Thermodynamic properties of gas-phase hydrogen-bonded complexes

Curtiss, Larry A.; Blander, M.

doi:10.1021/cr00088a002

Cited by 250 publications

(127 citation statements)

References 27 publications

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“…The dissociation energies and dissociation enthalpies for the various clusters at 0 K and at room temperature are given in Table VII. There is good agreement between the calculated dissociation enthalpies and previous theoretical 13 and experimental 43,44 values. From Table VI, we observe that the MP2 interaction energies are consistently improved as the size of the basis set is increased.…”

Section: E Energetics and Cooperativitysupporting

confidence: 81%

Hydrogen bonding and cooperative effects in mixed dimers and trimers of methanol and trifluoromethanol: An ab initio study

Parra

Zeng

1999

The Journal of Chemical Physics

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, "Hydrogen bonding and cooperative effects in mixed dimers and trimers of methanol and trifluoromethanol: An ab initio study" (1999 Ab initio calculations are used to provide information on the mixed dimers and cyclic trimers of the methanol-trifluoromethanol system. In order to better understand the systems, the monomers and their corresponding dimers and trimers are also investigated. Molecular structures and harmonic frequencies are obtained at the B3LYP/6-311ϩϩG(d,p) level. Interaction energies are calculated with the MP2 and B3LYP methods using the 6-311ϩϩG(d,p), 6-311ϩϩG(2d,2p), and 6-311ϩϩG(3d,2p) basis sets for the dimers and heterodimers. The 6-311ϩϩG(d,p) basis set was used to calculate the interaction energies for the trimers and heterotrimers. Because the primary goal of this study is to examine cooperative effects, particular attention is given to parameters such as O...O distances, electronic charge densities at the bond critical points, enhanced dipole moments, shifts in the stretching frequencies of the donor O-H bond, and the length of the donor O-H bond.

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Section: E Energetics and Cooperativitysupporting

confidence: 81%

Hydrogen bonding and cooperative effects in mixed dimers and trimers of methanol and trifluoromethanol: An ab initio study

Parra

Zeng

1999

The Journal of Chemical Physics

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“…Later Wilkinson and co-workers contributed to the topic in the 1940s with similar measurements, as well as by providing a theoretical explanation for the mentioned behaviour of acetaldehyde and other polar gases [26]. Just a few recent studies have reported on acetaldehyde dimerization [27][28][29][30], and the only experimental data known to us is the study by Curtiss and Blander, who also calculated the enthalpy of dimerization for a number of hydrogen-bond-forming compounds, including acetaldehyde [27]. They used results from the literature for the deviation from the ideal gas behaviour of vapour phase thermodynamic data.…”

Section: Introductionmentioning

confidence: 90%

Acetaldehyde adsorption and condensation on anatase TiO2: Influence of acetaldehyde dimerization

Stefanov

Topalian

Granqvist

et al. 2014

Journal of Molecular Catalysis A: Chemical

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Conversion of acetaldehyde to crotonaldehyde on anatase TiO 2 films was studied by in situ Fourier transform infrared spectroscopy (FTIR) and by density functional theory (DFT) calculations. In situ FTIR showed that acetaldehyde adsorption is accompanied by the appearance of a hitherto nonassigned absorption band at 1643 cm -1 , which is shown to be due to acetaldehyde dimers. The results were supported by DFT calculations. Vibrational frequencies calculated within a partially relaxed cluster model for molecular acetaldehyde and its dimer, and for the corresponding adsorbed species on the anatase (101) surface, were in good agreement with experimental results. A kinetic model was constructed based on the combined FTIR and DFT results, and was shown to explain the essential features of the acetaldehyde condensation reaction.

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“…Given a temperature of 150°C and thermodynamic constants available from literature [39,40], the equilibrium constants are calculated as K 2 ϭ 0.011 (dimer/monomer) and K 3 ϭ 0.030 (trimer/monomer). The trimer is a cyclic structure and is relatively more stable than the dimer.…”

Section: Generation Of Solvent Ions From Methanol With Appimentioning

confidence: 99%

APPI-MS: Effects of mobile phases and VUV lamps on the detection of PAH compounds

Short¹,

Cai²,

Syage³

2007

J. Am. Soc. Mass Spectrom.

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The technique of atmospheric pressure photoionization (APPI) has several advantages over electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), including efficient ionization of nonpolar or low charge affinity compounds, reduced susceptibility to ion suppression, high sensitivity, and large linear dynamic range. These benefits are greatest at low flow rates (i.e., Յ100 L/min), while at a higher flow, photon absorption and ion-molecule reactions become significant. Under certain circumstances, APPI signal and S/N have been observed to excel at higher flow, which may be due to a nonphotoionzation mechanism. To better understand APPI at higher flow rates, we have selected three lamps (Xe, Kr, and Ar) and four mobile phases typical for reverse-phase, high-pressure liquid chromatography: acetonitrile, methanol, (1:1) acetonitrile:water and (1:1) methanol:water. As test compounds, three polyaromatic hydrocarbons are studied: benzo[a]pyrene, indeno [1,2,3-c, d]pyrene and benz [a]anthracene. We find that solvent photoabsorption cross-section is not the only parameter in explaining relative signal intensity, but that solvent photo-ion chemistry can also play a significant role. Three conclusions from this investigation are: (1) [4,5]. Recent work has focused on the direct comparison of different sources (APPI, APCI, and ESI) with specific target compounds, e.g., polyaromatic hydrocarbons [6,7], hydrophobic peptides [8], pesticides [9,10], as well as fatty acids and lipids [4,5]. In many cases atmospheric pressure photoionization (APPI) [1,7] has demonstrated extended linear dynamic range [11], enhanced sensitivity and thus lower detection limits [6,9,[12][13][14][15], and reduced or no off-line sample cleanups [6,9] in comparison with direct APCI or ESI. Adding a dopant (dopant-assisted, DA) to the mobile phase in many cases can further increase sensitivity [2].A related analytical technique is atmospheric pressure laser ionization (APLI), which has shown excellent sensitivity for certain non-or low-polar compounds [3]. The enhanced sensitivity is a direct result of the high photon flux associated with a laser system, often several orders of magnitude higher than the noncoherent light sources, e.g., lamps used with APPI. The APLI source relies on one-color, two-photon (1 ϩ 1) resonantlyenhanced multiphoton ionization (REMPI), typically using a KrF excimer laser emitting light at 5.0 eV, efficiently ionizing nonpolar molecules. However, APLIis not yet widely used due to the large size, expense, and maintenance associated with the laser system. Furthermore, changing the wavelength of an excimer laser requires the replacement of the gas mixture and often re-tuning of the laser cavity, whereas with an APPI system, the wavelength can be changed by simply switching the lamp.To improve the capabilities of APPI for LC-MS, we have focused on the ion chemistry involved in and following the photoionization process. Although direct, single-photon ionization (SPI) of a compound [M] however, there is litt...

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Thermodynamic properties of gas-phase hydrogen-bonded complexes

Cited by 250 publications

References 27 publications

Hydrogen bonding and cooperative effects in mixed dimers and trimers of methanol and trifluoromethanol: An ab initio study

Hydrogen bonding and cooperative effects in mixed dimers and trimers of methanol and trifluoromethanol: An ab initio study

Acetaldehyde adsorption and condensation on anatase TiO2: Influence of acetaldehyde dimerization

APPI-MS: Effects of mobile phases and VUV lamps on the detection of PAH compounds

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