Hydrogen-bonded OH Research Articles

Effects of H2O on HCHO and CO oxidation at room-temperature catalyzed by MCo2O4 (M=Mn, Ce and Cu) materials

The abatement of HCHO and CO at room temperature by catalytic oxidation over metal oxides can be achieved. However, the catalytic performance of metal oxides is influenced by H2O vapor in the reaction air and the mechanism of H2O role is still debated. In this paper, the effect of H2O on the catalytic performance of an MCo2O4 (M = Mn, Ce and Cu) catalyst for HCHO and CO oxidation at room temperature was investigated. For both HCHO oxidation and CO oxidation, all the MCo2O4 catalysts in humid air are less active than in dry air except for HCHO oxidation catalyzed by CuCo2O4 catalyst. The CuCo2O4 is inactive for HCHO oxidation in dry air, but active for HCHO oxidation in humid air. XRD and XPS results indicated that there are no obvious changes of crystal structure and valance states of element between fresh and used MCo2O4 catalysts. The active sites of MCo2O4 catalysts and reaction/deactivation mechanism of HCHO and CO oxidation were studied by H2O-TPD and DRIFT. The associatively adsorbed H2O on MCo2O4 contributed to the active HOH sites for HCHO oxidation. Formate species are intermediates of HCHO oxidation. However, if formate cannot be further transferred into CO2, the formate adsorbed on active sites will result in catalyst deactivation. In humid air, hydrogen-bonded OH and free OH generated and covered active sites accelerated the catalyst deactivation in HCHO oxidation. The CO was oxidized by the active oxygen species but not included OH species. Thus, the H2O adsorbed on oxygen vacancies blocked the generation of active oxygen species, which resulted in MCo2O4 deactivation for CO oxidation in humid air. This work provide a fundamental understanding of the key role of H2O in the HCHO and CO oxidation at room temperature, which is helpful for the design of high activity and long lifetime catalyst used in dry or humid conditions.

Beyond Badger's Rule: The Origins and Generality of the Structure-Spectra Relationship of Aqueous Hydrogen Bonds.

The structure of hydrogen bonded networks is intimately intertwined with their dynamics. Despite the incredibly wide range of hydrogen bond strengths encountered in water clusters, ion-water clusters, and liquid water, we demonstrate that the previously reported correlation between the change in the equilibrium bond length of the hydrogen bonded OH covalent bond and the corresponding shift in its harmonic frequency in water clusters is much more broadly applicable. Surprisingly, this correlation describes the ratios for both the equilibrium OH bond length/harmonic frequency and the vibrationally averaged bond length/anharmonic frequency in water, hydronium water, and halide water clusters. Consideration of harmonic and anaharmonic data leads to a correlation of -19 ± 1 cm-1/0.001 Å. The fundamental nature of this correlation is further confirmed through the analysis of ab initio Molecular Dynamics (AIMD) trajectories for liquid water. We demonstrate that this simple correlation for both harmonic and anharmonic systems can be modeled by the response of an OH bond to an external field. Treating the OH bond as a Morse oscillator, we develop analytic expressions, which relate the ratio of the shift in the vibrational frequency of the hydrogen-bonded OH bond to the shift in OH bond length, to parameters in the Morse potential and the ratio of the first and second derivatives of the field-dependent projection of the dipole moment of water onto the hydrogen-bonded OH bond. Based on our analysis, we develop a protocol for reconstructing the AIMD spectra of liquid water from the sampled distribution of the OH bond lengths. Our findings elucidate the origins of the relationship between the molecular structure of the fleeting hydrogen-bonded network and the ensuing dynamics, which can be probed by vibrational spectroscopy.

Molecular hydrophobicity at a macroscopically hydrophilic surface

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.

Conformation of alkali metal ion-calix[4]arene complexes investigated by IR spectroscopy in the gas phase.

