Rapid growth of single crystals of PT(II)-CU(I)/AG(I) heteronuclear complexes by electric-field induced self-assembly and related application studies

Abstract

This thesis investigates the synthesis and application of heteronuclear metal complexes, particularly Pt(II)-M complexes, known for their unique structures and photophysical properties. Traditional synthesis methods often involve hazardous chemicals and harsh reaction conditions, limiting the production of high-quality single crystal samples suitable for single-crystal X-ray diffraction (SCXRD) analysis. Here, we employ electrochemical approaches, leveraging external electric fields, to offer a straightforward, environmentally friendly, and safe pathway for the synthesis. We propose a novel approach for in-situ synthesis and assembly of heteronuclear metal complexes under the influence of an electric field, leading to the formation of diverse supramolecular micro/nanostructures. Moreover, this method enables the direct and rapid acquisition of high-quality single crystals of heteronuclear metal complexes by employing specific electric field conditions. A series of Pt(II) precursor complexes were successfully synthesized using copper or silver foils as sacrificial anodes for coordination with functional groups under the influence of the electric field. Diverse supramolecular structures were achieved through precise control of electric field parameters, presenting a novel strategy for fabricating customized supramolecular functional materials. Subsequently, a systematic investigation was conducted on the crystal structure and photophysical properties of PtCu-c-1and PtCu-c-4 heteronuclear complexes. These Pt(II)-Cu(I) complexes exhibit a stimuli-responsive behavior, displaying emission wavelengths ranging from 500 nm to 640 nm in different solvent environments. Leveraging these stimuli-responsive emission properties, we have successfully developed luminous labels with highly effective anti-counterfeiting capabilities. In the Pt(II)-Ag(I) complex system, the presence of robust metal--metal interactions within the crystal yielded a stable structure, and the system did not exhibit stimulus-responsive properties. Nonetheless, the SWCNTs/Pt(II)-Ag(I) composite materials showcased outstanding thermoelectric performance. Owing to the superior interaction between the heteronuclear complexes and SWCNTs, coupled with a strong electron-donating capacity, both PtAg-c-1 and PtAg-c-4 effectively transformed the primary charge carriers in SWCNTs into electrons, resulting in high-performance N-type thermoelectric materials. Our research highlights the precise control over the assembly of functional materials and the customization of heteronuclear supramolecular morphologies, contributing to the advancement of innovative functional materials and offering valuable insights into molecular interactions across various disciplines. Future research will explore the electric field-induced assembly and supramolecular structure modulation of other metal complexes, aiming to expand the scope of material design. By combining different central metal ions and ligands, we anticipate the creation of new heteronuclear complexes, contributing to the progress of materials science and nanotechnology and offering new solutions for applications in sensors, optoelectronic devices, and catalysis.