1
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Church TL, Eriksson L, Leandri V, Gardner JM, Hedin N. A microporous polymer based on nonconjugated hindered biphenyls that emits blue light. Sci Rep 2024; 14:14923. [PMID: 38942951 PMCID: PMC11213909 DOI: 10.1038/s41598-024-65743-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 06/24/2024] [Indexed: 06/30/2024] Open
Abstract
Microporous organic polymers that have three-dimensional connectivity stemming from monomers with tetrahedral or tetrahedron-like geometry can have high surface areas and strong fluorescence. There are however few examples of such polymers based on hindered biaryls, and their fluorescence has not been studied. Hypothesizing that the contortion in a hindered biphenyl moiety would modulate the optical properties of a polymer built from it, we synthesized a meta-enchained polyphenylene from a 2,2',6,6'-tetramethylbiphenyl-based monomer, in which the two phenyl rings are nearly mutually perpendicular. The polymer was microporous with SBET = 495 m2 g-1. The polymer absorbed near-UV light and emitted blue fluorescence despite the meta-enchainment that would have been expected to break the conjugation. A related copolymer, synthesized from 2,2',6,6'-tetramethylbiphenyl-based and unsubstituted biphenyl-based monomers, was microporous but not fluorescent.
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Affiliation(s)
- Tamara L Church
- Department of Materials and Environmental Chemistry, Stockholm University, 106 91, Stockholm, Sweden
| | - Lars Eriksson
- Department of Materials and Environmental Chemistry, Stockholm University, 106 91, Stockholm, Sweden
| | - Valentina Leandri
- Department of Chemistry, Applied Physical Chemistry, KTH Royal Institute of Technology, 10044, Stockholm, Sweden
- RISE Chemical Process and Pharmaceutical Development, Forskargatan 20J, 15136, Södertälje, Sweden
| | - James M Gardner
- Department of Chemistry, Applied Physical Chemistry, KTH Royal Institute of Technology, 10044, Stockholm, Sweden
| | - Niklas Hedin
- Department of Materials and Environmental Chemistry, Stockholm University, 106 91, Stockholm, Sweden.
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2
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Nain S, Mukhopadhyaya A, Ali ME. Unravelling the Highest Magnetic Anisotropy Among all the nd-Shells in [WCp2]0 Metallocene. Inorg Chem 2024; 63:7401-7411. [PMID: 38578709 DOI: 10.1021/acs.inorgchem.4c00437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
Single-molecule magnets (SMMs) with a large magnetization reversal barrier are predominated by the lanthanide systems due to their strong spin-orbit coupling (SOC). However, the transition metals have also emerged as potential contenders and the largest magnetic anisotropy has been identified for a cobalt system among any d-series-based SMMs (Bunting et al. Science 2018, 362, eaat7319). In this work, we have explored the magnetic anisotropy in highly axial ligand field systems of metallocene, having different d-subshell (3d4, 4d4, and 5d4). The wave function-based multireference methods including static and dynamic electron correlations have been employed to investigate the zero-field splitting (ZFS) parameters. Here, we report exceptionally large magnetic anisotropy for a 5d complex of [WCp2]0 with the highest energy barrier that is nearly twice as high as the previous record value for the Co complex. We have also observed that the axial ZFS parameter (D) is increasing down the group in the order of 3d < 4d < 5d, pertaining to a large SOC.
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Affiliation(s)
- Sakshi Nain
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - Aritra Mukhopadhyaya
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
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3
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Ali HA, Ismail MA, Fouda AEAS, Ghaith EA. A fruitful century for the scalable synthesis and reactions of biphenyl derivatives: applications and biological aspects. RSC Adv 2023; 13:18262-18305. [PMID: 37333795 PMCID: PMC10274569 DOI: 10.1039/d3ra03531j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 06/10/2023] [Indexed: 06/20/2023] Open
Abstract
This review provides recent developments in the current status and latest synthetic methodologies of biphenyl derivatives. Furthermore, this review investigates detailed discussions of several metalated chemical reactions related to biphenyl scaffolds such as Wurtz-Fittig, Ullmann, Bennett-Turner, Negishi, Kumada, Stille, Suzuki-Miyaura, Friedel-Crafts, cyanation, amination, and various electrophilic substitution reactions supported by their mechanistic pathways. Furthermore, the preconditions required for the existence of axial chirality in biaryl compounds are discussed. Furthermore, atropisomerism as a type of axial chirality in biphenyl molecules is discussed. Additionally, this review covers a wide range of biological and medicinal applications of the synthesized compounds involving patented approaches in the last decade corresponding to investigating the crucial role of the biphenyl structures in APIs.
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Affiliation(s)
- Hajar A Ali
- Chemistry Department, Faculty of Science, Mansoura University 35516 Mansoura Egypt
| | - Mohamed A Ismail
- Chemistry Department, Faculty of Science, Mansoura University 35516 Mansoura Egypt
| | - Abd El-Aziz S Fouda
- Chemistry Department, Faculty of Science, Mansoura University 35516 Mansoura Egypt
| | - Eslam A Ghaith
- Chemistry Department, Faculty of Science, Mansoura University 35516 Mansoura Egypt
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4
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Nikaido M, Mizuse K, Ohshima Y. Torsional Wave-Packet Dynamics in 2-Fluorobiphenyl Investigated by State-Selective Ionization-Detected Impulsive Stimulated Raman Spectroscopy. J Phys Chem A 2023. [PMID: 37257002 DOI: 10.1021/acs.jpca.3c02138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report the creation and observation of vibrational wave packets pertinent to torsional motion in a biphenyl derivative in its electronic ground-state manifold. Adiabatically cooled molecular samples of 2-fluorobiphenyl were irradiated by intense nonresonant ultrashort laser pulses to drive impulsive stimulated Raman excitation of torsional motion. Spectral change due to the nonadiabatic vibrational excitation is probed in a state-selective manner using resonance-enhanced two-photon ionization through the S1 ← S0 electronic transition. The coherent nature of the excitation was exemplified by adopting irradiation with a pair of pump pulses: observed signals for excited torsional levels exhibit oscillatory variations against the mutual delay between the pump pulses due to wave-packet interference. By taking the Fourier transform of the time course of the signals, energy intervals among torsional levels with v = 0-3 were determined and utilized to calibrate a density functional theory (DFT)-calculated torsional potential-energy function. Time variation of populations in the excited torsional levels was assessed experimentally by measuring integrated intensities of the corresponding transitions while scanning the delay. Early time enhancement of the population (up to ∼2 ps) and gradual degradation of coherence (within ∼20 ps) appears. To explain the observed distinctive features, we developed a four-dimensional (4D) dynamical calculation in which one-dimensional (1D) quantum-mechanical propagation of the torsional motion was followed by solving the time-dependent Schrödinger equation, whereas three-dimensional (3D) molecular rotation was tracked by classical trajectory calculations. This hybrid approach enabled us to reproduce experimental results at a reasonable computational cost and provided a deeper insight into rotational effects on vibrational wave-packet dynamics.
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Affiliation(s)
- Makoto Nikaido
- Department of Chemistry, School of Science, Tokyo Institute of Technology, Meguro 152-8550, Japan
| | - Kenta Mizuse
- Department of Chemistry, School of Science, Tokyo Institute of Technology, Meguro 152-8550, Japan
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitazato, Minami, Sagamihara, Kanagawa 252-0373, Japan
| | - Yasuhiro Ohshima
- Department of Chemistry, School of Science, Tokyo Institute of Technology, Meguro 152-8550, Japan
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5
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Wang Y, Makkonen E, Chen X, Bürgi T. Absolute configuration retention of a configurationally labile ligand during dynamic processes of thiolate protected gold clusters. Chem Sci 2021; 12:9413-9419. [PMID: 34349915 PMCID: PMC8278927 DOI: 10.1039/d1sc01702k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/04/2021] [Indexed: 12/04/2022] Open
Abstract
Monolayer protected metal clusters are dynamic nanoscale objects. For example, the chiral Au38(2-PET)24 cluster (2-PET: 2-phenylethylthiolate) racemizes at moderate temperature. In addition, ligands and metal atoms can easily exchange between clusters. Such processes are important for applications of monolayer protected metal clusters; however, the mechanistic study of such processes turns out to be challenging. Here we use a configurationally labile, axially chiral ligand, biphenyl-2,2'-dithiol (R/S-BiDi), as a probe to study dynamic cluster processes. It is shown that the ligand exchange of free R/S-BiDi on a chiral Au38(2-PET)24 cluster is diastereospecific. Using chiral chromatography, isolated single diastereomers of the type anticlockwise/clockwise-Au38(2-PET)22(R/S-BiDi)1 could be isolated. Upon heating, the cluster framework racemizes, while the R/S-BiDi ligand does not. These findings demonstrate that during cluster racemization and/or ligand exchange between clusters, the R/S-BiDi ligand is sufficiently confined, thus preventing its racemization, and exclude the possibility that the ligand desorbs from the cluster surface.
