Coordination chemistry of p-block element Lewis acceptors: Applying principles of transition metal chemistry to non-metal elements

新化合物的合成和表征是发现新试剂、催化剂和材料的基础，这些新试剂、催化剂和材料具有新的性能，在社会上具有生产商品化学品、电解质、导电聚合物、阻燃剂、弹性体、药物和生物医学材料的潜在功能。在这些发现中，诸如硅、锗、锡、磷、锑、铋、硫和硒等p块元素的重要性逐渐显现，这促使了这些元素化合物的新的通用合成方法的发展。Burford NSERC发现基金以前支持开发新的合成方法来合成磷和第15族所有元素之间具有同原子和杂原子键的化合物。这项研究正在改变化学家对非金属元素的化学性质的一般理解。磷刘易斯受体上磷配体的配位化学新方向的发现，现在已被外推到其他p块元素，为p块元素作为刘易斯受体提供了一个非常多样化和快速发展的配位化学。过渡金属元素（d-嵌段）的化学结构和反应性现在可以外推到p-嵌段元素，实现新的结构、键和反应性，包括过渡金属刘易斯受体中不明显的模式。我们最近的发现包括一系列阳离子化合物，代表14和15基团路易斯受体中心的配位配合物，新的连环-磷化合物，以及涉及砷，锑和铋上磷化氢阳离子配合物的氧化还原化学。提出的研究为利用所有氧化态和阳离子分子电荷的tetrael（14族）、pnictogen（15族）和chalogen（16族）元素提供了一个系统的配位化学进化。此外，以前为致烟原开发的阳离子化化学将被外推到teraels和chargens，并将评估非金属元素的高电荷阳离子的反应性和潜在催化行为。我们的研究已经证实，在具有重（n > 3） p块元素的分子中存在阳离子（正电荷）可以增强分子中所有键的强度，并增强分子的刘易斯酸度。该提案描述了进化合成反应的方法，形成类似于过渡金属的经典配合物的配位配合物。它具有明显的多配体相互作用和多达6个配位数，以及配体交换反应性和可变氧化态等特点。在路易斯受体位点上出现立体化学活性的孤对代表了配位化学的一个新方向。

The synthesis and characterization of new compounds represents a fundamental foundation in the discovery of new reagents, catalysts and materials exhibiting new properties with potential function in society for production of commodity chemicals, electrolytes, conducting polymers, flame retardants, elastomers, pharmaceuticals and biomedical materials. The emerging importance of p-block elements such as silicon, germanium, tin, phosphorus, antimony, bismuth, sulfur and selenium in these discoveries has prompted the development of new versatile synthetic methods for the compounds of these elements. The Burford NSERC Discovery Grant has previously supported the development of new synthetic methods to compounds featuring homoatomic and heteroatomic bonds between phosphorus and all elements of group 15. This research is changing the way in which chemists understand the chemistry of non-metal elements in general. The discovery of a new direction in coordination chemistry involving phosphorus ligands on phosphorus Lewis acceptors has now been extrapolated to other p-block elements to provide a vastly diverse and rapidly evolving coordination chemistry for the p-block elements as Lewis acceptors. Chemical structure and reactivity that is well developed for transition metal elements (d-block) can now be extrapolated to the p-block elements with realisation of new structure, bonding and reactivity, including patterns that are not evident at transition metal Lewis acceptors. Our recent discoveries include series of cationic compounds that represent coordination complexes of group 14 and 15 Lewis acceptor centers, new catena-phosphorus compounds, and redox chemistry involving cationic complexes of phosphines on arsenic, antimony and bismuth. The proposed research offers a systematic evolution of the coordination chemistry for the tetrael (group 14), pnictogen (group 15), and chalcogen (group 16) elements exploiting all oxidation states and cationic molecular charges. In addition, catenation chemistry previously developed for the pnictogens will be extrapolated to the teraels and chalcogens, and the reactivity and potential catalytic behaviour of the highly charged cations of non-metal elements will be assessed. Our research has confirmed that the presence of a cationic charge (positive charge) in a molecule featuring a heavy (n > 3) p-block element augments the strength of all bonds in the molecule as well as enhancing the Lewis acidity of the molecule. The proposal describes approaches to evolve synthetic reactions to form coordination complexes that are analogous to the classic complexes of transition metals. Features such as multi-ligand interaction and coordination numbers of up to six are evident, as well as ligand exchange reactivity and variable oxidation state. The presence of a stereochemically active lone pair at a Lewis acceptor site represents a new direction for coordination chemistry.