Browsing by Author "Chang, Kai-Chi"

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A Bifunctional Chromogenic Calix[4]arene Chemosensor for Both Cations and Anions: A Potential Ca(2+) and F(-) Switched INHIBIT Logic Gate with a YES Logic Function
(2010-08-01)
Chang, Kai-Chi
;
Su, In-Hao
;
Wang, Yu-Yun
;
Chung, Wen-Sheng
;
應用化學系
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 Ca(2+) by 3 gave rise to a marked colour change from greenish 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 Ca(2+) and F- have been implemented to construct a combinational logic circuit at the molecular level.
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
(2010-08-01)
Chang, Kai-Chi
;
Su, In-Hao
;
Wang, Yu-Yun
;
Chung, Wen-Sheng
;
應用化學系
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 greenish 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.
Anthryl-1,2,4-oxadiazole-Substituted Calix[4]arenes as Highly Selective Fluorescent Chemodosimeters for Fe3+
(2015-04-01)
Chen, Ying-Jung
;
Yang, Shun-Chieh
;
Tsai, Chia-Chen
;
Chang, Kai-Chi
;
Chuang, Wen-Han
Fluorescent chemosensors 1 and 2, with 1,2,4-oxadiazoles as the binding ligands and anthracene as the fluorophore, were synthesized through sequential 1,3-dipolar cycloaddition reactions of 25,27-dioxyacetonitrilecalix[4]arenes 8 and 11. The fluorescence of 1 was severely quenched by both Fe3+ and Cu2+, whereas that of 2 was selectively quenched only by Fe3+. Control compound 4 was also selectively quenched by Fe3+, which implied the importance of anthryl-1,2,4-oxadiazole core; furthermore, it was shown to give various oxidation products such as oxanthrone 13, anthraquinone 14, and imidazolyl oxanthrone 15. In addition to product separation and identification, the fluorescent quenching mechanism of these 9-anthryl-1,2,4-oxadiazolyl derivatives by Fe3+ is also discussed. Furthermore, it should be noted that the oxadiazole-substituted anthracene 4 and calix[4]arene 2 are Fe3+-selective fluorescent chemodosimeters without the interference by Cu2+.
Biscalix[4]arene Derivative As a Very Efficient Phase Selective Gelator for Oil Spill Recovery
(2013-11-15)
Tsai, Chia-Chen
;
Cheng, Ying-Tsai
;
Shen, Li-Ching
;
Chang, Kai-Chi
;
Ho, I-Ting
A biscalixarene framework, without long alkyl chains, has been readily synthesized in three steps starting from the parent calix[4]arene. The biscalix[4]arene 1 was able to form organogels in various alcoholic solvents; furthermore, it exhibited an excellent phase selective gelation property that is potentially useful in oil spill recovery.
Cooperative Recognition of a Copper Cation and Anion by a Calix[4]arene Substituted at the Lower Rim by a beta-Amino-alpha,beta-Unsaturated Ketone
(2009)
Senthilvelan, Annamalai
;
ho, I. -Ting
;
Chang, Kai-Chi
;
Lee, Gene-Hsiang
;
Liu, Yi-Hung
We report herein a new ditopic calix[4]arene receptor 25,27-bis{[4-amino-4-(1-naphthyl)-2-oxo-3-butenyl]oxy}-26,28-dihydroxycalix[4]arene (2) for the simultaneous complexation of anionic and cationic species. The host molecule 25,27-bis{[3-(1-naphthyl)-5-isoxazolyl]methoxy}-26,28-dihydroxycalix[4]arene (1) was synthesised first and was followed by a [Mo(CO)(6)]mediated ring-opening reaction to give the target receptor 2. The binding properties of ligands 1 and 2 towards metal ions in CH(3)CN were investigated by UV/Vis and fluorescence spectroscopies. The results showed that both ligands I and 2 were highly selective for Cu(II) ions. Upon titration with Cu(II), the fluorescence of I was severely quenched, whereas 2 showed strong fluorescence enhancement because the metal ions help to lock the conformation of the fluorophores. During the complexation of 2 with Cu(II), the Cu(II) was reduced to Cu(I) by the free phenolic OH of 2, whereas the phenol was oxidised by Cu(II), after which it assisted in the trapping of Cu(I). Ditopic behaviour was observed for the complex 2 center dot Cu(I), which showed further enhancement of its fluorescence intensity upon complexation with anions such as acetate or fluoride.
