大环镍(Ⅱ)配合物与扁桃酸的手性识别  

Chiral recognition of mandelic acid and macrocyclic nickel(Ⅱ)complexes

作　　者：蒋亚南 邓远欢 王琼 谭英芝 欧光川 JIANG Ya‑Nan;DENG Yuan‑Huan;WANG Qiong;TAN Ying‑Zhi;OU Guang‑Chuan(College of Chemistry and Bioengineering,Hunan University of Science and Engineering,Yongzhou,Hunan 425199,China)

机构地区：[1]湖南科技学院化学与生物工程学院,永州425199

出　　处：《无机化学学报》2023年第6期1072-1078,共7页Chinese Journal of Inorganic Chemistry

基　　金：湖南省教育厅科研项目(No.20A210);国家自然科学基金(No.51772091);湖南省应用特色学科资助。

摘　　要：外消旋大环镍(Ⅱ)配合物[Ni(rac-L)](ClO_(4))_(2)分别与l-和d-扁桃酸阴离子在乙腈/水溶液中反应,通过手性识别得到六配位的[Ni(RR-L)(S-Man)]ClO_(4)(1)和[Ni(SS-L)(R-Man)]ClO_(4)(2)对映异构体(L=5,5,7,12,12,14-六甲基-1,4,8,11-四氮杂环十四烷,Man=扁桃酸)。当[Ni(rac-L)](ClO_(4))_(2)与dl-扁桃酸阴离子反应时得到一对对映体等量存在的共聚物,其中大环配体中RR和SS构型分别优先与l-和d-Man-配位形成外消旋混合物,反应过程中发生了手性识别现象,每颗晶体均为手性对映体。当[Ni(rac-L)](ClO_(4))_(2)分别与结构类似的dl-2-苯基丙酸和dl-托品酸阴离子反应时,分别得到化合物[Ni(rac-L)(dl-PPA)]ClO_(4)(3)(PPA=2-苯基丙酸)和[Ni(rac-L)(dl-Tro)]ClO_(4)(4)(Tro=托品酸)。X射线单晶衍射结果表明,4个配合物中Ni(Ⅱ)离子均与折叠大环配体L的4个氮原子和2个来自羧基与羟基的氧原子(1和2),或羧基氧原子(3和4)顺式配位,形成六配位八面体构型。配合物1和2属于一对对映异构体,分别通过[Ni(RR-L)(S-Man)]+和[Ni(SS-L)(R-Man)]+分子间氢键作用形成一维之字形链状结构。配合物1和2的单手性特征与圆二色(CD)谱测定结果一致。The reactions of a racemic four-coordinated macrocyclic nickel(Ⅱ)complex[Ni(rac-L)](ClO_(4))_(2)with l-and d-mandelic acid anion in acetonitrile/water gave six-coordinated enantiomers of[Ni(RR-L)(S-Man)]ClO_(4)(1)and[Ni(SS-L)(R-Man)]ClO_(4)(2)(L=5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane,Man=mandelic acid),respectively.The reaction of[Ni(rac-L)](ClO_(4))_(2)with dl-Man-gave a conglomerate,in which the RR and SS enantiomers preferentially coordinate to l-and d-Man-respectively to give a racemic mixture of 1 and 2,and the chiral recognition occurs during the reaction,in which each crystal crystallizes into enantiopure.The reactions of[Ni(rac-L)](ClO_(4))_(2)with dl-2-phenylpropionic acid and tropic acid anion gave complexes[Ni(rac-L)(dl-PPA)]ClO_(4)(3)(PPA=2-phenylpropionic acid)and[Ni(rac-L)(dl-Tro)]ClO_(4)(4)(Tro=tropic acid),respectively.Single-crystal X-ray diffraction analyses show that the Ni(Ⅱ)ions display an octahedral coordination geometry by coordination with four nitrogen atoms of macrocyclic ligand in a folded configuration,plus two oxygen atoms of carboxyl and hydroxyl for 1 and 2,or two oxygen atoms of carboxyl for 3 and 4 in cis-position.Complexes 1 and 2 belong to a pair of enantiomers,which are constructed via hydrogen bonding linking of[Ni(RR-L)(S-Man)]+and[Ni(SS-L)(R-Man)]+monomers to form 1D hydrogen bonded zigzag chain,respectively.The homochiral natures of 1 and 2 are confirmed by the results of circular dichroism(CD)spectra measurements.CCDC:2220158,1;2220159,2;2220160,3;2220161,4.

关 键 词：大环镍(Ⅱ)配合物 手性识别 扁桃酸 2-苯基丙酸 托品酸 

分 类 号：O614.813[理学—无机化学]