| Abstract
| - A 3-ureidobenzo-1,2,4-triazine 1-N-oxide (1) was synthesized successfully. The derivative displays anacceptor−donor−acceptor−acceptor (ADAA) hydrogen-bonding motif in CDCl3 and DMSO-d6 solutionas well as in the solid state. Although moderately strong association of 1 was observed with DAD motifs,nonspecific binding is observed with ureidopyridines featuring a complementary DADD array. Densityfunctional calculations of conformations 1a and 1b together with two complexes revealed the clearlynonplanar geometry of the multiply hydrogen-bonded complex, in which some bonds are significantlylonger (3.2 Å) than is optimal for H-bonds. As a result, only very small free energies of association werecalculated, in line with the experimentally observed absence of specific assembly of the components.
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