Towards a unified view of the solvatochromism of phenolate betaine dyes

Abstract

An attempt has been made in order to unify the three types of solvatochromisms (negative, positive and inverted) of phenolate betaine dyes by a working model which describes them as particular cases of a general behavior. The model, based on the calculation (gas phase) of the chemical hardness of donor and acceptor fragments, was applied to 56 examples from the literature. As a result, the investigated compounds were grouped according to the sum of the hardnesses of their (non-interacting) fragments, this sum being larger for a negative, intermediate for an inverted, and smaller for a positive solvatochromic behavior.

Derivatives of Dapsone (dap): Synthesis and Study on In Vitro Anticancer Activity and DNA Laddering Against Hep G2 and C6 Human Cancer Cell Lines

“…In continuation to our on-going research interest [14] on the evaluation of anticancer properties of relatively unexplored metallomacrocyclic dithiocarbamate complexes and in the light of a wide range of pharmacological activities exhibited by sulfone derivatives, [41][42][43][44][45][46] we have derivatize dap to obtained a novel series of organic diamines L 1 -L 3 and their ensuing transition metal metallomacrocyclic dithiocarbamate complexes 1 a-1 c, 2 a-2 c, 3 a-3 c. All the new compounds were structurally characterized by FT IR, MS, 1 H, 13 C, 1 H DOSY NMR spectroscopy, UV-visible, fluorescence spectrophotometers and by thermogravimetric analysis. The geometry of the compounds has been optimized by density functional theory and electrochemical responses have also been investigated.…”

NMR Spin–Spin Coupling Constants in Polymethine Dyes as Polarity Indicators

“…The optical properties of various merocyanines16 have been extensively studied and they typically show negative solvatochromic behavior (i.e., a blue shift in their absorption spectra). However, in less‐polar‐ or non‐polar solvents, such as CHCl 3 , they display a red shift in their absorption spectra, with a solvatochromic‐reversal behavior that has been the subject of some controversy in the literature 19–21. Several underlying mechanisms have been proposed to explain this behavior, such as the aggregation of dye molecules in non‐polar solvents19–21 and changes in molecular geometry (neutral‐ to zwitterionic‐like through a cyanine‐like structure) owing to the increase in solvent polarity 19–21.…”

“…However, in less‐polar‐ or non‐polar solvents, such as CHCl 3 , they display a red shift in their absorption spectra, with a solvatochromic‐reversal behavior that has been the subject of some controversy in the literature 19–21. Several underlying mechanisms have been proposed to explain this behavior, such as the aggregation of dye molecules in non‐polar solvents19–21 and changes in molecular geometry (neutral‐ to zwitterionic‐like through a cyanine‐like structure) owing to the increase in solvent polarity 19–21. In fact, our previous calculations on Brooker′s merocyanine dye supported this latter mechanism, that is, a change in molecular structure from neutral to zwitterionic in polar environments is responsible for the solvatochromic reversal 22.…”

Chalcone hybrids and their antimalarial activity

“…The mechanistic study revealed that these hybrids could inhibit P. falciparum MO15-related protein kinase (Pfmrk), an essential role in cell cycle control and differentiation in P. falciparum, and IC 50 values were 9-38 μM. [94] Besides the chalcone hybrids mentioned above, chalcone-furan/ thiophene, [95,96] chalcone-indole, [97] chalcone-pyrimidine, [98] and chalcone-sulfamide [99][100][101] hybrids also showed certain antiplasmodial activity, but the majority of them were not superior to the references.…”