Marushkevich Kseniya, Khriachtchev Leonid, Räsänen Markku
Laboratory of Physical Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland.
J Phys Chem A. 2007 Mar 22;111(11):2040-2. doi: 10.1021/jp070363m. Epub 2007 Feb 23.
We studied hydrogen bonding between formic acid (FA) and water in solid argon and identified the first water complex with the higher-energy conformer cis-FA. In sharp contrast to cis-FA monomer, cis-FA interacting with water is very stable at low temperatures, which was explained by strong O-H...O hydrogen bonding. These benchmark results show that hydrogen bonding can terminate proton tunneling reactions and efficiently stabilize intrinsically unstable conformational structures in complex asymmetrical hydrogen-bonded networks. This general effect occurs when the energy difference between conformers is smaller than the hydrogen bond interaction energy, which opens perspectives in chemistry on intrinsically unstable conformers.
我们研究了固态氩中甲酸（FA）与水之间的氢键，并确定了首个与高能构象顺式-FA形成的水络合物。与顺式-FA单体形成鲜明对比的是，顺式-FA与水相互作用在低温下非常稳定，这是由强O-H...O氢键所解释的。这些基准结果表明，氢键可以终止质子隧穿反应，并在复杂的不对称氢键网络中有效地稳定本质上不稳定的构象结构。当构象异构体之间的能量差小于氢键相互作用能时，就会出现这种普遍效应，这为化学中本质上不稳定的构象异构体开辟了新的前景。
