Liming Wang

Liming Wang
South China University of Technology | SCUT · School of Chemistry and Chemical Engineering

Ph.D.

About

95
Publications
6,462
Reads
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1,781
Citations
Citations since 2016
27 Research Items
1116 Citations
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
Introduction
We are currently working on the oxidation mechanism of VOCs in the atmosphere. My teaching duty in SCUT includes "Physical Chemistry", "Environmental Chemistry", and "Chemical Kinetics".
Additional affiliations
March 2012 - present
South China University of Technology
Position
  • Instructor
Description
  • Physical Chemistry, Each Year
March 2008 - present
South China University of Technology
Position
  • Instructor
Description
  • Environmental Chemistry, Each Year
October 2005 - present
South China University of Technology
Position
  • Research & Teaching
Education
September 1997 - August 2002
September 1991 - July 1994
Dalian Institute of Chemical Physics
Field of study
  • Physical Chemistry
September 1987 - July 1991
Fudan University
Field of study
  • Chemistry

Publications

Publications (95)
Article
Full-text available
The atmospheric oxidation mechanism of o-xylene (oX) initiated by hydroxyl (OH) radicals has been investigated by using quantum chemistry, transition state theory, and unimolecular theory (RRKM-ME) calculations. Molecular structures of reactants, transition states, and products are optimized at M06-2X/6-311++G(2df, 2p) level, and the electronic ene...
Article
The atmospheric oxidation mechanism of 2-methylnaphthalene (2-MN) initiated by OH radicals is investigated by using quantum chemistry at BH&HLYP/6-311++G(2df,2p) and ROCBS-QB3 levels and kinetic calculations by transient state theory and unimolecular reaction theory coupled with master equation (RRKM-ME). This reaction is mainly initiated by OH add...
Conference Paper
Full-text available
Results from the theoretical studies on the oxidation mechanism of aromatic compounds in the atmosphere, including BTEX and naphthalenes.
Article
Aromatic hydrocarbons contribute significantly to tropospheric ozone and secondary organic aerosols (SOA). Despite large efforts in elucidating the formation mechanism of aromatic-derived SOA, current models still substantially underestimate the SOA yields when comparing to field measurements. Here we present a new, up to now undiscovered pathway f...
Article
Calculations and experiments were conducted on ozonolysis of ethyl vinyl ether (EVE) and butyl vinyl ether to identify an unconventional diradical intermediate generated from the O-O bond cleavage of primary ozonide. The diradical can undergo a H atom shifting process that yields keto-hydroperoxide (KHP), the characteristic product that identifies...
Article
Nicotine is the most abundant alkaloid chemical in smoke emission. In this work, we investigated the gas-phase oxidation mechanism of nicotine initiated by its reactions with the OH radical and ozone. Both initiation reactions start dominantly by hydrogen atom abstractions from the C1, C3, and -CH3 groups of the methylpyrrolidinyl group and form ra...
Article
Ionic liquids (ILs) with promising application are likely to become ubiquitous contaminants in water environment for their high hydrophilicity, low biodegradability, and especially its potential toxicity. In this work, we have investigated photochemical transformation of six imidazolium ILs for fate prediction and ecological risk assessment. We fou...
Article
Pyridinium ionic liquids (Pyr⁺ ILs) with promising applications are likely to appear in large quantity in water environment and become emergent pollutants due to their high hydrophilicity and low biodegradability. Hence, we studied the indirect photochemical degradation of Pyr⁺ ILs, including their kinetics of reactions with transient oxidants (•OH...
Article
Limonene with endo- and exo-double bonds is a significant monoterpene in the atmosphere and has high reactivity towards O3. We investigated the atmospheric oxidation mechanism of limonene ozonolysis using a high level quantum chemistry calculation coupled with RRKM-ME kinetic simulation. The additions of O3 can take place at both the endo- and exo-...
Article
Gas-phase oxidation of PAH can result in formation of oxygenated PAHs (OPAHs) and nitro-PAH (NPAHs) as well as a series of secondary pollutants which contribute to formation of SOA. Acenaphthene (ACE) is one of the PAHs with three rings which exists mainly as gaseous form in the atmosphere, where the oxidation is mainly initiated by reaction with O...
