No abstract

The synthesis of water-soluble, organometallic macrocycles is described. They were obtained by self-assembly in reactions of the half-sandwich complexes [[Ru(C6H5Me)Cl2]2], [[Ru(p-cymene)Cl2]2], [[Rh(Cp)Cl2]2], and [[Ir(Cp*)Cl2]2] with the ligand 5-dimethylaminomethyl-3-hydroxy-2-methyl-4-(1H)-pyridone in buffered aqueous solution at pH 8. The structure of the Ru-(p-cymene) complex was determined by single-crystal X-ray crystallography. Upon mixing, these complexes undergo scrambling reactions to give dynamic combinatorial libraries. In combination with structurally related complexes based on amino-methylated 3-hydroxy-2-(1H)-pyridone ligands, an exchange of metal fragments but no mixing of ligands was observed. This self-sorting behavior was used to construct dynamic combinatorial libraries of macrocycles, in which two four-component sub-libraries are connected by two common building blocks. This type of network topology influences the adaptive behavior of the library as demonstrated in selection experiments with lithium ions as the target.

The first monomeric germanethiocarbamyl halides containing a chelating β-diiminate ligand, L2(Cl)GeY (L2 = PhNC(Me)CHC(Me)NPh; Y = S (2), Y = Se (3)), have been prepared by the reaction of the corresponding heteroleptic halogermylene L2(Cl)Ge (1) with elemental sulfur or black selenium in refluxing toluene. Single-crystal X-ray structural analyses of 2 and 3 reveal that the germanium centers reside in highly distorted tetrahedral environments in these compounds; short Ge−Y distances (Ge−S = 2.07 Å (2); Ge−Se = 2.21 Å (3)) are indicative of an unsaturated character of these germanium−chalcogen bonds. Selective reactions between 2 or 3 and MeLi afforded the corresponding alkylated germanechalcogenones L2(Me)GeY (Y = S (4), Se (5)).