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Affiliation(s)
- Yanan Wang
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest-Ansermet 1211 Geneva 4 Switzerland
| | - Esko Makkonen
- Department of Applied Physics, Aalto University Otakaari 1 FI-02150 Espoo Finland
| | - Xi Chen
- Department of Applied Physics, Aalto University Otakaari 1 FI-02150 Espoo Finland
| | - Thomas Bürgi
- Department of Physical Chemistry, University of Geneva 30 Quai Ernest-Ansermet 1211 Geneva 4 Switzerland
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6
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Pecorari D, Mazzanti A, Gianvittorio S, Foschi S, Stagni S, Fiorini V, Mancinelli M. Highly twisted carbazole-borane derivatives: B–N stereodynamic analysis and consequences on their emission properties. Org Chem Front 2021. [DOI: 10.1039/d1qo00715g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The manuscript describes the stereodynamic features of amino bis-mesityl-boranes bearing carbazole and benzocarbazole as donor heterocycles, and how they influence the photophysical properties.
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Affiliation(s)
- Daniel Pecorari
- Department of Industrial Chemistry “Toso Montanari”
- University of Bologna
- I-40136 Bologna
- Italy
| | - Andrea Mazzanti
- Department of Industrial Chemistry “Toso Montanari”
- University of Bologna
- I-40136 Bologna
- Italy
| | - Stefano Gianvittorio
- Department of Industrial Chemistry “Toso Montanari”
- University of Bologna
- I-40136 Bologna
- Italy
| | - Simone Foschi
- Department of Industrial Chemistry “Toso Montanari”
- University of Bologna
- I-40136 Bologna
- Italy
| | - Stefano Stagni
- Department of Industrial Chemistry “Toso Montanari”
- University of Bologna
- I-40136 Bologna
- Italy
| | - Valentina Fiorini
- Department of Industrial Chemistry “Toso Montanari”
- University of Bologna
- I-40136 Bologna
- Italy
| | - Michele Mancinelli
- Department of Industrial Chemistry “Toso Montanari”
- University of Bologna
- I-40136 Bologna
- Italy
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7
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Barbero H, Meunier A, Kotturi K, Smith A, Kyritsakas N, Killmeyer A, Rabbani R, Nazimuddin M, Masson E. Counterintuitive torsional barriers controlled by hydrogen bonding. Phys Chem Chem Phys 2020; 22:20602-20611. [PMID: 32966431 DOI: 10.1039/d0cp03285a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The torsional barriers along the Caryl-Caryl axis of a pair of isosteric disubstituted biphenyls were determined by variable temperature 1H NMR spectroscopy in three solvents with contrasted hydrogen bond accepting abilities (1,1,2,2-tetrachloroethane-d2, nitrobenzene-d5 and dimethyl sulfoxide-d6). One of the biphenyl scaffolds was substituted at its ortho and ortho' positions with N'-acylcarbohydrazide groups that could engage in a pair of intramolecular N-HO=C hydrogen bonding interactions at the ground state, but not at the transition state of the torsional isomerization pathway. The torsional barrier of this biphenyl was exceedingly low despite the presence of the hydrogen bonds (16.1, 15.6 and 13.4 kcal mol-1 in the three aforementioned solvents), compared to the barrier of the reference biphenyl (15.3 ± 0.1 kcal mol-1 on average). Density functional theory and the solvation model developed by Hunter were used to decipher the various forces at play. They highlighted the strong stabilization of hydrogen bond donating solutes not only by hydrogen bond accepting solvents, but also by weakly polar, yet polarizable solvents. As fast exchanges on the NMR time scale were observed above the melting point of dimethyl sulfoxide-d6, a simple but accurate model was also proposed to extrapolate low free activation energies in a pure solvent (dimethyl sulfoxide-d6) from higher ones determined in mixtures of solvents (dimethyl sulfoxide-d6 in nitrobenzene-d5).
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Affiliation(s)
- Héctor Barbero
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA.
| | - Antoine Meunier
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA.
| | - Kondalarao Kotturi
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA.
| | - Ashton Smith
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA.
| | - Nathalie Kyritsakas
- Molecular Tectonics Laboratory, University of Strasbourg, UMR UDS-CNRS 7140, Institut le Bel, F-67000 Strasbourg, France
| | - Adam Killmeyer
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA.
| | - Ramin Rabbani
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA.
| | - Md Nazimuddin
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA.
| | - Eric Masson
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA.
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8
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Zeindlhofer V, Hudson P, Pálvölgyi ÁM, Welsch M, Almarashi M, Woodcock HL, Brooks B, Bica-Schröder K, Schröder C. Enantiomerization of Axially Chiral Biphenyls: Polarizable MD Simulations in Water and Butylmethylether. Int J Mol Sci 2020; 21:E6222. [PMID: 32872113 PMCID: PMC7503397 DOI: 10.3390/ijms21176222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/20/2020] [Accepted: 08/25/2020] [Indexed: 01/14/2023] Open
Abstract
In this study, we investigate the influence of chiral and achiral cations on the enantiomerization of biphenylic anions in n-butylmethylether and water. In addition to the impact of the cations and solvent molecules on the free energy profile of rotation, we also explore if chirality transfer between a chiral cation and the biphenylic anion is possible, i.e., if pairing with a chiral cation can energetically favour one conformer of the anion via diastereomeric complex formation. The quantum-mechanical calculations are accompanied by polarizable MD simulations using umbrella sampling to study the impact of solvents of different polarity in more detail. We also discuss how accurate polarizable force fields for biphenylic anions can be constructed from quantum-mechanical reference data.
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Affiliation(s)
- Veronika Zeindlhofer
- Department of Computational Biological Chemistry, University of Vienna, Währingerstraße 17, 1090 Vienna, Austria; (V.Z.); (M.W.); (M.A.)
| | - Phillip Hudson
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD 20892, USA; (P.H.); (B.B.)
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA;
| | - Ádám Márk Pálvölgyi
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, 1060 Vienna, Austria; (Á.M.P.); (K.B.-S.)
| | - Matthias Welsch
- Department of Computational Biological Chemistry, University of Vienna, Währingerstraße 17, 1090 Vienna, Austria; (V.Z.); (M.W.); (M.A.)
| | - Mazin Almarashi
- Department of Computational Biological Chemistry, University of Vienna, Währingerstraße 17, 1090 Vienna, Austria; (V.Z.); (M.W.); (M.A.)
| | - H. Lee Woodcock
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA;
| | - Bernard Brooks
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD 20892, USA; (P.H.); (B.B.)
| | - Katharina Bica-Schröder
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, 1060 Vienna, Austria; (Á.M.P.); (K.B.-S.)
| | - Christian Schröder
- Department of Computational Biological Chemistry, University of Vienna, Währingerstraße 17, 1090 Vienna, Austria; (V.Z.); (M.W.); (M.A.)
