Article
Chemistry, Physical
Oleksii M. Dykun, Viktor M. Anishchenko, Andrii M. Redko, Volodymyr I. Rybachenko
Summary: The intramolecular hydrogen bond energies of twenty gossypol imine derivatives were evaluated using H-1 NMR spectroscopy and quantum chemistry methods. These derivatives exhibit various types of intramolecular hydrogen bonds. The position of the O-H group proton signals in the H-1 NMR spectra provided an initial estimation of hydrogen bond energies and proton involvement in non-covalent interactions. Geometric characteristics, such as hydrogen bond length and angle, allowed for comparison of the energies of all intramolecular hydrogen bonds. The strength of the C(6)O-H center dot center dot center dot OC(7) intramolecular hydrogen bond differed between dienamine and diimine tautomeric forms.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Pingping Sun, Devesh R. Kripalani, Weijie Chi
Summary: This study systematically investigated the excited-state intramolecular proton transfer (ESIPT) effect of three 3-thiolflavone derivatives containing sulfur-hydrogen bonds. The presence of intramolecular sulfur-hydrogen bonds was confirmed through bond length analysis, interaction energy calculations, and infrared vibrational spectra. It was found that the electron-withdrawing group stabilizes the tautomer, while the electron-donating group reduces the energy barrier of the ESIPT reaction. Additionally, the substituent group determines the excited-state electronic properties of keto tautomers, with the electron-withdrawing group significantly reducing the radiation rate and the electron-donating group leading to bright emission.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Biochemistry & Molecular Biology
Tsai I-Ting, M. Merced Montero-Campillo, Ibon Alkorta, Jose Elguero, Manuel Yanez
Summary: Intramolecular interactions, particularly beryllium bonds in ortho-substituted benzene derivatives, play a crucial role in stabilizing conformers with newly formed five or six-membered heterocycles. The strength of the beryllium bond is quantified using Natural Bond Orbital approach, showing significant interaction energies between the donor and acceptor. Energy is mostly spent on deforming donor-acceptor pairs to form new rings in these systems.
Article
Chemistry, Organic
Kavoos Kolahdouzan, O. Maduka Ogba, Daniel J. O'Leary
Summary: Methanol titrations of partially deuterated 1,4- and 1,3-diols dissolved in nonpolar solvents have revealed the presence or rupture of intramolecular hydrogen bonds through 1H NMR measurements. Isotope shifts were observed and analyzed to understand the behavior of these hydrogen bonds.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Ilya G. Shenderovich
Summary: From an academic and practical point of view, it is desirable to be able to assess the possibility of proton exchange in a molecular system based on the positions of the proton acceptor and donor. This study investigates the differences in intramolecular hydrogen bonds in 2,2'-bipyridinium and 1,10-phenanthrolinium. Experimental and computational evidence demonstrates that these hydrogen bonds are weak, with energies of 25 kJ/mol and 15 kJ/mol, respectively. The observed fast reversible proton transfer in 2,2'-bipyridinium cannot be attributed to these hydrogen bonds or N-H stretches, but rather to an external force of fluctuating electric fields present in the solution.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Catia I. C. Esteves, Luis F. B. Fontes, Joao Rocha, Artur M. S. Silva, Samuel Guieu
Summary: This paper investigates the influence of ESIPT groups on emission spectra and their sensitivity to pH variations. The assignment of each emission band was successfully made by using DFT and td-DFT calculations. The study emphasizes the versatility of triphenylpyridines and the synthesis method.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Nanoscience & Nanotechnology
Neil Robinson, Eric F. May, Michael L. Johns
Summary: Solid-fluid interactions are crucial for porous materials in various chemical processes, but the opaque nature of these systems hinders detailed characterization of interfacial phenomena. A low-magnetic-field two-dimensional H-1 nuclear spin relaxation measurement provides insights into adsorbate identity and interfacial dynamics, showcasing distinct relaxation responses correlated with adsorbate acidity. This approach offers a molecular-level perspective on interactions within optically opaque porous media.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Lorenz M. Urner, Ga Young Lee, Joseph W. Treacy, Aneta Turlik, Saeed Khan, K. N. Houk, Michael E. Jung
