Search results for "Catalysis"
showing 10 items of 5944 documents
A History of the Pharmacological Treatment of Bipolar Disorder.
2018
In this paper, the authors review the history of the pharmacological treatment of bipolar disorder, from the first nonspecific sedative agents introduced in the 19th and early 20th century, such as solanaceae alkaloids, bromides and barbiturates, to John Cade’s experiments with lithium and the beginning of the so-called “Psychopharmacological Revolution” in the 1950s. We also describe the clinical studies and development processes, enabling the therapeutic introduction of pharmacological agents currently available for the treatment of bipolar disorder in its different phases and manifestations. Those drugs include lithium salts, valproic acid, carbamazepine, new antiepilep…
Cover Feature: Excited‐State Kinetics of an Air‐Stable Cyclometalated Iron(II) Complex (Chem. Eur. J. 51/2019)
2019
Cover Feature: Alkali Blues: Blue‐Emissive Alkali Metal Pyrrolates (Chem. Eur. J. 26/2019)
2019
Characterization of Locally Excited and Charge-Transfer States of the Anticancer Drug Lapatinib by Ultrafast Spectroscopy and Computational Studies
2020
[EN] Lapatinib (LAP) is an anticancer drug, which is metabolized to theN- and O-dealkylated products (N-LAP andO-LAP, respectively). In view of the photosensitizing potential of related drugs, a complete experimental and theoretical study has been performed on LAP,N-LAP andO-LAP, both in solution and upon complexation with human serum albumin (HSA). In organic solvents, coplanar locally excited (LE) emissive states are generated; they rapidly evolve towards twisted intramolecular charge-transfer (ICT) states. By contrast, within HSA only LE states are detected. Accordingly, femtosecond transient absorption reveals a very fast switching (ca. 2 ps) from LE (lambda(max)=550 nm) to ICT states (…
Water Depollution by Advanced Oxidation Technologies
2020
This chapter deals with water treatments by advanced oxidation processes (AOPs) based on chemical and photochemical reactions. The most used processes are described, and for each of them, the main reaction mechanisms, principles, advantages, drawbacks, performances and formation of by-products, coupled with technologies and their applications to waters and wastewater depollution, have been analysed, supporting the main results of studies published in the pertinent literature.
Heavy enzymes—experimental and computational insights in enzyme dynamics
2014
The role of protein motions in the chemical step of enzyme-catalyzed reactions is the subject of an open debate in the scientific literature. The systematic use of isotopically substituted enzymes has been revealed as a useful tool to quantify the role of these motions. According to the Born-Oppenheimer approximation, changing the mass of the protein does not change the forces acting on the system but alters the frequencies of the protein motions, which in turn can affect the rate constant. Experimental and theoretical studies carried out in this field are presented in this article and discussed in the framework of Transition State Theory.
Halloysite nanotubes: a green resource for materials and life sciences
2020
Clay minerals are considered one of the materials of the 20th century for their peculiar physico-chemical features. Among them, halloysite nanotubes (HNTs) are an emerging nanomaterial with a particular tubular structure that makes them a low cost and valuable alternative to the most common carbon nanotubes. Due to their tubular morphology, HNTs are employed in several fields acting as nanocontainers for different compounds for applications in drug carrier and delivery fields, catalysis, and as filler for polymeric matrices. The modification of HNTs’ surfaces allows to the synthesis of different nanoarchitectures that can improve the mechanical and thermal performance of polymer as well as …
Improvement of membrane performances to enhance the yield of vanillin in a pervaporation reactor.
2014
In membrane reactors, the interaction of reaction and membrane separation can be exploited to achieve a “process intensification”, a key objective of sustainable development. In the present work, the properties that the membrane must have to obtain this result in a pervaporation reactor are analyzed and discussed. Then, the methods to enhance these properties are investigated for the photocatalytic synthesis of vanillin, which represents a case where the recovery from the reactor of vanillin by means of pervaporation while it is produced allows a substantial improvement of the yield, since its further oxidation is thus prevented. To this end, the phenomena that control the permeation of bot…
Gas-phase detection of HSOH: synthesis by flash vacuum pyrolysis of di-tert-butyl sulfoxide and rotational-torsional spectrum.
2003
Gas-phase oxadisulfane (HSOH), the missing link between the well-known molecules hydrogen peroxide (HOOH) and disulfane (HSSH), was synthesized by flash vacuum pyrolysis of di-tert-butyl sulfoxide. Using mass spectrometry, the pyrolysis conditions have been optimized towards formation of HSOH. Microwave spectroscopic investigation of the pyrolysis products allowed-assisted by high-level quantum-chemical calculations--the first measurement of the rotational-torsional spectrum of HSOH. In total, we have measured approximately 600 lines of the rotational-torsional spectrum in the frequency range from 64 GHz to 1.9 THz and assigned some 470 of these to the rotational-torsional spectrum of HSOH …
Structural flexibility of bis(phenoxyimine) titanium complexes in the early stages of olefin polymerization process: a DFT study
2010
The behaviors of three structurally similar salan- and phenoxyimine-based catalysts activated by perfluorophenylborate were compared in the early stages of ethylene polymerization. It was found that moderate modification of the ligand structure can dramatically reduce the interactions between the cationic active site and the counteranion and, as a result, decrease the theoretically calculated upper bound to the ion separation barrier from 15 to 2 kcal/mol. The interactions between the ions in the ion pair have further repercussions on the structure of the active sites (octahedral vs square pyramid), transition states and thus the insertion barriers.