Article
Formic acid (HCOOH), one of the most important and ubiquitous organic acids in the Earth’s atmosphere, contributes substantially to atmospheric acidity and affects pH-dependent reactions in the aqueous phase. However, based on the current mechanistic understanding, even the most advanced chemical models significantly underestimate the HCOOH concent...
Article
Syringic acid (Syr) is an abundant component in aerosol particles. Multiphase photo-oxidation in aerosol phase provides an important oxidation pathway for Syr in the atmosphere. In this work, we studied the multiphase degradation of Syr by measuring rate coefficients of its reactions with potential radical oxidants (OH and SO4⁻) in aqueous solution...
Article
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants. In the atmosphere, PAHs are oxidized to oxygenated PAHs (OPAHs) and nitrated PAHs (NPAHs). However, the formation mechanism of OPAHs and NPAHs are unclear. Here we investigated the oxidation mechanism of anthracene (ANT) and phenanthrene (PHE) initiated by OH radical u...
Article
Long-range atmospheric transport (LRAT) is the main route for circulating polychlorinated biphenyls (PCBs) from sources to sinks. In the atmosphere, PCBs containing six and less chlorine substitutions exist mainly as vapour, which can be oxidized by OH radical. Here, using quantum chemistry and transition state theory, we calculated the rate coeffi...
Article
The gas-phase ozonolysis mechanism of 3-carene is investigated using high level quantum chemistry and kinetic calculations. The reaction flows the Criegee mechanism with an initial addition of O3 to the >C=C< bond, followed by a chain of unimolecular isomerizations, as 3-carene + O3 → POZs (Primary Ozonides) → CIs (Criegee Intermediates, 4 conforme...
Article
Carbonyl peroxy radicals (RC(O)O 2) are the ubiquitous radical intermediates in the atmospheric oxidation of volatile organic compounds. In this work, theoretical studies are carried out to explore the role of the unimolecular H-migration in the carbonyl peroxy radicals by using quantum chemistry and kinetics calculations. The results showed that H...
Article
The atmospheric oxidation mechanism of sabinene initiated by the OH radical has been studied using quantum chemistry calculations at CBS-QB3 level and reaction kinetic calculations using transition state theory and unimolecular rate theory coupled with collisional energy transfer. The oxidation is initiated by OH radical additions to the CH2=C< bon...
Article
It is generally assumed that isoprene-derived secondary organic aerosol (SOA) precursors are mainly formed from the secondary reactions of intermediate products with OH radical in gas phase and multiphase oxidation in particle. In this paper, we predicted theoretically a mechanism for the primary formation of highly oxygenated molecules (HOM) in th...
Article
Furan and its methyl substituents, as promising alternative and renewable fuels and feedstock to chemical industry, would be emitted to the atmosphere in a large scale and be degraded there by their reactions with OH, O3, NO3, and Cl etc. In this study, we investigate the mechanism of gas-phase ozonolysis of furans using quantum chemistry and kinet...
Article
Mullite with an aspect ratio of 82.08 was prepared by adding 4.5 wt% Ca3(PO4)2 to citric acid activated kaolin. Phosphorus (P) has a significant role in the formation of well-developed mullite whiskers. The mechanisms were discussed based on X-ray diffraction, FTIR, SEM, EDS and ³¹P MAS NMR. The addition of P decreases the quartz content, but incre...
Article
The cyclohexadienyl radicals (CHR) with both methyl and isopropyl substitutions are formed in the atmospheric oxidation of cyclohexadiene-type terpenes through hydrogen abstraction by OH radical. In this Letter, theoretical study is carried out on the reactions of O2 with c-C6H7 and 2-methyl-5-isopropyl-, 2-isopropyl-5-methyl, and 1-isopropyl-4-met...