We measure the IR spectra of calix[4]arene (C4A) complexes with K+, Rb+, and Cs+ ions in the 3200-3700 cm-1 region by IR-UV double-resonance spectroscopy performed under cold (∼10 K) gas-phase conditions. All the complexes show two bands that can be assigned to the stretching vibrations of hydrogen-bonded OH groups in the C4A part. Quantum chemical calculations predict several isomers having different IR spectra, but the IR spectrum of the "cone" conformer reproduces the IR-UV spectrum very well, indicating that all the complexes adopt the cone conformation including the metal ions in the cone. The frequency of the OH stretching vibrations decreases with increasing the ion size from K+ (3357 and 3513 cm-1) to Rb+ (3323 and 3463 cm-1) and Cs+ (3279 and 3379 cm-1), but it is substantially higher than that of hydrogen-bonded OH groups in bare C4A (3158 cm-1). These results suggest that C4A encapsulates the metal ions by distorting the cone cavity, and that the distortion of the cone conformation is reduced more and the hydrogen bond between the OH groups becomes stronger with increasing the ion size from K+ to Cs+. The Cs+ complex has the smallest distortion of the C4A cavity among the alkali metal ion complexes. This can be one origin for the predominant encapsulation of Cs+ ions by C4A over smaller alkali metal ions in solution.

Coordination diversity in tin compounds with bis(benzoxazole)phenol as a polydentate ligand: Synthesis and crystal structure studies

The reaction of 2,6-bis(benzoxazolyl)-4-tert-butylphenol (HL) with [nBuxSnCl4−x] (x = 0, 1) in 1:1 stoichiometry yielded the tin coordination complexes [(HL)SnnBuxCl4−x] [x = 0 (1); x = 1 (2)]. Deprotonation of HL was performed using reagents having groups with high basicity such as nBuLi or [Sn{N(SiMe3)2}2]. These basic reagents prompted the coordination of the ligand in its anionic form, yielding the complexes [(thf)2Li(L)SnCl4] (3) and [(L)Sn{N(SiMe3)2}] (4), respectively. The molecular structure of HL displayed an intramolecular hydrogen bond OH—N and a planar arrangement of the bis(benzoxazolyl)phenolic system. In the molecular structures of both complexes containing HL an intramolecular hydrogen bond of NH—O type was also present. The coordination of the ligand in either neutral or anionic form is described by a κO,κN chelate mode toward Sn. All complexes displayed bis(benzoxazolyl)phenolic moieties close to planar; the least planar system was observed in 4 that was also studied by DFT methods.

New mononuclear dioxidomolybdenum(VI) complexes with hydrazone ligands: Synthesis, crystal structures and catalytic performance

Three new dioxomolybdenum (VI) complexes, [MoO2L1(MeOH)] (1), [MoO2L2(MeOH)] (2) and [MoO2L3(H2O)]·EtOH (3), where L1, L2 and L3 are the dianionic form of N′-(2-hydroxybenzylidene)-3-methylbenzohydrazide, 4-bromo-N′-(2-hydroxybenzylidene)benzohydrazide and 2-bromo-N′-(2-hydroxy benzylidene)benzohydrazide, respectively, have been prepared and characterized by IR, UV–Vis and NMR spectra, as well as single crystal X-ray diffraction. The Mo atoms in the complexes are in octahedral coordination, with the ONO donor set of the hydrazone ligands, O atoms of the solvents, and two oxo groups. Crystals of the complexes are stabilized by hydrogen bonds of types OH⋯N and OH⋯O. Moreover, the catalytic properties of complexes 1–3 are compared in cyclohexane oxidation. It was found that sebacic acid and FeCl3 could promote the catalytic activities of the complexes.

Structural, vibrational, Hirshfeld surfaces and optical studies of nonlinear optical organic imidazolium L-tartrate single crystal

Imidazolium L-tartrate (IMLT) single crystal was grown using solution growth technique. The grown crystal belongs to monoclinic crystal structure with space group P21. Intermolecular interactions of IMLT is executed by the Hirshfeld surface analysis. The structure of the grown crystal was stabilized by an extensive network of OH⋯O, NH⋯O and OH hydrogen bonds. The vibrational modes are assigned based on potential energy distribution (PED). 13C and 1H NMR spectra were recorded to interpret the environment of the molecular structure. The HOMO-LUMO energy gap shows that the molecular chemical stability is high for the IMLT molecule. The Mulliken charge distribution confirms that the highest value is noted in C17, whereas the lowest value is obtained in C10 atom. The natural bond orbital (NBO) analysis has been computed to find out the electron delocalization and conjugative interactions. The bonding and anti-bonding orbitals are performed using density of states (DOS) spectrum. From photoconductivity measurement, the dark current is seen to be less than photocurrent. The etching analysis was done on (0 0 1) plane of IMLT crystal and rectangular etch pits are observed.

