Constraints and Forces for p-Block Element Mediated Bond Activation and Catalysis

Objective

"Enabling p-block element species for challenging bond activations is crucial for advancing sustainable alternatives to transition metal catalysis. Even more transformative are concepts that guide reactivity in a generalizable manner and for cross-disciplinary impact. While sub-valent species or Frustrated Lewis pairs served as foundational paradigms for p-block-mediated bond activation in recent decades, the structural constraint strategy is emerging as a groundbreaking third approach. However, its fragmented and uncoordinated exploration has limited its broader potential and interdisciplinarity. CONSTRAINOPHORES will consolidate this concept by defining constrainophores (""constrain"" + -φόρος, meaning ""carrier of"")—molecular p-block systems with intrinsic structural constraints—and pre-constrainophores, flexible centers activated by external forces such as electric fields, light, and mechanical stimuli. Fundamentally, the project will establish a rigorous theoretical framework for molecular deformation with intuitive descriptors to connect constraint effects from molecular to material scales. On the applied front, it will achieve breakthroughs such as phosphorus-mediated C–C cross-coupling, unprecedented terminal oxido chemistry, or the first functional models for semiconductor active sites. Harnessing electric fields will enable cleavage of non-activated C–H bonds, while photochemistry will add an overlooked dimension to the field. Embedding (pre-)constrainophores into polymeric chains will create next-generation materials capable of deformation-induced p-block transformations under mechanical stress. CONSTRAINOPHORES addresses key limitations of abundant yet underutilized elements, reshapes design paradigms for main-group reactivity and catalysis, and couples previously unconnected research fields and size scales. Reducing reliance on rare metals provides a clear-cut approach to tackling pressing needs for sustainable technologies. "