Multifunctional Chiral d10‐Metal Coordination Polymers: Tunable Photoluminescence and Efficient Second‐Harmonic Generation with Circular Dichroic Response

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 20; no. 21; pp. e2309323 - n/a
• Main Authors: Lee, Jihyun, Cho, Jeong Bin, Li, Yang, Lee, Kyeong‐Hyeon, Jang, Joon Ik, Ok, Kang Min
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.05.2024
• Subjects: Bonding strength; Chemical synthesis; circular dichroism; Circular polarization; Coordination polymers; Dichroism; Excitation; Harmonic generations; homochiral coordination polymers; Hydrogen bonds; Laser damage; laser‐induced damage threshold; Ligands; Multifunctional materials; Nonlinear optics; Phase matching; Photoluminescence; Propionic acid; second‐harmonic generation; Self-assembly; tunable photoluminescence
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202309323

A series of homochiral coordination polymers (HCPs), [M2(SIAP)2(bpy)2] [M(S)] and [M2(RIAP)2(bpy)2] [M(R)] (M = Zn or Cd, SIAP or RIAP = (S,S)‐ or (R,R)‐ 2,2′‐(isophthaloylbis(azanediyl))di‐propionic acid, bpy = 4,4′‐bipyridine), is successfully synthesized through solvothermal reactions, self‐assembling d10 metal cations, chiral dicarboxylic ligands, and π‐conjugated bipyridyl ligands. The HCPs crystallize in the extremely rare triclinic chiral space group, P1, and present 3D framework structures attributed to the strong intermolecular interactions, such as hydrogen bonds and π–π stacking. Due to the unique crystal structures, the title compounds reveal efficient photoluminescence emission across a broad visible range, with significant brightness and color tuning by varying the excitation wavelength. Moreover, they exhibit efficient phase‐matched second‐harmonic generation (SHG) with very high laser‐induced damage thresholds, essential for high‐power nonlinear optical (NLO) applications. Intriguingly, the title compounds exhibit a measurable contrast in the SHG response under right‐ and left‐handed circularly polarized excitation, thereby providing a unique case of SHG circular dichroism from the chiral centers of SIAP2− or RIAP2− ligand packed in the noncentrosymmetric environment. These exceptional attributes position these HCPs as promising candidates for multifunctional materials, with potential applications ranging from NLO devices to tailored luminescent systems with polarization control. By revealing tunable photoluminescence behavior under varying UV excitations and demonstrating efficient second‐harmonic generation response at 1064 nm, homochiral d10‐metal coordination polymers exemplify unique crystal structures driven by intricate intermolecular interactions between two kinds of ligands, positioning them as promising candidates for multifunctional optical materials.