1
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Ono T, Ito Y, Ota M, Takebayashi Y, Furuya T, Inomata H. Difference in aqueous solution structure at 293.2 and 473.2 K between ethanol and ethylene glycol via molecular dynamics. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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2
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Han L, Cui X, Cai W, Shao X. Three-level simultaneous component analysis for analyzing the near-infrared spectra of aqueous solutions under multiple perturbations. Talanta 2020; 217:121036. [PMID: 32498916 DOI: 10.1016/j.talanta.2020.121036] [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: 12/19/2019] [Revised: 04/06/2020] [Accepted: 04/11/2020] [Indexed: 10/24/2022]
Abstract
Quantitative analysis under various perturbations is a difficult problem because the analytical signal changes with different factors. In this work, three-level simultaneous component analysis (3-MSCA) was used for analyzing the near-infrared (NIR) spectra of aqueous solutions under different perturbations. The spectral data of aqueous proline solutions at different pH, concentration and temperature were measured, and a three-level model was built to describe the effects of the three perturbations on the spectra, respectively. The first level model describes the change of the spectra with pH, from which significant aggregation of proline was observed around the isoelectric point. The second and third level model show the spectral change with concentration and temperature, respectively, and the spectral feature has a very good linear relationship with the corresponding influencing factors. Therefore, the pH and concentration scores can be used as the calibration curve for quantitative analysis of the pH and the content of proline, and the temperature scores can be used to predict the temperature of the solutions. In addition, the structural change of water molecules under different conditions is obtained from the loadings. A decline of the bulk water was found with the increase of concentration, implying an ascending trend of the bonded water due to the interaction of proline and water. The dissociation of water clusters with the increase of temperature is also displayed.
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Affiliation(s)
- Li Han
- Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Xiaoyu Cui
- Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Wensheng Cai
- Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Xueguang Shao
- Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin, 300071, China; Tianjin Key Laboratory of Biosensing and Molecular Recognition, Tianjin, 300071, China; State Key Laboratory of Medicinal Chemical Biology, Tianjin, 300071, China.
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3
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Beć KB, Grabska J, Huck CW, Czarnecki MA. Effect of conformational isomerism on NIR spectra of ethanol isotopologues. Spectroscopic and anharmonic DFT study. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113271] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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4
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Ellebracht NC, Jones CW. Functionalized cellulose nanofibril aerogels as cooperative acid-base organocatalysts for liquid flow reactions. Carbohydr Polym 2020; 233:115825. [PMID: 32059881 DOI: 10.1016/j.carbpol.2019.115825] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/13/2019] [Accepted: 12/31/2019] [Indexed: 10/25/2022]
Abstract
Cellulose nanomaterial aerogels are macroscopic porous solids with relatively high surface areas and are thus an interesting basis for renewable catalyst materials. Cross-linked acid-base bifunctional catalyst aerogels are produced here from TEMPO-oxidized cellulose nanofibrils (TOCNF) and demonstrated in both batch and flow catalysis. Recently established acid-base modification for catalysis is expanded upon for chemical or physical cross-linking with small molecules and polymers. Low density and relatively high surface area (up to 74 m2 g-1) aerogel catalysts are produced with a variety of processing approaches and then freeze-dried from water or tert-butyl alcohol/water mixtures. Finer pore structure and increased surface area are achieved with tert-butyl alcohol as co-solvent. Chemical cross-linking improved aerogel stability to solvents. Homogeneous and aerogel TOCNF catalysts are shown to be effective acid-base cooperative catalysts for aldol condensation reactions in batch reactions. Continuous flow reactions are performed with glass column reactors packed with aerogel catalysts that showed improved rates relative to batch experiments, while also demonstrating physical stability. Catalyst deactivation in flow reactions is observed and observations of deactivation support previously reported mechanisms of site poisoning by competitive chemisorption of reactants in analogous acid-base catalysts. This report is a key demonstration of cellulose nanofibril aerogels for catalysis in continuous liquid flow reactions.
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Affiliation(s)
- Nathan C Ellebracht
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr., Atlanta, GA, 30332-0100, United States.
| | - Christopher W Jones
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr., Atlanta, GA, 30332-0100, United States.
