Study on function-programmed molecular systems based on shape control

点击翻译按钮获取中文摘要

We summarized our research results on the title.1.Cooperative chirality induction using a bis(Zn(II)-prophyrin) with a large ring-size crown ether 1Our interest in developing novel molecular systems possessing "dynamic" functions coupled with chirality let us to synthesize a crown ether-bis(Zn(II)-porphyrin) conjugate with the large ring-based conformation flexibility. The achiral-to-chiral transformation upon complexation with chiral diamines is assisted by K^+ accommodated in the crown moiety. Further, the ionophoric property of crown ether enables us to read out the chirality of amino acids using circular dichroism (CD) spectra through liquid (1 in CH_2Cl_2) - (amino acids in 1N KOH aqueous solution) two-phase extraction. In this way, an intrigued synergistic effect of crown ether and porphyrins was observed on chirality induction.2.A self-organized chiral probe using 15-crown-5-derived metalloporphyrin 2Although 15-crown-5-derived Zn(II)-porphyrin 2a shows no CD spectra when adding … More a chiral diamine, the presence of K^+ in the solution allowed us to detect a significant CD spectra correlated with the chirality. The insight can be ascribed to a [K^+-chiral diamine - (2a)_2] complex formation. Similar phenomena were also observed for the case of Mg(II) porphyrin derivative 2b and chiral aminoalcohols.3.Self-organized molecular sensorsAlizarin-phenylboronic acid interactions have been used in a new design strategy for self-organized fluorescent sensors of metal ions and anions. First, Alizarin Red S (ARS), which binds effectively to phenylboronic acid (PBA) at neutral conditions in water, proved to be an excellent fluorescent indicator for the selective detections of metal ions ; the fluorescent ARS-PBA ensemble causes an efficient and selective quenching in the fluorescence by adding metal ions. It was also found that anion-induced phenylboronates can bind effectively to alizarin and greatly enhance the fluorescence in MeOH. The observation makes it possible to design new self-organized anion sensory systems. Less