산화환원 활성 다중자리 리간드 및 이를 이용한 다공성 배위 화합물의 설계

Abstract

In this doctoral thesis, I deal with the novel strategies to develop the functional porous coordination networks based on the redox-active multi-interactive ligand. Although many researchers highlighted radical inclusion into porous coordination networks, there was no detailed fundamental study. In that regard, theoretical and fundamental understanding of radical behavior will be a key issue in coordination chemistry. Through several experimental demonstrations, I studied how ligands cooperate for network formation and control network properties at a fundamental level. The experimental details are discussed in the following 5 chapters. In Chapter 1, I summarize the recent developments in porous coordination networks. Many kinds of research have been performed to find fascinating properties like gas sorption/desorption/separation, molecular recognition, drug delivery, magnetism, conductivity, catalyst and so on. This chapter describes the introductory aspects of rational ligand design for functional porous coordination networks and redox ligand cooperation system in coordination networks. In Chapter 2, I investigated the redox-active multi-interactive ligand, 2,5,8-tri(4-pyridyl)1,3-diazaphenalene (TPDAP) which showed two-step redox activity. TPDAP was synthesized by four-step reactions and characterized by UV-vis-NIR, 1H NMR, cyclic voltammetry (CV), and single crystal X-ray structure analysis. Furthermore, TPDAP neutral radical was generated by oxidation and characterized clearly by continuous wave-electron spin resonance spectroscopic (cw-ESR). In Chapter 3, I demonstrate the selective formation of conductive/non conductive porous coordination networks using a redox active ligand. The unique self-oxidative reaction of the ligand produce the oxidized species. Depending on the oxidation state of TPDAP, I could selectively prepare electron-conducting (paramagnetic) or insulating (diamagnetic) porous networks. The porous coordination network properties were characterized by solid state cyclic voltammogram (CV), two-probe conductivity measurement and X-ray crystal structure analysis. The redox active networks showed different molecular arrangements and, based on the electronic state, exhibited both electron conductive and insulating natures. In Chapter 4, I demonstrate the potential applications taking advantage of the redox activity. Thanks to the three fold symmetrical nature of the ligand, TPDAP showed dichotomic network formation with TPHAP. This irregular system produce a more stable network than a TPDAP network. The dichotomic network system showed CT interactions between TPDAP and electron acceptor to confirm the donor property of TPDAP in a network structure.