Search results for "kompleksi"
showing 10 items of 201 documents
Self-assembly of new cobalt complexes based on [Co(SCN)4], synthesis, empirical, antioxidant activity, and quantum theory investigations
2022
The cobalt (II) complexes have been synthesized from the reaction of the cationic entities (3,4-dimethylaniline (1) and histamine (2)) with metallic salt CoCl2⋅6H2O and thiocyanate ion (SCN−) as a ligand in H2O/ethanolic solution and processing by the evaporation crystal growth method at room temperature to get crystals. The synthesized complex has been fully characterized by single-crystal X-ray diffraction. UV–Visible, FTIR spectroscopy, TGA analysis, and DFT circulations were also performed. The crystal structural analysis reveals that the solid (1) {[Co(SCN)4] (C8H12N)3}·Cl crystallizes in the monoclinic system with the space group P21/n and the solid (2) {[Co(SCN)4](C5H11N3)2}·2Cl crys…
Apziņas koncepcija evolucionisma pieejas ietvaros Daniela Deneta filozofijā
2015
Šis darbs nodarbojas ar Daniela Deneta apziņas teorijas evolucionāro premisu interpretāciju un analīzi. Darba pirmās divas daļas koncentrējas uz metodoloģiskajiem un ontoloģiskajiem aspektiem, kas raksturo Deneta pieeju apziņas problemātikai. Darba trešā daļa izpēta modeļus un metaforas, ko Denets lieto, lai konstruētu jaunu un, cerams, labāku veidu, kā domāt par to, kā smadzeņu darbība ir spējīga radīt mentālu saturu. Un, visbeidzot, trešā daļa meklē analoģijas starp Deneta apziņas teoriju un komplekso sistēmu zinātni, cenšoties noskaidrot, kādā veidā kompleksitāte varētu būt noderīga gan kā jēgpilna premisa, gan arī kā intuitīvs veids, kā domāt par mūsu mentālo dzīvi.
Johtajien käsitykset sosiaali- ja terveyspalvelujen vaikeista ongelmista sote-uudistuksessa : kompleksisuusteoreettinen näkökulma
2016
Sosiaali- ja terveyspalvelun uudistaminen on yhteiskunnallisesti ajankohtainen aihe. Uudistaminen on ollut työlästä ja kuluttanut valtion ja kuntien työntekijöiden työaikaa ja resursseja. Näin ollen tuli aiheelliseksi selvittää miksi uudistaminen on näin vaikeaa. Pro gradu-tutkielmassani tarkastelen asiantuntijoiden näkemyksiä sosiaali- ja terveydenhuollon vaikeista ongelmista sote-uudistuksessa. Lisäksi tarkastelen miten monimutkaisuus ja kompleksisuus näyttäytyvät sote-uudistuksessa sekä mitä vaikeita ongelmia uudistus mahdollisesti ratkaisee ja tuottaa asiantuntijoiden näkemyksen mukaan. Aineistoni koostuu sosiaali- ja terveyspalvelun asiantuntijoiden (johtajien) puolistrukturoiduista te…
Exploiting the Chiral Ligands of Bis(imidazolinyl)- and Bis(oxazolinyl)thiophenes : Synthesis and Application in Cu-Catalyzed Friedel–Crafts Asymmetr…
2021
Five new C2-symmetric chiral ligands of 2,5-bis(imidazolinyl)thiophene (L1–L3) and 2,5-bis(oxazolinyl)thiophene (L4 and L5) were synthesized from thiophene-2,5-dicarboxylic acid (1) with enantiopure amino alcohols (4a–c) in excellent optical purity and chemical yield. The utility of these new chiral ligands for Friedel–Crafts asymmetric alkylation was explored. Subsequently, the optimized tridentate ligand L5 and Cu(OTf)2 catalyst (15 mol%) in toluene for 48 h promoted Friedel–Crafts asymmetric alkylation in moderate to good yields (up to 76%) and with good enantioselectivity (up to 81% ee). The bis(oxazolinyl)thiophene ligands were more potent than bis(imidazolinyl)thiophene analogues for …
Computational Analysis of n→π* Back-Bonding in Metallylene-Isocyanide Complexes R2MCNR′ (M = Si, Ge, Sn; R = tBu, Ph; R′ = Me, tBu, Ph)
2013
A detailed computational investigation of orbital interactions in metal–carbon bonds of metallylene–isocyanide adducts of the type R2MCNR′ (M = Si, Ge, Sn; R, R′ = alkyl, aryl) was performed using density functional theory and different methods based on energy decomposition analysis. Similar analyses have not been carried out before for metal complexes of isocyanides, even though the related carbonyl complexes have been under intense investigations throughout the years. The results of our work reveal that the relative importance of π-type back-bonding interactions in these systems increases in the sequence Sn < Ge ≪ Si, and in contrast to some earlier assumptions, the π-component cannot be …
