Lelja Fišer-Jakić

Synthesis and fluorescent properties of some new unsymmetricbis-benzothiazolyl furans and thiophenes

SummarySome newmono- andbis-benzothiazolyl compounds with furan or thiophene nuclei were synthesized by multistep reactions from the corresponding furan and thiophene aldehydes. The data obtained from emission spectra show a large influence of the benzothiazole rings on the relative quantum efficiency of the compounds under investigation.ZusammenfassungEinige neuebis-Benzothiazolylverbindungen mit einem Furan- bzw. Thiophenenring wurden in einer mehrstufigen Reaktion dargestellt. Die Fluoreszenzdaten der untersuchten Verbindungen zeigen einen großen Einfluß der Benzothiazolringe auf die relative Fluoreszenzquantenausbeute.

Synthesis and absorption spectral properties of substituted phenylfurylbenzothiazoles and their vinylogues

SummaryA number of substituted 2-(5-aryl-2-furyl)benzothiazoles and their vinylogues were synthesized from corresponding 5-arylfurfurals by convenient methods. The yields of products and their UV/Vis spectroscopic properties are substituent-dependent.ZusammenfassungEinige substituerte 2-(5-Aryl-2-furyl)benzthiazole und ihre Vinyloge wurden aus entsprechenden 5-Aryl-furfuralen synthetisiert. Die Ausbeuten an Produkten sowie ihre absorption-spektroskopischen Eigenschaften sind vom Substituenten abhängig.

Absorption and Fluorescence Characteristics of Some 2-Aryl-and 2-Heteroaryl-benzothiazoles in Different Solvents and at Various pH Values

Abstract The parameters characterizing the absorption and fluorescence of seven 2-substituted benzothiazoles in different solvents and at various acid/base concentrations were studied. It was found that both the kind of substituent and the solvent polarity influenced the changes of the spectral properties of the examined molecules. 2-Aryl substituted benzothiazoles exhibit larger Stokes shifts than 2-heteroaryl derivatives. The linear relationship between solvent polarity and pH values against Stokes shift and fluorescence sensitivity, respectively, was observed. The mostly fluorescent compound was 2-(2-benzofuryl)benzothiazole.

Electron Impact Mass Spectra of Some Unsaturated Derivatives of 2-Benzothiazoles

Abstract The electron impact mass spectra of some p-substituted styryl-2-benzothiazoles 1-6 and p-substituted phenyl-butadienyl-2-benzothiazoles 7 and 8 have been recorded and the identity of various ions in the mass spectra established. The compounds 1-6 exibit one main fragmentation route which include the formation of M-1 ion as the base peak, and after elimination of p-substituted phenylacetylene molecule, the formation of benzothiazole cation. Compounds 7 and 8 show the fragmentation pathway which include the formation of butadienyl-2-benzothiazole ion as the base peak.

Electron impact mass spectra of some bis-(2-benzothiazolyl)furans and bis-(2-benzothiazolyl)thiophenes.

The electron impact mass spectra of some bis-(2-benzothiazolyl)furans and bis-(2-benzothiazolyl)thiophenes have been recorded and the identity of various ions in the mass spectra established. Compounds 1 and 2 present model substances and it is found that their fragmentation pathway is similar to the mono-(2-benzothiazoles). Compounds where the benzothiazolyl groups are directly substituted on the furan nuclei, but in different positions, exhibit two main pathways of fragmentation: fragmentation of the furan nucleus and fragmentation of the benzothiazole nucleus. Other compounds studied show specific fragmentation characteristic for divinyl furan compounds and for compounds with a phenyl substituent between two heterocyclic nuclei.