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Artykuły w czasopismach na temat „OH Stretch Vibrations”

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Data publikacji: 6 września 2023

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1

Maksyutenko, Pavlo, Maxim Grechko, Thomas R. Rizzo i Oleg V. Boyarkin. "State-resolved spectroscopy of high vibrational levels of water up to the dissociative continuum". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, nr 1968 (13.06.2012): 2710–27. http://dx.doi.org/10.1098/rsta.2011.0277.

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We summarize here our experimental studies of the high rovibrational energy levels of water. The use of double-resonance vibrational overtone excitation followed by energy-selective photofragmentation and laser-induced fluorescence detection of OH fragments allowed us to measure previously inaccessible rovibrational energies above the seventh OH-stretch overtone. Extension of the experimental approach to triple-resonance excitation provides access to rovibrational levels via transitions with significant transition dipole moments (mainly OH-stretch overtones) up to the dissociation threshold of the O–H bond. A collisionally assisted excitation scheme enables us to probe vibrations that are not readily accessible via pure laser excitation. Observation of the continuous absorption onset yields a precise value for the O–H bond dissociation threshold, 41 145.94 ± 0.15 cm −1 . Finally, we detect long-lived resonances as sharp peaks in spectra above the dissociation threshold.

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2

Sofronov, Oleksandr O., i Huib J. Bakker. "Nature of hydrated proton vibrations revealed by nonlinear spectroscopy of acid water nanodroplets". Physical Chemistry Chemical Physics 22, nr 37 (2020): 21334–39. http://dx.doi.org/10.1039/d0cp03137b.

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3

Fischer, Wolfgang B., Hans H. Eysel, Ole F. Nielsen i John E. Bertie. "Corrections to the Baseline Distortions in the OH-Stretch Region of Aqueous Solutions". Applied Spectroscopy 48, nr 1 (styczeń 1994): 107–12. http://dx.doi.org/10.1366/0003702944027525.

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The intensity gains or intensity losses of the OH-stretch vibrations and their changes of band shapes as observed in IR or Raman spectra of dilute aqueous solutions of carboxylic acids, amino acids, and amines were able to be simulated. The difference spectra of the type {sample solution} – {standard} x {empirical factor} displayed essentially flat baselines throughout the OH-stretch region of isotropic Raman scattering. Peaks of the solute spectra which had been hidden by the OH-stretch contour emerged from the background. At concentrations below 1 M, pure water was the standard. Distortions of the isotropic Raman spectra at higher solute concentrations (1 M to 4 M) could be mimicked by phosphoric acid or sulfuric acid solutions as standards. The influence of solutes on the reorientational motions of water molecules made baseline corrections of anisotropic Raman scattering and IR absorption of the more concentrated solutions difficult, if not impossible.

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4

Athokpam, Bijyalaxmi, Sai G. Ramesh i Ross H. McKenzie. "Effect of hydrogen bonding on the infrared absorption intensity of OH stretch vibrations". Chemical Physics 488-489 (maj 2017): 43–54. http://dx.doi.org/10.1016/j.chemphys.2017.03.006.

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5

Saliu, Oluwaseyi D., Gabriel A. Olatunji, Azeh Yakubu, Mariam T. Arowona i Aminat A. Mohammed. "Catalytic crosslinking of a regenerated hydrophobic benzylated cellulose and nano TiO2 composite for enhanced oil absorbency". e-Polymers 17, nr 4 (27.06.2017): 295–302. http://dx.doi.org/10.1515/epoly-2016-0289.

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AbstractHydrophobic cellulosic composites with the nano form of metal oxides possess good absorptive and adsorptive potentials. Native cellulose was regenerated, benzylated, crosslinked and blended with TiO2 nanoparticles to absorb toluene, xylene, chloroform, kerosene and petrol. The composite was fully characterized by scanning electron microscopy (SEM), transmission emission microscopy (TEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The effect of crosslinker, catalyst and time of absorption was investigated. The FTIR shows stretch and bend vibrations of hydroxyl (-OH), alkyl (-CH), aromatic double bond (C=C) for benzyl cellulose while the appearance of new peaks at 816, 769 and 726 cm−1 for Ti-O stretching vibrations confirms the successful synthesis of the composite. The SEM images revealed the transformation of foam-like appearance of benzyl cellulose to a solidified mass after TiO2 compositing. Enhanced oil absorption was seen as the amount of the aluminum sulfate catalyst was doubled as a high Qmax of 24.16, 25.81, 27.22, 24.03 and 24.43 was obtained when the amount of catalyst used was doubled.

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6

Fu, H. B., Y. J. Hu i E. R. Bernstein. "IR+vacuum ultraviolet (118 nm) nonresonant ionization spectroscopy of methanol monomers and clusters: Neutral cluster distribution and size-specific detection of the OH stretch vibrations". Journal of Chemical Physics 124, nr 2 (14.01.2006): 024302. http://dx.doi.org/10.1063/1.2141951.

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7

Pato, Usman, Yusmarini, Emma Riftyan, Evy Rossi, Rahmad Hidayat, Sandra Fitri Anjani, Nabila Riadi, Ika Nur Octaviani, Agrina Syahrul i Daimon Syukri. "Physicochemical characteristics of oil palm frond and application of CMF Hydrogel as a natural encapsulant for probiotic". IOP Conference Series: Earth and Environmental Science 1228, nr 1 (1.08.2023): 012002. http://dx.doi.org/10.1088/1755-1315/1228/1/012002.

