Silver Iodate

InChI = 1S/Ag.HIO3/c;2-1(3)4/h;(H,2,3,4)/q+1;/p-1 InChIKey = YSVXTGDPTJIEIX-UHFFFAOYSA-M (reagent used as a versatile oxidative amidation and cyclization component) Physical Data: mp >200 °C; d 5.53 g cm^(−3). Solubility: soluble in aqueous ammonia; practically insoluble in water (0.3 g L^(−1) at 10 °C). Form Supplied in: white crystalline powder; commercially available. Handling, Storage, and Precautions: irritant; light sensitive; causes ignition with reducing agents or combustibles; store in cool and dry conditions in well-sealed containers; handle in fume hood

Chess on two wheels: Norwegian professional road cyclists’ perspectives on strategy, tactics and race craft

Målet med denne studien var å undersøke mannlige norske profesjonelle landeveissyklisters perspektiver på strategi, taktikk og race craft i landeveissykling. Den eksisterende litteraturen på forskingsfeltet er begrenset, så denne studien tar inspirasjon fra O’Grady et al. (2023) i dens søken etter å studere disse fenomenene nærmere i en annen sykkelkultur og på de høyeste nivåene i internasjonal sykkelsport. Fem mannlige norske landeveissyklister med erfaring fra enten UCI WorldTour- eller ProSeries nivå deltok i semistrukturerte intervjuer med åpne spørsmål. Datamateriale ble analysert tematisk i en hybrid metodologisk tilnærming inspirert av Swain (2018), gjennom kombinasjon av deduktive, induktive og abduktive prosesser. Resultatene ble delt inn i fire hovedtemaer og påfølgende undertemaer; Før løp (Kognitivt forberedelse og Planlegging av strategi), I løp (Lagdynamikk, Laghierarki (Roller), Lederskap, Kommunikasjon og Rittdynamikker), Etter løp (Muntlig gjennomgang, Analyse and Dokumentasjon og videre bruk) og Race craft. Resultatene og diskusjonen gir forskningsfeltet og profesjonelle lag og ryttere et generelt innblikk i fenomenene, og legger grunnlaget for videre, mer spesifikke, studier. For å konkludere, selv om strategi og taktikk i landeveissykling er et resultat av et komplekst samspill av ulike faktorer, tar studien og fremhever refleksive praksiser, nærhet til lagkamerater, tilpasningsevne og gode kommunikasjonsmetoder som faktorer respondenter positivt korrelerer med effektiv strategi og suksessfull taktikk.The aim of this study was to investigate male Norwegian professional road cyclists perspectives on strategy, tactics and race craft in road cycling. The existing literature on this research field is limited. This study draws inspiration from O’Grady et al. (2023) in its quest to explore these phenomena within a different cycling culture and at the highest levels of international cycling. Five male Norwegian road cyclists with experience from either the UCI WorldTour- or ProSeries level participated in semi-structured interviews with open-ended questions. The data material was analysed thematically through an hybrid methodological approach inspired by Swain (2018), combining deductive, inductive and abductive processes. Results were divided into four different main themes and subsequent subthemes; Pre-race (Cognitive preparedness and Planning of a strategy), In-race (Team dynamics, Team Hierarchy (Roles), Leadership, Communication and Race dynamics), Post-race (Verbal debriefing, Analysis and Documentation and continued use) and Race craft. The results and discussion provide the research field and professional teams and riders with a general insights into the phenomena, laying the groundwork for further, more specific, studies. In conclusion, even though tactics and strategy in road cycling is a result of a complex interplay of different factors, the study highlights reflective practices, proximity to teammates, adaptability and good communication methods as factors respondents positively correlated with effective strategy and successful tactics

A copper-benzotriazole based coordination polymer catalyzes the efficient one-pot synthesis of (N'-substituted)-hydrazo-4-aryl-1,4-dihydropyridines from azines

A series of new (N’-substituted)-hydrazo-4-aryl-1,4 dihydropyridines were successfully synthesized via a facile one pot catalytic pathway utilizing azines and propiolate esters as starting materials and 1D Cu benzotriazoles based coordination polymer as catalyst. In the absence of catalyst, the corresponding 5-substituted 4,5-dihydro pyrazoles were formed in moderate to high yields. Fine-tuning the catalysts allowed us to gain more insights regarding the plausible reaction mechanism

Computational Study of Enantioselective Carboligation Catalyzed by Benzoylformate Decarboxylase

