โ Scribed by O. A. Raevsky
No coin nor oath required. For personal study only.
This paper describes how empirical free energy and/or enthalpy values for hydrogen binding strength are derived from thousands of corresponding measurements between H-bond donors and acceptors, mostly in carbon tetrachloride, and how they can be used to construct common scales or factor values (increments) also for other reactions involving electron donor and acceptor ability of functions. The corresponding databases and programs (HYBOT) allow one to predict thermodynamic values for experimentally unknown equilibria, including also ionophore complexes with crown ethers or cryptands. Applications in QSAR involve the prediction of lipophilicity from any structure on the basis of only two variables, e.g. 234 systems are described this way with a correlation coefficient r = 0โข96. Similarly, permeabilities and some biological properties such as narcotic activities of chemicals and anti-HIV-1 activity of some porphyrins are evaluated.
๐ SIMILAR VOLUMES
The concept of the stereoelectronic effect has been widely used for the elucidation of organic reaction mechanisms. However, a detailed analysis of this effect has not been developed, especially at the level of the ab initio molecular orbital method. In the present article, the through spacerbond in