Search results for "ionit"

Penning-trap-assisted decay spectroscopy studies of neutron-rich nuclei in the A = 110 region

2011

Cationic and Anionic Impact on the Electronic Structure of Liquid Water

2017

Hydration shells around ions are crucial for many fundamental biological and chemical processes. Their local physicochemical properties are quite different from those of bulk water and hard to probe experimentally. We address this problem by combining soft X-ray spectroscopy using a liquid jet and molecular dynamics (MD) simulations together with ab initio electronic structure calculations to elucidate the water–ion interaction in a MgCl2 solution at the molecular level. Our results reveal that salt ions mainly affect the electronic properties of water molecules in close vicinity and that the oxygen K-edge X-ray emission spectrum of water molecules in the first solvation shell differs signi…

Dynamic Refolding of Ion-Pair Catalysts in Response to Different Anions.

2019

Four distinct folding patterns were identified in two foldamer-type urea-thiourea catalysts bearing a basic dimethylamino unit by a combination of X-ray crystallography, solution NMR studies, and computational studies (DFT). These patterns are characterized by different intramolecular hydrogen bonding schemes that arise largely from different thiourea conformers. The free base forms of the catalysts are characterized by folds where the intramolecular hydrogen bonds between the urea and the thiourea units remain intact. In contrast, the catalytically relevant salt forms of the catalyst, where the catalyst forms an ion pair with the substrate or substrate analogues, appear in two entirely dif…

Divergent reactivity of nucleophilic 1-bora-7a-azaindenide anions

2017

The reactions of 1-bora-7a-azaindenide anions, prepared in moderate to excellent yields by reduction of the appropriate 1-bora-7a-azaindenyl chlorides with KC8 in THF, with alkyl halides and carbon dioxide were studied. With alkyl halides (CH2Cl2, CH3I and BrCH(D)CH(D)tBu), the anions behave as boron anions, alkylating the boron centre via a classic SN2 mechanism. This was established with DFT methods and via experiments utilizing the neo-hexyl stereoprobe BrCH(D)CH(D)tBu. These reactions were in part driven by a re-aromatization of the six membered pyridyl ring upon formation of the product. Conversely, in the reaction of the 1-bora-7a-azaindenide anions with CO2, a novel carboxylation of …

Effect of Mg2+ ions on competitive metal ions adsorption/desorption on magnesium ferrite : mechanism, reusability and stability studies

2021

The adsorption behavior of magnesium ferrite in single- and multicomponent metal ions solutions in the presence of Mg2+ ions were studied. A dramatic decrease in the adsorption capacity of magnesium ferrite towards Mn2+, Co2+, and Ni2+ ions for comparison study of single- and multicomponent solutions was established. The affinity of the sorbent in accordance with the maximum sorption capacities increases in the following order Cu2+ > Co2+ > Ni2+ > Mn2+. High efficiency of magnesium ferrite regeneration (~100%) with aqueous solutions of magnesium chloride in the concentration range of 0.001-0.1 M was shown. The low degree of toxic metal ions desorption combined with XRD, IR spectroscopy, and…

Gas-Phase Hydrogenation of Propionitrile Catalyzed by LnCu2 (Ln = La, Ce, Pr, Nd)

2007

The hydrogenation of propionitrile over binary copper−lanthanide intermetallic compounds (LnCu2, Ln = La, Ce, Pr, Nd) was studied in the gas phase. The results show that the reaction main product is the primary amine, the n-propylamine. To our knowledge, it is the first time that such behavior is reported for copper catalysts.

An off-line tuning ion source for the optimization of the WITCH experiment

2007

ECR-ionilähteiden plasmapotentiaali ja ambipolaarinen diffuusio

2005

Ionisuihkun laadun ja siirtolinjan toiminnan kartoittaminen Jyväskylän yliopiston fysiikan laitoksen kiihdytinlaboratoriossa

2008

Testing of laser ablation ion source for JYFLTRAP

2015

In this work, we have constructed and tested a laser ablation ion source for JYFLTRAP Penning trap at the IGISOL (Ion Guide Isotope Separator On-line) facility. The calibration of the Penning trap parameters requires reference ions or ion clusters that have well-known masses with relatively small mass uncertainty. These ions and ion clusters can be created with certain solid targets, which contain large amounts of isotopes of reference masses and by using a laser for target ablation. In this work simulations of ion source parameters, construction, testing and improving a laser ablation ion source setup have been done. Targets with relatively large abundances of 63Cu and 65Cu, 85Rb, 87Rb, 11…