Formation of Multinuclear s‐Block Metal Systems by Enhancement of the Coordination Properties of 1,2,3‐Triazole

The 4,5‐{Ph2(HO)C}2‐1,2,3‐triazole ligand (2) with two bulky Ph2C(HO) substituents was synthesized and used in the preparation of coordination compounds with selected group 1 metals. In the solid state, the high Lewis acidity of lithium caused the formation of di‐ and tetrametallic L2Li2thf4·2THF and L4Li4thf2(Et2O)2·2Et2O (L = monoanionic form of 2) species, while only the dimetallic derivative L2Na2thf4·2THF was observed for sodium. The larger size of potassium caused the formation of L6K6(H2O)thf2·2THF with a hexagonal drumlike inorganic core. 1H DOSY NMR spectroscopic studies confirmed the presence of multimetallic species also in solution. The molecular structures of the compounds were determined by single‐crystal X‐ray diffraction. In a comparative study, magnesium derivatives of 2 were prepared to evaluate the effect of a higher covalent character of the M–O bond leading to multimetallic polycyclic systems with up to 29 rings. Finally, the lithium compounds showed catalytic activity in the polymerization of ε‐caprolactone. The design of the 4,5‐{Ph2(HO)C}2‐1,2,3‐triazole ligand enhanced the coordination properties of the parent triazole ring towards group 1 metals (Li, Na, and K) and Mg. This led to the formation of discrete di‐ or multimetallic (up to 12 metal atoms) systems, depending on the metal as well as on the coordination mode and the degree of deprotonation of the ligand.