Article
β-Myrcene is one of the major monoterpenes in the atmosphere. Ozonolysis is one of the oxidation removal for myrcene in the atmosphere during daytime. In this study, the mechanism of myrcene ozonolysis is studied using high-level quantum chemistry calculations and kinetic calculations. The reaction starts with the formation of primary ozonides (POZ...
Article
Atmospheric oxidation mechanism of furan and methyl furans (MFs) initiated by OH radicals is studied using high-level quantum chemistry and kinetic calculations. The reaction starts mainly with OH addition to C2/C5-position, forming highly chemically activated adduct radical R2*/R5*, which would either be stabilized by collision or promptly isomeri...
Article
Sabinene is one of the monoterpenes of biogenic origin in the atmosphere. Ozonolysis is one of important oxidation removal for sabinene in the atmosphere during daytime, leading to formation of secondary organic aerosol. In this study, we investigate the mechanism of gas-phase ozonolysis of sabinene using quantum chemistry and kinetic calculations....
Article
Mullite whiskers are potential candidates for improving the mechanical and thermal properties of ceramic, glass, and composite material. In this work, well-developed whisker-shaped mullite has been produced by adding tribasic calcium phosphate (Ca3(PO4)2) into kaolin before calcining in air. In the raw kaolin, rod-like mullite crystal of ~0.5-1.0 μ...
Article
Furfural is emitted into the atmosphere because of its potential applications as an intermediate to alkane fuels from biomass, industrial usages, and biomass burning. The kinetic and mechanistic information of the furfural chemistry is necessary to assess the fate of furfural in the atmosphere and its impact on the air quality. Here we studied the...
Article
Increasingly serious ozone (O3) pollution, along with decreasing NOx emission, is creating a big challenge in the control of volatile organic compounds (VOCs) in China. More efficient and effective measures are assuredly needed for controlling VOCs. In this study, a reactivity-based industrial VOCs emission inventory was established in China based...
Article
The atmospheric oxidation mechanisms of dimethyl ether (DME), diethyl ether (DEE) and diisopropyl ether (DiPE) are studied by using quantum chemistry and unimolecular reaction theory (RRKM-ME) calculations. For the peroxy radical CH3OCH2O2˙ from DME, a barrier height of ∼85 kJ mol(-1) is found for its intramolecular H-shift to ˙CH2OCH2OOH, which ca...
Article
Trans-sobrerol (Sob) and 8-p-menthen-1,2-diol (Limo-diol) are the primary products in the atmospheric oxidation of β-pinene and limonene, respectively. Because of their low volatility, they associate more likely to the liquid particles in the atmosphere, where they are subject to the aqueous phase oxidation by the atmospheric oxidants. In this work...
Article
Theoretical study has been carried out on the fate of methylthiomethylperoxy radical (CH3SCH2OO, MSP) in the atmosphere. The intramolecular H-shift followed by recombination with O2, MSP → CH2SCH2OOH → OOCH2SCH2OOH (MSPO2), is found to be fast enough, i.e., 2.1 s-1 at 293 K, to compete with and even surpass the possible bimolecular reactions of MSP...
Article
The atmospheric oxidation mechanism of m-xylene (mX) initiated by the OH radical is investigated at M06-2X and ROCBS-QB3 levels, coupled with reaction kinetics calculations by using transition state theory and unimolecular RRKM-ME theory. The calculations show that the reaction between OH and mX is dominated by OH addition to the C2 and C4 position...
Article
The atmospheric oxidation mechanism of chlorobenzene (CB) initiated by the OH radicals is investigated at M06-2X/6-311++G(2df, 2p) and ROCBS-QB3 levels. The oxidation is initiated by OH addition to the ortho (∼50%), para (∼33%) and meta (∼17%) positions, forming CB-OH adducts as R2, R3, and R4; while the ipso-addition is negligible (∼0.2%). The rea...
Conference Paper
Criegee intermediates (CIs) are the key intermediates in the ozonolysis reactions of alkenes, which are important in tropospheric oxidn. CIs are the precursors of OH radicals in the ozonolysis reactions of alkenes, and they react with many important atm. species such as SO_2, NO_2, O_3, and water, which lead to the secondary org. aerosol (SOA) form...
