Functionalization of shape-persistent aromatic oligoamides still represents a difficult task nowadays. A crescent aromatic oligothioamide was synthesized by simple thionation of the corresponding oligoamide with the L...Functionalization of shape-persistent aromatic oligoamides still represents a difficult task nowadays. A crescent aromatic oligothioamide was synthesized by simple thionation of the corresponding oligoamide with the Lawesson＇s reagent. The results from UV-vis spectra of the molecule upon metal ion complexation demonstrated its higher selectivity in recognizing Cu2~ ions compared to the oligoamide precursor. The stoichiometry of the complex formed between the thioamide and Cu2＋ was found to be 1：1 with a binding constant of （4.3 ± 0.9） × 104 mol/L.展开更多
A series of crescent aromatic oligothioamides(4, 6, 8, 15, and 18) bearing different number of sulfur atoms were designed and synthesized via thionation of their corresponding aromatic oligoamides(3, 5, and 7) using L...A series of crescent aromatic oligothioamides(4, 6, 8, 15, and 18) bearing different number of sulfur atoms were designed and synthesized via thionation of their corresponding aromatic oligoamides(3, 5, and 7) using Lawesson's reagent. The X-ray structure of a trimeric analogue(13) revealed the presence of intramolecular three-center hydrogen bonds that are responsible for the rigidification of the molecular backbone. The extraction by these novel receptors toward some representative heavy metal cations(Zn2+, Cd2+, Co2+, Ni2+, Pb2+, and Cu2+) and alkali and alkaline earth metal cations(Li+, Na+, K+, Rb+, Cs+, Ca2+, and Sr2+) demonstrated high efficiency(83.5%–96.4%) and superior selectivity for Cu2+ over other selected metal cations. Particularly, the extractability was correlated to both the number of sulfur atoms and orientation of thiocarbonyl groups as revealed in the order: 6 > 4 > 18 > 15. This is in stark contrast to the oligoamides that only gave much lower extractability(5.9%–16.4%), suggestive of the importance of replacement of carbonyl oxygen atoms with sulfur atoms in the extraction of Cu2+. The complexation behavior of 4, 6, and 8 with Cu2+ was also examined by UV-Vis and NMR techniques.展开更多
基金supported by the National Natural Science Foundation(No.21172158)NSAF(No.11076018)+2 种基金Sichuan Province Science and Technology Support Programme(No.2011FZ0048)the National Fund of China for Fostering Talents in Basic Science(No.J1210004)Open Project of Key Laboratory for Radiation Physics and Technology of Ministry of Education(No.2010-08)
文摘Functionalization of shape-persistent aromatic oligoamides still represents a difficult task nowadays. A crescent aromatic oligothioamide was synthesized by simple thionation of the corresponding oligoamide with the Lawesson＇s reagent. The results from UV-vis spectra of the molecule upon metal ion complexation demonstrated its higher selectivity in recognizing Cu2~ ions compared to the oligoamide precursor. The stoichiometry of the complex formed between the thioamide and Cu2＋ was found to be 1：1 with a binding constant of （4.3 ± 0.9） × 104 mol/L.
基金supported by the National Natural Science Foundation of China(21172158)the Joint Fund of National Natural Science Foundation of China and the China Academy of Engineering Physics(11076018)+3 种基金the Doctoral Program of the Ministry of Education of China(20130181110023)the National Science Foundation for Fostering Talents in Basic Research of the National Natural Science Foundation of China(J1210004,J1103315)Open Project of State Key Laboratory of Supramolecular Structure and Materials(SKLSSM201408)Open Project of State Key Laboratory of Structural Chemistry(20140013)
文摘A series of crescent aromatic oligothioamides(4, 6, 8, 15, and 18) bearing different number of sulfur atoms were designed and synthesized via thionation of their corresponding aromatic oligoamides(3, 5, and 7) using Lawesson's reagent. The X-ray structure of a trimeric analogue(13) revealed the presence of intramolecular three-center hydrogen bonds that are responsible for the rigidification of the molecular backbone. The extraction by these novel receptors toward some representative heavy metal cations(Zn2+, Cd2+, Co2+, Ni2+, Pb2+, and Cu2+) and alkali and alkaline earth metal cations(Li+, Na+, K+, Rb+, Cs+, Ca2+, and Sr2+) demonstrated high efficiency(83.5%–96.4%) and superior selectivity for Cu2+ over other selected metal cations. Particularly, the extractability was correlated to both the number of sulfur atoms and orientation of thiocarbonyl groups as revealed in the order: 6 > 4 > 18 > 15. This is in stark contrast to the oligoamides that only gave much lower extractability(5.9%–16.4%), suggestive of the importance of replacement of carbonyl oxygen atoms with sulfur atoms in the extraction of Cu2+. The complexation behavior of 4, 6, and 8 with Cu2+ was also examined by UV-Vis and NMR techniques.