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9
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Scharinger F, Márk Pálvölgyi Á, Zeindlhofer V, Schnürch M, Schröder C, Bica‐Schröder K. Counterion Enhanced Organocatalysis: A Novel Approach for the Asymmetric Transfer Hydrogenation of Enones. ChemCatChem 2020; 12:3776-3782. [PMID: 32999691 PMCID: PMC7507862 DOI: 10.1002/cctc.202000414] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/22/2020] [Indexed: 12/11/2022]
Abstract
We present a novel strategy for organocatalytic transfer hydrogenations relying on an ion-paired catalyst of natural l-amino acids as main source of chirality in combination with racemic, atropisomeric phosphoric acids as counteranion. The combination of a chiral cation with a structurally flexible anion resulted in a novel chiral framework for asymmetric transfer hydrogenations with enhanced selectivity through synergistic effects. The optimized catalytic system, in combination with a Hantzsch ester as hydrogen source for biomimetic transfer hydrogenation, enabled high enantioselectivity and excellent yields for a series of α,β-unsaturated cyclohexenones under mild conditions. Moreover, owing to the use of readily available and chiral pool-derived building blocks, it could be prepared in a straightforward and significantly cheaper way compared to the current state of the art.
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Affiliation(s)
- Fabian Scharinger
- Institute of Applied Synthetic ChemistryTU WienGetreidemarkt 9/1631060WienAustria
| | - Ádám Márk Pálvölgyi
- Institute of Applied Synthetic ChemistryTU WienGetreidemarkt 9/1631060WienAustria
| | - Veronika Zeindlhofer
- Department of Computational Biological ChemistryUniversity of ViennaWähringer Str. 171090WienAustria
| | - Michael Schnürch
- Institute of Applied Synthetic ChemistryTU WienGetreidemarkt 9/1631060WienAustria
| | - Christian Schröder
- Department of Computational Biological ChemistryUniversity of ViennaWähringer Str. 171090WienAustria
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10
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Vik EC, Li P, Maier JM, Madukwe DO, Rassolov VA, Pellechia PJ, Masson E, Shimizu KD. Large transition state stabilization from a weak hydrogen bond. Chem Sci 2020; 11:7487-7494. [PMID: 34123031 PMCID: PMC8159443 DOI: 10.1039/d0sc02806a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A series of molecular rotors was designed to study and measure the rate accelerating effects of an intramolecular hydrogen bond. The rotors form a weak neutral O–H⋯O
Created by potrace 1.16, written by Peter Selinger 2001-2019
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C hydrogen bond in the planar transition state (TS) of the bond rotation process. The rotational barrier of the hydrogen bonding rotors was dramatically lower (9.9 kcal mol−1) than control rotors which could not form hydrogen bonds. The magnitude of the stabilization was significantly larger than predicted based on the independently measured strength of a similar O–H⋯OC hydrogen bond (1.5 kcal mol−1). The origins of the large transition state stabilization were studied via experimental substituent effect and computational perturbation analyses. Energy decomposition analysis of the hydrogen bonding interaction revealed a significant reduction in the repulsive component of the hydrogen bonding interaction. The rigid framework of the molecular rotors positions and preorganizes the interacting groups in the transition state. This study demonstrates that with proper design a single hydrogen bond can lead to a TS stabilization that is greater than the intrinsic interaction energy, which has applications in catalyst design and in the study of enzyme mechanisms. A series of molecular rotors was designed to study and measure the rate accelerating effects of an intramolecular hydrogen bond.![]()
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Affiliation(s)
- Erik C Vik
- Department of Chemistry and Biochemistry, University of South Carolina Columbia SC 29208 USA
| | - Ping Li
- Department of Chemistry and Biochemistry, University of South Carolina Columbia SC 29208 USA
| | - Josef M Maier
- Department of Chemistry and Biochemistry, University of South Carolina Columbia SC 29208 USA
| | - Daniel O Madukwe
- Department of Chemistry and Biochemistry, University of South Carolina Columbia SC 29208 USA
| | - Vitaly A Rassolov
- Department of Chemistry and Biochemistry, University of South Carolina Columbia SC 29208 USA
| | - Perry J Pellechia
- Department of Chemistry and Biochemistry, University of South Carolina Columbia SC 29208 USA
| | - Eric Masson
- Department of Chemistry and Biochemistry, Ohio University Athens OH 45701 USA
| | - Ken D Shimizu
- Department of Chemistry and Biochemistry, University of South Carolina Columbia SC 29208 USA
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11
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He G, He H. Water Promotes the Oxidation of SO 2 by O 2 over Carbonaceous Aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:7070-7077. [PMID: 32338880 DOI: 10.1021/acs.est.0c00021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Severe haze episodes typically occur with concurrent high relative humidity. Here, the vital role of water in promoting the oxidation of SO2 by O2 on carbonaceous soot surfaces was identified at the atomic level by first-principles calculations. Water molecules can dissociate into surface hydroxyl groups through a self-catalyzed process under ambient conditions. The surface hydroxyl groups, acting as facilitators, can significantly accelerate the conversion of SO2 to SO3 (precursor of particulate sulfate) over soot aerosols by reducing the reaction barriers. Specifically, the hydroxyl groups activate the reactants and stabilize the transition states and products through hydrogen-bonding interactions, making the reactions both thermodynamically and kinetically more favorable at room temperature. The findings indicate that atmospheric humidity plays an important role in enhancing the atmospheric oxidation capacity, thus exacerbating SO2 oxidation and severe haze development. Also, this study unravels a mechanism of surface hydroxyl-assisted O2 and H2O dissociation over metal-free carbocatalysts under normal conditions.
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Affiliation(s)
- Guangzhi He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, Fujian 361021, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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12
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Barclay MS, Elles CG, Caricato M. On the Discrepancy between Experimental and Calculated Raman Intensities for Conjugated Phenyl and Thiophene Derivatives. J Phys Chem A 2020; 124:4678-4689. [PMID: 32392419 DOI: 10.1021/acs.jpca.0c00363] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Compared with experimental spectra, calculations for conjugated phenyl and thiophene oligomers tend to overestimate the ground state Raman intensities of higher-frequency vibrations (1200-1800 cm-1) relative to the intensities at lower frequencies (<1200 cm-1). The discrepancy was observed in previous benchmarking work that examined the method dependence of the calculated Raman spectra for a series of aromatic molecules. This paper further investigates the nature of the discrepancy by examining the role of anharmonic corrections and the dependence of the calculated Raman spectra on the inter-ring torsion angle for the representative molecules biphenyl (BP), 2-phenylthiophene (PT), and 2,2'-bithiophene (BT). Perturbative anharmonic corrections to the spectra calculated using density functional theory (DFT) provide only slightly better agreement with experiment. On the other hand, calculations at larger torsion angles give up to 30% improvement in the relative Raman intensities compared with the spectra calculated at the optimized geometries. The torsion-angle dependence of the Raman intensities is most pronounced for delocalized C-C and C-S stretching modes, and less pronounced for bending and ring distortion modes that do not involve inter-ring stretching. Higher-level calculations using the coupled cluster with single, double, and perturbative triple excitations [CCSD(T)] method indicate that DFT underestimates the energy barrier for torsion isomerization at small angles, and it overestimates the barriers at large angles, thus predicting minimum geometries at torsion angles that are too small. Therefore, the results suggest that the discrepancy in relative Raman intensities may be related to an overestimation of inter-ring conjugation by DFT, which also tends to favor geometries that are too planar.
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Affiliation(s)
- Matthew S Barclay
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Christopher G Elles
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Marco Caricato
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
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13
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Marsan ES, Bayse CA. Halogen Bonding Interactions of Polychlorinated Biphenyls and the Potential for Thyroid Disruption. Chemistry 2020; 26:5200-5207. [PMID: 31849117 PMCID: PMC8812442 DOI: 10.1002/chem.201903904] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 12/13/2019] [Indexed: 11/21/2023]
Abstract
Polychlorinated biphenyl (PCB) flame retardants are persistent pollutants and inhibit neurodevelopment, particularly in the early stages of life. Halogen bonding (XB) to the iodothyronine deiodinases (Dio) that modulate thyroid hormones (THs) is a potential mechanism for endocrine disruption. Cl⋅⋅⋅Se XB interactions of PCBs with SeMe- , a small model of the Dio active site selenocysteine, are compared with previous results on polybrominated diphenylethers (PBDEs) and THs using density functional theory. PCBs generally display weaker XB interactions compared to PBDEs and THs, consistent with the dependence of XB strength on the size of the halogen (I>Br>Cl). PCBs also do not meet a proposed energy threshold for substrates to undergo dehalogenation, suggesting they may behave as competitive inhibitors of Dio in addition to other mechanisms of endocrine disruption. XB interactions in PCBs are position-dependent, with ortho interactions slightly more favorable than meta and para interactions, suggesting that PCBs may have a greater effect on certain classes of Dio. Flexibility of PCBs around the biphenyl C-C bond is limited by ortho substitutions relative to the biphenyl linkage, which may contribute to the ability to inhibit Dio and other TH-related proteins.
