1778-65-0Relevant academic research and scientific papers
A bifunctional chromogenic calix[4]arene chemosensor for both cations and anions: A potential Ca2+ and F- switched INHIBIT logic gate with a YES logic function
Chang, Kai-Chi,Su, In-Hao,Wang, Yu-Yun,Chung, Wen-Sheng
, p. 4700 - 4704 (2010)
A bifunctional chromogenic calix[4]arene 3, which contains both triazoles and hydroxy azophenols as both cationic and anionic recognition sites and the azophenol moiety as a coloration unit, was designed and synthesized. The recognition of Ca2+ by 3 gave rise to a marked colour change from green- ish to bright yellow, whereas the recognition of F- by 3 showed a colour change from light green to bluish. The colour changes of 3 by the inputs of Ca2+ and F- have been implemented to construct a combinational logic circuit at the molecular level.
Solvatochromism of new substituted 4-[(E)-(4-nitrophenyl)diazenyl]phenolate dyes
de Melo, Carlos E.A.,Nicoleti, Celso R.,Nandi, Leandro G.,Schneider, Felipe S.S.,da S. Oliboni, Robson,Caramori, Giovanni F.,Machado, Vanderlei G.
, (2020/01/30)
Studies on the reverse solvatochromism of dyes in pure solvents are of interest to gain a better understanding of the nature of this phenomenon. In this paper, a series of nine compounds, exhibiting phenol and 4-nitrophenyl groups linked with an azo conjugated bridge, was synthesized and characterized. These compounds were deprotonated to generate solvatochromic phenolate dyes. The azo bridge makes the phenol more acidic, in comparison with the related compounds exhibiting a CH[dbnd]CH or CH[dbnd]N bridge in their molecular structure, indicating the electron withdrawing character of the azo bridge. The solvatochromism of the dyes was investigated in 29 solvents and their intense colors in solution were attributed to π-π* electronic transitions, with an intramolecular charge transfer from the phenolate towards the 4-nitroaryl group. The probes exhibited a reversal in their solvatochromism, in a similar fashion to the behavior verified with related dyes presenting CH[dbnd]CH or CH[dbnd]N as the conjugated bridge; however, the azo dyes are much less sensitive to solvent polarity changes. Multiparametric analysis showed that the azo dyes are very sensitive to the acidity of the medium, but still to a lesser degree than the corresponding imine and stilbene dyes, due to the electronegativity of the azo group. The reverse solvatochromism of the dyes is dictated by the electron-donor phenolate and by the electron-acceptor 4-nitroaryl groups, independently of the conjugated bridge, of the additional nitro group and of the nature of substituents in the 2,6-positions of the phenolate groups. Thus, the solvatochromic reversal verified represents a committed step involving the interaction of the nitro and phenolate groups in the probe with the molecules of structurally different solvents.
Evaluation of Through-Space Interaction in Metacyclophanes by Diazo Coupling Reaction
Tsuge, Akihiko,Moriguchi, Tetsuji,Mataka, Shuntaro,Tashiro, Masashi
, p. 2211 - 2216 (2007/10/02)
An azobenzene moiety was introduced into various metacyclophanes (MCPs) 1 via diazo coupling reactions.The functional groups on the inner (8,16-) or outer (13-) positions affect the reactivity of the outer (5-) position toward the diazonium salts to
Diazo Coupling of Metacyclophanes
Tsuge, Akihiko,Moriguchi, Tetsuji,Mataka, Shuntaro,Tashiro, Masashi
, p. 579 - 582 (2007/10/02)
Metacyclophanes(=MCPs) which carry hydroxy, methoxy or methyl group at the inner position exhibited a stronger reactivity toward diazonium salts than the corresponding phenol, anisole or toluene, respectively.Such a reactivity was also estimated in c
