Search results for "Dimer"
showing 10 items of 558 documents
Influences of Chemical Functionalities on Crystal Structures and Electrochemical Properties of Dihydro-benzoxazine Dimer Derivatives
2021
Dihydro-1,3,2H-benzoxazine dimer derivatives or dihydro-benzoxazine dimers are a class of compounds typically prepared by ring-opening reactions between dihydro-benzoxazines and phenols. Dihydro-benzoxazine dimers act as chelating agents for several transition and rare-earth cations. To better understand the chelating properties, it is necessary to examine their structural features and electrochemical characteristics thoroughly. However, the electrochemical properties of dihydro-benzoxazine dimers have not been tremendously examined. Herein, eight derivatives of dihydro-benzoxazine dimers possessing different substituents on the benzene ring and the tertiary-amine nitrogen were synthesized …
Crystal structure and Hirshfeld surface analysis of 1-(2,4-dichlorobenzyl)-5-methyl-N-(thiophene-2-sulfonyl)-1H-pyrazole-3-carboxamide
2018
In the title compound, C16H13Cl2N3O3S2, the thiophene ring is disordered in a 0.762 (3):0.238 (3) ratio by an approximate 180° rotation of the ring around the S—C bond linking the ring to the sulfonyl unit. The dichlorobenzene group is also disordered over two sets of sites with the same occupancy ratio. The molecular conformation is stabilized by intramolecular C—H...Cl and C—H...N hydrogen bonds, forming rings with graph-set notation S(5). In the crystal, pairs of molecules are linked by N—H...O and C—H...O hydrogen bonds, forming inversion dimers with graph-set notation R 2 2(8) and R 1 2(11), which are connected by C—H...O hydrogen-bonding interactions into ribbons parallel to (100). Th…
Crystal structure of bis{μ2-3-(pyridin-2-yl)-5-[(1,2,4-triazol-1-yl)methyl]-1,2,4-triazolato}bis[aquanitratocopper(II)] dihydrate
2016
The title complex is a centrosymmetric dimer with a copper–copper distance of 4.0408 (3) Å. The Cu ions in the dimer are bridged by two triazole rings and oxygen donor ligands from water molecules and nitrate anions in a distorted octahedral coordination geometry.
Crystal structure and Hirshfeld surface analysis of 2-[(1,3-benzoxazol-2-yl)sulfanyl]-N-(2-methoxyphenyl)acetamide
2019
Akkurt, Mehmet/0000-0003-2421-0929; Saylam, Merve/0000-0002-7602-4565
Crystal structure of (E)-pent-2-enoic acid
2015
The molecule of the title compound, C5H8O2, a low-melting α,β-unsaturated carboxylic acid, is essentially planar [maximum displacement = 0.0239 (13) Å]. In the crystal, molecules are linked into centrosymmetric dimersviapairs of O—H...O hydrogen bonds.
1,1-Diphenyl-4-(thiophen-2-yl)but-3-yn-1-ol
2018
The asymmetric unit of the title homopropargyl alcohol, C20H16OS, contains two independent molecules comprising a hydroxy group, a 3-(2-thiophenyl)- propargylic moiety and two aromatic rings linked to a central carbon atom. The two unique molecules are linked into a dimer by an O—HO hydrogen bond. In one molecule, the thiophene ring is disordered over two orientations rotated by 180 with a refined occupancy ratio of 0.575 (4):0.425 (4). The crystal structure is stabilized by O—H and C—H hydrogen-bond interactions. The crystal studied was a two-component non-merohedral twin, the refined ratio of the twin components being 0.575 (4):0.425 (4). UCR::Vicerrectoría de Docencia::Ciencias Básicas::…
Synthesis, structural, and thermal characterization of a new binuclear copper(II) chelate complex bearing an amine-hardener for epoxy resins
2016
A new di(μ-carbonato)bis[aqua(diethylenetriamine)copper(II)] hexahydrate complex, [{Cu(NH(C2H4NH2)2)(H2O)(μ-CO3)}2]⋅6H2O (1), was synthesized by direct interaction of malachite with diethylenetriamine (dien). The crystals of 1 were characterized by X-ray powder diffraction and IR spectra, as well as structurally characterized. Compound 1 consists of [{Cu(dien)(H2O)(μ-CO3)}2] discrete units whose CO32– anions play the role of bridging ligands combining two Cu(II) chelate cores into a centrosymmetric dimer. The elongated octahedral environment of Cu2+ consists of three nitrogens of dien and an oxygen from CO32– at the base of the bipyramid; the two apical positions of such polyhedron are occu…
Quinoidal oligothiophenes: towards biradical ground-state species.
2009
A family of quinoidal oligothiophenes, from the dimer to the hexamer, with fused bis(butoxymethyl)cyclopentane groups has been extensively investigated by means of electronic and vibrational spectroscopy, electrochemical measurements, and density functional calculations. The latter predict that the electronic ground state always corresponds to a singlet state and that, for the longest oligomers, this state has biradical character that increases with increasing oligomer length. The shortest oligomers display closed-shell quinoidal structures. Calculations also predict the existence of very low energy excited triplet states that can be populated at room temperature. Aromatization of the conju…
Dosaggio del D-dimero "alta sensibilità" (D-D HS): valutazione del test e applicazioni nella pratica laboratoristica (risultati preliminari)
2009
Allocation of Ambipolar Charges on an Organic Diradical with a Vinylene-Phenylenediyne Bridge.
2021
Two redox and magnetically active perchlorotriphenylmethyl (• PTM) radical units have been connected as end-capping groups to a bis(phenylene)diyne chain through vinylene linkers. Negative and positive charged species have been generated, and the influence of the bridge on their stabilization is discussed. Partial reduction of the electron-withdrawing • PTM radicals results in a class-II mixed-valence system with the negative charge located on the terminal PTM units, proving the efficiency of the conjugated chain for the electron transport between the two terminal sites. Counterintuitively, the oxidation process does not occur along the electron-rich bridge but on the vinylene units. The • …