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5
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Katsu S, Ito S, Yoshimura N, Takayanagi M. Variation in Near-Infrared Spectra of Water Containing Polyhydric Alcohol. J SOLUTION CHEM 2019. [DOI: 10.1007/s10953-019-00928-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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6
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Li D, Li L, Quan S, Dong Q, Liu R, Sun Z, Zang H. A feasibility study on quantitative analysis of low concentration methanol by FT-NIR spectroscopy and aquaphotomics. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2019.01.056] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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7
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Ozaki Y. Recent Advances in Molecular Spectroscopy of Electronic and Vibrational Transitions in Condensed Phase and Its Application to Chemistry. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2019. [DOI: 10.1246/bcsj.20180319] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Yukihiro Ozaki
- School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
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8
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Beć KB, Huck CW. Breakthrough Potential in Near-Infrared Spectroscopy: Spectra Simulation. A Review of Recent Developments. Front Chem 2019; 7:48. [PMID: 30854368 PMCID: PMC6396078 DOI: 10.3389/fchem.2019.00048] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 01/18/2019] [Indexed: 11/29/2022] Open
Abstract
Near-infrared (12,500–4,000 cm−1; 800–2,500 nm) spectroscopy is the hallmark for one of the most rapidly advancing analytical techniques over the last few decades. Although it is mainly recognized as an analytical tool, near-infrared spectroscopy has also contributed significantly to physical chemistry, e.g., by delivering invaluable data on the anharmonic nature of molecular vibrations or peculiarities of intermolecular interactions. In all these contexts, a major barrier in the form of an intrinsic complexity of near-infrared spectra has been encountered. A large number of overlapping vibrational contributions influenced by anharmonic effects create complex patterns of spectral dependencies, in many cases hindering our comprehension of near-infrared spectra. Quantum mechanical calculations commonly serve as a major support to infrared and Raman studies; conversely, near-infrared spectroscopy has long been hindered in this regard due to practical limitations. Advances in anharmonic theories in hyphenation with ever-growing computer technology have enabled feasible theoretical near-infrared spectroscopy in recent times. Accordingly, a growing number of quantum mechanical investigations aimed at near-infrared region has been witnessed. The present review article summarizes these most recent accomplishments in the emerging field. Applications of generalized approaches, such as vibrational self-consistent field and vibrational second order perturbation theories as well as their derivatives, and dense grid-based studies of vibrational potential, are overviewed. Basic and applied studies are discussed, with special attention paid to the ones which aim at improving analytical spectroscopy. A remarkable potential arises from the growing applicability of anharmonic computations to solving the problems which arise in both basic and analytical near-infrared spectroscopy. This review highlights an increased value of quantum mechanical calculations to near-infrared spectroscopy in relation to other kinds of vibrational spectroscopy.
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Affiliation(s)
- Krzysztof B Beć
- Center for Chemistry and Biomedicine, Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innsbruck, Austria
| | - Christian W Huck
- Center for Chemistry and Biomedicine, Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innsbruck, Austria
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9
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Chemometric methods for extracting information from temperature-dependent near-infrared spectra. Sci China Chem 2019. [DOI: 10.1007/s11426-018-9398-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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10
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Mutual factor analysis for quantitative analysis by temperature dependent near infrared spectra. Talanta 2018; 183:142-148. [PMID: 29567156 DOI: 10.1016/j.talanta.2018.02.043] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 02/08/2018] [Accepted: 02/10/2018] [Indexed: 11/22/2022]
Abstract
Temperature dependent near infrared (NIR) spectroscopy has been developed for analyzing multi-component mixtures and understanding the molecular interactions in solutions. In this work, a chemometric method named as mutual factor analysis (MFA) was proposed for the analysis of temperature dependent NIR spectra. The method extracts the common spectral feature contained in the spectra of different temperature or different concentration. The relative quantity of the extracted spectral feature is proportional to the temperature or concentration. From the spectra of water-glucose mixtures, both the spectral variations induced by temperature and concentration are obtained and the variations are correlated with the inducements, respectively, in a very good linearity. Serum samples were used for validation of the method. An acceptable calibration model with a good correlation coefficient (R2 = 0.8639) was obtained for glucose measurement. The relative deviations of the measured concentrations from the calibration model are in the range of -18.7-8.52%, which are in a reasonable level for clinical uses. More importantly, the calculations are based on the spectral information of water that has interactions with the analyte. This provides a new way for quantitative analyses of bio-systems.
