Rational Design and Smart Synthesis of Non-Transition-Metal Systems for Small Molecules Activation (SM-Act)

通过非过渡金属系统（即主族化合物）活化小分子是具有挑战性的。因此，具有与开壳过渡金属配合物相当的反应性和性质的热稳定的主族化合物是有吸引力的合成目标。该提案旨在探索由非常规碳供体配体，即N-杂环乙烯基（NHV）和N-杂环亚乙烯基（NHVD）配体稳定的磷和砷中心的自由基和类自由基化合物。这些配体是非常强的δ-以及π-供体。此外，它们的电子和空间特征为未成对电子自旋密度的离域提供了一个独特的平台，导致形成含有C2 E2，C2 EE ′，C2 E4或C2 E2 E ′2部分（通常是环）（E = P，E′ = As）的非常稳定的分子框架。对这些化合物进行系统的实验和理论研究将使我们能够了解它们的电子结构和成键情况，以及它们与小分子的反应性。G. H2、O2、CO、N2 O、CO2等）。将研究配体结构对所提出的化合物的结构和性质的影响，以概述调节其性质的关键因素。研究这种开壳层主族物种不仅对增强我们对化学键的理解很重要，而且对认识它们在合成和材料科学中的潜在应用也很重要。

Small molecules activation by non-transition metal systems (i.e. main-group compounds) is challenging. Thermally stable main-group compounds with a reactivity and properties comparable to open-shell transition-metal complexes are therefore appealing synthetic targets. This proposal aims at the exploration of phosphorus- and arsenic-centered radical and radicaloid compounds stabilized by unconventional carbon-donor ligands, namely N-heterocyclic vinyl (NHV) and N-heterocyclic vinylidene (NHVD) ligands. These ligands are very strong delta- as well as pi-donors. Moreover, their electronic and steric features provide a unique platform for the delocalization of unpaired electron spin density, leading to the formation of very stable molecular frameworks containing a C2E2, C2EE′, C2E4, or C2E2E′2 moiety (usually rings) (E = P, E′ = As). Systematic experimental and theoretical studies of the proposed compounds will enable us to understand their electronic structure and bonding situation, as well as their reactivity with small molecules (e. g. H2, O2, CO, N2O, CO2 etc). The impact of the ligand architecture on the structure and properties of proposed compounds will be studied to outline the key factors that regulate their properties. Investigation of such open-shell main-group species is not only important to enhance our understanding about chemical bonding but also to recognize their potential applications in synthesis and materials science.