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Abstract Oil palm solid waste from Indonesia’s large oil palm plantations has enormous potential to meet various human needs. Lb. fermentum InaCC B 1295 (LFB1295) was tested in vitro for viability, acid and bile tolerance, safety assessment, and antioxidant activities as a potential probiotic. The physiochemical characteristics of oil palm frond (OPF) and cellulose microfiber (CMF) were also examined. OPF mainly consisted of carbohydrates, particularly fiber, followed by ash, protein, and fat. The major components of OPF fiber were cellulose, lignin, and hemicellulose. The crystal index of the cellulose from OPF was 93.4%, according to an X-ray diffraction examination. The vibrations that stretch the cellulose’s -OH group were discovered via FTIR analysis at 3420.05 cm-1. The viability of LFB1295 was maintained at 9.99 log CFU/g by CMF from OPF. The persistence of LFB1295 under bile-containing conditions and at low pH was characterized by a decrease in cell number at 2.03 and 1.56 log CFU/mL, respectively. Based on its ability to repel hydrogen peroxide, neutralize DPPH radicals, and actively neutralize hydroxyl radicals. LFB1295, encapsulated in CMF hydrogel of OPF, has good antioxidant characteristics. This fact is demonstrated by the value of Hydroxyl radical scavenging activity, which is 78.43%, and the capacity to scavenge DPPH radicals, which has an inhibition and IC50 of 47.28%. Encapsulated LFB1295 by CMF hydrogel from OPF passed all in vitro safety tests.

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8

Rozhkov, Sergey, Andrey Goryunov, Vladimir Kolodey, Lyubov Pron’kina i Natalia Rozhkova. "The Role of Water Hydrogen Bonds in the Formation of Associates and Condensates in Dispersions of Serum Albumin with Shungite Carbon and Quartz Nanoparticles". Coatings 13, nr 2 (19.02.2023): 471. http://dx.doi.org/10.3390/coatings13020471.

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The role of the network of water hydrogen bonds in the regulation of the intermolecular interaction’s responsible for colloidal stability of dispersions has been studied in order to search for general patterns of interaction between water, nanoparticles, and bio-macromolecules. Raman spectroscopy for mixed dispersions of bovine serum albumin (SA), shungite carbon nanoparticles (ShC NPs), and quartz nanoparticles (quartz NPs) was performed within the wave number range 3200–3600 cm−1. The main spectral lines in this range are caused by the OH stretch vibrations of water molecules. We analyzed the state of the water hydrogen bonding network for dispersions of varied ratios of both fatty acid-containing and fatty acid-free SA macromolecules, ShC NPs, and silica NPs in the range 0.01–10 mg/mL.We used dynamic light scattering to control the sizes of the protein associates and protein associates with ShC NPs and quartz NPs. The strength of the hydrogen bonds in water depends essentially non-linearly, but in a qualitatively similar way, on the concentrations of the dispersion components. The initial strengthening of the bonds is followed by their loosening with a further increase in the concentration of the components. This is accompanied by the association of the dispersion components. We estimate the thickness of the protein corona layer as 20–25 nm for ShC NPs and 28–33 nm for quartz NPs, depending on the SA concentration. Colloidal stability of the aqueous dispersion is determined almost completely by an association of the protein with NPs. In contrast, colloidal stability of a pure protein solution is regulated by the formation of protein clusters of two main types and sizes. The association effects of SA with ShC NPs are evident in microscopic images of condensate films. The structures differ significantly for native and fatty acid-free SA in shape and size.

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9

Fry, Juliane L., Jamie Matthews, Joseph R. Lane, Coleen M. Roehl, Amitabha Sinha, Henrik G. Kjaergaard i Paul O. Wennberg. "OH-Stretch Vibrational Spectroscopy of Hydroxymethyl Hydroperoxide". Journal of Physical Chemistry A 110, nr 22 (czerwiec 2006): 7072–79. http://dx.doi.org/10.1021/jp0612127.

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10

Staib, Arnulf, i James T. Hynes. "Vibrational predissociation in hydrogen-bonded OH…O complexes via OH stretch-OO stretch energy transfer". Chemical Physics Letters 204, nr 1-2 (marzec 1993): 197–205. http://dx.doi.org/10.1016/0009-2614(93)85627-z.

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11

Zhang, Bingbing, Yong Yu, Yang-Yang Zhang, Shukang Jiang, Qinming Li, Han-Shi Hu, Gang Li i in. "Infrared spectroscopy of neutral water clusters at finite temperature: Evidence for a noncyclic pentamer". Proceedings of the National Academy of Sciences 117, nr 27 (15.06.2020): 15423–28. http://dx.doi.org/10.1073/pnas.2000601117.

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Infrared spectroscopic study of neutral water clusters is crucial to understanding of the hydrogen-bonding networks in liquid water and ice. Here we report infrared spectra of size-selected neutral water clusters, (H2O)n(n= 3−6), in the OH stretching vibration region, based on threshold photoionization using a tunable vacuum ultraviolet free-electron laser. Distinct OH stretch vibrational fundamentals observed in the 3,500−3,600-cm−1region of (H2O)5provide unique spectral signatures for the formation of a noncyclic pentamer, which coexists with the global-minimum cyclic structure previously identified in the gas phase. The main features of infrared spectra of the pentamer and hexamer, (H2O)n(n= 5 and 6), span the entire OH stretching band of liquid water, suggesting that they start to exhibit the richness and diversity of hydrogen-bonding networks in bulk water.