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11
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Cui X, Liu X, Yu X, Cai W, Shao X. Water can be a probe for sensing glucose in aqueous solutions by temperature dependent near infrared spectra. Anal Chim Acta 2017; 957:47-54. [DOI: 10.1016/j.aca.2017.01.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 11/19/2016] [Accepted: 01/03/2017] [Indexed: 10/20/2022]
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12
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Grabska J, Beć KB, Ozaki Y, Huck CW. Temperature Drift of Conformational Equilibria of Butyl Alcohols Studied by Near-Infrared Spectroscopy and Fully Anharmonic DFT. J Phys Chem A 2017; 121:1950-1961. [DOI: 10.1021/acs.jpca.7b00646] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Justyna Grabska
- Institute
of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 80-82, 6020 Innsbruck, Austria
- Faculty
of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
- Department
of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
| | - Krzysztof B. Beć
- Institute
of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 80-82, 6020 Innsbruck, Austria
- Department
of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
| | - Yukihiro Ozaki
- Department
of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
| | - Christian W. Huck
- Institute
of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 80-82, 6020 Innsbruck, Austria
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13
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Beć KB, Futami Y, Wójcik MJ, Ozaki Y. A spectroscopic and theoretical study in the near-infrared region of low concentration aliphatic alcohols. Phys Chem Chem Phys 2016; 18:13666-82. [DOI: 10.1039/c6cp00924g] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The near-infrared (NIR) spectra of low-concentration (5 × 10−3 M) solutions in CCl4 of basic aliphatic alcohols, methanol, ethanol, and 1-propanol were, for the first time, calculated by second-order vibrational perturbation theory computations and were compared with the corresponding experimental data.
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Affiliation(s)
- Krzysztof B. Beć
- Department of Chemistry
- School of Science and Technology
- Kwansei Gakuin University
- Sanda
- Japan
| | - Yoshisuke Futami
- Department of Biological and Chemical Systems Engineering
- National Institute of Technology
- Kumamoto College
- Yatsushiro
- Japan
| | - Marek J. Wójcik
- Faculty of Chemistry
- Jagiellonian University
- Ingardena 3
- Poland
| | - Yukihiro Ozaki
- Department of Chemistry
- School of Science and Technology
- Kwansei Gakuin University
- Sanda
- Japan
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14
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Cui X, Cai W, Shao X. Glucose induced variation of water structure from temperature dependent near infrared spectra. RSC Adv 2016. [DOI: 10.1039/c6ra18912a] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The different effects of glucose on water species provide evidence to explain the bioprotective function of carbohydrates in aqueous solutions.
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Affiliation(s)
- Xiaoyu Cui
- Research Center for Analytical Sciences
- College of Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
| | - Wensheng Cai
- Research Center for Analytical Sciences
- College of Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
| | - Xueguang Shao
- Research Center for Analytical Sciences
- College of Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
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15
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Czarnecki MA, Morisawa Y, Futami Y, Ozaki Y. Advances in Molecular Structure and Interaction Studies Using Near-Infrared Spectroscopy. Chem Rev 2015; 115:9707-44. [DOI: 10.1021/cr500013u] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Yusuke Morisawa
- Department
of Chemistry, School of Science and Engineering, Kinki University, Higashi-Osaka, Osaka 577-8502, Japan
| | - Yoshisuke Futami
- Department
of Biological and Chemical Systems Engineering, National Institute of Technology, Kumamoto College, Yatsushiro, Kumamoto 866-8501, Japan
| | - Yukihiro Ozaki
- Department
of Chemistry, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
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16
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Monakhova YB, Varlamova TM, Rubtsova EM, Mushtakova SP. Iodine-water-alkanol and potassium iodide-water-alkanol systems: Phase diagrams and regularities of association according to IR and NMR spectroscopic data. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2015. [DOI: 10.1134/s0036024415040184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Monakhova YB, Mushtakova SP, Kuballa T, Lachenmeier DW. Investigation into the structural composition of hydroalcoholic solutions as basis for the development of multiple suppression pulse sequences for NMR measurement of alcoholic beverages. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2014; 52:755-759. [PMID: 25139252 DOI: 10.1002/mrc.4129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 07/11/2014] [Accepted: 07/27/2014] [Indexed: 06/03/2023]
Abstract
An eight-fold suppression pulse sequence was recently developed to improve sensitivity in (1) H NMR measurements of alcoholic beverages [Magn. Res. Chem. 2011 (49): 734-739]. To ensure that only one combined hydroxyl peak from water and ethanol appears in the spectrum, adjustment to a certain range of ethanol concentrations was required. To explain this observation, the structure of water-ethanol solutions was studied. Hydroalcoholic solutions showed extreme behavior at 25% vol, 46% vol, and 83% vol ethanol according to (1) H NMR experiments. Near-infrared spectroscopy confirmed the occurrence of four significant compounds ('individual' ethanol and water structures as well as two water-ethanol complexes of defined composition - 1 : 1 and 1 : 3). The successful multiple suppression can be achieved for every kind of alcoholic beverage with different alcoholic strengths, when the final ethanol concentration is adjusted to a range between 25% vol and 46% vol (e.g. using dilution or pure ethanol addition). In this optimum region, an individual ethanol peak was not detected, because the 'individual' water structure and the 1 : 1 ethanol-water complex predominate. The nature of molecular association in ethanol-water solutions is essential to elucidate NMR method development for measurement of alcoholic beverages. The presented approach can be used to optimize other NMR suppression protocols for binary water-organic solvent mixtures, where hydrogen bonding plays a dominant role.
