Gyroscope-Like Metal Complexes

化学部的化学合成项目支持Gladysz教授的项目。Gladysz教授是德克萨斯农工大学化学系的一名教员，他正在开发一种类似陀螺仪的新型金属复合物。宏观陀螺仪作为感知和/或保持物体方向的设备（例如，空间站；鱼雷弹头；虚拟现实耳机；移动电话显示器；无人机；通过称为“halteres”的生物组件飞行的昆虫）。经典的机械陀螺仪是许多人童年时的玩具，它由一个轴、一个可以旋转的飞轮和一个保护壳组成。当物体偏离其旋转轴时，由于角动量守恒，会产生一个恢复力。分子水平上的基本物理原理使化学家能够追求陀螺仪微型化的极限。该项目旨在合成分子陀螺仪，该陀螺仪包含一个金属飞轮，该飞轮包含在一个新颖的笼状结构中，由两个相距180°的磷原子固定。最大限度地提高飞轮的旋转方便性，并寻求陀螺仪性能的证明。这些系统被连接成“齿轮箱”，并作为精细和商品化学合成的催化剂进行研究，这些合成通常需要金属。由于金属被限制在一个有限的空间，希望基于反应物或产物的尺寸或形状的新的选择性可以实现。本项目主要研究类陀螺仪金属基分子转子的合成、基本结构和动力学性质、反应性及其应用（分子器件、催化）。这些最常见的特征是一个反式二膦配体，其中磷原子由三条链跨越，通常为（CH2）n （n 10）式，但也含有杂原子、对苯基或其他官能团。它们是通过反式lym (P(CH2)mCH=CH2)3)2型前体的三倍分子内环闭合复合得到的，然后是C=C氢化（n = 2m+2）。配位几何可以是平面方形、三角双锥体或八面体（y = 2-4）。如果配体（Ly）相对于（CH2）n键足够小，则LyM单元可以在陀螺仪笼内旋转。类似于平行轴的陀螺仪单元阵列被合成为具有允许旋转器相互作用的间距，强制执行相关运动，例如在齿轮箱或水车中。金属碎片从陀螺仪笼中挤出，提供了迄今未知的一类大环二桥头堡二膦。它们是独立合成的，与各种金属物种结合形成新的陀螺仪状复合物，并且（鉴于它们“从内到外”的能力）作为有毒或有害金属物种的“运输容器”进行研究。

The Chemical Synthesis Program of the Chemistry Division supports the project by Professor Gladysz. Professor Gladysz is a faculty member in the Department of Chemistry at Texas A&M University and is developing novel gyroscope-like metal complexes. Macroscopic gyroscopes serve as devices for sensing and/or maintaining the orientation of an object (e.g., space stations; torpedo warheads; virtual reality headsets; mobile phone displays; drones; flying insects via biological assemblies termed "halteres"). The classic mechanical gyroscope, encountered by many as a childhood toy, consists of an axle, a flywheel that can rotate, and a protective housing. When the object is displaced from its axis of rotation, there is a restoring force arising from the conservation of angular momentum. The underlying physics holds at the molecular level, allowing chemists to pursue the limit of gyroscope miniaturization. This project is directed at the synthesis of molecular gyroscopes that contain a metal based flywheel contained in a novel cage-like structure anchored by two phosphorus atoms that are 180° apart. The ease of rotation of the flywheel is maximized, and the demonstration of gyroscopic properties sought. These systems are linked to give "gearboxes", and investigated as catalysts for fine and commodity chemical syntheses, for which metals are commonly required. Since the metals are confined to a restricted space, it is hoped that new selectivities based upon reactant or product size or shape can be realized. This project focuses on the synthesis, fundamental structural and dynamic properties, reactivity, and applications (molecular devices, catalysis) of gyroscope-like metal based molecular rotors. These most commonly feature a trans-diphosphine ligand in which the phosphorus atoms are spanned by three chains, usually of the formula (CH2)n (n 10) but also incorporating hetero-atoms, p-phenylene groups, or other functionalities. They are accessed by three-fold intramolecu-lar ring closing metatheses of precursors of the type trans-LyM(P((CH2)mCH=CH2)3)2, followed by C=C hydrogenation (n = 2m+2). The coordination geometry may be square planar, trigonal bipyramidal, or octahedral (y = 2-4). If the ligands (Ly) are sufficiently small relative the (CH2)n linkages, the LyM unit may rotate within the gyroscope cage. Arrays of gyroscope like units with parallel axes are synthesized with spacings that allow the rotators to interact, enforcing correlated motion such as in gearboxes or waterwheels. The metal fragments are extruded from the gyroscope cages, providing a heretofore unknown class of macrocyclic dibridgehead diphosphines. These are independently synthesized, combined with various metal species to form new gyroscope-like complexes, and (in view of their ability to turn themselves "inside out") investigated as "transport containers" for toxic or harmful metal species.