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Nishida Y, Aono R, Dohi H, Ding W, Uzawa H. 1H-NMR Karplus Analysis of Molecular Conformations of Glycerol under Different Solvent Conditions: A Consistent Rotational Isomerism in the Backbone Governed by Glycerol/Water Interactions. Int J Mol Sci 2023; 24:ijms24032766. [PMID: 36769086 PMCID: PMC9916874 DOI: 10.3390/ijms24032766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 02/04/2023] Open
Abstract
Glycerol is a symmetrical, small biomolecule with high flexibility in molecular conformations. Using a 1H-NMR spectroscopic Karplus analysis in our way, we analyzed a rotational isomerism in the glycero backbone which generates three kinds of staggered conformers, namely gt (gauche-trans), gg (gauche-gauche), and tg (trans-gauche), at each of sn-1,2 and sn-2,3 positions. The Karplus analysis has disclosed that the three rotamers are consistently equilibrated in water keeping the relation of 'gt:gg:tg = 50:30:20 (%)' at a wide range of concentrations (5 mM~540 mM). The observed relation means that glycerol in water favors those symmetric conformers placing 1,2,3-triol groups in a gauche/gauche geometry. We have found also that the rotational isomerism is remarkably changed when the solvent is replaced with DMSO-d6 or dimethylformamide (DMF-d7). In these solvents, glycerol gives a relation of 'gt:gg:tg = 40:30:30 (%)', which means that a remarkable shift occurs in the equilibrium between gt and tg conformers. By this shift, glycerol turns to also take non-symmetric conformers orienting one of the two vicinal diols in an antiperiplanar geometry.
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Affiliation(s)
- Yoshihiro Nishida
- Molecular Chirality Research Center, Department of Applied Biological Chemistry, Institute of Environmental Horticulture, Chiba University, Matsudo 271-8510, Japan
- Correspondence:
| | - Reina Aono
- Molecular Chirality Research Center, Department of Applied Biological Chemistry, Institute of Environmental Horticulture, Chiba University, Matsudo 271-8510, Japan
| | - Hirofumi Dohi
- Molecular Chirality Research Center, Department of Applied Biological Chemistry, Institute of Environmental Horticulture, Chiba University, Matsudo 271-8510, Japan
| | - Wuxiao Ding
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8565, Japan
| | - Hirotaka Uzawa
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8565, Japan
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Sengwa R, Saraswat M, Dhatarwal P. Comprehensive characterization of glycerol/ZnO green nanofluids for advances in multifunctional soft material technologies. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Chen Z, Huang C, Yao X, Benmore CJ, Yu L. Structures of glass-forming liquids by x-ray scattering: Glycerol, xylitol, and D-sorbitol. J Chem Phys 2021; 155:244508. [PMID: 34972382 DOI: 10.1063/5.0073986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Synchrotron x-ray scattering has been used to investigate three liquid polyalcohols of different sizes (glycerol, xylitol, and D-sorbitol) from above the glass transition temperatures Tg to below. We focus on two structural orders: the association of the polar OH groups by hydrogen bonds (HBs) and the packing of the non-polar hydrocarbon groups. We find that the two structural orders evolve very differently, reflecting the different natures of bonding. Upon cooling from 400 K, the O⋯O correlation at 2.8 Å increases significantly in all three systems, indicating more HBs, until kinetic arrests at Tg; the increase is well described by an equilibrium between bonded and non-bonded OH with ΔH = 9.1 kJ/mol and ΔS = 13.4 J/mol/K. When heated above Tg, glycerol loses the fewest HBs per OH for a given temperature rise scaled by Tg, followed by xylitol and by D-sorbitol, in the same order the number of OH groups per molecule increases (3, 5, and 6). The pair correlation functions of all three liquids show exponentially damped density modulations of wavelength 4.5 Å, which are associated with the main scattering peak and with the intermolecular C⋯C correlation. In this respect, glycerol is the most ordered with the most persistent density ripples, followed by D-sorbitol and by xylitol. Heating above Tg causes faster damping of the density ripples with the rate of change being the slowest in xylitol, followed by glycerol and by D-sorbitol. Given the different dynamic fragility of the three liquids (glycerol being the strongest and D-sorbitol being the most fragile), we relate our results to the current theories of the structural origin for the difference. We find that the fragility difference is better understood on the basis of the thermal stability of HB clusters than that of the structure associated with the main scattering peak.
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Affiliation(s)
- Zhenxuan Chen
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Chengbin Huang
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Xin Yao
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Chris J Benmore
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Lian Yu
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
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Jadżyn J, Świergiel J. Molecular understanding of the viscosity variety within self-assembled hydroxyl liquids. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Adsorption and Decomposition of Glycerol on Pristine and Oxygen Modified Au(111) Surfaces. Top Catal 2019. [DOI: 10.1007/s11244-019-01199-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Reina A, Serrano-Maldonado A, Teuma E, Martin E, Gómez M. Palladium nanocatalysts in glycerol: Tuning the reactivity by effect of the stabilizer. CATAL COMMUN 2018. [DOI: 10.1016/j.catcom.2017.10.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Reina A, Pradel C, Martin E, Teuma E, Gómez M. Palladium nanoparticles stabilised by cinchona-based alkaloids in glycerol: efficient catalysts for surface assisted processes. RSC Adv 2016. [DOI: 10.1039/c6ra19230k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cinchona-based alkaloids led to well-dispersed palladium nanoparticles in neat glycerol, leading to efficient eco-friendly catalytic phases in hydrogenations and hydrodehalogenations.