Summary: The 4-anilino-6,7-ethylenedioxy-5-fluoroquinazoline scaffold is proposed as a novel model system for studying weak NH...F hydrogen bonding interactions, with experimental and theoretical methods used to characterize this interaction. The results demonstrate that fluorine can act as a weak hydrogen bond acceptor, and the strength of the hydrogen bond can be modulated through changes in electron distribution and resonance.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Francisco A. Martins, Lucas de Azevedo Santos, Daniela Rodrigues Silva, Celia Fonseca Guerra, F. Matthias Bickelhaupt, Matheus P. Freitas
Summary: The gauche conformer in 1-X,2-Y-disubstituted ethanes is only favored for relatively small substituents, while the anti conformer is generally favored for larger substituents. In 2-iodoethanol, the gauche conformer is preferred when the hydroxyl hydrogen is oriented toward the iodine atom.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Naoya Suzuki, Tomoya Kubota, Naoki Ando, Shigehiro Yamaguchi
Summary: A new design strategy for an excited-state intramolecular proton transfer (ESIPT) fluorophore capable of functioning in acidic media has been reported. By utilizing an intramolecular charge-transfer transition, the fluorophore undergoes proton transfer from the amine to the pyridine moiety in the excited state, resulting in significantly red-shifted emission wavelength and increased fluorescence quantum yield.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Tadeja Gao, Jean-Pierre Korb, Miha Luksic, Guillaume Meriguet, Natalie Malikova, Anne-Laure Rollet
Summary: This study investigates the surface water dynamics and proton exchange at protein surfaces using NMR relaxometry. The addition of salt significantly affects the surface water dynamics, while the proton exchange between labile protein-protons and water-protons remains unchanged.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Biochemistry & Molecular Biology
Junghwa Lee, Pyoungsik Shin, Pi-Tai Chou, Taiha Joo
Summary: The excited state intramolecular proton transfer (ESIPT) dynamics of o-hydroxy analogs of the GFP chromophore were investigated using time-resolved spectroscopies and theoretical calculations. These compounds are an ideal system for studying the influence of electronic properties on the energetics and dynamics of ESIPT, as well as for applications in photonics. Through high-resolution time-resolved fluorescence and quantum chemical methods, the ultrafast ESIPT process was observed in 30 fs. While the ESIPT rates were not affected by the electronic properties of the substituents, the energetics, structures, dynamics following ESIPT, and possibly the product species were found to be distinct. The results suggest that fine tuning the electronic properties of these compounds can modify the molecular dynamics of ESIPT and subsequent structural relaxation to achieve brighter emitters with broad tuning capabilities.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Physical
Gongyue Huang, Luca Porcarelli, Yan Liang, Maria Forsyth, Haijin Zhu
Summary: The study found that the composite with TFSI anion exhibited the best ion conductivity, while a synergistic effect was observed for the composite with both TFSI and OTf mixed anion, resulting in significantly enhanced ionic conductivity reaching 1.47 mS/cm. This work demonstrates the potential of using a combination of TFSI and OTf anions as an effective strategy for improving ionic conductivity in proton-exchange membranes.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Marcus J. Giansiracusa, Michele Vonci, Yasmin L. Whyatt, Carys Williams, Kevin Mason, David Parker, Eric J. L. McInnes, Nicholas F. Chilton
Summary: EPR spectroscopy is used to show that a t-butyl-pyridyl-functionalised Er-III DOTA derivative coordinates water, while its methylphosphinate analogue does not.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Zuzana Osifova, Ondrej Socha, Lucie Muzikova Cechova, Michal Sala, Zlatko Janeba, Martin Dracinsky
Summary: This study investigated the intermolecular hydrogen bonding interactions of methylated derivatives of adenine with thymine. It was found that Hoogsteen pairing is preferred for adenine derivatives, with further stabilization of the Hoogsteen pair when methylation occurs at the N-6 position. This research provides insights into the noncovalent interactions between nucleobases and their impact on nucleic acid structure and function.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Yilin Liu, Ilia Denisov, Michael Gregory, Stephen G. Sligar, James R. Kincaid
Summary: This study investigates the impact of a CYP17A1 gene mutation on its catalytic activity. The results show that the mutation alters the lyase efficiency by affecting H-bonding interactions and protonation of the reactive ferric peroxo intermediate. The key reaction intermediates are successfully trapped and structurally characterized using cryoradiolysis and resonance Raman techniques.
