透過多醚分子與?離子於三段式四極矩質譜儀電灑游離源中進行離子-分子作用產生的多醚-?離子分子離子，比較?離子與不同多醚分子主-客間的鍵結作用，除了單分子的結合外，多醚分子於高濃度（1×10-2M）條件下與?離子形成二聚體錯合離子，選擇性活化交叉多醚與?離子二聚體 (M1-H3O+-M2)，可比較出多醚對?離子的相對親和力為： diethylene glycol dimether ether＜triethylene glycol＜12C4＜triethylene glycol dimether ether＜tetraethylene glycol＜15C5＜tetraethylene glycol dimether ether＜18C6 多醚對?離子的相對親和力大小受孔洞效應、多醚分子的極化率以及Double-Action等因素所控制，其中冠醚類受孔洞效應影響較大，孔洞最大的18C6與?離子產生最強的分子-離子間的氫鍵作用力，而具最高極化率的軟性4-glyme分子比其相對的冠醚與醚醇更能與?離子產生最佳化的多重氫鍵，因此對?離子的作用較強，相反的，終端具有兩個?基的醚醇類則因為Double-Action 效應的影響降低其與?離子間的作用。 在多醚與?離子、氫離子及銨離子的比較中，離子大小類似的?離子和銨離子出現相同的趨勢，顯示離子的大小也影響著離子-分子間的交互作用。 The intrinsic binding interactions involved in host-guest complexation of polyethers with hydronium ion were evaluated by electrospray mass techniques. The polyethers-hydronium ion complexes were generated by ion-molecule interactions between hydronium ions and polyether molecules in electrospray ionization source of a triple quadrupole mass spectrometer. The polyethers-hydronium ion dimeric complexes were detected under high concentration condition (1×10-2M). Selectively activaton of cross-sandwich complexes (M1-H3O+-M2) permitted us to establish a relative order of hydronium ion affinities of crown ethers and acyclic analogs. The order of hydronium ion affinities of the polyethers were determined to followed the trend : diethylene glycol dimether ether＜triethylene glycol＜12C4＜triethylene glycol dimether ether＜tetraethylene glycol＜15C5＜tetraethylene glycol dimether ether＜18C6. The relative affinities of polyethers to hydronium ion could be easily rationalized with cavity effect, polarizability and double-action effect. For crown ether, the larger cavity size, the stronger hydrogen bonding interactions between the host and hydronium ion as cavity size increased. The most polarizable 4-glyme demonstrated dramatically higher relative affinities for the hydronium ion than the corresponding analogs. This preference was attributed to the favorable ability of more flexible 4-glyme to form multiple optimal hydrogen bonding interactions. Oppositely, the polyethers with two terminal hydroxy group reduced the ability to interact with hydronium ion because of double-action effect. Compared to the proton and ammonium ion affinities, ammonium ion showed the same trend to hydronium ion but strikingly different to proton ion. The similar trends in cation affinities suggest that a size effect was operative involved in ion-molecule interactions.
