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代表了发现新试剂、催化剂和材料的基本基础，这些新试剂、催化剂和材料表现出在社会中具有潜在功能的新特性，用于生产商品化学品、电解质、导电聚合物、阻燃剂、弹性体、药物和生物医学材料。在这些发现中，p区元素如硅、锗、锡、磷、锑、铋、硫和硒的重要性日益显现，这促使人们开发了这些元素化合物的新的通用合成方法。Burford NSERC发现补助金先前支持开发新的合成方法，以磷和第15族所有元素之间的同原子和杂原子键为特征的化合物。这项研究正在改变化学家对非金属元素化学的理解方式。在涉及磷刘易斯受体上的磷配体的配位化学中的新方向的发现现在已经被外推到其他p-区元素，以提供作为刘易斯受体的p-区元素的广泛多样且快速发展的配位化学。过渡金属元素（d区）的化学结构和反应性已经得到很好的发展，现在可以外推到p区元素，实现新的结构、键合和反应性，包括在过渡金属刘易斯受体处不明显的模式。我们最近的发现包括一系列代表14和15族刘易斯受体中心的配位络合物的阳离子化合物，新的链状磷化合物，以及涉及膦在砷、锑和铋上的阳离子络合物的氧化还原化学。拟议的研究提供了一个系统的演变的配位化学的四（第14组），磷属元素（第15组），硫属元素（第16组）的元素，利用所有的氧化态和阳离子分子电荷。此外，以前开发的pnictogens的连锁化学将外推到teraels和硫属元素，和非金属元素的高电荷阳离子的反应性和潜在的催化行为将进行评估。我们的研究已经证实，在具有重（n > 3）p-区元素的分子中阳离子电荷（正电荷）的存在增加了分子中所有键的强度以及增强了分子的刘易斯酸性。该提案描述了发展合成反应以形成类似于过渡金属经典络合物的配位络合物的方法。多配体相互作用和多达六个的配位数等特征是明显的，以及配体交换反应性和可变的氧化态。在刘易斯受体位置上存在立体化学活性孤对电子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.