Department of General and Coordination Chemistry and Crystallography, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University in Lublin, Pl. Marii Curie-Sklodowskiej 3, 20-031 Lublin, Poland.
Int J Mol Sci. 2020 May 15;21(10):3493. doi: 10.3390/ijms21103493.
Chemistry of Schiff base (SB) ligands began in 1864 due to the discovery made by Hugo Schiff (Schiff, H., 1864, (1), 118-119). However, there is still a vivid interest in coordination compounds based on imine ligands. The aim of this paper is to review the most recent concepts on construction of homo- and hetero-oligonuclear Schiff base coordination compounds narrowed down to the less frequently considered complexes of platinum group metals (PGM). The combination of SB and PGM in oligonuclear entities has several advantages over mononuclear or polynuclear species. Such complexes usually exhibit better electroluminescent, magnetic and/or catalytic properties than mononuclear ones due to intermetallic interactions and frequently have better solubility than polymers. Various construction strategies of oligodentate imine ligands for coordination of PGM are surveyed including simple imine ligands, non-innocent 1,2-diimines, chelating imine systems with additional N/O/S atoms, classic NO-compartmental Schiff bases and their modifications resulting in acyclic fused ligands, macrocycles such as calixsalens, metallohelical structures, nano-sized molecular wheels and hybrid materials incorporating mesoionic species. Co-crystallization and formation of metallophilic interactions to extend the mononuclear entities up to oligonuclear coordination species are also discussed.
希夫碱（SB）配体的化学始于 1864 年，这要归功于 Hugo Schiff（希夫，H.，1864 年，（1），118-119）的发现。然而，基于亚胺配体的配位化合物仍然引起了人们的浓厚兴趣。本文的目的是综述近年来关于同核和杂核希夫碱配位化合物构建的最新概念，重点介绍较少考虑的铂族金属（PGM）配合物。SB 和 PGM 在寡核实体中的结合具有几个优点，超过单核或多核物种。由于金属间相互作用，这些配合物通常表现出比单核配合物更好的电致发光、磁性和/或催化性能，并且通常比聚合物具有更好的溶解度。综述了用于配位 PGM 的寡齿亚胺配体的各种构建策略，包括简单亚胺配体、非无辜 1,2-二亚胺、带有额外 N/O/S 原子的螯合亚胺系统、经典的 NO 分隔希夫碱及其导致非循环稠合配体的修饰、杯芳烃等大环、金属螺旋结构、纳米分子轮和包含杂芳族物种的混合材料。还讨论了共结晶和形成金属亲合相互作用，将单核实体扩展到寡核配位物种。
