- or AU-polynucleotides, which induced bisignate response. Namely, addition of AT(U) polynucleotides at excess over studied peptide induced the quenching (attributed to aggregation in the grooves of polynucleotides), whereas at excess of DNA/RNA over peptide the fluorescence increase of Trp was observed. The thermal denaturation and circular dichroism (CD) experiments supported peptides binding within the grooves of polynucleotides. The photogenerated quinone methide (QM) reacts with nucleophiles giving adducts, as demonstrated by the photomethanolysis (quantum yield ΦR = 0.11–0.13). Furthermore, we have demonstrated photoalkylation of AT oligonucleotides by QM, at variance to previous reports describing the highest reactivity of QMs with the GC reach regions of polynucleotides. Our investigations show a proof of principle that QM precursor can be imbedded into a peptide and used as a photochemical switch to enable alkylation of polynucleotides, enabling further applications in chemistry and biology.

Cationic Iridium Dendrimers: Synthesis and Photophysical Properties

2011 ◽  
Vol 64 (9) ◽  
pp. 1211 ◽  
Author(s):  
Bin Du ◽  
Si-Chun Yuan ◽  
Jian Pei
Keyword(s):  
Solid State ◽  
Photophysical Properties ◽  
Dendritic Structure ◽  
Benzimidazole Derivatives ◽  
Iridium Complex ◽  
Iridium Complexes ◽  
Efficient Energy Transfer ◽  
Ancillary Ligands ◽  
Synthetic Strategy ◽  
Yellow Orange

Two dendrimers, D1 and D2, containing the cationic iridium complexes (C1 and C2) as cores and truxene-functionalized chromophores as the branches, have been developed by a convergent synthetic strategy. The cationic complexes employ 3-(pyridin-2-yl)-1H-1,2,4-triazole and 2-(pyridin-2-yl)-benzimidazole derivatives as the ancillary ligands. To avoid the change in emission colour arising from the iridium complex, the conjugation between the dendron and the ligand is decoupled by separating them using the alkyl chain. An investigation of their photoluminescent features reveals that efficient energy transfer happens from the dendrons to the core in the solid state. Likewise, the charged dendritic structure is demonstrated to be an efficient method to improve the compatibility between the polar charged iridium complexes and typical hydrophobic hosts with the additional benefit of excellent solution processability. Both dendrimers exhibit strong solvatochromic behaviours in solvents and exclusive green and yellow-orange light in the solid state.

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