Article
Chemistry, Physical
Andrey Shishov, Firuza Shakirova, Ulyana Markova, Petr Tolstoy, Andrey Bulatov
Summary: In this study, a deep eutectic solvent based on thymol and 4-(dimethylamino)benzaldehyde was synthesized and characterized. The solvent is stable in the presence of water and can be used as a hydrophobic extractant. It was successfully applied to the derivatization and microextraction of urea in human urine and powdered milk samples, reducing sample pretreatment time and simplifying the determination procedure.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Multidisciplinary
V. A. Rozentsvet, D. M. Ulyanova, N. A. Sablina, M. G. Kuznetsova, P. M. Tolstoy
Summary: Cationic polymerization of penta-1,3-diene with catalytic systems containing organoaluminum compounds and isopropyl chloride allows for the synthesis of completely soluble solid polymers with a high yield and softening point ranging from 81 to 91 degrees C. The use of H-1 and C-13 NMR spectroscopy techniques, including T-2 filtering, as well as H-1, C-13 HSQC and HMBC 2D NMR spectroscopy, enables the identification of carbon atoms signals of the head isopropyl groups connected with the 1,4-trans-unit of polypentadiene.
RUSSIAN CHEMICAL BULLETIN
(2022)
Article
Chemistry, Physical
Anton Mazur, Peter Tolstoy, Konstantinos Sotiriadis
Summary: The effects of organic additives, specifically acetic acid and sodium acetate, on the hydration process of Portland-limestone cement pastes were studied using solid-state C-13, Al-27, and Si-29 NMR spectroscopy. The results showed that these additives retard the cement hydration at early age and influence the kinetics of phase formation.
Article
Biochemistry & Molecular Biology
Elena Yu Tupikina, Mark Sigalov, Peter M. Tolstoy
Summary: A computational method for estimating the geometry of two coupled hydrogen bonds with geometries close to linear using NMR parameters was proposed. The method was developed based on the quantum-chemical investigation of complexes formed by oxygen and nitrogen atoms with substituted methanols. The method selects pairs of NMR chemical shifts to determine the geometry of two hydrogen bonds and shows good agreement with direct quantum-chemical calculations.
Article
Biochemistry & Molecular Biology
Edem R. Chakalov, Elena Yu Tupikina, Daniil M. Ivanov, Ekaterina Bartashevich, Peter M. Tolstoy
Summary: This study presents a detailed analysis of electron density in 145 halogen-bonded complexes and demonstrates the possibility of predicting the strength of halogen bonds based on the distance between the minimum values of electron density and molecular electrostatic potential.
Article
Spectroscopy
E. Yu. Tupikina, A. A. Titova, M. V. Kaplanskiy, E. R. Chakalov, M. A. Kostin, P. M. Tolstoy
Summary: This computational work discusses the applicability of IR spectral parameters for evaluations of the OH center dot center dot center dot N hydrogen bond length. Geometries, energies, and IR parameters were calculated for a set of 124 complexes with OH center dot center dot center dot N hydrogen bond formed by combinations of methanol/acetic acid and pyridine (and their fluorine substituted versions) at the MP2/def2-TZVP level of theory. Equations linking several IR parameters (the shift of proton donor group stretching vibration Delta nu(s), increase of its intensity I, the low-frequency hydrogen bond stretching vibration nu(sigma), bending in-plane delta and out-of-plane gamma vibrations) with interatomic distances are proposed, and the robustness and accuracy of these equations are discussed. Additionally, the enthalpy of OH center dot center dot center dot N hydrogen bond formation Delta H was linked with electron density parameters in (3; -1) critical point.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Biochemistry & Molecular Biology
Ilia G. Denisov, Yelena V. Grinkova, Mark A. McLean, Tyler Camp, Stephen G. Sligar
Summary: Human cytochrome P450 CYP3A4 plays a significant role in the metabolism of more than 35% of pharmaceuticals, leading to drug-drug interactions. This study evaluated the use of midazolam as a probe substrate to detect and predict the involvement of new drug candidates in CYP3A4-mediated drug-drug interactions. The results suggest that the changes in the shape and volume of the substrate-binding pocket explain the occurrence of drug interactions.
