Spectroscopic and electrochemical properties of new amphiphilic donor–acceptor conjugated polyenes

Differentiating Between Dipolarity and Polarizability Effects of Solvents Using the Solvatochromism of Barbiturate Dyes

“…An occasionally described effect when dealing with polyene dyes is inverted solvatochromism, [18][19][20]36] that is, the change from positive to negative solvatochromism with increasing solvent polarity. This phenomenon is ascribed to a solvent-induced change in the ground-state structure from a less dipolar polyene-like structure (non-polar solvents) to a strongly dipolar betaine-like structure (polar solvents), the maximum wavelength being at the cyanine limit.…”

Polymerization of Chrysoidine with chemical and enzymatic oxidative preference: Synthesis, characterization, and spectroscopic study

“…The solvent effect on UV‐vis spectra is analyzed and given in Figure . In Figure A,B, maxima of the absorption bands undergo hyposochromic shift together with raising polar protic property whose effects are evidently observed on the positions and intensities, indicating that the spectral shifts in methanol and ethanol mainly depend on the strength of the intermolecular hydrogen bonds between (―N═N―) group of the polymer and ―OH functional group of the solvent molecules …”

“…Notwithstanding, the maximum peaks at 391 and 405 nm for poly (chry‐enz) and poly (chry‐ox), respectively, were hypsochromically shifted with a broadened absorption compared with the maximum absorption of CHRY. The reason was that the nitrogen atom lost its free pair of electrons as a result of an intermolecular hydrogen bonding between the ―NH group of polymers and the S═O functional group of DMSO . The observable band broadening for the synthesized polymers as in Figure was prevalent for a π‐delocalized molecule, eventuating that the polymerization was achieved.…”

“…The reason was that the nitrogen atom lost its free pair of electrons as a result of an intermolecular hydrogen bonding between the -NH group of polymers and the S═O functional group of DMSO. 43,44 The observable band broadening for the synthesized polymers as in Figure 6 was prevalent for a π-delocalized molecule, eventuating that the polymerization was achieved.…”

“…In Figure 7A of the solvent molecules. [43][44][45] Proceeding from polar protic to apolar protic solvent, the maxima of the absorption curves for n →π* bands appeared to undergo hyposochromic (blue) shift. λ max values of poly (chry-enz) were found to be 419, 417, 415, 407, 399, 399, and 399 in NMP, DMSO, DMF, THF, MeCN, methanol, and ethanol, respectively, as seen in Figure 7 A.…”