Quantum Roaming in the Complex Forming Mechanism of the Reactions of OH with formaldehyde and methanol at Low Temperature and Zero Pressure: A Ring Polymer Molecular Dynamics Approach.

08:00 EDT 2nd April 2019 | BioPortfolio

Summary of "Quantum Roaming in the Complex Forming Mechanism of the Reactions of OH with formaldehyde and methanol at Low Temperature and Zero Pressure: A Ring Polymer Molecular Dynamics Approach."

The quantum dynamics of the title reactions are studied using the Ring Polymer Molecular Dynamics (RPMD) method from 20 to 1200 K using recently proposed full dimensional potential energy surfaces which include long range dipole-dipole interactions. A V-shaped dependence of the reaction rate constants is found with a minimum at 200-300 K, in rather good agreement with the current experimental data. For temperatures above 300 K the reaction proceeds following a direct H-abstraction mechanism. However, below 100 K the reaction proceeds via organic-molecule-OH collision complexes, with very long lifetimes, longer than 10-7 s, associated to quantum roaming arising from the inclusion of quantum effects by the use of RPMD. The long lifetimes of these complexes are comparable to the time scale of the tunnelling to form reaction products. These complexes are formed at zero pressure due to quantum effects and not only at high pressure as suggested by Transition State Theory (TST) calculations for OH + methanol and other OH reactions. The zero-pressure rate constants reproduce quite well measured ones below 200 K, and this agreement opens the question of how important the pressure effects on the reaction rate constants are, as implied in TST-like formalisms. The zero pressure mechanism is the only applicable to very low gas density environments, such as the interstellar medium, unrepeatable by the experiments.


Journal Details

This article was published in the following journal.

Name: The journal of physical chemistry letters
ISSN: 1948-7185


DeepDyve research library

PubMed Articles [11249 Associated PubMed Articles listed on BioPortfolio]

Low amount of formaldehyde in topical medication and cosmetics: is it clinically relevant?

It is difficult for the patients allergic to formaldehyde to totally avoid contact with products containing it as its presence cannot be determined from the ingredient labelling with certainty (1). Th...

A "Dual-key-and-lock" Ruthenium Complex Probe for Lysosomal Formaldehyde in Cancer Cells and Tumors.

Biomedical investigations reveal that excessive formaldehyde generation is possibly a critical factor for tissue cancerization, cancer progression and metastasis. Responsive molecular probes that can ...

Ultralow Pt Catalyst for Formaldehyde Removal: The Determinant Role of Support.

Supported Pt catalyst has been intensively investigated for formaldehyde elimination owing to its superior reactivity at room temperature (RT). However, the high Pt content is challenging because of i...

Exploring Cycloreversion Reaction of Cyclobutane Pyrimidine Dimers Quantum Mechanically.

Cyclobutane pyrimidine dimer (CPD) is a major photoproduct of deoxyribonucleic acid (DNA) that is damaged by ultraviolet light. This DNA lesion can be repaired by DNA photolyase with the aid of UV lig...

Tuning the Reactivities of the Heteronuclear AlnV3-nO7-n+ (n = 1, 2) Cluster Oxides towards Methane by Varying the Composition of the Metal Centers.

The thermal gas-phase reactions of [Al₂VO₅]+ and [AlV₂O₆]+ with methane have been explored by using FT-ICR mass spectrometry complemented by high-level quantum chemical calculations. Both clus...

Clinical Trials [2621 Associated Clinical Trials listed on BioPortfolio]

Precancerous Myeloid Cells in Chinese Factory Workers Exposed or Not Exposed to Formaldehyde

RATIONALE: Exposure to formaldehyde in the work place may affect the risk of developing cancer later in life. Learning about the long-term effects of formaldehyde exposure may help the stu...

Personalized Quantum Sonotherapy in Regional Anesthesia

The objetive of the study is to evaluate the effect of personalized quantum sonotherapy on the level of anxiety and pain in outpatients schedule for orthopedic surgery under regional anest...

Intramedullary Fixation of Humerus Fractures Without Intramedullary Reaming

The purpose of the study is to evaluate the safety and efficacy of the composite Nail - the Quantum interlocking intramedullary nailing system in the reduction of humeral fractures.

Magnetic Therapy in Migraine Prophylaxis

Background: The therapy with pulsed electromagnetic fields (PEFs) has been used as a therapeutic modality for at least 40 years. However, their effect in the migraine prophylaxis is unclea...

Reactions to Contrast Media (CM) Administered at the Time of the Endoscopic Retrograde Cholangiopancreatography (ERCP)

The aim of this study is to prospectively document the incidence of CM adverse reactions at the time of ERCP and to determine whether various perceived risk factors are predictive of adver...

Medical and Biotech [MESH] Definitions

Nanometer sized fragments (the dots) of semiconductor crystalline material which emit PHOTONS. The wavelength is based on the quantum confinement size of the dot. They are brighter and more persistent than organic chemical INDICATORS. They can be embedded in MICROBEADS for high throughput ANALYTICAL CHEMISTRY.

A highly reactive aldehyde gas formed by oxidation or incomplete combustion of hydrocarbons. In solution, it has a wide range of uses: in the manufacture of resins and textiles, as a disinfectant, and as a laboratory fixative or preservative. Formaldehyde solution (formalin) is considered a hazardous compound, and its vapor toxic. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p717)

Complex sets of enzymatic reactions connected to each other via their product and substrate metabolites.

A family of enzymes that catalyze the stereoselective, regioselective, or chemoselective syn-dehydrogenation reactions. They function by a mechanism that is linked directly to reduction of molecular OXYGEN.

A 63-kDa serum glycoprotein encoded by gene C9. Monomeric C9 (mC9) binds the C5b-8 complex to form C5b-9 which catalyzes the polymerization of C9 forming C5b-p9 (MEMBRANE ATTACK COMPLEX) and transmembrane channels leading to lysis of the target cell. Patients with C9 deficiency suffer from recurrent bacterial infections.

Quick Search


DeepDyve research library

Relevant Topic

Collaborations in biotechnology
Commercial and academic collaborations are used throughout the biotechnology and pharmaceutical sector to enhance research and product development. Collaborations can take the form of research and evaluation agreements, licensing, partnerships etc. ...

Searches Linking to this Article