有机化学 ›› 2017, Vol. 37 ›› Issue (7): 1757-1763.DOI: 10.6023/cjoc201702012 上一篇    下一篇

研究论文

C-H…O氢键驱动的1,2,3-三氮唑折叠体:评估分子间C-H…X-(X=Cl,Br,I)和C-H…N氢键的稳定性

孙广军a, 聂承斌a, 赵新a, 黎占亭a,b   

  1. a. 中国科学院上海有机化学研究所 有机功能分子合成与组装化学实验室 上海 200032;
    b. 复旦大学化学系 上海 200433
  • 收稿日期:2017-02-11 修回日期:2017-03-07 发布日期:2017-03-17
  • 通讯作者: 赵新, 黎占亭 E-mail:xzhao@sioc.ac.cn;ztli@fudan.edu.cn
  • 基金资助:

    国家自然科学基金(Nos.21272042,21432004)资助项目.

Intramolecular C-H…O Hydrogen Bonding-Driven 1,2,3-Trazole Foldamers:Assessment of Intermolecular C-H…X- (X=Cl, Br, I) and C-H…N Hydrogen Bonding

Sun Guangjuna, Nie Chengbina, Zhao Xina, Li Zhantinga,b   

  1. a. Key Laboratory of Synthetic and Self-assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, Chinese Academy of Science, Shanghai 200032;
    b. Department of Chemistry, Fudan University, Shanghai 200433
  • Received:2017-02-11 Revised:2017-03-07 Published:2017-03-17
  • Contact: 10.6023/cjoc201702012 E-mail:xzhao@sioc.ac.cn;ztli@fudan.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos.21272042,21432004).

1,2,3-三氮唑芳香寡聚体可以通过分子内三中心C-H…O氢键诱导形成折叠或螺旋二级结构.通过1H NMR实验研究这类人工二级结构在氯仿和二氯甲烷中进一步形成分子间C-H…Cl-和C-H…N氢键的倾向性,发现分子内的两类C-H…O氢键可以通过进一步形成C-H…Cl-氢键而被弱化.在过量Cl-存在时,三氮唑N-1侧的六元环C-H…O氢键被显著破坏,由此形成分子间C-H…Cl-氢键,从而诱导骨架形成另一类更加扩展的折叠构象.过量的Br-和I-也可以形成类似的分子间氢键.对其中一个八聚体研究揭示,1,2,3-三氮唑螺旋体的内侧2,3-位N原子还可以与三炔和二炔衍生物的炔基C-H形成分子间弱的C-H…N氢键,三氮唑折叠结构通过诱导N原子形成环形定位促进这一分子间弱氢键产生协同效应.

关键词: 氢键, 折叠结构, 三氮唑, 炔烃, 分子识别, 非共价键相互作用

1,2,3-Triazole aromatic oligomers are driven by intramolecular three-center C-H…O hydrogen bonding to form folded or helical secondary structures. This paper reports the assessment of their ability to form intermolecular C-H…Cl- in CDCl3 or C-H…N hydrogen bonding in CD2Cl2 by using 1H NMR. It is revealed that the two kinds of intramolecular six-membered C-H…O hydrogen bondings of the backbones are both weakened by Cl- through the formation of intermolecular C-H…Cl- hydrogen bonding. In the presence of excess of Cl-, the C-H…O hydrogen bonding on the N-1 side of the triazole units is, to a large extent, broken by intermolecular C-H…Cl- hydrogen bonding, which induces the backbones to form another kind of more extended crescent secondary structures. Under similar conditions, excess of Br- and I- can also form similar intermolecular hydrogen bonding. It is also found that the inside-located N-2 and N-3 atoms of the triazole units of a 8-mer oligomer can also form weak intermolecular C-H…N hydrogen bonding with C-H atoms of the alkynyl units of several tri-and bi-alkynes, which is enhanced by the folded conformation of the oligomer through forcing the N-2 and N-3 atoms to arrange into a ring.

Key words: hydrogen bonding, foldamer, 1,2,3-triazole, alkyne, molecular recognition, non-covalent interaction