Kinetics and mechanism of the ligand hydrolysis of (hexafluoroacetylacetonato)(tetraamine)cobalt(III) complexes. Reactivity pattern

Structural diversity of copper(I) alkynyl cluster-based coordination polymers utilizing bifunctional pyridine carboxylic acid ligands

The utilization of bifunctional ligands, specifically pyridine carboxylic acids, endowed with dual coordination sites, has been instrumental in the assembly of polymer materials. The ambidentate characteristics of these ligands play a crucial role in shaping the structure and framework of cluster-based polymers. In this study, we have synthesized a diverse array of multidimensional copper(I) alkynyl cluster-based polymers (CACPs) by employing four distinct pyridine carboxylic acids - namely, isonicotinic acid (INA), 6-isoquinolinecarboxylic acid (IQL), 4-pyridin-4-yl-benzoic acid (4-PyBA), and 3-pyridin-4-yl-benzoic acid (3-PyBA) - as linking ligands. These pyridine carboxylic acids not only serve as protective ligands but also act as pivotal linkers in constructing the cluster-based framework materials, exerting significant influence on the overall framework structures. Furthermore, the incorporation of auxiliary ligands has been shown to markedly impact the structural integrity and framework architecture of the CACPs. This study elucidates the indispensable role of pyridine carboxylic acids in the construction and stabilization of cluster-based framework materials, thereby advancing the frontier of research in metal cluster-based framework material synthesis.

Assembly of Copper Alkynyl Clusters into Dimensionally Diverse Coordinated Polymers Mediated by Pyridine Ligands

Surface ligands play crucial roles in modifying the properties of metal nanoclusters and stabilizing atomically precise structures, and also serve as vital linkers for constructing cluster-based coordination polymers. In this study, we present the results of the solvothermal synthesis of eight novel copper alkynyl clusters incorporating pyridine ligands using a one-pot method. The resulting compounds underwent characterization through elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction (SCXRD). Our observations revealed that distinct pyridine ligands with varying lengths and coordination sites exert significant influence on the structure and dimensionality of the clusters. The structural diversity of these clusters led to the formation of one-dimensional (1D), two-dimensional (2D), or dimer arrangements linked by seven pyridine bridging ligands. Remarkably, these complexes exhibited unique UV-vis absorption and photoluminescence properties, which were influenced by the specific bridging ligand and structural framework. Furthermore, density functional theory (DFT) calculations demonstrated the capability of the conjugated system in the pyridine ligand to impact the band gap of clusters. This study not only unveils the inherent structural diversity in coordination polymers based on copper alkynyl clusters but also offers valuable insights into harnessing ligand engineering for structural and property modulation.

Silver ethynide clusters constructed with fluorinated β-diketonate ligands

Phosphonate can act as the intermediate connector to link two silver ethynide clusters functionalized by hfac ligands together to enlarge the silver cluster.