Molecular Recognition in the Gas Phase: Rates, Structures, and Energetics Without Solvents or Counterions

这笔来自有机动力学项目的拨款支持了德克萨斯大学阿灵顿分校的迪尔登教授的工作。本研究将利用离子回旋共振和串联质谱学技术研究冠醚及其相关配体对气相中金属离子和分子离子的固有分子识别性能。具体领域涉及(A)显示识别效应的化学体系的识别，(B)主-客体亲和力的测量，以及(C)气相识别反应的速率和机理的研究。将研究的次级主题是：(A)改变腔体大小以及配体给体原子的数量和类型的影响，(B)自然产生的离子载体的本征反应性，以及(C)离子-分子反应中的手性识别。Dearden教授关于冠醚与金属/分子离子相互作用的气相研究结果将补充有关溶液中分子识别的现有数据，从而能够区分本征效应和溶剂效应。这项研究还涉及手性识别，并包括自然产生的、具有生物活性的离子载体(促进离子通过膜的传输的分子)。这项研究的结果将使笼型试剂的鉴定和表征成为可能，笼型试剂根据大小和形状选择性地反应。

This grant from the Organic Dynamics Program supports the work of Professor Dearden at the University of Texas at Arlington. The study will investigate the intrinsic molecular recognition properties of crown ethers and related ligands for metal and molecular ions in the gas phase using ion cyclotron resonance and tandem mass spectrometric techniques. The specific areas concern (a) the identification of chemical systems which exhibit recognition effects, (b) the measurement of host-guest affinities, and (c) the investigation of the rates and mechanisms of gas phase recognition reactions. Subtopics that will be studied are (a) the effects of varying the cavity size and the number and types of ligand donor atoms, (b) intrinsic reactivity of naturally occurring ionophores, and (c) chiral recognition in ion-molecule reactions. %%% The results from Professor David D. Dearden's gas phase study on the interaction between crown ethers and metal/molecular ions will complement data available on molecular recognition in solution and will thereby enable the differentiation between intrinsic and solvent effects. The study also addresses chiral recognition and includes naturally-occurring, biologically-active ionophores (molecules facilitating ion transport through membranes). The outcome of this research will enable an identification and characterization of cage-type reagents which react selectively on the basis of size and shape.