Search results for "general [BL Lacertae objects]"
showing 10 items of 27644 documents
Synthesis, X-Ray Structure, Tautomerism Aspect, and Chemical Insight of The 3-(1H-Indol-2-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-6-ol
2021
The 3-(1H-indol-2-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-6-ol 2 was obtained exclusively in the enol configuration starting from triazolyl-indole derivative 1 and alkyl halo-esters in the presence of K2CO3. Chemical structure elucidations with the aid of physicochemical characterizations were used to predict its molecular structure while single crystal X-ray diffraction technique was used to shed the light on the supramolecular structure of 2. DFT calculations agreed very well with the reported X-ray structure where the most stable form thermodynamically is the enol form. Its optimized geometry agreed very well with the experimental structure where the correlation coefficients betwe…
Dioxomolybdenum(VI) and -Tungsten(VI) Amino Bisphenolates as Epoxidation Catalysts
2016
Low-cost metallate salts Na2MO4·2H2O (M = molybdenum, tungsten) react with a tridentate amine bisphenol bis(2-hydroxy-3-tert-butyl-5-methylbenzyl)methylamine (H2ONOtBu) under ambient conditions in acidic methanol solutions. The reactions lead to the formation of isostructural dioxo complexes [MO2(ONOtBu)(MeOH)]·MeOH in convenient yields. Spectral data as well as X-ray analyses reveal these complexes to be isostructural. Both compounds were tested as catalysts for epoxidation of olefins using cis-cyclooctene, cyclohexene, norbornene and styrene as substrates and tert-butyl hydroperoxide and hydrogen peroxide as oxidants. The molybdenum complex catalyses selectively the oxidation of cis-cyclo…
Organocatalytic Enantioselective Vinylogous Henry Reaction of 3,5-Dimethyl-4-nitroisoxazole with Trifluoromethyl Ketones
2017
The enantioselective vinylogous Henry reaction of 3,5-dimethyl-4-nitroisoxazole with trifluoromethyl ketones employing a bifunctional squaramide organocatalyst has been developed. A series of isoxazole bearing trifluoromethyl-substituted tertiary alcohols, 2-substituted (R)-1,1,1-trifluoro-3-(3-methyl-4-nitroisoxazol-5-yl)propan-2-ols, were obtained under these mild reaction conditions in good yields and moderate to good enantioselectivities
Acid–base properties of functionalised tripodal polyamines and their interaction with nucleotides and nucleic acids
2010
Novel, highly positively charged tripodal polyamines with appended heterocyclic moieties revealed an intriguing panel of protonation species within the biologically relevant range. Studied compounds bind nucleotide monophosphates by mostly electrostatic interactions but only the imidazole analogue showed selectivity toward UMP in respect to other nucleotides. Strong binding of all the studied compounds to both ds-DNA and ds-RNA is to some extent selective toward the latter, showing rather rare RNA over DNA preference.
The Aqua-Planet Experiment (APE): CONTROL SST Simulation
2013
Climate simulations by 16 atmospheric general circulation models (AGCMs) are compared on an aqua-planet, a water-covered Earth with prescribed sea surface temperature varying only in latitude. The idealised configuration is designed to expose differences in the circulation simulated by different models. Basic features of the aqua-planet climate are characterised by comparison with Earth. The models display a wide range of behaviour. The balanced component of the tropospheric mean flow, and mid-latitude eddy covariances subject to budget constraints, vary relatively little among the models. In contrast, differences in damping in the dynamical core strongly influence transient eddy amplitudes…
Economic and Life Cycle Analysis of Passive and Active Monitoring of Ozone for Forest Protection
2021
At forest sites, phytotoxic tropospheric ozone (O3) can be monitored with continuously operating, active monitors (AM) or passive, cumulative samplers (PM). For the first time, we present evidence that the sustainability of active monitoring is better than that of passive sensors, as the environmental, economic, and social costs are usually lower in the former than in the latter. By using data collected in the field, environmental, social, and economic costs were analyzed. The study considered monitoring sites at three distances from a control station in Italy (30, 400, and 750 km), two forest types (deciduous and Mediterranean evergreen), and three time windows (5, 10, and 20 years of moni…
Kenen ehdoilla ja mille perustalle työelämäkuntoutuksessa rakennetaan toivoa?
2023
Labor market performance of dropouts: the role of personality
2014
Purpose – The purpose of this paper is to provide evidence on labor market careers of dropouts with various levels of education. Design/methodology/approach – The paper compares the labor market careers of dropouts and non-dropouts between ages 15 and 50 by using longitudinal data. The paper analyses how the results change when the authors control for differences in personality characteristics. Findings – The paper finds that dropping out diminishes one's success in the labor market but this connection is reduced when the model is augmented with personality. Dropouts seem to have or lack certain personality characteristics that are associated with labor market success. These findings sugge…
An experimental and theoretical study of a heptacoordinated tungsten(VI) complex of a noninnocent phenylenediamine bis(phenolate) ligand
2018
Abstract [W(N2O2)(HN2O2)] (H4N2O2 = N,N′-bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,2-phenylenediamine) with a noninnocent ligand was formed by reaction of the alkoxide precursor [W(eg)3] (eg = the 1,2-ethanediolate dianion) with two equivalents of ligand. The phenol groups on one of the ligands are completely deprotonated and the ligand coordinates in a tetradentate fashion, whereas the other ligand is tridentate with one phenol having an intact OH group. The molecular structure, magnetic measurements, EPR spectroscopy, and density functional theory calculations indicate that the complex is a stable radical with the odd electron situated on the tridentate amidophenoxide ligand. The formal ox…
On the mechanism of imine elimination from Fischer tungsten carbene complexes
2016
(Aminoferrocenyl)(ferrocenyl)carbene(pentacarbonyl)tungsten(0) (CO)5W=C(NHFc)Fc (W(CO)5(E-2)) is synthesized by nucleophilic substitution of the ethoxy group of (CO)5W=C(OEt)Fc (M(CO)5(1Et)) by ferrocenyl amide Fc-NH– (Fc = ferrocenyl). W(CO)5(E-2) thermally and photochemically eliminates bulky E-1,2-diferrocenylimine (E-3) via a formal 1,2-H shift from the N to the carbene C atom. Kinetic and mechanistic studies to the formation of imine E-3 are performed by NMR, IR and UV–vis spectroscopy and liquid injection field desorption ionization (LIFDI) mass spectrometry as well as by trapping experiments for low-coordinate tungsten complexes with triphenylphosphane. W(CO)5(E-2) decays thermally i…