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Affiliation(s)
- Eric S Marsan
- Department of Chemistry and Biochemistry, Old Dominion University, 1 Old Dominion University, Norfolk, VA, 23529, USA
| | - Craig A Bayse
- Department of Chemistry and Biochemistry, Old Dominion University, 1 Old Dominion University, Norfolk, VA, 23529, USA
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14
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Mancinelli M, Bencivenni G, Pecorari D, Mazzanti A. Stereochemistry and Recent Applications of Axially Chiral Organic Molecules. European J Org Chem 2020. [DOI: 10.1002/ejoc.201901918] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Michele Mancinelli
- Department of Industrial Chemistry “Toso Montanari” University of Bologna Viale Risorgimento 4 40136 Bologna Italy
| | - Giorgio Bencivenni
- Department of Industrial Chemistry “Toso Montanari” University of Bologna Viale Risorgimento 4 40136 Bologna Italy
| | - Daniel Pecorari
- Department of Industrial Chemistry “Toso Montanari” University of Bologna Viale Risorgimento 4 40136 Bologna Italy
| | - Andrea Mazzanti
- Department of Industrial Chemistry “Toso Montanari” University of Bologna Viale Risorgimento 4 40136 Bologna Italy
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15
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Chernikova EY, Berdnikova DV, Peregudov AS, Fedorova OA, Fedorov YV. Encapsulation-Controlled Photoisomerization of a Styryl Derivative: Stereoselective Formation of the Anti Z-Isomer in the Cucurbit[7]uril Cavity. Chemphyschem 2020; 21:442-449. [PMID: 31863708 DOI: 10.1002/cphc.201901095] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/20/2019] [Indexed: 02/04/2023]
Abstract
The photochemical isomerization of a styrylpyridinium dye (SP) bearing an unsymmetrically attached benzo-15-crown-5 ether has been studied in aqueous solution in the absence and presence of cucurbit[7]uril (CB[7]). The detailed analysis of the UV/Vis and NMR spectra showes that the isomeric composition of the photostationary mixtures of SP can be modulated by the host-guest complexation with CB[7]. It was found that steric hindrance caused by encapsulation of SP in the host cavity induces the exclusive formation of the anti conformer of Z-SP in contrast with the mixture of both anti and syn conformers obtained during photoisomerization of the dye without CB[7]. Remarkably, the displacement of anti Z-SP from CB[7] does not lead to the transformation of the anti Z-isomer into the syn Z-isomer pointing out the conformational memory of the system. The results provide an interesting example of the supramolecular stereorecognition by the achiral CB[7] host.
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Affiliation(s)
- Ekaterina Y Chernikova
- Laboratory of Photoactive Supramolecular Systems, A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Science, Vavilova st. 28, 119991, Moscow, Russia
| | - Daria V Berdnikova
- Universität Siegen, Organische Chemie II, Adolf-Reichwein-Str. 2, 57076, Siegen, Germany
| | - Alexander S Peregudov
- Laboratory of Nuclear Magnetic Resonances, A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Science, Vavilova st. 28, 119991, Moscow, Russia
| | - Olga A Fedorova
- Laboratory of Photoactive Supramolecular Systems, A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Science, Vavilova st. 28, 119991, Moscow, Russia
| | - Yuri V Fedorov
- Laboratory of Photoactive Supramolecular Systems, A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Science, Vavilova st. 28, 119991, Moscow, Russia
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16
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Sigalov M, Lokshin V, Larina N, Khodorkovsky V. Hindered rotational barriers in conjugated donor-acceptor substituted systems: calculations vs. experiments. Phys Chem Chem Phys 2020; 22:1214-1221. [PMID: 31848559 DOI: 10.1039/c9cp06234c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Quantum mechanical calculations of barriers to rotation within push-pull π-conjugated molecules involving strong electron donors (D) and acceptors (A) using the generally accepted approach fail to reproduce the experimental barriers determined by temperature-dependent NMR spectra. On the examples of seven derivatives of this type with substituents of varying electron donating and accepting strength, we find that determination of one of the rotational barriers, for instance, that of the acceptor substituent, requires not only the energy calculation of the respective transition state of this substituent, but also the transition state of the donor and the transition state involving both donor and acceptor substituents. Calculations of the rotation barriers using B3LYP and APFD functionals considering three transition states produce the results with mean absolute deviations from 10 experimental barriers of 0.28-0.19 kcal mol-1 depending on the basis set.
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Affiliation(s)
- Mark Sigalov
- Dept. of Chemistry, Ben-Gurion Univ. of the Negev, Beer-Sheva, 84105, Israel
| | - Vladimir Lokshin
- Aix Marseille Université, CNRS, CINaM UMR 7325, 13288, Marseille, France.
| | - Nina Larina
- Aix Marseille Université, CNRS, CINaM UMR 7325, 13288, Marseille, France.
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17
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Guo F, Wang Z, Zhao L, Liu W. A proposed method of enantioselectivity analysis for residual chiral PCBs in gas chromatography. CHEMOSPHERE 2019; 229:401-408. [PMID: 31082707 DOI: 10.1016/j.chemosphere.2019.04.162] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/26/2019] [Accepted: 04/21/2019] [Indexed: 06/09/2023]
Abstract
Polychlorinated biphenyls (PCBs) are harmful and persistent organic pollutants. The influence of chiral PCBs acts mainly on the different enantiomer fraction, bioaccumulation and even degradation in environmental media. Solvents and temperatures existed almost everywhere during the analysis of extraction, purification, concentration and detection, which was often underestimated in previous studies. In our study, the configuration stability of the chiral PCBs was examined from solvent and temperature aspects. Transformation phenomena for the analytic stereoisomer monomers of PCB45, PCB95, and PCB149 affected by temperature were observed. We demonstrated that higher inlet temperatures could increase the sensibility for the low-concentration environmental samples, resulting in isomerization of chiral PCBs. Real rice samples were used to verify our analysis method. Combined with density functional theory, we verified the mechanism of isomer conversion with various numbers and sites of the -Cl substituent. PCBs with tetra-ortho substituents (2, 2', 6, 6') were relatively stable and showed the highest rotational barriers (Ea) at approximate 240 kJ mol-1. Others with trio-ortho substituents (2, 2', 6/6') showed Ea from 170 to 190 kJ mol-1, whose enantiomeric fractions would be affected by temperature during the analysis process for environmental detection. The method we developed was a promising means to understand the mechanism of isomerization and to predict stabilities of chiral PCBs.