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12

Gulmen, Tolga S., i Edwin L. Sibert. "Vibrational Energy Relaxation of the OH Stretch in Liquid Methanol". Journal of Physical Chemistry A 108, nr 13 (kwiecień 2004): 2389–401. http://dx.doi.org/10.1021/jp037417m.

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13

Garrett-Roe, Sean, i Peter Hamm. "The OH stretch vibration of liquid water reveals hydrogen-bond clusters". Physical Chemistry Chemical Physics 12, nr 37 (2010): 11263. http://dx.doi.org/10.1039/c004579a.

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14

Schwarzer, Dirk, Jörg Lindner i Peter Vöhringer. "OH-Stretch Vibrational Relaxation of HOD in Liquid to Supercritical D2O†". Journal of Physical Chemistry A 110, nr 9 (marzec 2006): 2858–67. http://dx.doi.org/10.1021/jp0530350.

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15

Shi, Congyun, Li Ren i Fanao Kong. "Excitation of the Asymmetric Stretch Vibration of CO2in OH+CO→H+CO2Reaction". ChemPhysChem 7, nr 4 (10.03.2006): 820–23. http://dx.doi.org/10.1002/cphc.200500695.

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16

Cyran, Jenée D., Michael A. Donovan, Doris Vollmer, Flavio Siro Brigiano, Simone Pezzotti, Daria R. Galimberti, Marie-Pierre Gaigeot, Mischa Bonn i Ellen H. G. Backus. "Molecular hydrophobicity at a macroscopically hydrophilic surface". Proceedings of the National Academy of Sciences 116, nr 5 (17.01.2019): 1520–25. http://dx.doi.org/10.1073/pnas.1819000116.

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Interfaces between water and silicates are ubiquitous and relevant for, among others, geochemistry, atmospheric chemistry, and chromatography. The molecular-level details of water organization at silica surfaces are important for a fundamental understanding of this interface. While silica is hydrophilic, weakly hydrogen-bonded OH groups have been identified at the surface of silica, characterized by a high O-H stretch vibrational frequency. Here, through a combination of experimental and theoretical surface-selective vibrational spectroscopy, we demonstrate that these OH groups originate from very weakly hydrogen-bonded water molecules at the nominally hydrophilic silica interface. The properties of these OH groups are very similar to those typically observed at hydrophobic surfaces. Molecular dynamics simulations illustrate that these weakly hydrogen-bonded water OH groups are pointing with their hydrogen atom toward local hydrophobic sites consisting of oxygen bridges of the silica. An increased density of these molecular hydrophobic sites, evident from an increase in weakly hydrogen-bonded water OH groups, correlates with an increased macroscopic contact angle.

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17

Pakoulev, Andrei, Zhaohui Wang i Dana D. Dlott. "Vibrational relaxation and spectral evolution following ultrafast OH stretch excitation of water". Chemical Physics Letters 371, nr 5-6 (kwiecień 2003): 594–600. http://dx.doi.org/10.1016/s0009-2614(03)00314-2.

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18

Pipino, Andrew C. R., i Marcin Michalski. "Climbing the Vibrational Ladder To Probe the OH Stretch of HNO3on Silica". Journal of Physical Chemistry C 111, nr 26 (lipiec 2007): 9442–47. http://dx.doi.org/10.1021/jp0690244.

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19

Yamada, Yuji, Naohiko Mikami i Takayuki Ebata. "Real-time detection of doorway states in the intramolecular vibrational energy redistribution of the OH/OD stretch vibration of phenol". Journal of Chemical Physics 121, nr 23 (15.12.2004): 11530–34. http://dx.doi.org/10.1063/1.1829634.

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20

Walters, Richard S., i Michael A. Duncan. "Infrared Spectroscopy of Solvation and Isomers in Fe+(H2O)1,2Arm Complexes". Australian Journal of Chemistry 57, nr 12 (2004): 1145. http://dx.doi.org/10.1071/ch04118.

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Vibrational spectroscopy in the OH-stretching region is reported for the mass-selected ion–molecule complexes Fe+(H2O)Ar2 and Fe+(H2O)2Ar. These species are produced by laser vaporization in a pulsed nozzle cluster source, mass-selected with a reflectron time-of-flight mass spectrometer, and studied with infrared laser photodissociation spectroscopy. To achieve efficient photodissociation, the pure metal–water complexes are ‘tagged’ with weakly bound argon atoms. Such tagging is expected to exert a minor perturbation on the spectroscopy. However, we find that this may not be true depending on the binding site. The symmetric stretch and asymmetric stretch of water in these complexes shifts 30–50 cm−1 to the red as a result of binding to the metal cation, and an additional redshift is found for isomers with argon bound to the OH of water. The relationships between isomers and infrared spectra are discussed.

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21

Gao, Jing, i Xueyin Yuan. "Vibrational Investigation of Pressure-Induced Phase Transitions of Hydroxycarbonate Malachite Cu2(CO3)(OH)2". Minerals 10, nr 3 (19.03.2020): 277. http://dx.doi.org/10.3390/min10030277.