Communication: Gas phase vibrational spectroscopy of the azide-water complex.

The vibrational spectra of the azide-water complex, N3 -(H2O), and its fully deuterated isotopologue are studied using infrared photodissociation (IRPD) spectroscopy (800-3800 cm-1) and high-level ab initio computations. The IRPD spectrum of the H2-tagged complex exhibits four fundamental transitions at 3705, 3084, 2003, and 1660 cm-1, which are assigned to the free OH stretching, the hydrogen-bonded O-H stretching, the antisymmetric N3 stretching, and the water bending mode, respectively. The IRPD spectrum is consistent with a planar, singly hydrogen-bonded structure according to an MP2 and CCSD(T) anharmonic analysis via generalized second-order vibrational perturbation theory. The red-shift of the hydrogen-bonded OH stretching fundamental of 623 cm-1 associated with this structure is computed within 6 cm-1 (or 1%) and is used to estimate the proton affinity of azide (1410 kJ mol-1). Born-Oppenheimer molecular dynamics simulations show that large amplitude motions are responsible for the observed band broadening at cryogenic temperature. Temperature-dependent (6-300 K) IR multiphoton dissociation spectra of the untagged complex are also presented and discussed in the context of spectral diffusion observed in the condensed phase.

Phonon interaction with OH complexes and products of their radiative decomposition in LiF crystals

This article deal with study of the vibration spectra of hydroxyl ions and radiation-induced molecular complexes with H-bond in LiF:OH crystals. The IR spectra of the crystals were measured at 300, 80 and 10 K temperatures. The low-temperature behavior of the bands in the 3570–3700 cm−1 region indicates that corresponding vibration energy levels are not associated with phonons. It is shown that the broadening of 3730 cm−1 band with increasing temperature due to phonon interactions, namely, resonant scattering of phonons by vibrations of free hydroxyl. The frequencies of the transverse and longitudinal optical modes of phonons take part in the Fermi resonance splitting of the absorption band of molecular complexes with a strong hydrogen bond in the region of 1800–2300 cm−1 in LiF:Mg, OH crystals. It is determined that the narrow bands in the 3400–3700 cm−1 region can appear in the spectrum of LiF:OH without magnesium ions. It was concluded that narrow bands in the 3400–3700 cm−1 region in y-irradiated to a dose of 2.58×104 C/kg at T = 525 K LiF:OH crystals are caused by an associates of two or more hydroxyl ions or by a complexes with a hydrogen bond OH…O or OH…F.

Insights on structural characteristic of Xilinguole lignite chars from low-temperature pyrolysis

The cleavage behavior of covalent bonds in Xilinguole (XLGL) lignite and changes in chemical structure of lignite and its chars during low-temperature pyrolysis were investigated by thermogravimetric (TG) analysis and Fourier-transform infrared (FTIR) spectroscopy. Based on the TG and differential thermogravimetric (DTG) analysis results, the cleavage of different types of chemical bonds in lignite occurred mainly at four certain temperatures, 170 °C, 376 °C, 432 °C, and 521 °C. The latter three were selected as the final pyrolysis temperatures of chars evaluated in this study. The FTIR analysis results indicate that thermal treatment increased the relative content of two and three adjacent H deformation structures but decreased that of four adjacent H deformation structure. This was caused by the cleavage of Cal–Cal and Car–Cal bonds. The oxygen-containing functional groups in lignite are dominated by C–O and C–OH groups with a lower chemical reactivity than C=O–C and conjugated C=O groups. Moreover, XLGL lignite has the highest ratio of CH2/CH3 which declines with increasing temperature, indicating the decrease in the length of aliphatic chains and increase in the degree of branching of aliphatic side chains. This change mainly resulted from the cleavage of Cal–O, Cal–Cal, and Car–Cal bonds. Furthermore, XLGL lignite and its chars contain five specific hydrogen bonds: OH–N, cyclic OH, OH–ether O, OH–OH, and OH–π hydrogen bonds. The relative content of OH–OH hydrogen bond was the highest, indicating that OH–OH hydrogen bond has the highest thermal stability.

