Search results for "Andit"
showing 9 items of 89 documents
Photodynamics studies of ligand-protected gold nanoclusters by using ultrafast transient infrared spectroscopy
2015
Highly monodisperse samples of three ligand-protected gold nanoclusters Au102(pMBA)44, Au144(SC2H4Ph)60, and a cluster tentatively identified as Au130(pMBA)50, were characterized by UV/vis and infrared spectroscopy, and their photodynamics was studied by transient absorption spectroscopy. The dynamics study for each cluster was performed by electronically exciting the cluster with a pump pulse in the visible or near infrared region and by monitoring the transient absorption of vibrational modes of the ligands with a mid-IR probe pulse. The photodynamics studies were used to determine the molecular or metallic behavior of the cluster, and also to gain important size dependent information abo…
Influencing the self‐sorting behavior of [2.2]paracyclophane based ligands by introducing isostructural binding motifs
2020
Two isostructural ligands with either nitrile ( L nit ) or isonitrile ( L iso ) moieties directly connected to a [2.2]paracyclophane backbone with pseudo‐meta substitution pattern have been synthesized. The ligand itself ( L nit ) or its precursors ( L iso ) were resolved via HPLC on a chiral stationary phase and the absolute configuration of the isolated enantiomers was assigned by XRD analysis and/or by comparison of quantum‐chemical simulated and experimental ECD‐spectra. Surprisingly, the resulting metallosupramolecular aggregates formed in solution upon coordination of [(dppp)Pd(OTf) 2 ] differ in their composition: whereas L nit forms dinuclear complexes L iso exclusively forms trinuc…
Arm Space Decomposition as a Strategy for Tackling Large Scale Multi-armed Bandit Problems
2013
Recent multi-armed bandit based optimization schemes provide near-optimal balancing of arm exploration against arm exploitation, allowing the optimal arm to be identified with probability arbitrarily close to unity. However, the convergence speed drops dramatically as the number of bandit arms grows large, simply because singling out the optimal arm requires experimentation with all of the available arms. Furthermore, effective exploration and exploitation typically demands computational resources that grow linearly with the number of arms. Although the former problem can be remedied to some degree when prior knowledge about arm correlation is available, the latter problem persists. In this…
Yhteisöllisyys uskollisuuden huipentumana : yhteisöllisyyden käsite teleoperaattorialalla
2010
Teleoperaattorialalla kilpailu asiakkaista on kovaa. Ala on dynaaminen ja muuttuu suurella nopeudella jatkuvasti. Prospektien houkuttelu asiakkaiksi ja uusien asiakkuuksien solmiminen on huomattavasti kalliimpaa yrityksen näkökulmasta kuin vanhojen asiakkaiden säilyttäminen. Haasteena alalle onkin se, miten jo olemassa olevista asiakkaista saataisiin uskollisia. Määräaikaisuudet ovat usein käytetty ratkaisu, mutta ne eivät saa asiakasta sitoutumaan kokonaisvaltaisesti. Jos asiakas saataisiin vietyä uskollisuuden ”yli”, asiakasyhteisöön saakka, yritys olisi vahvoilla. Tämä tutkimus selvittää sitä, onko teleoperaattoreista puhuttaessa olemassa yhteisöllisyyttä, mistä se rakentuu ja miten siih…
Weak Interactions between Trivalent Pnictogen Centers: Computational Analysis of Bonding in Dimers X3E···EX3 (E = Pnictogen, X = Halogen)
2009
The nature of weak interactions in dimers X3E···EX3 (E = N−Bi, X = F−I) was investigated by wave function and density functional theory (DFT)-based methods. Out of the 20 systems studied, 10 are found to be bound at the CP-MP2 and LMP2 levels of theory. Detailed partition of the interaction energy into different components revealed that dispersion is the primary force holding the dimers together but there also exists an important ionic component whose contribution increases with increasing halogen size. As expected, standard density functionals fail to describe bonding in the studied systems. However, the performance of DFT methods can be easily improved via empirical dispersion correction …
New Tetraphosphane Ligands {(X2P)2NC6H4N(PX2)2} (X = Cl, F, OMe, OC6H4OMe-o): Synthesis, Derivatization, Group 10 and 11 Metal Complexes and Catalyti…
2008
The reaction of p-phenylenediamine with excess PCl3 in the presence of pyridine affords p-C6H4[N(PCl2)2]2 (1) in good yield. Fluorination of 1 with SbF3 produces p-C6H4[N(PF2)2]2 (2). The aminotetra(phosphonites) p-C6H4[N{P(OC6H4OMe-o)2}2]2 (3) and p-C6H4[N{P(OMe)2}2]2 (4) have been prepared by reacting 1 with appropriate amount of 2-(methoxy)phenol or methanol, respectively, in the presence of triethylamine. The reactions of 3 and 4 with H2O2, elemental sulfur, or selenium afforded the tetrachalcogenides, p-C6H4[N{P(O)(OC6H4OMe-o)2}2]2 (5), p-C6H4[N{P(S)(OMe)2}2]2 (6), and p-C6H4[N{P(Se)(OMe)2}2]2 (7) in good yield. Reactions of 3 with [M(COD)Cl2] (M = Pd or Pt) (COD = cycloocta-1,5-diene)…
Effect of ligand-binding on protein function
2014
Alkyl-Substituted Aminobis(phosphonates) : Efficient Precipitating Agents for Rare Earth Elements, Thorium, and Uranium in Aqueous Solutions
2021
The efficient and environmentally sustainable separation process for rare earth elements (REE), especially for adjacent lanthanoids, remains a challenge due to the chemical similarity of REEs. Tetravalent actinoids, thorium, and traces of uranium are also present in concentrates of REEs, making their separation relevant. This study reports six simple water-soluble aminobis(phosphonate) ligands, RN[CH2P(O)(OH)2]2 (1 R = CH2CH3, 2 R = (CH2)2CH3, 3 R = (CH2)3CH3, 4 R = (CH2)4CH3, 5 R = (CH2)5CH3, 6 R = CH2CH(C2H5)(CH2)3CH3) as precipitating agents for REEs, Th, and U, as well as gives insight into the coordination modes of the utilized ligands with REEs at the molecular level. Aminobis(phospho…