Article
The atmospheric oxidation mechanism of 1,2,4-trimethylbenzene (1,2,4-TMB) initiated by OH radicals is investigated using quantum chemistry calculations at M06-2X and ROCBS-QB3 levels. The calculations show that the initiation of the reaction is dominated by OH addition to C1, C3 and C5 to form 1,2,4-TMB-OH adducts R1, R3, and R5 with branching rati...
Article
ABSTRACT The atmospheric oxidation mechanism of toluene initiated by OH radical addition is investigated by quantum chemistry calculations at M06-2X, G3MP2-RAD, and ROCBS-QB3 levels and by kinetics calculation using transition state theory and unimolecular reaction theory coupled with master equation (RRKM-ME). The predicted branching ratios are 0....
Article
This paper presents a new classification of industrial sector on basis of a source-tracing method for the historical industrial emissions of non-methane volatile organic compounds (NMVOCs). The industrial sources were divided into four major source categories: production of NMVOCs, storage and transport, industrial processes using NMVOCs as raw mat...
Article
The fate of alkoxy radicals formed in the atmospheric oxidation of benzene initiated by OH radical is investigated by using quantum chemistry and kinetics calculations. The two alkoxy radicals (R2 and R3), formed from the commonly accepted bicyclic radical intermediates, are found to undergo ring-closure preferentially, in addition to the ring-brea...
Article
The gas-phase oxidation mechanism of phenol initiated by OH radical was investigated using DFT and ab initio calculations. The initiation of the reaction is dominated by OH addition to ortho-position, forming P2, which subsequently combines with O2 at the ipso-position to form P2-1-OO adduct. A concerted HO2 elimination process from P2-1-OO was fou...
Article
The atmospheric oxidation mechanism of 2,7-dimethyl naphthalene (27DMN) initiated by OH radical is investigated at levels of BB1K and G3MP2-RAD//BH&HLYP. The reaction is mainly initiated by OH addition to C1 position to form radical adduct R1. In the atmosphere, R1 reacts with O2 via two comparable pathways as direct H-abstraction to form 27DMN-1-o...
Article
Full-text available
A metal-organic framework with open 2,2'-bipyridine sites can efficiently activate molecular oxygen for selective oxidation of a variety of saturated hydrocarbons with unprecedented activities and selectivities.
Article
The atmospheric polychlorinated dibenzo-p-dioxins (PCDDs) partition appreciably in the gas phase, where they undergo rapid oxidation. The atmospheric oxidation mechanisms of a few PCDDs, initiated by OH radical, are studied using density functional theory calculations. The oxidations start with OH-addition to the aromatic rings, dominantly at γ-sit...
Article
The atmospheric oxidation mechanism of naphthalene (Nap) initiated by the OH radical is investigated using density functional theory at B3LYP and BB1K levels. The initial step is dominated by OH addition to the C(1)-position of Nap, forming radical C(10)H(8)-1-OH (R1), followed by the O(2) additions to the C(2) position to form peroxy radical R1-2O...
Article
The structural and energetic information of SixGeyHz and ions is crucial in understanding the deposition processes in producing SixGe1−x semiconductor materials. This work presents theoretical studies on the structures and energetics of the simplest SiGe-hydrides and cations, SiGeHz0,+1, as well as Ge2Hz0,+1 and Si2Hz0,+1 for comparison. The struct...
Article
The reaction mechanisms for dimethyl selenide (DMSe) and dimethyl selenoxide (DMSeO) with OH radical are studied by using quantum chemistry calculations. The structures are optimized at MP2 levels, and electronic energies at Gaussian-4 level. Addition complexes are found between reactants as (CH3)2Se·OH, (CH3)2Se(O)·OH, and (CH3)2SeO·HO, which serv...
Article
The bond dissociation enthalpies (BDEs) in chlorinated benzenes and phenols and the standard gas-phase enthalpies of formation of chlorinated phenyl and phenoxy radicals are predicted by using Gaussian-4 (G4) and Gaussian-3X (G3X) model chemistries. The predicted G4 BDEs are systematically smaller than the G3X ones, with difference as much as ∼15 k...