Sensing mechanism of HBT based F anion fluorescence sensor: A theoretical study

Previous study shows that HBT-based fluorophore HBT-Ratio-F1 and F2 are excellent sensor with selectivity and sensitivity towards F anion showing binate ratiometric characteristics. In this work, we study the whole sensing process by DFT and TDDFT methods in detail. The electronic structures and electronic characters of the neutral sensor, F anion attached complex, and anionic form after deprotonation are investigated in both S0 and S1 states. In neutral sensor, the potential energy profile of proton transfer is investigated to understand the tautomerization process. In anion, the cis-trans isomerization process is also investigated in both S0 and S1 states to unveil the behavior of anion. The calculated results show that intra molecular hydrogen bond OH⋯ N in neutral sensor is disturbed upon addition of F anion, forming new inter molecular hydrogen bond (O)N⋯ HF in the (S0) S1 state in anion complex and HF is likely to be bonded with HBT derivative without further dissociation. The comparison of the calculated absorption (emission) energies in both HBT-Ratio-F1 and HBT-Ratio-F2 with experimental spectral peaks is also included and the binate ratiometric character in spectra is discussed based on calculation results.

Preparation of a 1:1.5 cocrystal of kaempferol with 4,4′-bipyridine based on analyzing intermolecular interaction of building units

Based on analyzing intermolecular interaction in building unit of cocrystal of quercetin with 4,4′-bipyridine (QUE·BPY) reported by us on before, a new cocrystal of kaempferol with 4,4′-bipyridine (KAE·BPY) has been designed and synthesized. Within the reported QUE·BPY, 3′OH was neither involved in the formation of the building unit nor played a big role in the 2D layer. Consequently, we boldly speculate kaempferol without 3′OH might crystallize with 4,4′-bipyridine to form similar structure to QUE·BPY. Just as expected, structural analysis shows kaempferol molecules and 4,4′-bipyridine molecules alternate connect to form the building units through 7-OH and 4′OH hydrogen bonds, the structure of KAE·BPY is similar to QUE·BPY. This work proves that new cocrystals could be designed and synthetized by analyzing the intermolecular interaction in building unit and seeking right structure of Active Pharmaceutical Ingredients (APIs). Additionally, the cocrystal of kaempferol with 4,4′-bipyridine shows advantages in terms of hygroscopic stability in comparison to pure kaempferol.

Crystal structures of [Cu2(2,2′-bipyridine-N,N′)2(H2O)2(μ2-OH)2](barbiturate)2·2H2O and [Cu(2,2′-bipyridine-N,N′)(H2O)(barbiturate-O)Cl]·2H2O

Two mixed-ligand Cu(II) complexes [Cu2(Bipy)2(H2O)2(OH)2](Hba)2·2H2O (1) and [Cu(Bipy)(H2O)(Hba)Cl]·2H2O (2) (Bipy = 2,2′-bipyridine and Hba− = barbiturate anion) were synthesized and structurally characterized by single crystal X-ray diffraction. In 1, structural data revealed distorted square-pyramidal geometry for each of two crystallographic independent copper(II) atom with the basal plane formed by two nitrogen atoms of the 2,2′-bipyridine ligand and two oxygen atoms of bridging hydroxo groups. The apical positions are filled by the oxygen atoms from a water molecule. In 2, the Cu atom is also in distorted square pyramidal geometry, where the equatorial sites are occupied by two N atoms of one Bipy ligand, one O atom of the barbiturate ion and one chloride ion and the apical position by one aqua ligand. Numerous intermolecular hydrogen bonds OH⋯O, NH⋯O, CH⋯O in the structures 1–2 and in addition OH⋯Cl, CH⋯Cl in the structure 2 form the 3D networks. Topological analysis showed that these H-bonded networks are new. An additional factor that plays a role in the crystal packing of the discussed complexes is the π-π stacking interaction between the aromatic rings of Hba− and Bipy forming infinite chains –Hba–Bipy–Bipy–Hba–. The spectroscopic and thermal properties of compounds were analyzed.

