Experimental and ab initio computational studies of self-association: 2-aminopyridine and 3-aminopyridine

The self-association of 2-aminopyridine (2AP) in deuterated chloroform (CDCl3) and deuterated dimethyl sulfoxide (DMSO-d6) and 3- aminopyridine (3AP) in CDCl3 have been studied experimentally by 1H nuclear magnetic resonance spectroscopy. At 291 K, the measured association constants for 2AP are found to be 0.166 and 0.0229 l mol21 in CDCl3 and DMSO-d6, respectively, whereas the association constant for 3AP in CDCl3 is 0.271 l mol21. To rationalise the experimental data, ab initio computational methods have been employed to identify the dimer structures which are of major importance in these self-association processes. In addition, the performance of continuum solvation models applied to 2AP association have been evaluated. q 2003 Elsevier B.V. All rights reserved.