Development of External Stimuli Responsive-Dynamic Helicity Inversion Systems based on Coordination Chemistry

(1)超分子螺旋结构手性信息的反转和传递是自然界中普遍存在的现象。我们成功地证明了合成的肽-金属复合物的动态肽螺旋反转，其中金属中心充当时间调谐装置。所使用的金属配合物由手性六配位金属中心和两个非手性五肽链组成。在NO_3 ~+-的刺激下，配体的肽链发生螺旋反转，随后八面体金属中心发生螺旋度反转。由于复合物螺旋的反转速率是基于金属中心的取代不稳定性来调节的，因此本发明的金属-肽复合物提供了时间可调的肽螺旋反转，其具有从毫秒到小时的时间尺度。(2)在自然界中，分子的运动是动态的，连续的，包括拉伸、缠绕和旋转。我们开发了基于手性Co（II）配合物的具有双模运动的化学装置。配体 ...更多信息 所用的配体包括通过酰胺键连接到螺旋四齿配体的两端的2，5-二甲氧基苯部分。其金属配合物的酸碱反应引发了酰胺氮原子和酰胺氧原子之间的配位原子的相互转化，提供了分子的伸缩运动。所采用的Co（II）配合物也表现出螺旋反转运动。然后，本类型的动力学不稳定的Co（II）配合物允许双分子运动在一个高度动态的方式，这是需要作为复杂的超分子开关装置。(3)制备了含手性四齿配体的Zn（II）配合物的聚合物膜，用于测定硝酸根离子。电位选择性系数进行了评估，使用固定的干扰方法，这些Zn（II）配合物表现出更好的选择性硝酸根阴离子相对于各种无机阴离子。由于新的Zn（II）络合物为基础的传感器被用作指示电极在合成水样中的硝酸根阴离子的测定，它们被认为是硝酸根阴离子的选择性载体。少

(1) The inversion and transfer of chirality information of supramolecular helices are ubiquitous phenomena in nature. We successfully demonstrated dynamic peptide helix inversion of synthetic peptide-metal complex, in which metal center acts as a time-tuning device. The metal complex used is composed of a chiral hexa-coordinated metal center and two achiral penta-peptide chains. The helix inversion of the peptide chains of the ligand can be followed by helicity inversion of the octahedral metal center upon addition of NO_3^- anion stimulus. Since the inversion rate of complex helicity is tuned based on the substitution lability of the metal center, the present metallo-peptide complex offers time-tunable peptide helix inversion which has time scale from milliseconds to hours.(2) Dynamic and consecutive molecular motions including stretching, winding and rotation are observed in nature. We developed chemical device exhibiting dual mode motions based on a chiral Co(II) complex. The ligand … More employed includes 2,5-dimethoxy benzene moieties attaching to the both terminals of helical tetradentate ligand via amide linkages. The acid-base reaction of its metal complex triggered interconversion of coordinating atoms between amide nitrogen atoms and amide oxygen atoms to offer stretching molecular motion. The employed Co(II) complex also showed helicity inverting motions. Then, the present type of kinetically labile Co(II) complex allows dual molecular motion in a highly dynamic fashion, which is required as sophisticated supramolecular switching device.(3) Polymeric membranes containing Zn(II) complexes with chiral tetradentate ligands were prepared for the determination of nitrate anion. The potentiometric selectivity coefficients were evaluated using fixed interference method, and these Zn(II) complexes exhibited better selectivity for nitrate anion with respect to wide variety of inorganic anions. Since the new Zn(II) complex-based sensors were used as indicator electrodes in determination of the nitrate anion in synthetic water samples, they are recognized as selective carriers for nitrate anions. Less