The Effect of Dispersion on the Structure of Diphenyl Ether Aggregates.

Dispersion interactions can play an important role in understanding unusual binding behaviors. This is illustrated by a systematic study of the structural preferences of diphenyl ether (DPE)-alcohol aggregates, for which OH⋅⋅⋅O-bound or OH⋅⋅⋅π-bound isomers can be formed. The investigation was performed through a multi-spectroscopic approach including IR/UV and microwave methods, combined with a detailed theoretical analysis. The resulting solvent-size-dependent trend for the structural preference turns out to be counter-intuitive: the hydrogen-bonded OH⋅⋅⋅O structures become more stable for larger alcohols, which are expected to be stronger dispersion energy donors and thus should prefer an OH⋅⋅⋅π arrangement. Dispersion interactions in combination with the twisting of the ether upon solvent aggregation are key for understanding this preference.

Novel 1,3-diethyl-2-thiobarbiturates of 2,2′-bipyridine and 1,10-phenanthroline: Synthesis, crystal structure and thermal stability

Co-crystallization of 1,3-diethyl-2-thiobarbituric acid (HDetba) with 2,2′-bipyridine (Bipy) and 1,10-phenanthroline (Phen) results in preparing a salt co-crystal, BipyH(Detba)(HDetba) (1), and the salt, PhenH(Detba)·H2O (2). The compounds are characterized by single–crystal and powder X–ray diffraction and TG-DSC. The nitrogen atoms of BipyH+ adopt a cis conformation and the NCCN torsion angle is −17.3(1)º. There are six intermolecular hydrogen bonds OH⋯O, NH⋯O, CH⋯O and CH⋯S in (1) which form a 2D plane network. One Detba– ion and one HDetba molecule form a pair by means of OH⋯O hydrogen bonds. Detba− anions in (2) do not form dimers, they are connected by NH⋯O, CH⋯S, and CH⋯O hydrogen bonds only with PhenH+ cations and water molecules which form a 3D net. Different π−π interactions between the rings are found in (1)−(2).

Low Hydroxylated Fullerenes: Stability, Thermal Behavior, and Vibrational Properties

Extensive density functional theory (DFT) calculations dedicated to analyze the stability, thermal behavior, as well as the infrared (IR) and Raman spectra of low hydroxylated C60(OH)12 fullerenols are presented. Adsorbed configurations in which OH groups form various types of molecular islands on the carbon surface are the preferred atomic arrays, while random distributions of hydroxyl species are the highest energy molecular structures. It is found that the formation of local networks of hydrogen-bonded OH groups plays a fundamental role in the stability of these complexes. The calculated dipole moments, polarizability values, optical gap, and Fukui functions of C60(OH)12 isomers strongly depend on the structure of the hydroxyl overlayer, thus being an important parameter to tune the material properties. DFT Born–Oppenheimer molecular dynamics calculations at T = 300 K reveal that aggregated forms of OH groups on the fullerene surface show an interesting dynamical behavior, characterized by a continuous...

TDDFT investigation of excitation of water tetramer under femtosecond laser pulse irradiation

We study the static properties of water tetramer in ground state, the optical absorption spectra and ultrafast nonadiabatic dynamical response of water tetramer to short and intense laser pulses with different intensities by a real-space, real-time implementation of time-dependent density functional theory coupled to molecular dynamics (TDDFT–MD) nonadiabatically. The calculated results are in good agreement with available values in literature. Four typical irradiated scenarios of water tetramer in laser field, which are “normal vibration,” “break and reorganization,” “fragmentation and new formation” and “pure fragmentation”, are explored by discussing the ionization, the bond lengths of OH bonds and hydrogen bonds and the kinetic energy of ions. The dynamic simulation shows that the reaction channel of water tetramer can really be controlled by choosing appropriate laser parameters referring to the optical absorption spectra and hydrogen ions play an important role in the reaction channel. Furthermore, it is found that the laser intensity affects the kinetic energy of ejected protons more than that of the remaining fragments and all dynamic processes are somehow directly related to the velocity of departing protons.