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Malachite Cu2(CO3)(OH)2 is a common hydroxycarbonate that contains about 15.3 wt % H2O. Its structural chemistry sheds light on other hydroxyl minerals that play a role in the water recycling of our planet. Here using Raman and infrared spectroscopy measurements, we studied the vibrational characteristics and structural evolution of malachite in a diamond anvil cell at room temperature (25 °C) up to ~29 GPa. Three types of vibrations were analyzed including Cu–O vibrations (300–600 cm−1), [CO3]2− vibrations (700–1600 cm−1), and O–H stretches (3200–3500 cm−1). We present novel observations of mode discontinuities at pressures of ~7, ~15, and ~23 GPa, suggesting three phase transitions, respectively. First, pressure has a great effect on the degree of deformation of the [CuO6] octahedron, as is manifested by the various shifting slopes of the Cu–O modes. [CuO6] deformation results in a rotation of the structural unit and accordingly a phase transition at ~7 GPa. Upon compression to ~15 GPa, the O–H bands redshift progressively with significant broadness, indicative of an enhancement of the hydrogen bonding, a shortening of the O···O distance, and possibly somewhat of a desymmetrization of the O–H···O bond. O–H mode hardening is identified above ~15 GPa coupled with a growth in the amplitude of the lower-energy bands. These observations can be interpreted as some reorientation or reordering of the hydrogen bonding. A further increment of pressure leads to a change in the overall compression mechanism of the structure at ~23 GPa, which is characterized by the blueshift of the O–H stretches and the softening of the O–C–O in-plane bending bands. The hydrogen bonding weakens due to a substantial enhancement of the Cu–H repulsion effect, and the O···O bond length shows no further shortening. In addition, the change in the local geometry of hydrogen is also induced by the softening of the [CO3]2− units. In this regard we may expect malachite and other analogous hydroxyl minerals as capable of transporting water downward towards the Earth’s transition zone (~23 GPa). Our results furnish our knowledge on the chemistry of hydrogen bonding at mantle conditions and open a new window in understanding the synergistic relations of water and carbon recycling in the deep Earth.

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22

Lock, A. J., J. J. Gilijamse, S. Woutersen i H. J. Bakker. "Vibrational relaxation and coupling of two OH-stretch oscillators with an intramolecular hydrogen bond". Journal of Chemical Physics 120, nr 5 (luty 2004): 2351–58. http://dx.doi.org/10.1063/1.1637576.

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Kananenka, Alexei A., i J. L. Skinner. "Fermi resonance in OH-stretch vibrational spectroscopy of liquid water and the water hexamer". Journal of Chemical Physics 148, nr 24 (28.06.2018): 244107. http://dx.doi.org/10.1063/1.5037113.

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Benoit, David M. "Fast vibrational calculation of anharmonic OH-stretch frequencies for two low-energy noradrenaline conformers". Journal of Chemical Physics 129, nr 23 (21.12.2008): 234304. http://dx.doi.org/10.1063/1.3040427.

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Gulmen, Tolga S., i Edwin L. Sibert. "Vibrational energy relaxation of the OH(D) stretch fundamental of methanol in carbon tetrachloride". Journal of Chemical Physics 123, nr 20 (22.11.2005): 204508. http://dx.doi.org/10.1063/1.2131055.

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26

Engholm, J. R., U. Happek i A. J. Sievers. "Observation of site-dependent relaxation of the OH vibrational stretch mode in fused silica". Chemical Physics Letters 249, nr 5-6 (luty 1996): 387–91. http://dx.doi.org/10.1016/0009-2614(95)01423-3.

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27

Masella, Michel, i Jean Pierre Flament. "Can the OH stretch vibrational spectra of (H2O)n clusters (n=1–6) be estimated from an empirical many-body model and a polynomial OH stretch potential?" Chemical Physics Letters 286, nr 1-2 (kwiecień 1998): 177–82. http://dx.doi.org/10.1016/s0009-2614(98)00084-0.

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Takayama, Tetsuyuki, Takuhiro Otosu i Shoichi Yamaguchi. "Transferability of vibrational spectroscopic map from TIP4P to TIP4P-like water models". Journal of Chemical Physics 158, nr 13 (7.04.2023): 136101. http://dx.doi.org/10.1063/5.0146084.

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We computed the IR, Raman, and sum frequency generation spectra of water in the OH-stretch region by employing the quantum/classical mixed approach that consists of a vibrational spectroscopic map and molecular dynamics (MD) simulation. We carried out the MD simulation with the TIP4P, TIP4P/2005, and TIP4P/Ice models and applied the map designed for TIP4P by Skinner et al. to each MD trajectory. Although the map is not tuned for TIP4P-like models, TIP4P/2005 and TIP4P/Ice provide the best reproduction of the experimental vibrational spectra of liquid water and crystalline ice, respectively. This result demonstrates the transferability of the map from TIP4P to TIP4P/2005 and TIP4P/Ice, meaning that one can choose an appropriate TIP4P-like model to calculate the vibrational spectra of an aqueous system without rebuilding the map.

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29

Choi, Jun-Ho, i Minhaeng Cho. "Computational IR spectroscopy of water: OH stretch frequencies, transition dipoles, and intermolecular vibrational coupling constants". Journal of Chemical Physics 138, nr 17 (7.05.2013): 174108. http://dx.doi.org/10.1063/1.4802991.

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Smit, Wilbert J., Fujie Tang, Yuki Nagata, M. Alejandra Sánchez, Taisuke Hasegawa, Ellen H. G. Backus, Mischa Bonn i Huib J. Bakker. "Observation and Identification of a New OH Stretch Vibrational Band at the Surface of Ice". Journal of Physical Chemistry Letters 8, nr 15 (25.07.2017): 3656–60. http://dx.doi.org/10.1021/acs.jpclett.7b01295.