Unusual B4N2C2 Ligand in a Ruthenium Pseudo-Triple-Decker Sandwich Complex Displaying Three Reversible Electron-Transfer Steps
2008
Open, sesame: The reaction of a heterobicyclic pentalenediyl-like Me2Ph4B4N2C2 dianion with [{(C5Me5)RuCl}4] cleaves the N[BOND]N bond of the ligand and affords a pseudo-triple-decker sandwich complex containing a B4N2C2 middle deck (see picture). This eight-membered ring features nearly linear B-N-B moieties and brings the ruthenium centers unusually close. Cyclic voltammetry indicates efficient electron delocalization over the framework. peerReviewed
Synthesis, X-ray structures and redox behaviour of the group 14 bis-boraamidinates M[PhB(μ-N-t-Bu)2]2 (M = Ge, Sn) and Li2M[PhB(μ-N-t-Bu)2]2 (M = Sn,…
2009
The solid-state structures of the complexes M[PhB(μ-N-t-Bu)2]2 (1a, M= Ge; 1b, M = Sn) were determined to be spirocyclic with two orthogonal boraamidinate (bam) ligands N,N′-chelated to the group 14 centre. Oxidation of 1b with SO2Cl2 afforded the thermally unstable, blue radical cation {Sn[PhB(μ-N-t-Bu)2]2}•+, identified by electron paramagnetic resonance (EPR) spectroscopy supported by density functional theory (DFT) calculations, whereas the germanium analogue 1a was inert towards SO2Cl2. The reaction between Li2[PhB(μ-N-t-Bu)2]2 and SnCl2 or PbI2 in 2:1 molar ratio in diethyl ether produced the novel heterotrimetallic complexes Li2Sn[PhB(μ-N-t-Bu)2]2 (2b) and (Et2O·Li)LiPb[PhB(μ-N-t-Bu)…
A nucleophilic gold complex.
2019
Solid-state auride salts featuring the negatively charged Au– ion are known to be stable in the presence of alkali metal counterions. While such electron-rich species might be expected to be nucleophilic (in the same manner as I–, for example), their instability in solution means that this has not been verified experimentally. Here we report a two-coordinate gold complex (NON)AlAuPtBu3 (where NON is the chelating tridentate ligand 4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene) that features a strongly polarized bond, Auδ––Alδ+. This is synthesized by reaction of the potassium aluminyl compound [K{Al(NON)}]2 with tBu3PAuI. Computational studies of the complex, includ…
1‑Phenyl-3-(pyrid-2-yl)benzo[e][1,2,4]triazinyl: The First "Blatter Radical" for Coordination Chemistry
2014
A neutral air- and moisture-stable N,N′-chelating radical ligand, 1-phenyl-3-(pyrid-2-yl)benzo[e][1,2,4]triazinyl (1) was synthesized and characterized by electron paramagnetic resonance spectroscopy, X-ray crystallography, and magnetic measurements. Subsequent reaction of 1 with Cu(hfac)2·2H2O (hfac = hexafluoroacetylacetonate) under ambient conditions afforded the coordination complex Cu(1)(hfac)2 in which the radical binds to the metal in a bidentate fashion. Magnetic susceptibility data collected from 1.8 to 300 K indicate a strong ferromagnetic metal-radical interaction in the complex and weak antiferromagnetic radical···radical interactions between the Cu(1)(hfac)2 units. Detailed com…
Spin Switching with Triazolate-Strapped Ferrous Porphyrins
2019
Fe(III) porphyrins bridged with 1,2,3-triazole ligands were synthesized. Upon deprotonation, the triazolate ion coordinates to the Fe(III) ion, forming an overall neutral high-spin Fe(III) porphyrin in which the triazolate serves both as an axial ligand and as the counterion. The second axial coordination site is activated for coordination and binds p-methoxypyridine, forming a six-coordinate low-spin complex. Upon addition of a phenylazopyridine as a photodissociable ligand, the spin state of the complex can be reversibly switched with ultraviolet and visible light. The system provides the basis for the development of switchable catalase- and peroxidase-type catalysts and molecular spin sw…