Interpreting Quasi-Thermal Effects in Ultrafast Spectroscopy of Hydrogen-Bonded Systems.

Vibrational excitation of molecules in the condensed phase relaxes through vibrational modes of decreasing energy to ultimately generate an equilibrium state in which the energy is distributed among low-frequency modes. In ultrafast vibrational spectroscopy, changes in the vibrational features of hydrogen-bonded NH and OH stretch modes are typically observed to persist long after these high-frequency vibrations have relaxed. Due to the resemblance to the spectral changes caused by heating the sample, these features are typically described as arising from a hot ground state. However, these spectral features appear on ultrafast time scales that are much too fast to result from a true thermal state, and significant differences between the thermal difference spectrum and the induced quasi-thermal changes in ultrafast spectroscopy are often observed. Here, we examine and directly compare the thermal and quasi-thermal responses of the hydrogen-bonded homodimer of 7-azaindole with temperature-dependent FTIR spectroscopy and ultrafast mid-IR continuum spectroscopy. We find that the thermal difference spectra contain contributions from both dissociation of the hydrogen bonds and from frequency shifts due to changes in the thermal population of low-frequency modes. The transient spectra in ultrafast vibrational spectroscopy are also found to contain two contributions: initial frequency shifts over 2.3 ± 0.11 ps associated with equilibration of the initial excitation, and frequency shifts associated with the excitation of several fingerprint modes, which decay over 21.8 ± 0.11 ps, giving rise to a quasi-thermal response caused by a distribution of fingerprint modes being excited within the sample ensemble. This resembles the thermal frequency shifts due to population changes of low-frequency modes, but not the overall thermal spectrum, which is dominated by features caused by dimer dissociation. These findings provide insight into the changes in the vibrational spectrum from different origins and are important for assigning, analyzing, and comparing features in thermal and ultrafast vibrational spectroscopy of hydrogen-bonded complexes.

Spectroscopic investigation on structure (monomer and dimer), molecular characteristics and comparative study on vibrational analysis of picolinic and isonicotinic acids using experimental and theoretical (DFT & IVP) methods

In this investigation, the monomeric structure is determined for picolinic and isonicotinic acids based on geometry optimization for one of the four possible conformers and intramolecular hydrogen bond of OH⋯O using density functional theory (DFT) employing B3LYP functional supplemented with 6–311++G(d,p) basis set. Using this optimized monomeric form, the dimer structure is determined based on minimum energy and length of hydrogen bonds obtained for two possible dimeric forms yielded due to head-to-tail intermolecular OH⋯N hydrogen bond (dimer 1) linkage and tail-to -tail intermolecular OH⋯O hydrogen bond (dimer 2) linkage between pyridine ring and carboxyl group. The structure parameters obtained for monomer and dimer forms are in good agreement with the experimental literature values. The vibrational assignments have been made unambiguously for all the vibrations from FTIR and FT-Raman spectra based on the potential energy distribution (PED) and eigen vectors obtained in DFT and inverse vibrational problem (IVP) computations. The rms error between the observed and scaled frequencies is 7.7 and 9.4 cm−1 for PIA and INA, respectively. A 74-element modified valence force field is derived by Wilson's GF matrix method using 58 experimental frequencies of the two molecules in overlay least-squares technique. The average error between observed and computed frequencies by this method is calculated to be 10.39 cm−1. The results of both DFT and IVP computations yielded good agreement between observed and calculated frequencies. The NLO behaviour using hyperpolarizability values; and HOMO and LUMO energies; of the two molecules are investigated by DFT. Charge density distribution and site of chemical reactivity of the molecules are studied by molecular electrostatic surface potential (MESP). Stability of the molecules arising from hyper conjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The 13C and 1H NMR chemical shifts of the molecules are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. UV–visible (UV–Vis) spectra of the compounds are also recorded in the region 200–400 nm. Thermodynamic parameters and rotational constants are also determined and found that they are comparable with experimental literature values for these molecules.

Водородная связь OH∙∙∙πГТС при адсорбции изобутанола, трет-бутанола и трет-амилового спирта на графитированной термической саже

Водородная связь OH∙∙∙πГТС при адсорбции изобутанола, трет-бутанола и трет-амилового спирта на графитированной термической саже