Article
Sulfur dioxide (SO(2)) is a major air pollutant that can contribute to the production of particulate sulfate and increase the acidity in the environment. SO(2) is detected by cavity ring-down spectroscopy (CRDS) utilizing the SO(2) absorption in the 308 nm region. A ferrous sulfate scrubber and a sodium carbonate annular denuder are used to reduce...
Article
The reaction mechanisms of dibenzo-p-dioxin (DD) and 2,3,7,8-TCDD with OH radical have been studied using density functional theory calculations. Under the atmospheric conditions, ca 42% of DD+OH reaction proceeds as formation of DD-OH-β adduct, which will react with O(2) slowly; while the rest will proceed as formation of DD-OH-γ adduct, which wil...
Article
Chlorinated benzoates are widely spread in the environment and are subject to anaerobic degradations, where chlorinated benzoates are used as electron acceptor by certain groups of anaerobic bacteria and the energy of the reduction reactions is used by bacteria for growth. The energies, namely the change of Gibbs energy of the reduction reaction (Δ...
Article
The enthalpies of formation of brominated benzenes and phenols were predicted using Gaussian-4 (G4), G3X, and G3XMP2 model chemistries and a few popular density functional methods, coupled with homodesmic reactions (HR1) and (HR2) in which C6H6, C6H5Br, and C6H5OH are used as reference compounds. The results from G4, G3X, and G3XMP2 agree closely w...
Article
The proton affinities (PAs) and potential energy surfaces (PESs) of hydrochlorofluoromethanes (HCFMs) have been predicted by using Gaussian-3X (G3X) method. The G3X PAs agree with previous G3 predictions, while the large discrepancies between theoretical and experimental PAs persisted for CH2F2, CHF3, and CF3Cl. Protonated HCFMs usually have multip...
Article
The standard gas-phase enthalpies of formation of polychlorinated naphthalenes (PCNs) have been predicted using G3X model chemistry, density functional theory (DFT), and second-order Muller-Plesset (MP2) theory. Two isodesmic reactions are used for better prediction of formation enthalpies. The first (IR1) employs chlorobenzene as a reference speci...
Article
Full-text available
The DFT-B3LYP and G3X model chemistry were used to predict the cation structures and energetics of fluorinated, chlorinated, and brominated methanes. Ion–complex structures between methylene cations and HX (X=F, Cl, Br) were found for all H-containing cations, and [CHF–FH]+, [CF2–FH]+, [CCl2–ClH]+, and [CCl2–FH]+ structures are more stable than the...
Article
The oxidation of aromatic compounds in the troposphere substantially contributes to the formation of O(3) and secondary aerosol on a regional scale. Nevertheless, the initial stages of aromatic oxidation remain poorly understood. In this work, we present a quantitative analysis of previous experimental measurements relevant to atmospheric benzene o...
Article
The standard gas-phase enthalpies of formation of polychlorinated dibenzofurans (PCDFs) have been predicted by using G3XMP2 model chemistry, density functional theory (DFT), and second-order Muller-Plesset (MP2) theory, coupled with isodesmic reactions. The results show a large difference between G3XMP2 and DFT methods with 6-31G(2df,p) and 6-311++...
Article
The mineral schreibersite, (Fe,Ni) 3 P, a ubiquitous component of iron meteorites, is known to undergo anoxic hydrolytic modification to afford a range of phosphorus oxyacids. H-phosphonic acid (H 3 PO 3 ) is the principal hydrolytic product under hydrothermal conditions, as confirmed here by ³¹ P-NMR spectroscopic studies on shavings of the Seymch...
Article
Quantum chemistry study has been carried out on the structure and energetics of halogenated silanes, radicals, and cations (SiHxXy0,+1, X = F, Cl, Br; x + y = 1–4). The geometries are optimized at B3LYP/6-31+G(2df,p) level. The adiabatic ionization energiess (IEas), relative energetics of cations, proton affinities (PAs) of silanes, and the enthalp...
