Microscopy Reveals: Impact of Lithium Salts on Elementary Steps Predicts Organozinc Reagent Synthesis and Structure

2019 ◽  
Vol 141 (25) ◽  
pp. 9879-9884 ◽  
Author(s):  
Kristof Jess ◽  
Kazuhiro Kitagawa ◽  
Tristen K. S. Tagawa ◽  
Suzanne A. Blum
Keyword(s):  
Lithium Salts ◽  
Elementary Steps ◽  
Organozinc Reagent

A Systematic DFT Study of Two Elementary Steps Involving Hydrogen Peroxide and the Hydroxyl Radical in the Fenton Reaction

2018 ◽  
Author(s):  
Danilo Carmona ◽  
David Contreras ◽  
Oscar A. Douglas-Gallardo ◽  
Stefan Vogt-Geisse ◽  
Pablo Jaque ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Ab Initio ◽  
Fenton Reaction ◽  
Basis Set ◽  
Basis Sets ◽  
Dft Methods ◽  
Elementary Steps ◽  
Oxygen Oxygen ◽  
Complete Basis Set

The Fenton reaction plays a central role in many chemical and biological processes and has various applications as e.g. water remediation. The reaction consists of the iron-catalyzed homolytic cleavage of the oxygen-oxygen bond in the hydrogen peroxide molecule and the reduction of the hydroxyl radical. Here, we study these two elementary steps with high-level ab-initio calculations at the complete basis set limit and address the performance of different DFT methods following a specific classification based on the Jacob´s ladder in combination with various Pople's basis sets. Ab-initio calculations at the complete basis set limit are in agreement to experimental reference data and identified a significant contribution of the electron correlation energy to the bond dissociation energy (BDE) of the oxygen-oxygen bond in hydrogen peroxide and the electron affinity (EA) of the hydroxyl radical. The studied DFT methods were able to reproduce the ab-initio reference values, although no functional was particularly better for both reactions. The inclusion of HF exchange in the DFT functionals lead in most cases to larger deviations, which might be related to the poor description of the two reactions by the HF method. Considering the computational cost, DFT methods provide better BDE and EA values than HF and post--HF methods with an almost MP2 or CCSD level of accuracy. However, no systematic general prediction of the error based on the employed functional could be established and no systematic improvement with increasing the size in the Pople's basis set was found, although for BDE values certain systematic basis set dependence was observed. Moreover, the quality of the hydrogen peroxide, hydroxyl radical and hydroxyl anion structures obtained from these functionals was compared to experimental reference data. In general, bond lengths were well reproduced and the error in the angles were between one and two degrees with some systematic trend with the basis sets. From our results we conclude that DFT methods present a computationally less expensive alternative to describe the two elementary steps of the Fenton reaction. However, choice of approximated functionals and basis sets must be carefully done and the provided benchmark allows a systematic validation of the electronic structure method to be employed

scholarly journals Experimental Evidence that Halogen Bonding Catalyzes the Heterogeneous Chlorination of Alkenes in Submicron Liquid Droplets

2021 ◽  
Author(s):  
Meirong Zeng ◽  
Kevin Roger Wilson
Keyword(s):  
Experimental Evidence ◽  
Halogen Bonding ◽  
Liquid Droplets ◽  
Elementary Steps ◽  
Kinetics Of

A key challenge in predicting the multiphase chemistry of aerosols and droplets is connecting reaction probabilities, observed in an experiment, with the kinetics of individual elementary steps that control the...

scholarly journals Overview of lithium's use: a nationwide survey

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Xabier Pérez de Mendiola ◽  
Diego Hidalgo-Mazzei ◽  
Eduard Vieta ◽  
Ana González-Pinto
Keyword(s):  
Adverse Effects ◽  
Clinical Guidelines ◽  
Lithium Treatment ◽  
Scientific Evidence ◽  
Plasma Concentrations ◽  
Maintenance Phase ◽  
Nationwide Survey ◽  
Developed Countries ◽  
Lithium Salts ◽  
National Society

Abstract Background Lithium is considered the gold standard treatment for bipolar disorder (BD). Current clinical guidelines and scientific evidence support its use as a first-line treatment in BD. However, over the last two decades, there has been a downward tendency in lithium's use in several developed countries. Based on a nationwide survey, this study's objective is to analyze in a large sample of psychiatrists relevant issues of the use of lithium salts in BD. Methods Data were collected through an anonymous survey sent by email among 500 psychiatrists who belong to a National Society of Psychiatry (Spanish Society of Biological Psychiatry). The survey is a self-administered questionnaire consisting of 21 items on the most key aspects of lithium's use (indication, dosage, monitoring, and information for patients). Results 212 psychiatrists completed the survey. 70% of psychiatrists prescribe lithium to more than 50% of patients diagnosed with BD. Adverse effects are the main reason not to use lithium salts. Over 75% of the participants consider lithium salts the treatment of choice for the maintenance phase of BD, both in women and men. Most of the participants (> 50%) start lithium after the first affective episode, use conservative plasma concentrations (0.6–0.8 mmol/L), and generally prescribe it twice a day. 57% of psychiatrists who treat patients under 18 do not use lithium in this population. About 70% of the survey respondents use official protocols to inform and monitor patients on lithium treatment. Conclusions From the results of the present study, it can be concluded that the use of lithium in Spain is in line with the recommendations of the main international clinical guidelines and current scientific literature. The first reason not to prescribe lithium in our country is the perception of its adverse effects and not the aspects related to its practical use or its effectiveness. Considering that BD is a chronic disease with a typical onset in adolescence, the low rate of prescription of lithium salts in patients under 18 must be thoroughly studied.

scholarly journals Lithium Salts in the Treatment of Psychotic Excitement

1982 ◽  
Vol 16 (3) ◽  
pp. 129-133 ◽  
Author(s):  
John F. Cade
Keyword(s):  
Medical Journal ◽  
Lithium Salts ◽  
Seminal Paper

Dr John Cade, one of the most distinguished Australian psychiatrists, died in November, 1980. We republish his seminal paper and acknowledge our debt to The Medical Journal of Australia for allowing us to reprint the article from their September 1949 issue.

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