293733-87-6Relevant academic research and scientific papers
Alkyl-substituted dipyrrylmethenes and their oxa- and thia-analogs: Structure - Solvation properties correlations
Semeikin,Berezin,Chernova,Antina,Syrbu,Lyubimova,Kutepov
, p. 1807 - 1813 (2003)
New data on the spectral properties and solution enthalpies of unsymmetrically substituted 2-(alkyl-2-pyrrolylmethylidene)methylpyrrolium bromides (or α,α-dipyrrylmethene hydrobromides), their α,β-, β,β-isomers, as well as their oxa and thia analogs, that is, 2-(2-furylmethylidene)- and 2-(2-thienylmethylidene)-3,4,5-trimethyl- 1H-pyrrolium bromides, in solutions of organic solvents of different nature are presented. A decrease in the number of substituents, as well as replacement of the heteroatom (N) in one five-membered ring of the dipyrrylmetnehe by oxygen or sulfur atoms cause a monotonic hypsochromic shift of absorption bands in the electronic absorption spectrum and weakening of the chromophore properties of the compounds. The chromophore properties of isomers are weakened from the α,α- to α,β- and β,β-dipyrrylmethenes. Main trends in the influence of structural factors on the specific features of thermooxidative destruction of the above-mentioned compounds were analyzed.
Thermal destruction of alkylated α,α-dipyrrolylmethene hydrobromides, their furyl and thienyl derivatives, and complexes with Zn(II)
Chernova,Berezin,Antina
, p. 896 - 900 (2007/10/03)
The thermooxidative destruction of alkylated α,α-dipyrrolylmethene hydrobromides, their furyl and thienyl derivatives, and dipyrrolylmethene complexes with zinc(II) containing different numbers of methyl substituents in the pyrrole fragments of molecules was studied thermogravimetrically. A decrease in the number of alkyl substituents and molecular symmetry lowered the thermal stability of dipyrrolylmethene complexes and salts. The replacement of oxygen by nitrogen or sulfur in one of the pyrrole fragments of a chromophore molecule increased the thermal stability of the thienyl derivative hydrobromide in comparison with the corresponding salts of dipyrrolylmethene and its furyl analogue.
