Recent Advances in the Chemistry of “Clusters” and Coordination Polymers of Alkali, Alkaline Earth Metal and Group 11 Compounds

Abstract

This contribution gives an overview on the different subjects treated in our group. One of our fundamental interests lies in the synthesis and study of low‐dimensional polymer and molecular solid state structures. We have chosen several synthetic approaches in order to obtain such compounds.Firstly, the concept of cutting out structural fragments from a solid state structure of a binary compound will be explained on behalf of BaI2. Oxygen donor ligands, used as chemical scissors on BaI2, allow obtaining three‐, two‐, one‐ and zero‐dimensional derived compounds depending on their size and concentration. Thus, a structural genealogy tree for BaI2 can be established. This method, transferred to alkali halides using crown ethers and calix[n]arenes as delimiting ligands, leads us to the subject of one‐dimensional ionic channels.A second chapter deals with the supramolecular approach for the synthesis of different dimensional polymer structures derived from alkaline earth metal iodides, and based on the combination of metal ion coordination with hydrogen bonding between the cationic complexes and their anions. Under certain circumstances, rules can be established for the prediction of the dimensionality of a given compound, thus contributing to the fundamental problem of structure prediction in crystal engineering.A third part describes a fundamentally new synthetic pathway for generating pure alkaline earth metal cage compounds as well as alkali and alkaline earth mixed metal clusters. In a first step, different molecular precursors, such as solvated alkaline earth metal halides are investigated as a function of the ligand size and reactivity. They are then reacted with some alkali metal compound in order to partially eliminate alkali halide and to form the clusters. The so obtained unique structures of ligand stabilized metal halide, hydroxide and/or alkoxide and aryloxide aggregates are of interest as potential precursors for oxide materials. Approaches to two synthetic methods of the latter, sol‐gel and (MO)‐CVD, are investigated with our compounds.In order to generate single source precursors for oxide materials, we started to investigate transition metal ions, especially Cu and Ag, using multitopic ligands. This has led us into the fundamental problematic of “crystal engineering” and solid state structure prediction and we found ourselves confronted to numerous interesting cases of polymorphism and pseudo‐polymorphism. Weak interactions, such as π‐stacking, H‐bonding and metal‐metal interactions, and solvent, counter ion and concentration effects seem to play important roles in the construction of such low‐dimensional structures.Finally, the physical properties of some of our compounds are described qualitatively in order to show the wide spectrum of possibilities and potential applications for the chemistry in this field.

Transport properties of solid state crown ether channel systems

“…Under the polarisers of a light microscope, they show a strong dichroism (measured by Dr. Jean-Pierre Rivera at the University of Geneva) depending on the angles of the polarisers [40]. The red-brown color is typical for the triiodide absorptions at 288 and 350 nm.…”

Polyether Adducts of d‐Block Metal Compounds as Starting Materials for New Cluster Compounds

“…Again, the diglyme ligand adopts a meridional coordination mode with slightly larger O x -Ni1-O y angles than for 9 of 78.64(17)°and 78.75(18)°, respectively, and an O1-Ni1-O3 angle of 155.86(17)°for the oxygen atoms trans to each other. The angle between the two μ-I is 86.13(3)°, between I2 and I1 93.26(13)°, and between I1 and O2 177.31 (14)°. The angles with the two other oxygen atoms, I1-Ni1-O1 and I1-Ni1-O3, are 99.82(12)°and 102.43(12)°, respectively.…”

“…clusters, and polymers or metal organic frameworks [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Indeed, since more than two decades, metal aggregates are used in the low-cost synthesis of superconductors and other oxide materials based on the sol-gel technique or as volatile precursors in the MOCVD (Metal Organic Chemical Vapor Deposition) process [3,11,13,[17][18][19][20][21].…”

Silver coordination polymers with isonicotinic acid derived short polyethylene glycol – Synthesis, structures, anion effect and solution behavior

“…We started to investigate silver coordination polymers using the neutral ligand ethanediyl bis(isonicotinate) Li1 (Scheme 1) [9,10] and its derivatives, which can be modified by simple elongation of the middle spacer, using diethylene glycol [11], triethylene glycol [12,13] and tetraethylene glycol [13,14] as starting materials for the synthesis of the ligands. In this manuscript however, we will focus on the shortest variant of the ligand, Li1.…”