3- and 4-[(Azulen-1-yl)-azo]-azo-benzenes were obtained in good yields using the buffered coupling reaction between several alkyl-substituted azulenes and diazotized phenylazo-phenylamines in dichloroacetic acid. The coupling products were characterized and the recorded electronic spectra are discussed. The isosbestic points obtained by protonation enabled the determination of their pKa values.

The electrochemical study some azo-azulene compounds (Az-N=N-Y,where Y = substituted phenyl,pyridine,thiazole) was performed by cyclic and differential pulse voltammetry as well as rotating disk electrode methods in order to find their electrochemical properties and to establish the influence of donor and acceptor substituents on the behaviour of azulene and azo groups. Calculations were performed by using quantum mechanics based methods to correlate

2-(Azulen-1-yl)-4,6-diphenyl substituted pyranylium salts, pyridinium salts and pyridines were efficiently synthesized and the new obtained compounds were completely characterized. Comparative structural analysis between these compounds and their corresponding isomers which contain azulen-1-yl moiety in the 4 position of the heterocycles were carried out. These studies are based on calculated dihedral angles formed between central heterocycle and

The synthesis of new biazulenyl system which contains azulene moieties coupled in 1 and 6 positions is reported. The structure of the isolated compounds, as well as the calculated dihedral angle between the planes of the coupled moieties, has been correlated with the recorded spectra

The reactivity of 4-, 8- and/or 6-azulene methyl group in condensation with thiophene-2-carboxaldehyde or the corresponding azomethines in basic media was studied. The compounds obtained and the yields depend on the starting materials as well as on the base used. esides mono- and di(2-(thien-2-yl)vinyl)azulenes, many carbonyl derivatives and other more complicated compounds were obtained and characterized. Amounts of oligomers and polymers are also

(Azulen-1-yl)carboxylic acids 3-substituted by 2-(thiazol-2- or 3-yl)-ethenyl groups and their esters were synthesized starting either from the corresponding 1-azulenyl-2-thiazolyl-ethenes, 3, or from methyl 3-formyl-azulen-1-yl carboxylate, 7. The ethenes 3 were phosgenated in an electrophylic reaction followed by the reaction with water or alcohol. The aldehyde 7 was transformed in Schiff base which was reacted with corresponding thienylacetic

The reaction of azulenes with phthalic and naphthalene-1,8-dicarboxylic acid derivatives was investigated. Working with acids chlorides in the presence of Lewis acids (SnCl4 and AlCl3) the obtained products were gem-di-(azulen-1-yl)-lactones, di-(1-azulenyl) ketones and (1-azulenoyl)-carboxylate acids. The reaction of phthalic anhydride in the same conditions occured with low yields affording only corresponding lactone whereas the naphthalic anhydride

4-Azulen-1-yl substituted 2,6-dimethyl-and 2,6-diphenyl-pyridinium salts are obtained in yields between 50 % and 100 % in the reaction of corresponding 4-azulen-1-yl-pyranylim salts and various amines. The effects of amine structure and of substitution in the heterocycle or at azulene moieties on the synthesis have been investigated. The uv-vis and NMR spectra of reaction products are examined and discussed in correlation with their structure.

4-Azulen-1-yl substituted 2,6-dimethyl-and 2,6-diphenyl-pyridines are obtained in good yields from the reaction of corresponding 4-azulen-1-yl-pyranylium salts and ammonium acetate in ethanol or starting from 4-chloro-2,6-diphenyl-pyranylium salts in two steps: reaction with azulenes followed by in situ treatment with ammonium acetate. The effect of substitution at the 3-position of the heterocycle was taken into account. The structure assignment

Azulen-1-yl-benzothiazol-2-yl diazenes substituted at thiazole and/or at azulene moiety have been prepared by diazotization of the corresponding benzothiazol-2-ylamines in inorganic acids mixtures or dichloroacetic acid followed by diazonium salts coupling with azulenes. The nitrosyl sulfate was also used for diazonium salts synthesis. The systematic substitution of pattern structure enabled to study the interdependence between the polarity of different