63856-18-8Relevant articles and documents
Experimental and theoretical insights into molecular and solid-state properties of isomeric Bis(salicylaldehydes)
Durka, Krzysztof,Górski, Bartosz,B?ocki, Krzysztof,Urban, Mateusz,Wo?niak, Krzysztof,Barbasiewicz, Micha?,Luliński, Sergiusz
, p. 8674 - 8689 (2019/10/11)
A series of five bis(salicylaldehydes), including four isomeric compounds based on a benzene scaffold and a closely related naphthalene derivative, were investigated in order to elucidate the impact of resonance effects and intramolecular hydrogen bonds (HBs) on the macroscopic properties of these systems. Density functional theory (DFT) computations revealed important differences between isomers on the molecular level, which was reflected in different charge distributions, aromatic C-C bond orders, and aromaticity characters. The consequences of these features were evidenced by the UV-vis absorption spectra: for 1,3-diformyl-4,6-dihydroxybenzene (2), the longest wavelength absorption band is observed at 285 nm, while its isomers 1,4-diformyl-2,5-dihydroxybenzene (1), 1,4-diformyl-2,3-dihydroxybenzene (3), and 1,2-diformyl-3,6-dihydroxybenzene (4) are characterized by absorption in the visible range (379-407 nm). The specificity of 2 results from simultaneous lowering and elevation of HOMO and LUMO energy levels, respectively. We have found that the HOMO/LUMO energy variations follow trends observed in isomeric dihydroxybenzenes (HOMO) and phthalaldehydes (LUMO), and these effects operate separately to some extent. Furthermore, theoretical calculations indicate that the UV-vis spectral properties of bis(salicylaldehydes) are directly transferable to the corresponding bis(salicylaldimines) and their boron complexes. Finally, the influence of structural and molecular stabilization effects was analyzed by means of X-ray structural analysis and periodic DFT computations.
Octa-alkoxy Phthalocyanine and Naphthalocyanine Derivatives: Dyes with Q-band Absorption in the Far Red or Near Infrared
Cook, Michael J.,Dunn, Adrian J.,Howe, Steven D.,Thomson, Andrew J.,Harrison, Kenneth J.
, p. 2453 - 2458 (2007/10/02)
The lithium alkoxide-catalysed cyclic tetramerisation of various 3,6-dialkoxy-4,5-dichlorophthalonitriles, 1,4-dialkoxynaphthalene-2,3-dicarbonitriles and 3,6-dialkoxyphthalonitriles to give the corresponding metal-free octa-alkoxyoctachlorophthalocyanines, octa-alkoxynaphthalocyanines and octa-alkoxyphthalocyanines is described.An unexpected trans-alkoxylation reaction occurs during the cyclisation of the first two series of precursors.Metal-free phthalocyanines and naphthalocyanines have been converted into derivatives containing various metal ions.Compounds show Q-band absorption in the region 739-862 nm in toluene solution.The fluorescence spectra of selected examples are reported.The solubility of some of the compounds has been measured in a formulation of liquid crystal materials.
2-Azetidinone compounds and processes for preparation thereof
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, (2008/06/13)
This invention relates to new 2-azetidinone compounds, which have antimicrobial activities, and to processes for the preparation thereof, and more particularly, this invention provides new 2-azetidinone compounds, especially ones having various substituted carboxyalkyl radicals at the first position and having various groups at the fourth position of the azetidinone nucleus, which have antimicrobial activities against various pathogenic microorganisms and are useful as antibiotics in treatment for microbial infections in mammal including human being and animals.