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Affiliation(s)
- Fangjie Guo
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Zhongyu Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Lu Zhao
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Weiping Liu
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
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18
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Barclay M, Bjornsson R, Cipriani M, Terfort A, Fairbrother DH, Ingólfsson O. The role of the dihedral angle and excited cation states in ionization and dissociation of mono-halogenated biphenyls; a combined experimental and theoretical coupled cluster study. Phys Chem Chem Phys 2019; 21:4556-4567. [PMID: 30741276 DOI: 10.1039/c8cp07785a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a combined theoretical and experimental study on the ionization and primary fragmentation channels of the mono-halogenated biphenyls; 2-chlorobiphenyl, 2-bromobiphenyl and 2-iodobiphenyl. The ionization energies (IEs) of the 2-halobiphenyls and the appearance energies (AEs) of the principal fragments are determined through electron impact ionization, while quantum mechanical calculations at the coupled cluster level of theory are used to elucidate the observed processes and the associated dynamics. The primary fragmentation channels are the direct loss of the halogen upon ionization, the loss of the respective hydrogen halides (HX) as well as loss of the hydrogen halide and an additional hydrogen. We find that the dihedral angle strongly influences the relative potential energy of the neutral and the cation on their respective ground state surfaces, an effect caused by the strong influence of the nuclear motion on the conjugation between the phenyl rings. For the principal dissociative ionization channels from the mono-halogenated biphenyls we reason that these can not be described as statistical decay from the ground state cation, but must rather be understood as direct, state-selective processes from specific excited cationic states characterized through local ionization of either the halogenated or the non-substituted phenyl ring.
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Affiliation(s)
- Michael Barclay
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA
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19
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Thompson NA, Barbero H, Masson E. Templating conformations with cucurbiturils. Chem Commun (Camb) 2019; 55:12160-12163. [DOI: 10.1039/c9cc06766c] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The trans- and cis conformations of 5,5′-substituted 2,2′-dithiophenes can be stabilized when those are secured with two Cucurbit[8]uril macrocycles (CB[8]) on top of rigid 2,6- and 2,7-substituted naphthalenes, which respectively mimic the trans and cis conformations of the dithiophene.
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Affiliation(s)
- Nathan A. Thompson
- Department of Chemistry and Biochemistry
- Ohio University
- Athens
- Ohio 45701
- USA
| | - Héctor Barbero
- Department of Chemistry and Biochemistry
- Ohio University
- Athens
- Ohio 45701
- USA
| | - Eric Masson
- Department of Chemistry and Biochemistry
- Ohio University
- Athens
- Ohio 45701
- USA
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20
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Aparicio F, Mayoral MJ, Montoro-García C, González-Rodríguez D. Guidelines for the assembly of hydrogen-bonded macrocycles. Chem Commun (Camb) 2019; 55:7277-7299. [DOI: 10.1039/c9cc03166a] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This article highlights selected examples on the synthesis of hydrogen-bonded macrocycles from ditopic molecules and analyze the main factors, often interrelated, that influence the equilibrium between ring and chain species.
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Affiliation(s)
- F. Aparicio
- Nanostructured Molecular Systems and Materials (MSMn) group
- Departamento de Química Orgánica
- Facultad de Ciencias
- Universidad Autónoma de Madrid
- 28049 Madrid
| | - M. J. Mayoral
- Nanostructured Molecular Systems and Materials (MSMn) group
- Departamento de Química Orgánica
- Facultad de Ciencias
- Universidad Autónoma de Madrid
- 28049 Madrid
| | - C. Montoro-García
- Nanostructured Molecular Systems and Materials (MSMn) group
- Departamento de Química Orgánica
- Facultad de Ciencias
- Universidad Autónoma de Madrid
- 28049 Madrid
| | - D. González-Rodríguez
- Nanostructured Molecular Systems and Materials (MSMn) group
- Departamento de Química Orgánica
- Facultad de Ciencias
- Universidad Autónoma de Madrid
- 28049 Madrid
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21
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Yamashita Y, Saito Y, Kikkawa S, Mutoh Y, Hosoya S, Azumaya I, Saito S. Evaluation of the Steric Bulk of Substituents Utilizing the Shuttling Behavior of [2]Rotaxanes with N
-Arylpyrrole Moieties. European J Org Chem 2018. [DOI: 10.1002/ejoc.201801476] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Yoshiaki Yamashita
- Department of Chemistry; Faculty of Science; Tokyo University of Science; 1-3 Kagurazaka 162-8601 Shinjuku-ku Tokyo Japan
| | - Yuuki Saito
- Faculty of Pharmaceutical Sciences; Toho University; 2-2-1 Miyama 274-8510 Funabashi-shi Chiba Japan
| | - Shoko Kikkawa
- Faculty of Pharmaceutical Sciences; Toho University; 2-2-1 Miyama 274-8510 Funabashi-shi Chiba Japan
| | - Yuichiro Mutoh
- Department of Chemistry; Faculty of Science; Tokyo University of Science; 1-3 Kagurazaka 162-8601 Shinjuku-ku Tokyo Japan
| | - Shoichi Hosoya
- Institute of Research; Tokyo Medical and Dental University; 1-5-45 Yushima 113-8510 Bunkyo-ku Tokyo Japan
| | - Isao Azumaya
- Faculty of Pharmaceutical Sciences; Toho University; 2-2-1 Miyama 274-8510 Funabashi-shi Chiba Japan
| | - Shinichi Saito
- Department of Chemistry; Faculty of Science; Tokyo University of Science; 1-3 Kagurazaka 162-8601 Shinjuku-ku Tokyo Japan
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22
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Montoro‐García C, Bilbao N, Tsagri IM, Zaccaria F, Mayoral MJ, Fonseca Guerra C, González‐Rodríguez D. Impact of Conformational Effects on the Ring–Chain Equilibrium of Hydrogen‐Bonded Dinucleosides. Chemistry 2018; 24:11983-11991. [DOI: 10.1002/chem.201801704] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/07/2018] [Indexed: 01/07/2023]
Affiliation(s)
- Carlos Montoro‐García
- Nanostructured Molecular Systems and Materials groupOrganic Chemistry DepartmentUniversidad Autónoma de Madrid 28049 Madrid Spain
| | - Nerea Bilbao
- Nanostructured Molecular Systems and Materials groupOrganic Chemistry DepartmentUniversidad Autónoma de Madrid 28049 Madrid Spain
| | - Iris M. Tsagri
- Theoretical Chemistry and ACMMVrije Universiteit Amsterdam Amsterdam The Netherlands
| | - Francesco Zaccaria
- Theoretical Chemistry and ACMMVrije Universiteit Amsterdam Amsterdam The Netherlands
| | - Maria J. Mayoral
- Nanostructured Molecular Systems and Materials groupOrganic Chemistry DepartmentUniversidad Autónoma de Madrid 28049 Madrid Spain
| | - Célia Fonseca Guerra
- Theoretical Chemistry and ACMMVrije Universiteit Amsterdam Amsterdam The Netherlands
- Leiden Institute of ChemistryGorlaeus Laboratories, Leiden University Leiden The Netherlands
| | - David González‐Rodríguez
- Nanostructured Molecular Systems and Materials groupOrganic Chemistry DepartmentUniversidad Autónoma de Madrid 28049 Madrid Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem)Universidad Autónoma de Madrid 28049 Madrid Spain
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23
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Karupnaswamy R, Ganesan P. Three atropisomers of biphenyl: twist by tunable para substituents. J CHEM SCI 2018. [DOI: 10.1007/s12039-018-1482-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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24
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Qi C, Wang W, Reichl KD, McNeely J, Porco JA. Total Synthesis of Aurofusarin: Studies on the Atropisomeric Stability of Bis-Naphthoquinones. Angew Chem Int Ed Engl 2018; 57:2101-2104. [PMID: 29318760 PMCID: PMC5890919 DOI: 10.1002/anie.201711535] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/21/2017] [Indexed: 12/19/2022]
Abstract
An efficient annulation involving pyrone addition to a quinone and Dieckmann condensation was developed for rapid assembly of a γ-naphthopyrone monomeric precursor to the bis-naphthoquinone natural product aurofusarin. Dimerization was achieved through PdII -catalyzed dehydrogenative coupling. Further studies employing asymmetric nucleophilic epoxidation indicate that the atropisomers of aurofusarin and derivatives are not configurationally stable at ambient temperature.