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Grubbs, W. Tandy, Thomas P. Dougherty i Edwin J. Heilweil. "Bimolecular Interactions in Et3SiOH:Base:CCl4 Hydrogen-Bonded Solutions Studied by Deactivation of the "Free" OH-Stretch Vibration". Journal of the American Chemical Society 117, nr 48 (grudzień 1995): 11989–92. http://dx.doi.org/10.1021/ja00153a020.

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Doroshenko, Irina, Valeriy Pogorelov i Valdas Sablinskas. "Infrared Absorption Spectra of Monohydric Alcohols". Dataset Papers in Chemistry 2013 (24.10.2013): 1–6. http://dx.doi.org/10.7167/2013/329406.

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FTIR spectra of homologous series of monohydric alcohols which belong to the class of partly ordered liquids were registered. The molecules of monohydric alcohols containing hydroxyl group are able to form hydrogen-bonded clusters in the condensed phase. The existence of clusters is clearly observed from the position and the contour of the stretch OH band in the vibrational spectra of liquid alcohols. In this work, the experimentally registered FTIR spectra of liquid n-alcohols from methanol to decanol are presented as well as the same spectra of methanol, ethanol, propanol, butanol, pentanol, and hexanol in gas phase.

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Nagasawa, Takumi, Reo Sato, Takeshi Hasegawa, Naoki Numadate, Nobutaka Shioya, Takafumi Shimoaka, Takeshi Hasegawa i Tetsuya Hama. "Absolute Absorption Cross Section and Orientation of Dangling OH Bonds in Water Ice". Astrophysical Journal Letters 923, nr 1 (1.12.2021): L3. http://dx.doi.org/10.3847/2041-8213/ac3a0e.

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Abstract The absolute absorption cross section of dangling OH bonds in water ice, a free OH stretch mode by three-coordinated surface water molecules, is derived experimentally as 1.0 ± 0.2 × 10−18 cm2 at 3696 cm−1 for amorphous water at 90 K using infrared multiple-angle incidence resolution spectrometry (IR–MAIRS). The integrated absorption cross section (band strength) of the dangling OH bond at 90 K (1.4 ± 0.3 × 10−17 cm molecule−1 at 3710–3680 cm−1) is found to be more than 1 order of magnitude smaller than those in bulk ice or liquid water. This indicates that a lack of hydrogen-bonding significantly decreases the band strength of dangling OH bonds. The present study also provides average molecular orientations of dangling OH bonds at 10 K and 90 K, because both the surface-parallel (in-plane) and surface-perpendicular (out-of-plane) vibration spectra of dangling OH bonds are quantitatively measured by IR–MAIRS. The intensity ratio of the dangling-OH peaks between in-plane to out-of-plane spectra shows the isotropic nature (random orientation) of the two- and three-coordinated dangling OH bonds in microporous amorphous water prepared at 10 K; however, the three-coordinated dangling OH bonds in nonporous amorphous water prepared at 90 K are dominantly located at the top ice surface and oriented perpendicular to it. These findings provide fundamental insights into the relationship between the structure and optical properties of ice surfaces, and aid quantitative understanding of the surface structure of interstellar ices and their laboratory analogs.

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Widyayanti, Oksita Asri, Sri Sudiono i Nurul Hidayat Aprilita. "Adsorption of Cd(II) Ion Using α-Cellulose Immobilized Humic Acid with Crosslinker Agent Epichlorohydrin". Key Engineering Materials 884 (maj 2021): 39–46. http://dx.doi.org/10.4028/www.scientific.net/kem.884.39.

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An environment is said to be polluted if there have been changes in the environmental order so that it is no longer the same as its original form, as a result of the entry and inclusion of a foreign substance or object in the environmental order. Various cases of heavy metal pollution have been reported in both developed and developing countries, as well as adverse effects on the population living in the vicinity. This heavy metal pollution including cadmium metal. Generally, the contamination of cadmium in waters originates from the waste of the metal ore processing industry. Cadmium which accumulates in the body of living things has a long half-life and generally accumulates in the liver and kidneys. This study focuses on reducing levels of heavy metals in the environment with an adsorbent from natural products, namely palm oil empty fruit bunches and humic acid from peat soils. This research combines two adsorbents of natural products, namely by immobilizing cellulose and humic acid with the epichlorohydrin crosslinker agent. The purpose of this study was to determine the effect of the optimum dose of epichlorohydrin on cellulose and humic acid immobilization, determine the optimum pH, adsorption isotherm, cadmium metal adsorption kinetics and determine the type of interaction between adsorbent and adsorbate. The results showed a link between cellulose and humic acid which was connected via epichlorohydrin from FT-IR results in certain wavenumbers, including OH vibration (3415cm–1), stretching CH vibration (2903 cm–1), NH bending vibration (1625 cm–1), COO stretch vibration (1373 cm–1) and CO stretch vibration (1058 cm–1). For the optimum dose of epichlorohydrin obtained at 15 mL (1 recipe) with an adsorption capacity of 7.4705 mg/g. While the optimum pH was obtained at pH 6, the adsorption isotherm obtained the largest capacity at 200 ppm by following the Freundlich isotherm (R2 = 0.9512).

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Craig, Stephanie M., Fabian S. Menges, Chinh H. Duong, Joanna K. Denton, Lindsey R. Madison, Anne B. McCoy i Mark A. Johnson. "Hidden role of intermolecular proton transfer in the anomalously diffuse vibrational spectrum of a trapped hydronium ion". Proceedings of the National Academy of Sciences 114, nr 24 (31.05.2017): E4706—E4713. http://dx.doi.org/10.1073/pnas.1705089114.

