Advanced theoretical methodologies and photoelectron photoion coincidence spectroscopy were used to investigate the photoionization of ethanolamine in the 8-18 eV energy range. We identified the low-lying cation conformers and the excited cation electronic states after vertical excitation from the most stable neutral conformer computationally. The TPES is composed of broad, structureless bands because of unfavorable Franck-Condon factors for origin transitions upon ionization, populating the D-D cationic states from the most stable neutral conformer, g'Gg'. The adiabatic ionization energy of ethanolamine is calculated at 8.940 ± 0.010 eV, and the 0 K appearance energies of aminomethylium, NHCH (+CHOH), and methyleneammonium, NHCH (+HCO), are determined experimentally to be 9.708 ± 0.010 eV and 9.73 ± 0.03 eV, respectively. The former is used to re-evaluate the ethanolamine enthalpy of formation in the gas and liquid phases as Δ⊖298K[NH(CH)OH, g] = -208.2 ± 1.2 kJ mol and Δ⊖298K[NH(CH)OH, l] = -267.8 ± 1.2 kJ mol. This represents a substantial correction of the previous experimental determination and is supported by calculations.
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http://dx.doi.org/10.1039/d4cp03015j | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0309, United States.
Controlling molecular actions on demand is a critical step toward developing single-molecule functional devices. Such control can be achieved by manipulating the interactions between individual molecules and their nanoscale environment. In this study, we demonstrate the conformational transition of a single pyrrolidine molecule adsorbed on a Cu(100) surface, driven by vibrational excitation through tunneling electrons using scanning tunneling microscopy.
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Chemistry and Nuclear Science & Engineering Center, Colorado School of Mines, Golden, Colorado 80401, United States.
Three Sm(II) dibenzo-24-crown-8 (db24c8) complexes were synthesized in anhydrous, air-free conditions via the reaction of SmI with db24c8 and tetrabutylammonium tetraphenylborate ([TBA][BPh]; where needed) in acetonitrile (CHCN), dimethoxyethane (DME), and tetrahydrofuran (THF) to yield [Sm(db24c8)(CHCN)][BPh][I]·CHCN, [Sm(db24c8)(DME)]I, and [Sm(db24c8)(THF)]I, respectively. In each case, a 10-coordinate, staggered dodecahedral (2:6:2) environment is formed around the Sm center that is completed by either two solvent molecules (CHCN or THF) or one bidentate solvent molecule (DME). Inner-sphere solvent molecules can be excluded by reacting SmI with db24c8 in 1:3 THF:toluene to yield Sm(db24c8)I.
View Article and Find Full Text PDFPLoS Comput Biol
January 2025
College of Food and Bioengineering, Zhengzhou University of Light Industry, Zhengzhou, People's Republic of China.
Gaussia Luciferase (GLuc) is a renowned reporter protein that can catalyze the oxidation of coelenterazine (CTZ) and emit a bright light signal. GLuc comprises two consecutive repeats that form the enzyme body and a central putative catalytic cavity. However, deleting the C-terminal repeat only limited reduces the activity (over 30% residual luminescence intensity detectable), despite being a key part of the cavity.
View Article and Find Full Text PDFChemistry
January 2025
Beijing University of Posts and Telecommunications, School of Science, Beijing, CHINA.
Cofacial electron donor-acceptor dyads exhibiting through-space charge-transfer (TSCT) characteristics are widely employed in the development of optoelectronic functional materials. The flexible molecular frameworks between the electron donor and acceptor components allow dynamic modulation of electronic coupling, influenced by excited-state structural relaxation or intermolecular interactions, thereby affecting the charge-transfer (CT) dynamics and the emission properties of TSCT states. In this work, we examine the TSCT dynamic processes of two electron donor-acceptor dyads, CzPhNI and CzPhPI formed by ortho-substitution of phenyl linkage with V-shaped flexible TSCT structures using carbazole as donor and naphthalimide or phthalimide as acceptor.
View Article and Find Full Text PDFDalton Trans
January 2025
Institute for Organic Synthesis and Photoreactivity (ISOF) - National Research Council (CNR), Via P. Gobetti 101, 40129 Bologna, Italy.
A supramolecular system, consisting of a tetrapyrenylporphyrinic core surrounded by arene-ruthenium prisms, has been assembled and characterized by means of electrochemical and photophysical techniques. The photophysical study shows that quantitative energy transfer from the peripheral pyrenyl units towards the central porphyrin core is operative in the tetrapyrenylporphyrinic system. Interestingly, encapsulation of the pyrenyl units into the ruthenium cages affects the photophysics of the central porphyrin component, since its emission quantum yield is reduced in the supramolecular array.
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