Benzoylformate decarboxylase (BFDC) is a thiamin-diphosphate enzyme that catalyzes the decarboxylation of benzoylformate to yield benzaldehyde and carbon dioxide. In addition to its natural reaction, BFDC is able to catalyze carboligation reactions in a highly enantioselective fashion, making the enzyme a potentially important biocatalyst. Here we use density functional theory calculations to investigate the detailed mechanism of BFDC-catalyzed carboligation and to elucidate the sources of the enantioselectivity. Benzaldehyde and acetaldehyde are studied as acceptors, for, when reacting with a benzaldehyde donor, they yield products with opposite enantiospecificity. For each of the acceptors, several possible binding modes to the active site are initially examined before the individual reaction paths leading to the two enantiomeric products are followed. The calculated energies are in good agreement with the experimental results, and the analysis of the transition states gives insight into the origins of the enantioselectivity

Metal Fluorides as Analogs for Studies on Phosphoryl Transfer Enzymes

The 1994 structure of a transition state analog with AlF4- and GDP complexed to G1, a small G protein, heralded a new field of research into structure and mechanism of enzymes that manipulate transfer of the phosphoryl (PO3-) group. The list of enzyme structures that embrace metal fluorides, MFx, as ligands that imitate either the phosphoryl group or a phosphate, is now growing at over 80 per triennium. They fall into three distinct geometrical classes: (i) Tetrahedral complexes, based on BeF3-, mimic ground state phosphates; (ii) Octahedral complexes, primarily based on AlF4-, mimic "in-line" anionic transition state for phosphoryl transfer; and (iii) Trigonal bipyramidal complexes, represented by MgF3- and putative AlF30 moieties, additionally mimic the tbp geometry of the transition state. The interpretation of these structures provides a deeper mechanistic understanding of the behavior and manipulation of phosphate monoesters in molecular biology. This review provides a comprehensive overview of these structures, their uses, and their computational development. It questions the identification of AlF30 and MgF4= as tbp species in protein complexes and discusses the relevance of physical organic chemistry and water-based model studies for understanding phosphoryl group transfer in enzymes. It describes two roles for amino acid side-chains that mediate proton transfers during phosphoryl transfer, based on the analysis of protein/MFx structures. First, they deploy hydrogen bonding to neutral oxygen nucleophiles so as to orientate them for correct orbital overlap with the electrophilic phosphorus center. Secondly, they behave as classical general acid/base catalysts

A Theoretical Study of the Benzoylformate Decarboxylase Reaction Mechanism

Density functional theory calculations are used to investigate the detailed reaction mechanism of benzoylformate decarboxylase, a thiamin diphosphate (ThDP)-dependent enzyme that catalyzes the nonoxidative decarboxylation of benzoylformate yielding benzaldehyde and carbon dioxide. A large model of the active site is constructed on the basis of the X-ray structure, and it is used to characterize the involved intermediates and transition states and evaluate their energies. There is generally good agreement between the calculations and available experimental data. The roles of the various active site residues are discussed and the results are compared to mutagenesis experiments. Importantly, the calculations identify off-cycle intermediate species of the ThDP cofactor that can have implications on the kinetics of the reaction

Catalysis by [Ga4L6]12− metallocage on the Nazarov cyclization : the basicity of complexed alcohol is key

The Nazarov cyclization is investigated in solution and within K[GaL] supramolecular organometallic cage by means of computational methods. The reaction needs acidic condition in solution but works at neutral pH in the presence of the metallocage. The reaction steps for the process are analogous in both media: (a) protonation of the alcohol group, (b) water loss and (c) cyclization. The relative Gibbs energies of all the steps are affected by changing the environment from solvent to the metallocage. The first step in the mechanism, the alcohol protonation, turns out to be the most critical one for the acceleration of the reaction inside the metallocage. In order to calculate the relative stability of protonated alcohol inside the cavity, we propose a computational scheme for the calculation of basicity for species inside cavities and can be of general use. These results are in excellent agreement with the experiments, identifying key steps of catalysis and providing an in-depth understanding of the impact of the metallocage on all the reaction steps

Combined computational-experimental study of Ru(0)-catalyzed Guerbet reaction

The homologation of bioethanol to higher alcohols by means of the Guerbet reaction is a promising way to obtain biofuels. Herein, we present an efficient ruthenium-catalyzed process and a detailed investigation of the reaction mechanism using a combined experimental-computational approach. Density functional theory calculations of the free energy profiles are corroborated by designed experiments. Microkinetic simulations are performed based on the calculated energies, providing good agreement with experimental observations of the time-evolving ethanol conversion and product distribution. Analysis of the kinetics network elucidates the key steps governing the conversion and selectivity of the Guerbet process, pointing out the unexpected role of the molecular hydrogen evolution step and suggesting strategies to design new catalysts for the Guerbet reaction