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Affiliation(s)
- Yulia B Monakhova
- Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Strasse 3, 76187, Karlsruhe, Germany; Bruker Biospin GmbH, Silberstreifen, 76287, Rheinstetten, Germany
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18
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Afrin T, Mafy NN, Rahman MM, Mollah MYA, Susan MABH. Temperature perturbed water structure modification by d(−)-fructose at different concentrations. RSC Adv 2014. [DOI: 10.1039/c4ra08244c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Temperature dependence of water structure modification has been studied at different d(−)-fructose concentrations by near-infrared (NIR) spectroscopy.
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Affiliation(s)
- Tanjina Afrin
- Department of Chemistry
- University of Dhaka
- Dhaka 1000, Bangladesh
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19
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Du L, Mackeprang K, Kjaergaard HG. Fundamental and overtone vibrational spectroscopy, enthalpy of hydrogen bond formation and equilibrium constant determination of the methanol-dimethylamine complex. Phys Chem Chem Phys 2013; 15:10194-206. [PMID: 23695525 DOI: 10.1039/c3cp50243k] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have measured gas phase vibrational spectra of the bimolecular complex formed between methanol (MeOH) and dimethylamine (DMA) up to about 9800 cm(-1). In addition to the strong fundamental OH-stretching transition we have also detected the weak second overtone NH-stretching transition. The spectra of the complex are obtained by spectral subtraction of the monomer spectra from spectra recorded for the mixture. For comparison, we also measured the fundamental OH-stretching transition in the bimolecular complex between MeOH and trimethylamine (TMA). The enthalpies of hydrogen bond formation (ΔH) for the MeOH-DMA and MeOH-TMA complexes have been determined by measurements of the fundamental OH-stretching transition in the temperature range from 298 to 358 K. The enthalpy of formation is found to be -35.8 ± 3.9 and -38.2 ± 3.3 kJ mol(-1) for MeOH-DMA and MeOH-TMA, respectively, in the 298 to 358 K region. The equilibrium constant (Kp) for the formation of the MeOH-DMA complex has been determined from the measured and calculated transition intensities of the OH-stretching fundamental transition and the NH-stretching second overtone transition. The transition intensities were calculated using an anharmonic oscillator local mode model with dipole moment and potential energy curves calculated using explicitly correlated coupled cluster methods. The equilibrium constant for formation of the MeOH-DMA complex was determined to be 0.2 ± 0.1 atm(-1), corresponding to a ΔG value of about 4.0 kJ mol(-1).
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Affiliation(s)
- Lin Du
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
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20
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Monakhova YB, Rubtsova EM, Varlamova TM, Mushtakova SP. Association in solutions of monoatomic alcohols and their mixtures with water. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2012. [DOI: 10.1134/s0036024412030223] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Czarnecki MA. Determination of relative rate of spectral events by novel modification of two-dimensional correlation spectroscopy. Anal Chim Acta 2011; 702:72-80. [DOI: 10.1016/j.aca.2011.06.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 06/05/2011] [Accepted: 06/13/2011] [Indexed: 11/28/2022]
Affiliation(s)
- Mirosław A Czarnecki
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
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22
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Quantitative determination by temperature dependent near-infrared spectra: a further study. Talanta 2011; 85:420-4. [PMID: 21645719 DOI: 10.1016/j.talanta.2011.03.089] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 03/24/2011] [Accepted: 03/31/2011] [Indexed: 11/21/2022]
Abstract
Quantitative spectra-temperature relationship (QSTR) between near-infrared (NIR) spectra and temperature has been studied in our previous work (Talanta, 2010, 82, 1017-1021). In this study, applicability of the QSTR model for quantitative determination is further studied using the spectra of aqueous ethanol samples in the temperature range of 31-40°C and the concentration range of 1-99%. The results show that QSTR model can be built by using the spectra in a small temperature range and the quantitative analysis can be achieved by only two spectra at different temperatures. Moreover, calibration curves for different concentration ranges (1-5%, 20-70%, 95-99%, v/v) are investigated by using linear and nonlinear curve fitting, respectively. Both of the linear and nonlinear curves are found to be applicable within these concentration ranges. Therefore, the temperature dependent NIR spectra may provide a new way for quantitative determination and may have high potential in bio-fluids analysis or industrial practices.