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Affiliation(s)
- A. Reina
- Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA)
- Université de Toulouse
- UPS
- CNRS UMR 5069
- 31062 Toulouse cedex 9
| | - C. Pradel
- Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA)
- Université de Toulouse
- UPS
- CNRS UMR 5069
- 31062 Toulouse cedex 9
| | - E. Martin
- Departamento de Química Inorgánica
- Facultad de Química
- Universidad Nacional Autónoma de México
- Mexico
| | - E. Teuma
- Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA)
- Université de Toulouse
- UPS
- CNRS UMR 5069
- 31062 Toulouse cedex 9
| | - M. Gómez
- Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA)
- Université de Toulouse
- UPS
- CNRS UMR 5069
- 31062 Toulouse cedex 9
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Kasina A, Putzeys T, Wübbenhorst M. Dielectric and specific heat relaxations in vapor deposited glycerol. J Chem Phys 2015; 143:244504. [PMID: 26723689 DOI: 10.1063/1.4937795] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Recently [S. Capponi, S. Napolitano, and M. Wübbenhorst, Nat. Commun. 3, 1233 (2012)], vapor deposited glasses of glycerol have been found to recover their super-cooled liquid state via a metastable, ordered liquid (MROL) state characterized by a tremendously enhanced dielectric strength along with a slow-down of the relaxation rate of the structural relaxation. To study the calorimetric signature of this phenomenon, we have implemented a chip-based, differential AC calorimeter in an organic molecular beam deposition setup, which allows the simultaneous measurement of dielectric relaxations via interdigitated comb electrodes and specific heat relaxation spectra during deposition and as function of the temperature. Heating of the as-deposited glass just above the bulk Tg and subsequent cooling/reheating revealed a step-wise increase in cp by in total 9%, indicating unambiguously that glycerol, through slow vapour deposition, forms a thermodynamically stable glass, which has a specific heat as low as that of crystalline glycerol. Moreover, these glasses were found to show excellent kinetic stability as well as evidenced by both a high onset-temperature and quasi-isothermal recovery measurements at -75 °C. The second goal of the study was to elucidate the impact of the MROL state on the specific heat and its relaxation to the super-cooled state. Conversion of "MROL glycerol" to its "normal" (ordinary liquid, OL) state revealed a second, small (∼2%) increase of the glassy cp, a little gain (<10%) in the relaxed specific heat, and no signs of deviations of τcal from that of normal "bulk" glycerol. These findings altogether suggest that the MROL state in glycerol comprises largely bulk-type glycerol that coexist with a minor volume fraction (<10%) of PVD-induced structural anomalies with a crystal-like calorimetric signature. Based on the new calorimetric findings, we have proposed a new physical picture that assumes the existence of rigid polar clusters (RPCs) and conclusively explains the extraordinary high kinetic stability of the MROL state, its specific calorimetric signature, the enhanced strength, and apparent slow-down of the dielectric α-relaxation. In this new picture, the incredibly slow and strengthened dielectric response is ascribed to driven rotational diffusion of whole RPCs, a mechanism that perfectly couples to the relaxation time of the "normal" glycerol fraction. First considerations based on the strength and the retardation of the dielectric RPCs' response yield independently a size estimate for the RPCs in the order of 4-5 nm. Finally, we have discussed possible crystallisation and reorganisation effects, which give rise to pronounced out-of phase components of the specific heat at higher temperatures.
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Affiliation(s)
- A Kasina
- Department of Physics and Astronomy, Soft Matter and Biophysics Section, KU Leuven, Leuven, Belgium
| | - T Putzeys
- Department of Physics and Astronomy, Soft Matter and Biophysics Section, KU Leuven, Leuven, Belgium
| | - M Wübbenhorst
- Department of Physics and Astronomy, Soft Matter and Biophysics Section, KU Leuven, Leuven, Belgium
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Rodríguez-Rodríguez M, Gras E, Pericàs MA, Gómez M. Metal-Free Intermolecular Azide-Alkyne Cycloaddition Promoted by Glycerol. Chemistry 2015; 21:18706-10. [PMID: 26541267 DOI: 10.1002/chem.201503858] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Indexed: 12/30/2022]
Abstract
Metal-free intermolecular Huisgen cycloadditions using nonactivated internal alkynes have been successfully performed in neat glycerol, both under thermal and microwave dielectric heating. In sharp contrast, no reaction occurs in other protic solvents, such as water, ethanol, or diols. DFT calculations have shown that the BnN3/glycerol adduct promotes a more important stabilization of the corresponding LUMO than that produced in the analogous BnN3/alcohol adducts, favoring the reactivity with the alkyne in the first case. The presence of copper salts in the medium did not change the reaction pathway (Cu(I) acts as spectator), except for disubstituted silylalkynes, for which desilylation takes place in contrast to the metal-free system.
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Affiliation(s)
- Marta Rodríguez-Rodríguez
- Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA), Université de Toulouse, UPS and CNRS UMR 5069, 118, route de Narbonne, 31062 Toulouse cedex 9 (France).,Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avda. Països Catalans, 16, 43007 Tarragona (Spain)
| | - Emmanuel Gras
- Laboratoire de Chimie de Coordination (LCC), Centre National de la Recherche Scientifique (CNRS), 205, route de Narbonne, 31077 Toulouse cedex 4 (France)
| | - Miquel A Pericàs
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avda. Països Catalans, 16, 43007 Tarragona (Spain).
| | - Montserrat Gómez
- Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA), Université de Toulouse, UPS and CNRS UMR 5069, 118, route de Narbonne, 31062 Toulouse cedex 9 (France).
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