Article
The enthalpies of formation of stable closed shell C1 and C2 brominated hydrocarbons have been predicted using Gaussian-3X model chemistry. The entropy, heat capacity, and thermal corrections are calculated from B3LYP/6-31G(2df,p) geometries and vibrational frequencies using rigid-rotor-harmonic-oscillator approximation, except for the quantities o...
Article
The structures and vibrational frequencies of cations of fluorinated and chlorinated germanes and radicals (GeHxXy+, X = F, Cl; x + y = 1-4) and protonated germanes are investigated theoretically at B3LYP/6-31+G(2df,p) level. For GeH2, GeHX, GeH2X, GeHX2, and germanes, the most stable cationic structures are largely distorted from their neutral one...
Article
The standard gas-phase enthalpies of formation of chlorinated benzenes, phenols and dibenzo-p-dioxins have been predicted using G3X and/or G3XMP2 model chemistries coupled with isodesmic reactions and compared to the previous theoretical and experimental values. A set of values for chlorinated benzenes are first suggested based on experimental meas...
Article
Quantum chemistry calculations have been carried out on selenium fluorides SeF1–6 at Gaussian-3 level for thermodynamic properties including the enthalpies of formation, adiabatic ionization potentials, electron affinities, and the appearance energies of cation fragments in the photoionization of SeF6. The G3 calculations on SeH0–20,±1 and enthalpy...
Article
The kinetics of the reaction OH + C2H2 have been studied using laser flash photolysis at 248 nm to generate OH radicals and laser-induced fluorescence to monitor OH removal. An attempt was made to use the rate coefficients OH (v = 1,2) + C2H2 to determine the limiting high-pressure rate coefficient, k(1a)(infinity), over the temperature range of 19...
Article
Ab initio and density functional methods have been used to examine the structures and energetics of the hydrated clusters of methane sulfonic acid (MSA), CH3SO3H.(H2O)n (n = 1-5). For small clusters with one or two water molecules, the most stable clusters have strong cyclic hydrogen bonds between the proton of OH group in MSA and the water molecul...
Article
Ambientdetection of NO2 by cavity ring-down spectroscopy is examined in the wavelength region near 405.23 nm, and possible interferences by particulates, water vapor, and carbon dioxide are characterized. Particulates can be efficiently removed by the use of a 0.45 microm fluoropolymer filter. Water vapor has a response of 2.8 ppb (NO2 equivalent)...
Article
The pressure and temperature dependence for the reaction of OH + C(2)H(4) was studied over the range of conditions: 200-400 K and 5-600 Torr by laser flash photolysis, laser-induced fluorescence (FP-LIF). Additional experiments were conducted at room temperature by laser flash photolysis, cavity ring-down spectroscopy to facilitate determination of...
Article
The kinetics of chlorine atom abstractions from normal and selectively deuterated propane and isobutane have been measured at room temperature and 195 K using a laser flash photolysis system, and following the course of the reaction via IR diode laser absorption measurements of HCl product. In conjunction with the kinetic measurements, a comparison...
Article
Ab initio calculations, combined with experimental studies on the anaerobic hydrolysis of phosphaalkynes under thermal and photochemical conditions suggest a potential, exogenous source of reduced oxidation state phosphorus for the early Earth.
Article
Many reactions in the atmosphere include 3-body stabilization of hot adduct. The complex pressure and temperature dependence of these reactions depend on the potential energy surface for the reaction and the efficiency of energy transfer during collisions. These reactions must be parameterized for the full extent of tropospheric conditions for use...
Article
The thermal decomposition of 1,3-butadiene, 1,3-butadiene-1,1,4,4-d(4), 1,2-butadiene, and 2-butyne at temperatures up to 1520 K was carried out by flash pyrolysis on a approximately 20 mus time scale. The reaction products were isolated by supersonic expansion and detected by single-photon (lambda = 118 nm) vacuum-ultraviolet time-of-flight mass s...
