Browsing by Author "Tsai, Chia-Chen"

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Anthryl-1,2,4-oxadiazole-Substituted Calix[4]arenes as Highly Selective Fluorescent Chemodosimeters for Fe3+
(2015-04-01)
Chen, Ying-Jung
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Yang, Shun-Chieh
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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
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Cheng, Ying-Tsai
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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.
Evolution of nano- to microsized spherical assemblies of fluorogenic biscalix[4]arenes into supramolecular organogels
(2013)
Tsai, Chia-Chen
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Chang, Kai-Chi
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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.
Modelling leadership and team performance: the moderation of politics and leadership self-efficacy
(1970-01-01)
Lin, Chieh-Peng
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Liu, Chu-Mei
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Joe, Sheng-Wuu
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Chen, Kuang-Jung
;
Tsai, Chia-Chen
This study develops a research model that explains the development of team performance based on team reflexivity theory and social cognitive theory. In the model, team performance relates to considerate leadership and autocratic leadership indirectly via the mediation of team reflexivity. At the same time, politics and leadership self-efficacy are hypothesised as moderators in the model. Primary and secondary data were used via a two-wave investigation from three different sources for verifying our hypotheses. The team-level analyses show that team reflexivity mediates the positive relationship between considerate leadership and team performance. Politics positively moderates the relationship between autocratic leadership and team reflexivity. Leadership self-efficacy positively moderates the relationships between autocratic leadership and team reflexivity and between considerate leadership and team reflexivity. Finally, research implications based on our empirical results are discussed.
Synthesis of 9,10-Bis-ketoenaminoanthryl and 9,10-Bisi-isoxazolylanthryl Linked Biscalix[4]arenes: Atropisomers and Molecular Recognitions
(2012-03-02)
Tsai, Chia-Chen
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Ho, I-Ting
;
Chu, Jean-Ho
;
Shen, Li-Ching
;
Huang, Shou-Ling
An efficient synthetic pathway for the synthesis of biscalix[4]arenes 5-10 using 1,3-dipolar cycloaddition reactions is reported. Biscalix[4]arene 10 is capable of forming a complex with methyl viologen because of favorable cation-pi interactions and a proper cavity size to accommodate the guest. Moreover, biscalix[4]arenes 8a and 8b were found to be atropisomers at room temperature. These two conformers were unable to exchange at room temperature because of the restricted rotation of the C-9-C-11 or C-10-C-12 bonds of the beta-amino-alpha,beta-unsaturated ketones of anthracene.