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Affiliation(s)
| | | | - Kyle D. Reichl
- Department of Chemistry and Center for Molecular Discovery (BU-CMD) Boston University, Boston, MA 02215 (USA)
| | - James McNeely
- Department of Chemistry and Center for Molecular Discovery (BU-CMD) Boston University, Boston, MA 02215 (USA)
| | - John A. Porco
- Department of Chemistry and Center for Molecular Discovery (BU-CMD) Boston University, Boston, MA 02215 (USA)
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25
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Qi C, Wang W, Reichl KD, McNeely J, Porco JA. Total Synthesis of Aurofusarin: Studies on the Atropisomeric Stability of Bis-Naphthoquinones. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201711535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Chao Qi
- Department of Chemistry and Center for Molecular Discovery (BU-CMD); Boston University; Boston MA 02215 USA
| | - Wenyu Wang
- Department of Chemistry and Center for Molecular Discovery (BU-CMD); Boston University; Boston MA 02215 USA
| | - Kyle D. Reichl
- Department of Chemistry and Center for Molecular Discovery (BU-CMD); Boston University; Boston MA 02215 USA
| | - James McNeely
- Department of Chemistry and Center for Molecular Discovery (BU-CMD); Boston University; Boston MA 02215 USA
| | - John A. Porco
- Department of Chemistry and Center for Molecular Discovery (BU-CMD); Boston University; Boston MA 02215 USA
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26
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Fleming JT, Wills C, Waddell PG, Harrington RW, Higham LJ. A comparison of MOP-phosphonite ligands and their applications in Rh(i)- and Pd(ii)-catalysed asymmetric transformations. Dalton Trans 2018; 45:15660-15670. [PMID: 27711828 DOI: 10.1039/c6dt02390h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Six chiral MOP-phosphonites have been synthesised and compared via experimental and computational methods in an effort to quantify their differing structural and electronic profiles. They were found to be electron-poor ligands in comparison to their arylphosphine analogues and have a larger trans influence in square planar Pt(ii) complexes. Four [Rh(LP)(η2:η2-cod)Cl] complexes were synthesised and characterised by NMR, HRMS and X-ray crystallography. Two [Rh(LP)2]BF4 complexes were prepared where one ligand acts as a chelating P,C-π-donor; detailed NMR studies demonstrated a hemilabile η6-coordination mode, which in one case was confirmed by X-ray crystallography. Rh(i) complexes were used as catalysts in asymmetric hydrogenation and hydroformylation reactions and in the addition of phenyl boronic acid to an isatin. Pd(ii) complexes were successfully employed in asymmetric Suzuki-Miyaura cross-coupling reactions yielding binaphthyl products. Two [Pd(LP)2Cl2] complexes were synthesised and characterised by X-ray crystallography, both adopting cis orientations, with one of the complexes crystallising as two pseudo-polymorphs.
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Affiliation(s)
- James T Fleming
- School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
| | - Corinne Wills
- School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
| | - Paul G Waddell
- School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
| | - Ross W Harrington
- School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
| | - Lee J Higham
- School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
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27
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Guo F, Tang Q, Xie J, Zhao L, Liu K, Liu W. Enantioseparation and identification for the rationalization of the environmental impact of 4 polychlorinated biphenyls. Chirality 2018; 30:475-483. [PMID: 29315818 DOI: 10.1002/chir.22811] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/12/2017] [Accepted: 07/18/2017] [Indexed: 12/29/2022]
Abstract
Polychlorinated biphenyls (PCBs) are harmful and persistent organic pollutants that have long been used in industrial manufacturing. Their persistence leads to accumulation in the food chain causing potential toxic effects. As 19 out of 78 of the chiral congeners have stable atropisomers at ambient temperature, we studied some typical enantiomers: PCB45, PCB95, PCB136, and PCB149. The chiral stationary phases OD-H and OJ-H were used for separation in analytic high-performance liquid chromatography (HPLC), as well as for collection in semi-preparative HPLC. The resolution was optimized with respect to n-hexane-based mobile phases, temperature, and flow rate. All pure enantiomers were recovered from semi-preparative HPLC within 15 minutes for practical purpose. Characterization of the absolute configurations were conducted with a combination of theoretical and experimental electronic circular dichroism measurements. The enantiomers of PCB45, PCB95, PCB136, and PCB149 proved to be eluted as R > S, S > R, R > S, and S > R, respectively. Molecular structures (eg, substituent groups) and properties (eg, bond lengths, bond angles, and dipole moments) were quantitatively analyzed to understand the toxicity effect of PCBs. In summary, we have developed a well-established methodology of collection and configuration identification for analogous PCB derivatives.
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Affiliation(s)
- Fangjie Guo
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Qiaozhi Tang
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Jingqian Xie
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Lu Zhao
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Kai Liu
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California
| | - Weiping Liu
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
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28
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Della Sala P, Capobianco A, Caruso T, Talotta C, De Rosa M, Neri P, Peluso A, Gaeta C. An Anthracene-Incorporated [8]Cycloparaphenylene Derivative as an Emitter in Photon Upconversion. J Org Chem 2018; 83:220-227. [PMID: 29231727 DOI: 10.1021/acs.joc.7b02590] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The anthracene-incorporated [8]cycloparaphenylene 2 has been synthesized and its optoelectronic properties studied by UV-vis spectroscopy, cyclic voltammetry, and DFT calculations. NMR and computational studies indicate that the new cycloparaphenylene derivative possesses a Cs point group symmetry. The new CPP 2 exhibits peculiar optoelectronic properties: (i) fluorescence emission is blue-shifted with respect to [8]cycloparaphenylene 1, and its quantum yield is higher; (ii) in the presence of an octaethylporphyrin Pd complex, as sensitizer, it undergoes a visible light upconversion. This is the first case in which a cycloparaphenylene derivative is involved as an emitter in low power light frequency conversion.
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Affiliation(s)
- Paolo Della Sala
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno , Via Giovanni Paolo II 132, I-84084 Fisciano (Salerno), Italy
| | - Amedeo Capobianco
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno , Via Giovanni Paolo II 132, I-84084 Fisciano (Salerno), Italy
| | - Tonino Caruso
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno , Via Giovanni Paolo II 132, I-84084 Fisciano (Salerno), Italy
| | - Carmen Talotta
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno , Via Giovanni Paolo II 132, I-84084 Fisciano (Salerno), Italy
| | - Margherita De Rosa
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno , Via Giovanni Paolo II 132, I-84084 Fisciano (Salerno), Italy
| | - Placido Neri
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno , Via Giovanni Paolo II 132, I-84084 Fisciano (Salerno), Italy
| | - Andrea Peluso
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno , Via Giovanni Paolo II 132, I-84084 Fisciano (Salerno), Italy
| | - Carmine Gaeta
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno , Via Giovanni Paolo II 132, I-84084 Fisciano (Salerno), Italy
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29
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Summers TJ, Cheng Q, DeYonker NJ. A transition state “trapped”? QM-cluster models of engineered threonyl-tRNA synthetase. Org Biomol Chem 2018; 16:4090-4100. [DOI: 10.1039/c8ob00540k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
QM-cluster models demonstrate how protein bioengineering alters the local energy landscape of p-biphenylalanine to stabilize a transition state analogue.