Evolution of nano- to microsized spherical assemblies of fluorogenic biscalix[4]arenes into supramolecular organogels
(2013)
Tsai, Chia-Chen
;
Chang, Kai-Chi
;
Ho, I-Ting
;
Chu, Jean-Ho
;
Cheng, Ying-Tsai
A biscalix[4]arene (1) capable of spontaneous self-assembly into nanoparticles and microspheres in CH3CN was serendipitously observed, and it eventually formed stable blue-light emitting supramolecular organogels.
Highly selective fluorescent sensing of Cu(2+) ion by an arylisoxazole modified calix[4]arene
(2008-08-18)
Chang, Kai-Chi
;
Luo, Li-Yang
;
Diau, Eric Wei-Guang
;
Chung, Wen-Sheng
;
應用化學系
A novel fluorescent chemosensor 1 with two anthraceneisoxazolymethyl groups at the lower rim of calix[4]arene has been synthesized, which revealed a dual emission (monomer and excimer) when excited at 375 nm. This chemosensor displayed a selective fluorescence quenching only with Cu(2+) ion over all other metal ions examined. When Cu(2+) ion was bound to 1, the fluorescence intensities of both monomer and excimer were quenched. Furthermore, the association constant for the 1:1 complex of 1.Cu(2+) was determined to be (1.58 +/- 0.03) x 10(4) M(-1). (c) 2008 Elsevier Ltd. All rights reserved.
Light-driven nanofiber and nanoring morphological transformations in organogels based on an azobenzene-bridged biscalix[4]arene
(2017-12-25)
Su, Pei-Mei
;
Chang, Kai-Chi
;
Yang, Cheng-Jhang
;
Liu, Yi-Chieh
;
Chung, Wen-Sheng
The morphologies of an azobenzene-bridged biscalix[4]arene organogel in different organic solvents can be photo-reversibly switched between nanofibers and nanorings as well as between closed and open-form vesicles.
MO(CO)(6)-mediated synthesis of calix[4]arenes carrying beta-hydroxy ketones or alpha,beta-unsaturated-beta-amino ketones
(2006-12-18)
Senthilvelan, Annamalai
;
Tsai, Ming-Tsung
;
Chang, Kai-Chi
;
Chung, Wen-Sheng
;
應用化學系
MO(CO)(6)-mediated ring opening reactions of calix[4]arene isoxazolines/isoxazoles provide a new synthetic methodology for calix[4]arenes carrying bifunctional beta-hydroxy ketones or alpha,beta-unsaturated-beta-amino ketones. MO(CO)(6) is a highly selective and convenient reagent for the ring opening process of these supramolecular isoxazolines/isoxazoles. (c) 2006 Elsevier Ltd. All rights reserved.
Triazole- and azo-coupled calix[4]arene as a highly sensitive chromogenic sensor for Ca2+ and Pb2+ ions
(2007-10-08)
Chang, Kai-Chi
;
Su, In-Hao
;
Lee, Gene-Hsiang
;
Chung, Wen-Sheng
;
應用化學系
A novel chromogenic calix[4]arene 3, which has within a molecule both the triazoles and the hydroxyl azophenols as the metal-binding sites and the azophenol moiety as a coloration sites was designed and synthesized. Calix[4]arene 3 is highly sensitive to Ca2+ and Pb+ ions, which can be detected by the naked eye. Furthermore, the association constants for the 1:1 complexes of 3 center dot Ca2+ and 3 center dot Pb2+ were determined to be 7.06 x 104 M-1 and 8.57 x 103 M-1, respectively. (c) 2007 Elsevier Ltd. All rights reserved.
Triazole-modified calix[4]crown as a novel fluorescent on-off switchable chemosensor
(2007-08-16)
Chang, Kai-Chi
;
Su, In-Hao
;
Senthilvelan, Annamalai
;
Chung, Wen-Sheng
;
應用化學系
A novel fluorescent on-off switchable chemosensor 1 with two different types of cationic binding sites is synthesized, which is composed of a triazole-modified calix[4]crown in the 1,3-alternate conformation. Among 15 metal ions examined, the fluorescence of 1 was strongly quenched by Hg2+, Cu2+, Cr3+, and Pb2+; however, the revival of emission from the strongly quenched 1 center dot Pb2+ complex was achievable by the addition of K+, Ba2+, or Zn2+ ions. Thus, metal ion exchange can trigger an on-off switchable fluorescent chemosensor.