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23
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Wang M, Sun S, Wu P. Spectral insight into intensity variations in phase-transition processes using two-dimensional correlation analysis. APPLIED SPECTROSCOPY 2010; 64:1396-1406. [PMID: 21144158 DOI: 10.1366/000370210793561529] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Two-dimensional correlation spectroscopy (2D-COS) is widely used in studies of phase-transition processes to provide valuable order information that is useful in investigating these mechanisms. During phase-transition processes, the spectral intensity always changes in an "S"- or "anti-S"-shaped curve. Sample selection of the large and complicated dataset for 2D correlation analysis may impact the resulting sequence and should be given serious consideration. Additionally, the relationship between the sequential order obtained from 2D-COS and the parameters of the intensity change, namely, the transition point and the change rate, is still poorly defined. This article makes an attempt to resolve these problems based on the analysis of simulated spectra by assuming that the band intensity changes in a sigmoid manner without a step delay. It is concluded that the sample range around a transition point with a drastic intensity change defined by asynchronous perturbation-correlation moving-window (PCMW2D) analysis is a reasonable choice, and in this region a band that changes earlier as determined by 2D-COS most likely has an earlier phase-transition point. Also, from the results of segmental analysis, it is proposed that 2D-COS can distinguish the sequence of two bands using only rate difference; however, the rate difference and the form of the intensity change should be considered comprehensively. The insights from the simulated results are applied to analyze the temperature-dependent infrared (IR) spectra of poly[di(butyl)vinyl terephthalate] (PDBVT). The phase-transition mechanism of PDBVT can be clearly found using a suitable sample selection method.
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Affiliation(s)
- Mengyin Wang
- The Key Laboratory of Molecular Engineering of Polymers (Ministry of Education), Department of Macromolecular Science and Laboratory of Advanced Materials, Fudan University, Shanghai 200433, People's Republic of China
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24
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Palombo F, Tassaing T, Paolantoni M, Sassi P, Morresi A. Elucidating the Association of Water in Wet 1-Octanol from Normal to High Temperature by Near- and Mid-Infrared Spectroscopy. J Phys Chem B 2010; 114:9085-93. [DOI: 10.1021/jp1009548] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Francesca Palombo
- Dipartimento di Chimica, Università degli Studi di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy, Institut des Sciences Moléculaires, Groupe Spectroscopie Moléculaire, CNRS, UMR 5255, 351, Cours de la Libération, F-33405, Talence Cedex, France, and Institut des Sciences Moléculaires, Groupe Spectroscopie Moléculaire, Université de Bordeaux, UMR 5255, 351, Cours de la Libération, F-33405, Talence Cedex, France
| | - Thierry Tassaing
- Dipartimento di Chimica, Università degli Studi di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy, Institut des Sciences Moléculaires, Groupe Spectroscopie Moléculaire, CNRS, UMR 5255, 351, Cours de la Libération, F-33405, Talence Cedex, France, and Institut des Sciences Moléculaires, Groupe Spectroscopie Moléculaire, Université de Bordeaux, UMR 5255, 351, Cours de la Libération, F-33405, Talence Cedex, France
| | - Marco Paolantoni
- Dipartimento di Chimica, Università degli Studi di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy, Institut des Sciences Moléculaires, Groupe Spectroscopie Moléculaire, CNRS, UMR 5255, 351, Cours de la Libération, F-33405, Talence Cedex, France, and Institut des Sciences Moléculaires, Groupe Spectroscopie Moléculaire, Université de Bordeaux, UMR 5255, 351, Cours de la Libération, F-33405, Talence Cedex, France
| | - Paola Sassi
- Dipartimento di Chimica, Università degli Studi di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy, Institut des Sciences Moléculaires, Groupe Spectroscopie Moléculaire, CNRS, UMR 5255, 351, Cours de la Libération, F-33405, Talence Cedex, France, and Institut des Sciences Moléculaires, Groupe Spectroscopie Moléculaire, Université de Bordeaux, UMR 5255, 351, Cours de la Libération, F-33405, Talence Cedex, France
| | - Assunta Morresi
- Dipartimento di Chimica, Università degli Studi di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy, Institut des Sciences Moléculaires, Groupe Spectroscopie Moléculaire, CNRS, UMR 5255, 351, Cours de la Libération, F-33405, Talence Cedex, France, and Institut des Sciences Moléculaires, Groupe Spectroscopie Moléculaire, Université de Bordeaux, UMR 5255, 351, Cours de la Libération, F-33405, Talence Cedex, France