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Affiliation(s)
| | - Qianyi Cheng
- The Department of Chemistry
- The University of Memphis
- Memphis
- USA
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30
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Schwertz G, Frei MS, Witschel MC, Rottmann M, Leartsakulpanich U, Chitnumsub P, Jaruwat A, Ittarat W, Schäfer A, Aponte RA, Trapp N, Mark K, Chaiyen P, Diederich F. Conformational Aspects in the Design of Inhibitors for Serine Hydroxymethyltransferase (SHMT): Biphenyl, Aryl Sulfonamide, and Aryl Sulfone Motifs. Chemistry 2017; 23:14345-14357. [DOI: 10.1002/chem.201703244] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/15/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Geoffrey Schwertz
- Laboratorium für Organische Chemie; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | - Michelle S. Frei
- Laboratorium für Organische Chemie; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | | | - Matthias Rottmann
- Swiss Tropical and Public Health Institute (SwissTPHI); Socinstrasse 57 4051 Basel Switzerland
- Universität Basel; Petersplatz 1 4003 Basel Switzerland
| | - Ubolsree Leartsakulpanich
- National Center for Genetic Engineering and Biotechnology; 113 Thailand Science Park, Phahonyothin Road Pathumthani 12120 Thailand
| | - Penchit Chitnumsub
- National Center for Genetic Engineering and Biotechnology; 113 Thailand Science Park, Phahonyothin Road Pathumthani 12120 Thailand
| | - Aritsara Jaruwat
- National Center for Genetic Engineering and Biotechnology; 113 Thailand Science Park, Phahonyothin Road Pathumthani 12120 Thailand
| | - Wanwipa Ittarat
- National Center for Genetic Engineering and Biotechnology; 113 Thailand Science Park, Phahonyothin Road Pathumthani 12120 Thailand
| | - Anja Schäfer
- Swiss Tropical and Public Health Institute (SwissTPHI); Socinstrasse 57 4051 Basel Switzerland
- Universität Basel; Petersplatz 1 4003 Basel Switzerland
| | | | - Nils Trapp
- Laboratorium für Organische Chemie; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | - Kerstin Mark
- Laboratorium für Organische Chemie; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | - Pimchai Chaiyen
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology; Faculty of Science Mahidol University; 272 Rama VI Road Bangkok 10400 Thailand
- Department of Biomolecular Science and Engineering; School of Biomolecular Science & Engineering; Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan Valley; Rayong 21210 Thailand
| | - François Diederich
- Laboratorium für Organische Chemie; ETH Zurich; Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
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31
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Waterman MJ, Nugraha AS, Hendra R, Ball GE, Robinson SA, Keller PA. Antarctic Moss Biflavonoids Show High Antioxidant and Ultraviolet-Screening Activity. JOURNAL OF NATURAL PRODUCTS 2017; 80:2224-2231. [PMID: 28783339 DOI: 10.1021/acs.jnatprod.7b00085] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ceratodon purpureus is a cosmopolitan moss that survives some of the harshest places on Earth: from frozen Antarctica to hot South Australian deserts. In a study on the survival mechanisms of the species, nine compounds were isolated from Australian and Antarctic C. purpureus. This included five biflavonoids, with complete structural elucidation of 1 and 2 reported here for the first time, as well as an additional four known phenolic compounds. Dispersion-corrected DFT calculations suggested a rotational barrier, leading to atropisomerism, resulting in the presence of diastereomers for compound 2. All isolates absorbed strongly in the ultraviolet (UV) spectrum, e.g., biflavone 1 (UV-A, 315-400 nm), which displayed the strongest radical-scavenging activity, 13% more efficient than the standard rutin; p-coumaric acid and trans-ferulic acid showed the highest UV-B (280-315 nm) absorption. The more complex and abundant 1 and 2 presumably have dual roles as both UV-screening and antioxidant compounds. They are strongly bound to Antarctic moss cell walls as well as located inside the cells of moss from both locations. The combined high stability and photoprotective abilities of these isolates may account for the known resilience of this species to UV-B radiation and its survival in some of the toughest locations in the world.
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Affiliation(s)
| | | | | | - Graham E Ball
- School of Chemistry, UNSW , Sydney, NSW 2052, Australia
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32
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Storch G, Maier F, Wessig P, Trapp O. Rotational Barriers of Substituted BIPHEP Ligands: A Comparative Experimental and Theoretical Study. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600836] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Golo Storch
- Organisch-Chemisches Institut; Ruprecht-Karls Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Frank Maier
- Organisch-Chemisches Institut; Ruprecht-Karls Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Pablo Wessig
- Institut für Chemie; Universität Potsdam; Karl-Liebknecht-Str. 24-25 14476 Potsdam Germany
| | - Oliver Trapp
- Organisch-Chemisches Institut; Ruprecht-Karls Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
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33
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Escribano A, Steenbock T, Herrmann C, Heck J. Limits of Molecular Dithienylethene Switches Caused by Ferrocenyl Substitution. Chemphyschem 2016; 17:1881-94. [DOI: 10.1002/cphc.201600085] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Alejandra Escribano
- Institut für Anorganische und Angewandte Chemie; Universität Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Germany
| | - Torben Steenbock
- Institut für Anorganische und Angewandte Chemie; Universität Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Germany
| | - Carmen Herrmann
- Institut für Anorganische und Angewandte Chemie; Universität Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Germany
| | - Jürgen Heck
- Institut für Anorganische und Angewandte Chemie; Universität Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Germany
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34
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Mazzanti A, Chiarucci M, Prati L, Bentley KW, Wolf C. Computational and DNMR Analysis of the Conformational Isomers and Stereodynamics of Secondary 2,2′-Bisanilides. J Org Chem 2015; 81:89-99. [DOI: 10.1021/acs.joc.5b02330] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrea Mazzanti
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Michel Chiarucci
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Luca Prati
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Keith W. Bentley
- Department
of Chemistry, Georgetown University, Washington, DC 20057, United States
| | - Christian Wolf
- Department
of Chemistry, Georgetown University, Washington, DC 20057, United States
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35
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Richards GJ, Gobo Y, Yamamura M, Nabeshima T. Biphenyl appended BODIPY derivatives showing combined environmental polarity and heavy metal cation sensing functionality. NEW J CHEM 2015. [DOI: 10.1039/c5nj00611b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Novel BODIPY derivatives exhibiting environmental polarity and combined environmental polarity/Hg2+ and Pb2+ fluorescence sensing properties have been prepared. The sensing properties are the result of a switchable photoinduced electron transfer (PeT) quenching mechanism.
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Affiliation(s)
- Gary James Richards
- Graduate School of Pure and Applied Sciences
- Tsukuba Research Centre for Interdisciplinary Materials Science (TIMS)
- University of Tsukuba
- Tsukuba
- Japan
| | - Yuki Gobo
- Graduate School of Pure and Applied Sciences
- Tsukuba Research Centre for Interdisciplinary Materials Science (TIMS)
- University of Tsukuba
- Tsukuba
- Japan
| | - Masaki Yamamura
- Graduate School of Pure and Applied Sciences
- Tsukuba Research Centre for Interdisciplinary Materials Science (TIMS)
- University of Tsukuba
- Tsukuba
- Japan
| | - Tatsuya Nabeshima
- Graduate School of Pure and Applied Sciences
- Tsukuba Research Centre for Interdisciplinary Materials Science (TIMS)
- University of Tsukuba
- Tsukuba
- Japan
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36
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Bihlmeier A, Rotzler J, Rickhaus M, Mayor M, Klopper W. Activation enthalpies and entropies of the atropisomerization of substituted butyl-bridged biphenyls. Phys Chem Chem Phys 2015; 17:11165-73. [DOI: 10.1039/c4cp06009a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Contradictory results for activation enthalpies and entropies are obtained from HPLC, CD and DFT while the atropisomerization energies are similar.
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Affiliation(s)
- Angela Bihlmeier
- Institute of Physical Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe
- Germany
| | - Jürgen Rotzler
- Department of Chemistry
- University of Basel
- 4056 Basel
- Switzerland
| | - Michel Rickhaus
- Department of Chemistry
- University of Basel
- 4056 Basel
- Switzerland
| | - Marcel Mayor
- Department of Chemistry
- University of Basel
- 4056 Basel
- Switzerland
- Institute of Nanotechnology
| | - Wim Klopper
- Institute of Physical Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe
- Germany
- Institute of Nanotechnology
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37
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Alkorta I, Cancedda C, Cocinero EJ, Dávalos JZ, Ecija P, Elguero J, González J, Lesarri A, Ramos R, Reviriego F, Roussel C, Uriarte I, Vanthuyne N. Static and dynamic properties of 1,1'-bi-2-naphthol and its conjugated acids and bases. Chemistry 2014; 20:14816-25. [PMID: 25234135 DOI: 10.1002/chem.201402686] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 07/10/2014] [Indexed: 11/10/2022]
Abstract
Several convergent techniques were used to characterize 1,1'-bi-2-naphthol (BINOL) and some of its properties. Its acidity in the gas-phase, from neutral species to monoanion, was measured by mass spectrometry. The conformation and structure of BINOL in the gas phase was determined by microwave rotational spectroscopy. NMR experiments in fluorosulfonic acid established that BINOL was monoprotonated on one of the hydroxyl oxygen atoms. The enantiomerization barriers reported in the literature for BINOL under neutral, basic, and acid conditions were analyzed with regard to the species involved. Finally, DFT calculations allowed all of these results to be gathered in a coherent picture of the BINOL structure.