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We report the vibrational spectra of the hydronium and methyl-ammonium ions captured in the C3v binding pocket of the 18-crown-6 ether ionophore. Although the NH stretching bands of the CH3NH3+ ion are consistent with harmonic expectations, the OH stretching bands of H3O+ are surprisingly broad, appearing as a diffuse background absorption with little intensity modulation over 800 cm−1 with an onset ∼400 cm−1 below the harmonic prediction. This structure persists even when only a single OH group is present in the HD2O+ isotopologue, while the OD stretching region displays a regular progression involving a soft mode at about 85 cm−1. These results are rationalized in a vibrationally adiabatic (VA) model in which the motion of the H3O+ ion in the crown pocket is strongly coupled with its OH stretches. In this picture, H3O+ resides in the center of the crown in the vibrational zero-point level, while the minima in the VA potentials associated with the excited OH vibrational states are shifted away from the symmetrical configuration displayed by the ground state. Infrared excitation between these strongly H/D isotope-dependent VA potentials then accounts for most of the broadening in the OH stretching manifold. Specifically, low-frequency motions involving concerted motions of the crown scaffold and the H3O+ ion are driven by a Franck–Condon-like mechanism. In essence, vibrational spectroscopy of these systems can be viewed from the perspective of photochemical interconversion between transient, isomeric forms of the complexes corresponding to the initial stage of intermolecular proton transfer.

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Osu, C. I., H. C. Ugwu i G. N. Iwuoha. "Characterization of chitosan from Rhynchophorus phoenicis and synthesis of its alumina nanocomposite". Scientia Africana 20, nr 3 (26.01.2022): 149–60. http://dx.doi.org/10.4314/sa.v20i3.13.

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Rhynchophorus phoenicis, found in the tropical regions of Africa where it is regarded as a pest was used to synthesize chitosan and alumina-chitosan nano-composite. The synthesized Chitosan and alumina-chitosan nano-composite were characterized using instrumental methods of analysis which include Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM). FTIR reveals the existence of OH stretching vibration –NH stretching, NH bonding, vibration of methylene C-H bonding, O=C=O stretching, C-N bonding stretching and CO stretching vibration at 3842.33 cm-1, 3402.54 cm-1, 3286.81 cm-1, 2939.61 cm-1, 1527.67 cm-1, 1303.92 cm-1 and 1041.60 cm-1 respectively. The scanning electron micrograph proves that the chitosan has large particles that are regular with paltry pores while alumina-chitosan nano-composite has fairly small particles and porous surface with significant pores. X-ray diffractogram showed a distinct stretch at 22o; 16o and 25o; 17o for chitosan and alumina-chitosan nano-composite. The characterization of the products confirmed that the synthesis of chitosan and alumina-chitosan nano-composiote was effective.

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Vener, Mikhail V., Oliver Kühn i Joel M. Bowman. "Vibrational spectrum of the formic acid dimer in the OH stretch region. A model 3D study". Chemical Physics Letters 349, nr 5-6 (grudzień 2001): 562–70. http://dx.doi.org/10.1016/s0009-2614(01)01248-9.

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Rizkita, Aden Dhana, Sintia Ayu Dewi, Emas Agus Prastyo Wibowo i Iham Maulana. "Isolasi dan Identifikasi Saponin dari Ekstrak Leunca (Solanium ningrum L) Secara Spektrofotometri Infra Merah". JURNAL ILMIAH SAINS 21, nr 2 (29.10.2021): 166. http://dx.doi.org/10.35799/jis.v21i2.34635.

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Penelitian ini dilakukan untuk mengisolasi dan mengidentifikasi senyawa saponin dengan maserasi menggunakan etanol 95% sampai mendapat ekstrak kering sebanyak 20 gram dengan dipanaskan menggunakan evaporator. Ekstraksi kedua dilakukan menggunakan corong pisah dengan pelarut dietil eter dan n-butanol. Identifikasi saponin dilakukan dengan tiga parameter uji diantaranya uji busa, uji warna dan gugus fungsi menggunakan Spektrofotometer Infra Merah. Hasil pengukuran Spektrofotometri Infra Merah menunjukkan Ekstrak Daun Launca mengandung beberapa gugus fungsi sebagai berikut : gugus –OH (puncak yang lebar pada bilangan gelombang 3444,87 cm-1), regang –CH alifatik simetri (bilangan gelombang 2926,01 cm-1 dan2854,65 cm-1, regang C=C tidak terkonjugasi pada bilangan gelombang 1606,7 cm-1, adanya regang C-H (bilangan gelombang 1074,35 cm-1 dan 1045,42 cm-1), dan adanya vibrasi bengkokan simetris C-O pada bilangan gelombang 1386,82 cm-1.Kata kunci: Daun leunca; spektrofotometer infra merah; saponin Isolation and Identification of Saponin from Leunca (Solanium ningrum L) Extract by Infrared SpectrophotometryABSTRACTThis research was conducted to isolate and identify saponin compounds by maceration using 95% ethanol to obtain 20 grams of dry extract by heating using an evaporator. The second extraction was carried out using a separating funnel with diethyl ether and n-butanol as solvents. Saponin identification was carried out with three test parameters including foam test, color test and functional group using Infrared Spectrophotometer. Infrared Spectrophotometry measurement results show that the Launca Leaf Extract contains the following functional groups: -OH group (wide peak at wave number 3444.87 cm-1), aliphatic symmetrical -CH stretch (wave number 2926.01 cm-1 and 2854 ,65 cm-1, unconjugated C=C stretch at wave number 1606.7 cm-1, presence of CH stretch (wave number 1074.35 cm-1 and 1045.42 cm-1), and the presence of symmetrical bending vibration of CO at wave number 1386.82 cm-1.Keywords: Infrared spectrophotometer; leunca leaf; saponin

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39

Benoit, David M. "Efficient correlation-corrected vibrational self-consistent field computation of OH-stretch frequencies using a low-scaling algorithm". Journal of Chemical Physics 125, nr 24 (28.12.2006): 244110. http://dx.doi.org/10.1063/1.2423006.

