Search results for "hopea"
showing 10 items of 42 documents
Synthesis, X-ray Structure, Antimicrobial and Anticancer Activity of a Novel [Ag(ethyl-3-quinolate)2(citrate)] Complex
2022
A novel Ag(I) citrate complex with ethyl-3-quinolate (Et3qu) was synthesized. Its structure was confirmed using X-ray single crystal to be [Ag(Et3qu)2(citrate)]. It crystallized in the Triclinic crystal system and P-1 space group with unit cell parameters of a = 8.6475(2) Å, b = 11.4426(3) Å, c = 15.2256(3) Å, α = 73.636(2)°, β = 79.692(2)° and γ = 86.832(2)°, while the unit cell volume was 1422.19(6) Å3. In the unit cell, there are two [Ag(Et3qu)2(citrate)] molecules and one unit as the asymmetric formula. The molecular structure comprised one Ag(I) coordinated with two Et3qu molecules via two almost equidistant Ag-N bonds and one citrate ion acting as a mono-negative monodentate ligand vi…
Jalometallialan koulutuksen muutokset Kuopiossa vuosina 1977-2009
2012
Pro gradussa tarkastellaan jalometallialan koulutuksen kehittymistä Kuopiossa vuosien 1977−2009 välisenä aikana. Työssä selvitetään, miten koulutus on muuttunut ja miksi alan koulutusta alettiin opettaa Kuopiossa. Viimeisenä pohditaan elinikäisen oppimisen merkitystä kyseisellä alalla, joka oletettavasti liittyy läheisesti käsityöläisyyteen. Tutkimuksen lähteinä on käytetty Kuopion Muotoiluakatemian arkistomateriaaleja kuten toimintakertomuksia sekä opinto-oppaita. Näistä on selvitetty, mitä opiskelijoiden oli tarkoitus oppia. Arkistoaineistoa on täydennetty vuonna 2010 tehtyjen jalometallialan ammattilaisten haastatteluilla eli muistitiedolla sekä Kuopion Muotoiluakatemian lehtileikekokoel…
New Microbe Killers : Self-Assembled Silver(I) Coordination Polymers Driven by a Cagelike Aminophosphine
2019
New Ag(I) coordination polymers, formulated as [Ag(μ-PTAH)(NO3)2]n (1) and [Ag(μ-PTA)(NO2)]n (2), were self-assembled as light- and air-stable microcrystalline solids and fully characterized by NMR and IR spectroscopy, electrospray ionization mass spectrometry (ESI-MS(±), elemental analysis, powder (PXRD) and single-crystal X-ray diffraction. Their crystal structures reveal resembling 1D metal-ligand chains that are driven by the 1,3,5-triaza-7-phospaadamantane (PTA) linkers and supported by terminal nitrate or nitrite ligands; these chains were classified within a 2C1 topological type. Additionally, the structure of 1 features a 1D!2D network extension through intermolecular hydrogen bonds…
Chloride ligands on DNA-stabilized silver nanoclusters
2023
DNA-stabilized silver nanoclusters (AgN-DNAs) are known to have one or two DNA oligomer ligands per nanocluster. Here, we present the first evidence that AgN-DNA species can possess additional chloride ligands that lead to increased stability in biologically relevant concentrations of chloride. Mass spectrometry of five chromatographically isolated near-infrared (NIR)-emissive AgN-DNA species with previously reported X-ray crystal structures determines their molecular formulas to be (DNA)2[Ag16Cl2]8+. Chloride ligands can be exchanged for bromides, which red-shift the optical spectra of these emitters. Density functional theory (DFT) calculations of the 6-electron nanocluster show that the …
Partitioning of nanoparticle-originated dissolved silver in natural and artificial sediments
2017
Sediments are believed to be a major sink for silver nanoparticles (AgNPs) in the aquatic environment, but there is a lack of knowledge about the environmental effects and behavior of AgNPs in sediments. The release of highly toxic Ag+ through dissolution of AgNPs is one mechanism leading to toxic effects in sediments. We applied an ultrasound-assisted sequential extraction method to evaluate the dissolution of AgNPs and to study the partitioning of dissolved Ag in sediments. Silver was spiked into artificial and 2 natural sediments (Lake Höytiäinen sediment and Lake Kuorinka sediment) as silver nitrate (AgNO3), uncoated AgNPs, or polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs). In addition, …