Article
Chemistry, Multidisciplinary
Irina I. Fedorova, Natalia S. Soldatova, Daniil M. Ivanov, Ksenia Nikiforova, Irina S. Aliyarova, Mekhman S. Yusubov, Peter M. Tolstoy, Rosa M. Gomila, Antonio Frontera, Vadim Yu. Kukushkin, Pavel S. Postnikov, Giuseppe Resnati
Summary: This study reports the planarity of the benzothienoiodolium cation and the preorganization it provides for the hydrogen, halogen, and chalcogen bonds formed by the phenyl hydrogen, iodolium iodine, and thienyl sulfur. Crystallographic analysis reveals the coupling of these bonds to a single anion, coordinated via the supramolecular and heteroditopic synthon XB/HB or XB/ChB. The interactions of these synthons act synergistically and result in unusually short chalcogen bonds formed by the thienyl sulfur.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Biochemistry & Molecular Biology
Ilya Khodov, Valentina Sobornova, Valeriya Mulloyarova, Konstantin Belov, Alexey Dyshin, Luis Batista de Carvalho, Peter Tolstoy, Michael Kiselev
Summary: This study investigates the impact of mefenamic acid on the physical and chemical properties of silica aerogels, as well as its influence on the sorption characteristics of the composite material. Through solid state magic angle spinning nuclear magnetic resonance (MAS NMR) and high-pressure C-13 NMR kinetic studies, the presence of mefenamic acid was identified and the kinetic rates of CO2 sorption were measured. Additionally, high-pressure T-1-T-2 relaxation-relaxation correlation spectroscopy (RRCOSY) and high-pressure nuclear Overhauser effect spectroscopy (NOESY) studies were conducted to estimate the relative amount of mefenamic acid in the aerogel's pores and investigate its conformational preference when released from the aerogel.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Physical
Elena Yu. Tupikina, Vladislav O. Korostelev, Danil V. Krutin, Peter M. Tolstoy
Summary: This study computationally investigated the geometry and IR parameters of arsinic acid (H2AsOOH) and its hydrogen-bonded complexes in different media. The effects of the medium on the complexes were examined both implicitly using the IEFPCM model and explicitly by considering hydrogen-bonded complexes with various hydrogen bond donors or acceptors. The results showed that the transition from vacuum to a polar medium caused changes in the geometry and IR parameters of the complexes, with weak hydrogen bonds becoming weaker and strong and medium hydrogen bonds becoming stronger. The preferential solvation of charge-separated structures was identified as the driving force behind these changes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
E. R. Chakalov, R. P. Shekurov, V. A. Miluykov, P. M. Tolstoy
Summary: The structure of two intramolecular hydrogen-bonded motifs in ferrocene-1,1'-diyl-bisphosphinic acid has been experimentally revealed using NMR spectroscopy. The study also addressed the localization of bridging hydrons and the origins of opposite signs of H/D isotope effects on P-31 NMR chemical shifts in a cyclic dimer and a homoconjugated anion, utilizing DFT calculations.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Vladimir Y. Mikshiev, Peter M. Tolstoy, Elena Yu Tupikina, Aleksandra M. Puzyk, Mikhail A. Vovk
Summary: In this study, for the first time, energetic profiles for the reaction of AmPS with charged and uncharged nucleophiles have been established through quantum-chemical calculations. The structural motifs promoting the decay of the amide bond and decreasing the Gibbs activation energy (Delta G(double dagger)) for nucleophilic attack have been determined for a range of similar AmPSs. The proposed structural modification of the classic AmPS can facilitate the design of a new acylation agent for practical use.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Mikhail V. Dobrynin, Ilya V. Mongilev, Alexey A. Lezov, Igor Perevyazko, Peter M. Tolstoy, Yurii A. Anufrikov, Anna Yu. Shasherina, Petr S. Vlasov, Vadim Yu. Kukushkin, Regina M. Islamova
Summary: Newly obtained amphiphilic glycosilicones, synthesized via catalytic hydrosilylation, are soluble in water and form aggregates. The block-copolymeric structure of these glycosilicones was confirmed by NMR spectroscopy. They exhibit similar critical micelle concentration to commonly used alkylglucoside surfactants.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Polymer Science
Victor A. Rozentsvet, Daria M. Ulyanova, Nelly A. Sablina, Sergei Kostjuk, Peter M. Tolstoy, Ivan A. Novakov
Summary: The cationic polymerization of butadiene using secondary alkyl chlorides and alkylaluminum compounds as initiators has been investigated. The results show that this initiating system can efficiently prepare fully soluble solid polybutadienes with reduced unsaturation and high glass transition and softening temperatures. The formation of EtAlCl2 during the reaction acts as a true co-initiator.