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Haufa KZ, Czarnecki MA. Molecular structure and hydrogen bonding of 2-aminoethanol, 1-amino-2-propanol, 3-amino-1-propanol, and binary mixtures with water studied by Fourier transform near-infrared spectroscopy and density functional theory calculations. APPLIED SPECTROSCOPY 2010; 64:351-358. [PMID: 20223073 DOI: 10.1366/000370210790918445] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The effect of temperature and water content on the molecular structure and hydrogen bonding of 2-aminoethanol (2AE), 1-amino-2-propanol (2AP), and 3-amino-1-propanol (3AP) has been examined by Fourier transform near-infrared (FT-NIR) spectroscopy. The experimental spectra were analyzed using the two-dimensional (2D) correlation approach and chemometrics methods. Interpretation of the spectra was guided by density functional theory (DFT) calculations. The novelty of the present work relates to the interpretation of the spectra of aminoalcohols in the liquid phase and their mixtures with water based on dimeric structures. The molecules of 2AE and 2AP form stable cyclic dimers through the intermolecular O-H...N hydrogen bonds (HBs), whereas the intramolecular HBs are absent. In contrast, the molecules of 3AP create two kinds of dimers. The first dimer has two intermolecular O-H...N HBs and two intramolecular N-H...O HBs, while the second dimer has the opposite. In the liquid phase the cyclic dimers interact with each other and form higher associates through the intermolecular N-H...O HBs. The temperature rise weakens these interactions but the structure of the dimers remains intact. The majority of the molecules of water act as double proton donors to oxygens linking different molecules of aminoalcohol. This cooperative hydrogen bonding is stronger than that in bulk water. A small amount of one-bonded water occurs in the mixtures, and the population of this species increases with the temperature rise. At higher water content small clusters of water are formed. On the basis of the present results one can conclude that addition of water does not lead to noticeable variations in the structure of liquid aminoalcohols. More significant changes are induced by the temperature variations.
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Czarnecki MA, Wojtków D. Effect of varying water content on the structure of butyl alcohol/water mixtures: FT-NIR two-dimensional correlation and chemometric studies. J Mol Struct 2008. [DOI: 10.1016/j.molstruc.2007.11.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Wojtków D, Czarnecki MA. Two-dimensional attenuated total reflection infrared and near-infrared correlation study of the structure of butyl alcohol/water mixtures. APPLIED SPECTROSCOPY 2007; 61:928-34. [PMID: 17910788 DOI: 10.1366/000370207781745900] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The effect of temperature on attenuated total reflection infrared (ATR-IR) and near-infrared (NIR) transmission spectra of pure butan-1-ol, butan-2-ol, 2-methyl-propan-1-ol, 2-methyl-propan-2-ol, and mixtures with a small water content (X(H2O) </= 0.1) have been examined. The spectra were analyzed using a two-dimensional (2D) correlation approach. Two kinds of correlation analysis were performed: IR-IR and NIR-NIR homo-correlation and IR-NIR hetero-correlation. Our results reveal that the addition of small to moderate amounts of water does not destroy the structure of alcohol. The presence of water stabilizes the structure of alcohols and this effect is more evident for sec-butanol and tert-butanol. The ATR-IR spectra provide information on the most associated species, whereas absorption of the smaller associates and the free OH group is hardly seen. On the contrary, in the NIR spectra the absorption of the free OH groups dominates. The ability of resolution enhancement in the hetero-correlation asynchronous spectra is reduced as compared to that in the homo-correlation spectra. On the other hand, peaks may appear in the hetero-correlation synchronous spectra that are not observed in the homo- correlation contour plots. The positions of the synchronous peaks were used for evaluation of anharmonicity constants. These values for the free OH group do not depend on the experimental conditions. In contrast, the anharmonicity constants for the bonded OH groups determined from the spectra of pure alcohols may significantly differ from those obtained from diluted solutions.
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Affiliation(s)
- Dagmara Wojtków
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
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