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1.
The protonation and alkylation of cross-conjugated ketones containing a terminal N-methylpyrrole ring takes place at the oxygen atom. Protonation is accompanied by a strong bathochromic shift of the absorption maximum in the electron spectrum, while alkylation leads to ethoxypolymethine salts. The possibility of using these salts for the synthesis of ethoxycyanine dyes was studied. 相似文献
2.
本文利用循环伏安法研究了电子给-受体模型化合物——氰基乙烯基苯胺衍生物的电化学行为,并对推电子取代基团—NH_2和—N(CH_3)_2与吸电子取代基团氰基乙烯基对化合物电化学行为的影响进行了较为详细的讨论.提出了这些化合物的电氧化态和电还原态的结构,通过分析比较叔、仲和伯自由基对化合物电化学行为的影响,探讨了电极反应机理. 相似文献
3.
L. A. Leites A. V. Zabula S. S. Bukalov P. S. Koroteev O. S. Maslennikova M. P. Egorov O. M. Nefedov 《Russian Chemical Bulletin》2005,54(5):1117-1120
The vibrational spectra of tetravalent metal halides (M = Si, Ge, Sn) and the corresponding dihalocarbene analogs MIIHal2, obtained by the authors, and the relevant published data are compared. The spectra of the MIIHal2 species exhibit inversion of the M-Hal stretching frequencies (νs(MIIHal) > ν as(MIIHal)). This can be used for analytical purposes and allows one to distinguish between the spectra of the MIV and MII halides. The IR and Raman spectra of the complexes of dihalogermylenes and -stannylenes with triphenylphosphine and 1,4-dioxane
also exhibit inversion of the ν(MHal) stretching frequencies. This confirms the conclusion drawn earlier based on the analysis
of the geometric parameters and reactivities of the complexes in question that the divalent state of the M atom in these species
is retained.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1089–1092, May, 2005. 相似文献
4.
The change in semiconductive properties of β-apo-8′-carotenal, astacene and methyl bixin on adsorption of various vapours
on the crystallite surfaces has been studied at a constant sample temperature. The adsorption of vapours enhances the semiconductivity
of the polyenes appreciably. This enhancement depends on the chemical nature and also on the pressure of the adsorbed vapour.
The adsorption and desorption kinetics follow the modified Roginsky-Zeldovich relation. A two stage desorption process, the
first stage of which gives a Lennard-Jones potential energy curve and is followed by a rate-determining transition over a
potential energy barrier to the second stage of adsorption forming weakly bound complexes between the vapour molecules and
the polyene crystallites, can explain satisfactorily the experimentally observed kinetic data. 相似文献
5.
Yozo Kosaka Toshiyuki Uryu 《Journal of polymer science. Part A, Polymer chemistry》1995,33(13):2221-2232
Side-chain liquid-crystalline copolymers and polymer blends containing an electron-donating (carbazolylmethylene)aniline group and electron-accepting nitrophenyl groups with various central linking groups between aromatic groups in the mesogenic units, i.e., N?CH, CH?CH, N?N, and COO, were prepared to examine effects of the mesogenic structure on thermal behaviours. The most remarkable effects of the central linking group on the thermal properties and the miscibility were observed for the polymer blends. The 1:1 miscible polymer blends were prepared from the electron-donating polymer containing (carbazolylmethylene)aniline group (PM6Cz) and the electron-accepting polymers with similar central linking groups, i.e., N?CH, CH?CH, and N?N. For example, the 1: 1 polymer blend of PM6Cz and the electron-accepting polymer containing the nitrostilbene group induced a smectic phase from 73 to 207°C. This isotropic temperature was 46°C higher than the calculated value (161°C) based on the composition without the electron donor-acceptor interaction. On the other hand, the 1: 1 polymer blend of PM6Cz and the electron-accepting polymer containing the nitrophenylbenzoate group showed phase separation. Thus, the remarkable thermal stability and the miscibility of the polymer blends containing the electron donor and acceptor groups might be caused by planar structures between the mesogenic side groups which have similar central linking groups through the electron donor-acceptor interaction. A similar tendency was seen for copolymers and binary mixtures of both low-molecular-weight compounds containing the same mesogenic groups. © 1995 John Wiley & Sons, Inc. 相似文献
6.
M. J. Tornaritis A. G. Coutsolelos 《Journal of polymer science. Part A, Polymer chemistry》1992,30(13):2791-2795
Polyene polymers [natural rubber (cis-polyisoprene), trans-polyisoprene, and cis-polybutadiene] were transformed to the corresponding polyepoxides which are a polyalcohol and soap precursor. The catalysts used were chloro- or acetato-manganese(III) tetraphenylporphyrin [MnIII(TPP)Cl or MnIII(TPP)OAc] in association with two different oxygen donors, sodium hypochloride and iodosylbenzene (Por, unspecified porphyrinato ligand; TPP, 5,10,15,20-tetraphenylporphyrinato ligand). This transformation in either biphasic system, H2O(aqua)-CH2Cl2 or PhIO(solid)-CH2Cl2, was monitored by 1H-NMR and IR spectroscopy. In both cases the transformation to the polyepoxide was completed within a few hours. © 1992 John Wiley & Sons, Inc. 相似文献
7.
A correspondence is pointed out between the triangulation of convex polygons on the one hand and the enumeration of isomers of conjugated polyenes on the other. 相似文献
8.
The influence of solvents on the electronic absorption spectra of chromium (III) complexes was investigated. The dependence of the crystal field parameter Dq on dielectric constant as well as Gutmann donor number DN of solvent was found and described. By using the proposed model, unknown in the literature donor numbers for a few alcohols were estimated. 相似文献
9.
W.W. Schoeller R. Schneider U. Tubbesing 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):781-784
Mono-and bis-donor-acceptor formation (donor=AH3, Y = N, P, As, Sb, Bi and AH2, O, S, Se, Te) is discussed on the basis of quantum chemical (ab initio) calculations for π-bonded low-coordinated phosphorus cations, evaluating new types of bis-donor adducts. 相似文献
10.
Bettina Schweda Dr. Matiss Reinfelds Jakob Hofinger Georg Bäumel Dr. Thomas Rath Dr. Petra Kaschnitz Prof. Dr. Roland C. Fischer Prof. Dr. Michaela Flock Prof. Dr. Heinz Amenitsch Prof. Dr. Markus Clark Scharber Prof. Dr. Gregor Trimmel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(23):e202200276
A series of non-fullerene acceptors based on perylene monoimides coupled in the peri position through phenylene linkers were synthesized via Suzuki-coupling reactions. Various substitution patterns were investigated using density functional theory (DFT) calculations in combination with experimental data to elucidate the geometry and their optical and electrochemical properties. Further investigations of the bulk properties with grazing incidence wide angle X-ray scattering (GIWAXS) gave insight into the stacking behavior of the acceptor thin films. Electrochemical and morphological properties correlate with the photovoltaic performance of devices with the polymeric donor PBDB-T and a maximum efficiency of 3.17 % was reached. The study gives detailed information about structure–property relationships of perylene-linker-perylene compounds. 相似文献