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Affiliation(s)
- Ibon Alkorta
- Instituto de Química Médica, CSIC, Juan de la Cierva, 3, 28006 Madrid (Spain), Fax: (+34) 91-5644853.
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38
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Bondarchuk SV, Minaev BF. Theoretical Study of Relationships between Structural, Optical, Energetic, and Magnetic Properties and Reactivity Parameters of Benzidine and Its Oxidized Forms. J Phys Chem A 2014; 118:8872-82. [DOI: 10.1021/jp507479p] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sergey V. Bondarchuk
- Department
of Organic Chemistry, Bogdan Khmelnitsky Cherkasy National University, blvd. Shevchenko 81, 18031 Cherkasy, Ukraine
| | - Boris F. Minaev
- Department
of Organic Chemistry, Bogdan Khmelnitsky Cherkasy National University, blvd. Shevchenko 81, 18031 Cherkasy, Ukraine
- Department
of Physics, Tomsk State University, pr. Lenina 36, 634050 Tomsk, Russian Federation
- Department
of Theoretical Chemistry and Biochemistry, Royal Institute of Technology, AlbaNova, S-106 91 Stockholm, Sweden
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39
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Dutta B, Chowdhury J. Origins of threefold rotational barriers of molecule containing two methyl groups: Ethyl propionate as paradigm. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.07.075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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40
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Galan JF, Germany E, Pawlowski A, Strickland L, Galinato MGI. Theoretical and spectroscopic analysis of N,N'-diphenylurea and N,N'-dimethyl-N,N'-diphenylurea conformations. J Phys Chem A 2014; 118:5304-15. [PMID: 24971844 DOI: 10.1021/jp503539m] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Structural organization of macromolecules is highly dependent on the conformational propensity of the monomer units. Our goal is to systematically quantify differences in the conformational propensities of aromatic oligourea foldamer units. Specifically, we investigate the conformational propensities of N,N'-diphenylurea and N,N'-dimethyl-N,N'-diphenylurea in different media using a combination of theoretical methods, and infrared and nuclear magnetic resonance spectroscopies. Our results show variation in the conformational behavior upon adding methyl substituents on N,N'-diphenylurea, and varying the environments surrounding the compounds. Our energetic analyses and conformational distributions in the gas phase show predominance of the cis-trans and trans-trans conformations for N,N'-diphenylurea, while cis-cis conformation is favored for N,N'-dimethyl-N,N'-diphenylurea. In solution, our results support the trans-trans conformer as the predominant conformer for N,N'-diphenylurea, whereas the cis-cis and cis-trans forms are favored in N,N'-dimethyl-N,N'-diphenylurea. N,N'-Dimethyl-N,N'-diphenylurea also exhibits a more dynamic conformational behavior in solution, with constant fluctuations between cis-cis and cis-trans conformations. Our detailed quantitative analyses are an important aspect in fine-tuning desired conformations and dynamic properties of this class of oligomers by providing a molecular basis for the behavior at the monomeric level.
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Affiliation(s)
- Jhenny F Galan
- Department of Marine Sciences, Texas A&M University at Galveston , 200 Seawolf Parkway, Galveston, Texas 77553, United States
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41
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Berber H, Lameiras P, Denhez C, Antheaume C, Clayden J. Atropisomerism about Aryl–Csp3 Bonds: The Electronic and Steric Influence of ortho-Substituents on Conformational Exchange in Cannabidiol and Linderatin Derivatives. J Org Chem 2014; 79:6015-27. [DOI: 10.1021/jo5006069] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Hatice Berber
- ICMR, CNRS UMR
7312, Faculté de Pharmacie, Université de Reims Champagne-Ardenne, 51 rue Cognacq-Jay, F-51096 Reims Cedex, France
| | - Pedro Lameiras
- ICMR, CNRS UMR
7312, Université de Reims Champagne-Ardenne, Moulin de la Housse, Bâtiment
18, BP 1039, F-51687 Reims Cedex 2, France
| | - Clément Denhez
- ICMR, CNRS UMR
7312, Faculté de Pharmacie, Université de Reims Champagne-Ardenne, 51 rue Cognacq-Jay, F-51096 Reims Cedex, France
- Multiscale
Molecular Modeling Platform, Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, F-51687 Reims Cedex
2, France
| | - Cyril Antheaume
- Faculté de
Pharmacie, Service Commun d’Analyse, 74 route du Rhin, BP 60024, F-67401 Illkirch Cedex, France
| | - Jonathan Clayden
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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42
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Bondarchuk SV, Minaev BF. Electronic descriptors for analytical use of the benzidine-based compounds and the mechanism of oxidative coupling of anilines. J PHYS ORG CHEM 2014. [DOI: 10.1002/poc.3311] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sergey V. Bondarchuk
- Department of Organic Chemistry; Bogdan Khmelnitsky Cherkasy National University; Blvd. Shevchenko 81 18031 Cherkasy Ukraine
| | - Boris F. Minaev
- Department of Organic Chemistry; Bogdan Khmelnitsky Cherkasy National University; Blvd. Shevchenko 81 18031 Cherkasy Ukraine
- Department of Physics; Tomsk State University; Pr. Lenina, 36 634050 Tomsk Russia
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43
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Mazzanti A, Chiarucci M, Bentley KW, Wolf C. Computational and DNMR Investigation of the Isomerism and Stereodynamics of the 2,2′-Binaphthalene-1,1′-diol Scaffold. J Org Chem 2014; 79:3725-30. [DOI: 10.1021/jo5005229] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Andrea Mazzanti
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Michel Chiarucci
- Department
of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - Keith W. Bentley
- Department
of Chemistry, Georgetown University, Washington, D.C. 20057, United States
| | - Christian Wolf
- Department
of Chemistry, Georgetown University, Washington, D.C. 20057, United States
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44
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Haloui A, Haloui E. Ability of DFT to evaluate the torsional barriers in neutral and CO* protonated aromatic carbonyl compounds. J PHYS ORG CHEM 2014. [DOI: 10.1002/poc.3280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Abir Haloui
- Department of Chemistry, Faculty of Sciences of Tunis; El Manar University; 2092- Tunis Tunisia
| | - Ezzeddine Haloui
- Department of Chemistry, Faculty of Sciences of Tunis; El Manar University; 2092- Tunis Tunisia
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45
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Joseph R, Masson E. Atropisomerization in Confined Space; Cucurbiturils as Tools to Determine the Torsional Barrier of Substituted Biphenyls. European J Org Chem 2013. [DOI: 10.1002/ejoc.201301460] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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46
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Dammer SJ, Solntsev PV, Sabin JR, Nemykin VN. Synthesis, Characterization, and Electron-Transfer Processes in Indium Ferrocenyl-Containing Porphyrins and Their Fullerene Adducts. Inorg Chem 2013; 52:9496-510. [DOI: 10.1021/ic401163y] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Samantha J. Dammer
- Department of Chemistry and Biochemistry, University of Minnesota Duluth, 1039 University Drive,
Duluth, Minnesota 55812, United States
| | - Pavlo V. Solntsev
- Department of Chemistry and Biochemistry, University of Minnesota Duluth, 1039 University Drive,
Duluth, Minnesota 55812, United States
| | - Jared R. Sabin
- Department of Chemistry and Biochemistry, University of Minnesota Duluth, 1039 University Drive,
Duluth, Minnesota 55812, United States
| | - Victor N. Nemykin
- Department of Chemistry and Biochemistry, University of Minnesota Duluth, 1039 University Drive,
Duluth, Minnesota 55812, United States
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47
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Joseph R, Masson E. Subtle “supramolecular buttressing effects” in Cucurbit[7]uril/guest assemblies. Org Biomol Chem 2013; 11:3116-27. [DOI: 10.1039/c3ob40250a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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