Article
Quantum yields for acyl (RCO) radical production from ketone photolysis as a function of temperature, pressure and the atmospherically relevant wavelengths (308 and 320 nm) have been determined for methylethyl ketone (MEK), methylvinyl ketone (MVK) and diethyl ketone (DEK) via direct observation of the OH product from the RCO + O2 reaction. The met...
Article
The structures, vibrational frequencies, enthalpies of formation, and dissociation energies of germane, chlorinated and fluorinated germanes, and their radical fragments have been examined with density functional theory and quantum chemistry ab initio methods. The theoretical vibrational frequencies of the germanes at the B3LYP/6-31G(2df,p) level a...
Article
Radical pathways: Experimental and theoretical spectroscopic and kinetic data for the phenylvinyl radical and its oxidation product (see picture), and two key pathways for the C6H5C2H 2+O2 reaction are presented.
Article
The kinetics of C6H5 reactions with n-CnH2n+2 (n = 3, 4, 6, 8) have been studied by the pulsed laser photolysis/mass spectrometric method using C6H5COCH3 as the phenyl precursor at temperatures between 494 and 1051 K. The rate constants were determined by kinetic modeling of the absolute yields of C6H6 at each temperature. Another major product C6H...
Article
Nitrogen dioxide $(NO_{2})$ is a principle component of photochemical smog that is present in polluted atmospheres at the parts per billion (ppb) level. In this work, cavity ring-down spectroscopy (CRDS) is utilized for the detection of ambient $NO_{2}$. Sub ppb limit of detection is routinely achieved. Experimental approaches to remove the particu...
Article
Ozonolysis reactions of alkenes are important oxidation pathways of alkenes in the atmosphere, and they are also significant sources of tropospheric hydroxyl radicals. In this work, ozone reactions with trans- and cis-2-butene are studied using cavity ring-down spectroscopy (CRDS). Vinoxy $(CH_{2}CHO)$ radical, a proposed co-product of OH from diss...
Article
Bare and partially hydrogenated neutral silicon clusters, SinHx (n = 3-10, x = 0-3), were produced upon flash pyrolysis of dilute (1%) mixtures of disilane, Si2H6, in Ar and of silane, SiH4, in He at temperatures above similar to 1000 K. Immediately following the flash pyrolysis of the precursors (on an similar to20 mus time scale), the clusters we...
Article
Enthalpies of formation of CH3S(O)xOH (x=0–2) and HOS(O)yOH (y=0,1) in gas phase are calculated by Gaussian-3 (G3) method with B3LYP/6-31G(d) and MP2/cc-pVTZ geometries (denoted as G3B3 and G3//MP2 here, respectively). The atomization procedure using both G3B3 and G3//MP2 predicts the enthalpies of formation larger than the experimental values with...
Article
Gas-phase reaction of dimethyl sulfoxide (DMSO) with OH radical is investigated using ab initio calculations. The CH3S(O)OH+CH3 product channel has an overall negative reaction activation energy, and it could proceed by formation of an addition complex (CH3)2S(O)·OH and subsequent dissociation into CH3S(O)OH+CH3 via an energy barrier at −29.8 kJ/mo...
Article
Two weakly bound complexes between CH3SCH3 (DMS) and OH, via 2-center-3-electron (2c-3e) bonding and dipole–dipole interaction, have been identified by density functional theory (DFT-B3LYP). The 2c-3e bonding complex is more stable at Gaussian-2 level with −31kJ/mol relative to DMS+OH. Similar structures are found for the complex of CH3SH with OH....
Article
Nitrous acid (HONO) plays an important role in the formation of hydroxyl radical and the nitrogen cycle in atmospheric chemistry. Cavity ring-down spectroscopy (CRDS) has been utilized for detection of gaseous HONO in the near-UV spectral region. At the maximum absorption wavelength (354.2 nm), HONO can be detected with a low limit of 5 parts per b...
Article
The influence of hydrogen bonding (HB) on the 13C chemical shift tensors in four solid amino acids was studied by the ab initio gauge-included atomic orbital (GIAO) approach. The results of the present calculations were compared with those predicted previously and with the experimentally observed shieldings. The RMS error (without HB) found on comp...