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Lawrence, C. P., i J. L. Skinner. "Vibrational spectroscopy of HOD in liquid D2O. VII. Temperature and frequency dependence of the OH stretch lifetime". Journal of Chemical Physics 119, nr 7 (15.08.2003): 3840–48. http://dx.doi.org/10.1063/1.1591178.

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Vener, Mikhail V., i Joachim Sauer. "Vibrational spectra of the methanol tetramer in the OH stretch region. Two cyclic isomers and concerted proton tunneling". Journal of Chemical Physics 114, nr 6 (8.02.2001): 2623–28. http://dx.doi.org/10.1063/1.1319647.

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Lee, Christopher M., James D. Kubicki, Bingxin Fan, Linghao Zhong, Michael C. Jarvis i Seong H. Kim. "Hydrogen-Bonding Network and OH Stretch Vibration of Cellulose: Comparison of Computational Modeling with Polarized IR and SFG Spectra". Journal of Physical Chemistry B 119, nr 49 (30.11.2015): 15138–49. http://dx.doi.org/10.1021/acs.jpcb.5b08015.

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Medel, Robert, Johann R. Springborn, Deborah L. Crittenden i Martin A. Suhm. "Hydrogen Delocalization in an Asymmetric Biomolecule: The Curious Case of Alpha-Fenchol". Molecules 27, nr 1 (24.12.2021): 101. http://dx.doi.org/10.3390/molecules27010101.

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Rotational microwave jet spectroscopy studies of the monoterpenol α-fenchol have so far failed to identify its second most stable torsional conformer, despite computational predictions that it is only very slightly higher in energy than the global minimum. Vibrational FTIR and Raman jet spectroscopy investigations reveal unusually complex OH and OD stretching spectra compared to other alcohols. Via modeling of the torsional states, observed spectral splittings are explained by delocalization of the hydroxy hydrogen atom through quantum tunneling between the two non-equivalent but accidentally near-degenerate conformers separated by a low and narrow barrier. The energy differences between the torsional states are determined to be only 16(1) and 7(1) cm−1hc for the protiated and deuterated alcohol, respectively, which further shrink to 9(1) and 3(1) cm−1hc upon OH or OD stretch excitation. Comparisons are made with the more strongly asymmetric monoterpenols borneol and isopinocampheol as well as with the symmetric, rapidly tunneling propargyl alcohol. In addition, the third—in contrast localized—torsional conformer and the most stable dimer are assigned for α-fenchol, as well as the two most stable dimers for propargyl alcohol.

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Mustakim, Yatim, Nurlina Nurlina i Intan Syahbanu. "SINTESIS DAN KARAKTERISASI GEOPOLIMER BERBAHAN DASAR KAOLIN CAPKALA DENGAN VARIASI RASIO MOL SiO2/Al2O3". Indonesian Journal of Pure and Applied Chemistry 2, nr 2 (9.10.2019): 84. http://dx.doi.org/10.26418/indonesian.v2i2.36912.

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One of the potential raw materials for the preparation of geopolymers is kaolin. In the present report, the used activated kaolin is from Capkala Village in West Borneo. This paper presents an experimental study on the influence of different SiO2/Al2O3 molar ratios on the compressive strength and microstructural characteristics of the Capkala kaolin-based geopolymer. The used Capkala kaolin was a product of the calcination of the source material at 750ºC 2 h. The alkaline activator solutions that were used to activate the activated capkala kaolin precursor were prepared by mixing NaOH solution with Na2SiO3 solution. The activator solution was allowed to equilibrate for a minimum of 24 h at a room temperature before use. The geopolymer was prepared by hand mixing of the Capkala kaolin and the activator solution. Experiments conducted with SiO2/Al2O3 molar ratios of 3.8; 3.9; 4.0; 4.1 and 4.2 for all mixing. The resulting pastes are cast in cylinder molds of 2.3 × 4.6 cm. The pastes hardened 24 h in the forms, at room temperature for 24 h. The geopolymer was dried at 60ºC 2 h. The geopolymer was tested for compressive strength and sample pieces were taken from ones with the highest strength for XRD and SEM. Based on the test was obtained that geopolymer with 3.9 SiO2/Al2O3 ratios has the highest compressive strength that is 2.820 Mpa. The XRD analysis showed the peak at 2θ(º) 26,69o, 20,92o dan 19,77 o. The spectra FTIR of geopolymer showed the absorption at 3289.96 cm-1; 1647.67 cm-1 and 955.65 cm-1. Moreover, there are functional groups absorption for geopolymer such Al-OH stretch vibration (near 900 cm-1), stretch vibration of Si-O and Al-O (600-700 cm-1), Si-O-Al bend vibration (near 500 cm-1). The morphology of the capkala kaolin based geopolymer with SEM has succeeded in changing the kaolin structures in the form of regular slabs to be more irregular due to heating with a temperature of 750ºC.

