Gold complexes containing redox-active ambiphilic P/Sb ligands: Synthesis, structure and catalytic properties

在化学系化学合成计划的支持下，德克萨斯农工大学化学系的François Gabba ai教授研究了膦金络合物的化学，该络合物包含一个Lewis酸性锑原子作为配体结构的一部分。该项目的目标是确定锑中心的氧化还原状态是否可以用来调节金中心的Lewis酸性和催化性能。这一想法正在通过研究络合物在烯烃亲电活化中的催化性能而得到验证。总之，该研究计划有助于验证将膦与锑中心结合的配体可用于构建新型氧化还原响应型催化剂的概念。除了对不同学生群体的教育做出贡献外，该项目还允许首席调查员继续参与涉及K-6学生的各种服务和外展活动。研究了一系列以含膦为供体和一个锑原子为受体的双亲配体的金络合物，最终目的是了解锑原子的氧化还原状态是否可以用来调节金中心的刘易斯酸性和催化性能。这一想法正在通过研究具有单(膦)锑和双(膦)锑配体的金配合物来验证。对于这两种类型的络合物，Sb原子从+III状态氧化到+V状态有望激活金中心，并增强其对Lewis碱性底物(包括炔烃)的亲和力。单(膦)锑衍生物被设计成通过邻近的Lewis酸性锑中心提取金结合的卤化物配体来进行活化。具有双(膦)锑配体的配合物的活化预计将通过形成直接的Au&Sb相互作用而发生。对于这两类络合物，金中心经历的活化程度来自于对其Lewis酸性的实验测定，以及它催化涉及炔的反应的能力。这个项目的核心是一个基本概念，即锑配体的氧化还原状态可以作为一种手段来调节辅助配体附近的过渡金属中心的反应性。这些根本性的进展可能会在氧化还原反应配体领域产生革命性的变化，并在传感和催化方面得到应用。该项目的另一个重要成果是不同学生群体的参与和教育。该教育计划还包括在当地小学和中学招收参加西班牙语/英语K-6双语班的学生。

With the support of the Chemical Synthesis Program of the Chemistry Division, Professor François Gabbaï of the Chemistry Department at Texas A&M University iinvestigates the chemistry of phosphine gold complexes that incorporate a Lewis acidic antimony atom as part of the ligand architecture. The goal of this project is to determine if the redox state of the antimony center can be used to modulate the Lewis acidity and catalytic properties of the gold center. This idea is being tested by investigating the catalytic properties of the complexes in the electrophilic activation of alkynes. Altogether, this research program helps to validate the notion that ligands combining a phosphine with an antimony center can be used for the construction of novel redox-responsive catalysts. In addition to contributing to the education of a diverse group of students, this project allows the principle investigator to maintain his involvement in various service and outreach activities involving K-6 students.A series of gold complexes featuring ambiphilic ligands containing phosphines as σ-donors and an antimony atom as a σ-acceptor are investigated with the ultimate goal of understanding whether the redox state of the antimony atom can be used to modulate the Lewis acidity and catalytic properties of the gold center. This idea is being tested by studying gold complexes featuring mono(phosphino)antimony and bis(phosphino)antimony ligands. For both type of complexes, oxidation of the antimony atom from the +III to the +V state is expected to activate the gold center and enhance its affinity for Lewis basic substrates including alkynes. The mono(phosphino)antimony derivatives is designed such that activation occurs by abstraction of a gold-bound halide ligand by the neighboring Lewis acidic antimony center. Activation of the complexes featuring a bis(phosphino)antimony ligand is expected to occur through formation of a direct Au→Sb interaction. For both families of complexes, the extent of activation experienced by the gold center is derived from an experimental determination of its Lewis acidity, as well as from its ability to catalyze reactions involving alkynes. At the heart of this project lies the fundamental notion that the redox state of antimony ligands can be manipulated as a means to adjust the reactivity of a transition metal center held in proximity by ancillary ligands. These fundamental advances may prove transformative in the area of redox-responsive ligands, with applications in sensing and catalysis. Another important outcome of this project is the involvement and education of a diverse group of students. The educational plan also includes outreach to students enrolled in Spanish/English K-6 dual language classes at local elementary and intermediate schools.