ChemInform Abstract: Pyrido[1,2‐a]quinoxalines: Synthesis, Crystal Structure Determination and pH‐Dependent Fluorescence.

Abstract

Pyrido[1,2-a]quinoxalines: Synthesis, Crystal Structure Determination and pH-Dependent Fluorescence.

pH- and DNA-induced dual molecular light switches based on a novel ruthenium(II) complex

“…For instance, defective pH regulation of acidic compartments has been observed in human breast cancer cells [19]. Recently, Diwu et al [20] and Duffy et al [21] reported some compounds which are effective as pH dependent fluorescent dye indicators. It would, therefore, be extremely desirable to find a variety of ruthenium(II) complexes which are sensitive to changes in pH in a relevant physiological range, especially in acidic organelles regions.…”

Dual-Responsive and Reusable Optical Sensors Based on 2,3-Diaminoquinoxalines for Acidity Measurements in Low-pH Aqueous Solutions

“…As shown in Table 1 and Table S2 , development of pH-sensitive materials for acidic vapors and low-pH aqueous solutions has attracted considerable attention [ 18 , 20 , 22 , 24 , 27 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 ]. Many dyes were immobilized according to various strategies, but LB and LS techniques were not used in this field to our knowledge.…”

“…Quinoxaline derivatives absorbing the light in the visible region attract great attention as optical sensors. The ability of quinoxalines to change their optical properties when N -heterocycle is protonated was thoroughly investigated to obtain colorimetric and fluorescent pH chemosensors [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ] because these compounds change the color in acidic media with pH < 4 in which many of pH indicators are insensitive [ 28 , 29 , 30 , 31 , 32 ]. Unfortunately, most of the quinoxaline derivatives reported elsewhere in the literature for pH monitoring can be used only in organic solvents or binary solvent mixtures and are inconvenient for real-world analyses.…”

“…Water-soluble quinoxalines or solid-state devices (litmus strip, for instance) based on these compounds are required for practical usefulness. Surprisingly, halochromic materials based on quinoxalines are limited to chromogenic drop-cast films prepared by evaporation of chemosensor solutions on glass surfaces [ 18 ] and paper strips [ 20 , 22 , 24 ]. All these materials were used only for qualitative analyses of acidic vapors, with the exception of paper strips for a semi-quantitative determination of picric acid through fluorescence changes [ 20 ].…”

Ultrasound‐promoted novel route to triazabenzo[b]cyclopenta[lm]fluorenes: An efficient NiFe2O4@SiO2–SO3H nanocatalyst‐assisted green synthesis

“…Poly‐ N ‐heterocycles have universally been adapted in the exploration of novel biologically sound compounds [ 16 ] due to their wide pharmaceutical activity. Various quinoxaline derivatives show versatile applications like pH‐dependent ultraviolet (UV) and fluorescence characteristics, [ 17 ] antineoplastic activity, [ 18 ] prostaglandin D2 receptor antagonist property, [ 19 ] potent IKK‐2 inhibitor, [ 20 ] potent AChE inhibitor, [ 21 ] vasopressin V2 receptor antagonists and [ 22 ] antibacterial, [ 23 ] antimetabolic [ 24 ] and anticancer activity. [ 25 ] They also extensively exploited as building block for the construction of organic semiconductors [ 26 ] and bioactive spiro compounds.…”