Bi-, Tetra-, and Hexanuclear AuI and Binuclear AgI Complexes and AgI Coordination Polymers Containing Phenylaminobis(phosphonite), PhN{P(OC6H4OMe-o)2…
2008
The reactions of phenylaminobis(phosphonite), PhN{P(OC6H4OMe-o)2}2 (1) (PNP), with [AuCl(SMe2)] in appropriate ratios, afford the bi- and mononuclear complexes, [(AuCl)2(µ-PNP)] (2) and [(AuCl)(PNP)]2 (3) in good yield. Treatment of 2 with 2 equiv of AgX (X = OTf or ClO4) followed by the addition of 1 or 2,2′-bipyridine affords [Au2(µ-PNP)2](OTf)2 (4) and [Au2(C10H8N2)2(µ-PNP)](ClO4)2 (5), respectively. Similarly, the macrocycles [Au4(C4H4N2)2(µ-PNP)2](ClO4)4 (6), [Au4(C10H8N2)2(µ-PNP)2](ClO4)4 (7), and [Au6(C3H3N3)2(µ-PNP)3](ClO4)6 (8) are obtained by treating 2 with pyrazine, 4,4′-bipyridine, or 1,3,5-triazine in the presence of AgClO4. The reaction of 1 with AgOTf in a 1:2 molar ratio pr…
Asymmetric and symmetric fission of excited nuclei of 180,190Hg and 184,192,202Pb formed in the reactions with 36Ar and 40,48Ca ions
2021
Background: Observation of asymmetric fission of 180Hg has led to intensive theoretical and experimental studies of fission of neutron-deficient nuclei in the lead region. Purpose: The study of asymmetric and symmetric fission modes of 180,190Hg and 184,192,202Pb nuclei. Methods: Mass-energy distributions of fission fragments of 180,190Hg and 184Pb formed in the 36Ar+144,154Sm and 40Ca+144Sm reactions, respectively, at energies near the Coulomb barrier have been measured using the double-arm time-of-flight spectrometer CORSET and compared with previously measured 192,202Pb isotopes produced in the 48Ca+144,154Sm reactions. The mass distributions for 180,190Hg and 184,192,202Pb together with…
Mercury accumulation in the northern pike (Esox lucius) and its intestinal parasite, Triaenophorus nodulosus (Cestoda)
2010
Combinatorial Identification of Hydrides in a Ligated Ag40 Nanocluster with Non-compact Metal Core
2019
No formation of bulk silver hydride has been reported. Until very recently, only few silver nanoclusters containing hydrides have been successfully prepared. However, due to the lack of effective techniques and also poor stability of hydride-containing Ag nanoclusters, the identification of hydrides’ location within Ag nanoclusters is challenging and not yet achieved although some successes have been reported on clusters of several Ag atoms. In this work, we report a detailed structural and spectroscopic characterization of the [Ag40(DMBT)24(PPh3)8H12]2+ (Ag40H12) cluster (DMBT=2,4-dimethylbenzenethiol). The metal framework consists of three-concentric shells of Ag8@Ag24@Ag8 which can be de…
Hopeananoklusterien synteesit, stabiilisuus ja monodispersiivisyys
2014
Tämän pro gradun kirjallisuusosassa tarkastellaan hopeananoklustereiden synteesejä. Tarkastelussa keskitytään erityisesti hopeaklustereiden stabiilisuuteen ja monodispersiivisyyteen. Hopeaklustereiden synteesimenetelmät on jaoteltu liuoksessa tehtyihin synteeseihin, kiinteässä olomuodossa tehtyihin synteeseihin ja templaattisynteeseihin. Lisäksi tarkastellaan hopean seosklustereiden synteesejä. Työn lopussa on lyhyet katsaukset klustereiden stabiilisuuteen vaikuttavista tekijöistä ja klustereiden karakterisoitimenetelmistä. Kokeellisen osan tarkoituksena oli syntetisoida hopeaklustereita käyttäen ligandina C5-tetrametoksiresorsinareeni-bis-tiakruunua ja muita resorsinareenipohjaisia molekyy…