Conceptual Development of Structurally Constrained Heavier p-Block Elements

Abstract

The reaction of a diazene derivative of 1,8-naphthyridine with low-valent germanium halide precursors gave access to dichloro-digermylene [3] and a germylene in spiro geometry [4]. This synthetic route gives easy access to germanium-incorporated extended π-conjugated frameworks. Additionally, reactivity of diazene [2] with antimony triflates yields a Lewis acidic bis(antimony dication) [5][OTf]4. Effective Lewis acidity has been estimated in the solution phase by means of NMR spectroscopy. In compounds [2] and [5][OTf]4, the two metalloid centers are electronically influenced by each other through the π-conjugated ligand backbone. In an effort to enforce spatial proximity between the metalloidal centers, a novel 1,8- naphthyridine ligand [10] with phosphinimine sidearms have been synthesized in five steps. For a larger-scale synthesis of [10], earlier reported procedures have been scaled up with necessary modifications. Additionally, a machine learning dataset has been compiled to gain further insights into the trends of Coulomb explosion in charged bimetallic species.