Search results for "ionic liquids"
showing 10 items of 186 documents
Meinvalda pārgrupēšanās jonu šķidrumu vidē
2016
Meinvalda pārgrupēšanās jonu šķidrumu vidē. Ikkere L.E., darba vadītājs Dr.h.ķīm., prof. Zicmanis A. Bakalaura darbs, 54 lappuses, 24 attēli, 12 tabulas, 42 literatūras avoti, 5 pielikumi. Latviešu valodā. Bakalaura darba literatūras apskatā ir apkopota galvenā informācija par Meinvalda pārgrupēšanās reakcijām, to katalizatoriem, kā arī par jonu šķidrumiem. Laboratorijā tika veikta trīs jonu šķidrumu sintēze. To struktūras tika pierādītas, izmantojot 1H KMR un IS spektroskopijas metodes. Tika piemeklēti piemērotākie gāzu hromatogrāfijas apstākļi, lai noteiktu pārgrupēšanās reakciju izejvielas un produktus. Tika pārbaudīti dažādu anjonu un slāpekli saturošu katjonu jonu šķidrumu izmantošana …
Knēvenāgela kondensācijas kinētika jonu šķidrumos
2015
Knēvenāgela kondensācijas kinētika jonu šķidrumos. Ūdris N., zinātniskā vadītāja Mag. ķīm. Priede E. Kursa darbs 20 lappuses, 6 attēli, 5 tabulas, 12 literatūras avoti. Latviešu valodā. Darbā veikta četru jonu šķidrumu sintēze un attīrīšana, izmantojot dažādas metodes. Visiem sintezētajiem jonu šķidrumiem tika veikti Knēvenāgela kondensācijas kinētikas pētījumi, izmantojot jonu šķidrumu kā reakcijas vidi. Visiem jonu šķidrumam tika noteikta reakcijas ātruma konstante.
Skābekļa atomu saturošie imidazolija sāļi kondensācijas reakcijās
2021
Skābekļa atomu saturošie imidazolija sāļi kondensācijas reakcijās. Gradovska L., darba vadītāji Dr.h.ķīm., prof. Zicmanis A., Dr.chem. Baķis E. Maģistra darbs, 59 lappuses, 31 attēls, 5 tabulas, 43 literatūras avoti, 1 pielikums. Latviešu valodā. Literatūras apskatā apkopota informācija par biežāk aprakstītajiem jonu šķidrumiem un polietilēnglikola funkcionalizētajem jonu šķidrumiem, to iegūšanu un izmantošanas iespējām organiskajā katalīzē. Eksperimentālajā daļā sintezēti polietilēnglikola, spirtu un alkilvirkņu funkcionalizētie imidazolija rindas jonu šķidrumi, kuri izmantoti kā katalizatori un reakcijas vide Knēvenāgela kondensācijā. Reakcijas konversija atkarībā no laika novērtēta, izma…
Effect of ionic liquids in acid-promoted heterocyclic rearrangement reaction
Reactivity of phenylhydrazones in ionic liquids solution: the effect of copper(II) salts
Multiple points of view of heteronuclear NOE: long range vs short range contacts in pyrrolidinium based ionic liquids in the presence of Li salts.
2015
The nuclear Overhauser enhancement (NOE) is a powerful tool of NMR spectroscopy extensively used to gain structural information in ionic liquids (ILs). A general model for the distance dependence of intermolecular NOE in ILs was recently proposed showing that NOE spots beyond the first solvation shell and accounts for long-range effects. This conclusion prompted for a deep rethinking of the NOE data interpretation in ILs. In this paper we present an extensive and quantitative study of N-propyl-N-methyl pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR13TFSI), the homologue with bis(fluorosulfonyl)imide (PYR13FSI), and their mixtures with LiTFSI based on 1H-19F and 1H-7LiNOE correlation …
Dispersion and Stabilization of Exfoliated Graphene in Ionic Liquids.
2019
The liquid-phase exfoliation of graphite is one of the most promising methods to increase production and commercial availability of graphene. Because ionic liquids can be easily obtained with chosen molecular structures and tuneable physicochemical properties, they can be use as media to optimise the exfoliation of graphite. The under- standing of the interactions involved between graphite and various chemical functions in the solvent ions will be helpful to find liquids capable of dissociating and stabilising im- portant quantities of large graphene layers. After a step of sonication, as a mechanical precursor, samples of suspended exfoliated graphene in different ionic liquids have been c…
Structural features of selected protic ionic liquids based on a super-strong base
2019
Protic ionic liquids (PIL) were prepared from a super-strong base 1,7-diazabicyclo[5.4.0]undec-7-ene (DBU) and super-strong acids, trifluoromethane sulfonic acid (TfOH), and (trifluoromethanesulfonyl)-(nonafluorobutylsulfonyl)imide, (IM14H), ([DBUH][TfO] and [DBUH][IM14], respectively; the latter for the first time) and their chemical and physical properties and structural features have been explored using a synergy of experimental and computational tools. The short range order in neat DBU, as well as the long range structural correlations induced by charge correlation and hydrogen bonding interactions in the ionic liquids, have been explored under ambient conditions, where these compounds …
Ionic Liquid-Based Electrolytes for Supercapacitor and Supercapattery
2019
There is a strong desire to replace or complement aqueous and organic electrolytes by ionic liquids (ILs) in electrochemical energy storage (EES) devices to achieve high operating voltages and hence high energy capacity. ILs are regarded as the inherent and competitive electrolytes since they were introduced to the electrochemical research community because they can overcome many disadvantages of the conventional aqueous and organic electrolytes, such as narrow potential windows, volatility, and flammability. This paper reviews critically the recent literatures of IL-based electrolytes used in supercapacitor, supercapattery, and micro-supercapacitor. Supercapattery is a generic term for var…
Hybrid catalysts for CO 2 conversion into cyclic carbonates
2019
The conversion of carbon dioxide into valuable chemicals such as cyclic carbonates is an appealing topic for the scientific community due to the possibility of valorizing waste into an inexpensive, available, nontoxic, and renewable carbon feedstock. In this regard, last-generation heterogeneous catalysts are of great interest owing to their high catalytic activity, robustness, and easy recovery and recycling. In the present review, recent advances on CO 2 cycloaddition to epoxide mediated by hybrid catalysts through organometallic or organo-catalytic species supported onto silica-, nanocarbon-, and metal-organic framework (MOF)-based heterogeneous materials, are highlighted and discussed.