| 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 |
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| 摘要: 外消旋大环镍(Ⅱ)配合物[Ni (rac-L)](ClO4)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)]ClO4(1)和[Ni (SS-L)(R-Man)]ClO4(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)](ClO4)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)](ClO4)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)]ClO4(3)(PPA=2-苯基丙酸)和[Ni (rac-L)(dl-Tro)]ClO4(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。 |
| 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 |
| 基金项目: 湖南省教育厅科研项目(No.20A210)、国家自然科学基金(No.51772091)和湖南省应用特色学科资助。 |
| Abstract: The reactions of a racemic four-coordinated macrocyclic nickel(Ⅱ) complex[Ni(rac-L)](ClO4)2 with l- and d-mandelic acid anion in acetonitrile/water gave six-coordinated enantiomers of[Ni(RR-L) (S-Man)]ClO4 (1) and[Ni(SS-L)(R-Man)]ClO4 (2) (L=5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, Man=mandelic acid), respectively. The reaction of[Ni(rac-L)](ClO4)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)] (ClO4)2 with dl-2-phenylpropionic acid and tropic acid anion gave complexes[Ni(rac-L)(dl-PPA)]ClO4 (3) (PPA=2-phenylpropionic acid) and[Ni(rac-L)(dl-Tro)]ClO4 (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. |
| Keywords: macrocyclic nickel(Ⅱ) complex chiral recognition mandelic acid 2-phenylpropionic acid tropic acid |
| 投稿时间：2022-11-27 修订日期：2023-03-20 |
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| 蒋亚南,邓远欢,王琼,谭英芝,欧光川.大环镍(Ⅱ)配合物与扁桃酸的手性识别[J].无机化学学报,2023,39(6):1072-1078. |
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| Support information: 相关附件： 220493_Supporting_Information_R4.doc |
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