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Lees, R. M. "GiantKDoubling in the Infrared Spectrum of CH3OH: A Sensitive Probe for CH3-Rock/CO-Stretch/OH-Bend Vibrational Coupling". Physical Review Letters 75, nr 20 (13.11.1995): 3645–48. http://dx.doi.org/10.1103/physrevlett.75.3645.

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Steen, Gerwin W., Adam D. Wexler, Elmar C. Fuchs i Herman L. Offerhaus. "A First Step towards Determining the Ionic Content in Water with an Integrated Optofluidic Chip Based on Near-Infrared Absorption Spectroscopy". Optics 1, nr 2 (11.07.2020): 175–90. http://dx.doi.org/10.3390/opt1020014.

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In this work, we present a feasibility study of integrated optofluidic chips to measure the ionic content in water using differential absorption spectroscopy. The second overtone of the OH-stretch vibration of water is used as indicator for both the type and concentration of the dissolved ions. The optofluidic chips are based on silicon nitride (TripleX) containing Mach–Zehnder interferometers (MZI) with two 5 cm sensing paths for the sample and reference arms, respectively. Simulations show that, theoretically, the determination of both the type and concentration of a mixture of four electrolytes is possible with the techniques presented. However, the performance of the chips deviated from the expected results due to the insufficient reproducibility and precision in the fabrication process. Therefore, at this early stage, the chips presented here could only determine the ion concentration, but not differentiate between the different ion types. Still, this work represents the first steps towards the realization of an online and real-time sensor of ionic content in water.

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Schuler, Manuel J., Thomas S. Hofer, Yusuke Morisawa, Yoshisuke Futami, Christian W. Huck i Yukihiro Ozaki. "Solvation effects on wavenumbers and absorption intensities of the OH-stretch vibration in phenolic compounds – electrical- and mechanical anharmonicity via a combined DFT/Numerov approach". Physical Chemistry Chemical Physics 22, nr 23 (2020): 13017–29. http://dx.doi.org/10.1039/c9cp05594k.

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A previously measured oscillatory intensity pattern in phenolic compounds between different solvents was successfully reproduced for the first time, employing modern grid-based methods to solve the time-independent vibrational Schrödinger equation.

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Schulz, Eike C., Johannes Kaub, Frederik Busse, Pedram Mehrabi, Henrike M. Müller-Werkmeister, Emil F. Pai, Wesley D. Robertson i R. J. Dwayne Miller. "Protein crystals IR laser ablated from aqueous solution at high speed retain their diffractive properties: applications in high-speed serial crystallography". Journal of Applied Crystallography 50, nr 6 (20.11.2017): 1773–81. http://dx.doi.org/10.1107/s1600576717014479.

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In order to utilize the high repetition rates now available at X-ray free-electron laser sources for serial crystallography, methods must be developed to softly deliver large numbers of individual microcrystals at high repetition rates and high speeds. Picosecond infrared laser (PIRL) pulses, operating under desorption by impulsive vibrational excitation (DIVE) conditions, selectively excite the OH vibrational stretch of water to directly propel the excited volume at high speed with minimized heating effects, nucleation formation or cavitation-induced shock waves, leaving the analytes intact and undamaged. The soft nature and laser-based sampling flexibility provided by the technique make the PIRL system an interesting crystal delivery approach for serial crystallography. This paper demonstrates that protein crystals extracted directly from aqueous buffer solutionviaPIRL-DIVE ablation retain their diffractive properties and can be usefully exploited for structure determination at synchrotron sources. The remaining steps to implement the technology for high-speed serial femtosecond crystallography, such as single-crystal localization, high-speed sampling and synchronization, are described. This proof-of-principle experiment demonstrates the viability of a new laser-based high-speed crystal delivery system without the need for liquid-jet injectors or fixed-target mounting solutions.

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Bakker, H. J., A. J. Lock i D. Madsen. "Comment on ‘Vibrational relaxation and spectral evolution following ultrafast OH stretch excitation of water’ by A. Pakoulev, Z.Wang, D.D. Dlott". Chemical Physics Letters 385, nr 3-4 (luty 2004): 329–31. http://dx.doi.org/10.1016/j.cplett.2003.12.079.

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Kolthoff, Izaak M., i Miran K. Chantooni JR. "Binding of water in aqua 18-crown-6 dichloropicric acid complexes in the solid state and its reversible thermal removal". Canadian Journal of Chemistry 70, nr 1 (1.01.1992): 177–85. http://dx.doi.org/10.1139/v92-029.

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Thermogravimetry, differential scanning calorimetry, and FT-IR vibrational spectral studies on the 1:1:1 18-crown-6: dichloropicric acid: water complex reveal that it remains unaltered when heated to melting. On the other hand, one molecule of water is expelled from the 1:2:2 complex by heating prior to melting. This results in an ionic microcrystalline product of undetermined crystal structure, in which the conformation of the crown is lower than D3d in symmetry. The enthalpy accompanying this process, which involves rupturing of two water–crown hydrogen bonds, is −44 to −55 kJ mol−1. The original 1:2:2 complex is regenerated by exposure of the heated adduct to water vapor. It was found that H2O in the structure of the solid 1:2:2 adduct was partially replaced by D2O at room temperature upon exposure to D2O vapor. The crown–H2O OH stretch in the IR exhibits a small or negligible positive isotope effect on deuteration. Keywords: crown ether, hydrogen bonding, water, dichloropicric acid.

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