Upper Rim Arylazo-Coupled Calix[4]arenes Modified with Oxyacetonitrile, Ester or Tetrazole Groups as Highly Sensitive Chromogenic Sensors for Metal Ions

• Main Authors: Peng, Hsiao-Hua, 彭筱華
• Other Authors: Chung, Wen-Sheng
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/67664146977962231016

碩士 === 國立交通大學 === 應用化學研究所 === 98 === First of all, 4-(4-methoxyphenyl)azo-coupled calix[4]arenes 34 and 36 were synthesized. UV-vis screening of calix[4]arenes 34 (with ester and oxyacetonitrile) and 36 (with oxypropyl and oxyacetonitrile) with 15 metal ions showed that both of them gave rise to color changes toward Cr3+ ion, and 34 exhibited good binding ability to Ca2+. According to NOE, Job plot and NMR titration experiments, we proposed that 34 chelated Ca2+ with the helps of both oxyacetonitrile and ester groups, and it moved form flattened cone toward cone conformation upon complexation with metal ion. The Ka of 34?杭a2+, 34?杭r3+ and 36?杭r3+ calculated by Benesi-Hildebrand plots were 3.7 ?e 104, 2.1 ?e 104 and 8.1 ?e104 , respectively. In the second part, the syntheses of calix[4]arenes with 4-(4-nitrophenyl)azo calix[4]arenes 38 and 41 were carried out. UV-vis screening showed that calix[4]arene 38 exhibited large bathochromic shifts toward Ca2+ and Ba2+ in more polar protic solvent systems, such as CH3CN/CH3OH (v/v = 19:1). Moreover, 41 was deficient in this ability.The 1H NMR titration results suggested that both azophenols and ester/or oxyacetonitrile groups are required in the chromogenic sensing with metal ions. The Ka of 38?杭a2+, 38?朋a2+ , 41?杭a2+ and 41?朋a2+ were 7.3 ?e104, 2.9 ?e 104, 1.7 ?e 105 and 3.9 ?e 103 , respectively. In the final part, the tetrazole-modified azocalix[4]arenes 44 were synthesized using 1,3-dipolar cycloaddition. We evaluated the metal ion screening abilities of azocalix[4]arenes in more polar protic solvent systems, such as CH3OH or H2O contained solvent systems. The utilities of calix[4]arenes in biological systems or pharmaceutical studies were improved upon tetrazole substitution.