An overcrowded ethylene composed of electron-donating anion, naphthoxide, and electron-accepting cation, acridinium, has been synthesized. It is in equilibrium between a folded conformer having a smaller permanent dipole moment with visible light absorption and a twisted conformer having a larger permanent dipole moment with NIR light absorption. The overcrowded ethylene shows multiple NIR chromisms, such as solvatochromism, thermochromism, mechanochromism, vapochromism, halochromism, and amphoteric electrochromisms, which are caused by the conformational change between folded and twisted conformers or by controlling the energy difference between the HOMO of the donor moiety and the LUMO of the acceptor moiety. The small difference between the HOMO energy level of naphthoxide moiety and the LUMO energy level of acridinium moiety, and their weak interaction are crucial for NIR absorption and large dipole moment in the twisted conformer. The drastic change in the ratio of folded and twisted conformers by changing the polarity of solvents, the detection of CO2, and the disappearance of NIR absorption by electrochemical oxidation and reduction are noteworthy for this new type of organic dye.
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http://dx.doi.org/10.1002/anie.202422448 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Osaka University Graduate School of Engineering Science School of Engineering Science: Osaka Daigaku Daigakuin Kiso Kogaku Kenkyuka Kiso Kogakubu, Department of Materials Engineering Science, Machikaneyama 1-3, 560-8531, Toyonaka, JAPAN.
An overcrowded ethylene composed of electron-donating anion, naphthoxide, and electron-accepting cation, acridinium, has been synthesized. It is in equilibrium between a folded conformer having a smaller permanent dipole moment with visible light absorption and a twisted conformer having a larger permanent dipole moment with NIR light absorption. The overcrowded ethylene shows multiple NIR chromisms, such as solvatochromism, thermochromism, mechanochromism, vapochromism, halochromism, and amphoteric electrochromisms, which are caused by the conformational change between folded and twisted conformers or by controlling the energy difference between the HOMO of the donor moiety and the LUMO of the acceptor moiety.
View Article and Find Full Text PDFJ Chem Phys
December 2024
Department of Physics, University of Central Florida, Orlando, Florida 32816, USA.
This study presents Born-Oppenheimer energies and transition dipole moments of the 36 lowest electronic states of the N2+ ion as a function of internuclear distance in the interval between 1.5 and 10 bohrs obtained in first-principles calculations. The electronic states are of the total electronic spin S = 1/2, 3/2, and 5/2, dissociating toward to the lowest four N(4S0) + N+(3P), N(2P0) + N+(3P), N(2D0) + N+(3P), and N(4S0) + N+(1D) dissociation limits.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
University of Fribourg, Adolphe Merkle Institute, Fribourg, Switzerland.
Background: Tau protein phosphorylation and aggregation are the pathological hallmarks of Alzheimer's disease (AD) and other tauopathies. Multiple phosphorylation sites in Tau protein at serine (S), threonine (T), and tyrosine result in high heterogeneity and enhanced aggregation kinetics.
Method: Here, we used nanopores coated with a fluid lipid bilayer to characterize native and hyperphosphorylated Tau proteins on a single-molecule level.
J Chem Phys
January 2025
Volgograd State University, University Avenue 100, Volgograd 400062, Russia.
The first excited state of conjugated donor-acceptor molecules of C3 symmetry (octupolar molecules) is doubly degenerate. Such a doublet is known to be isomorphic to a spin 1/2. It is shown that a large electric dipole moment is associated with this spin.
View Article and Find Full Text PDFEur J Mass Spectrom (Chichester)
January 2025
QuantumSIMM, Kangra, HP, India.
Phthalate esters, frequently used as plasticizers in consumer products, raise concerns because of potential health effects. Using density functional theory (DFT) with BLYP and 6-311++G(d, p) basis sets, their properties, such as dipole moment, polarizability, proton affinity and ionization energy of phthalate esters are obtained. Reaction kinetics and thermodynamics of popular reagent ions like HO, NH, NO and O are computed to know the feasibility of the reactions with such ions.
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