핵산염기인 adenine과 salicylic acid 유도체들간의 본자수준에서의 결합양식을 분광학 및 구조화학적 수단으로 측정하였다. IR 및 NMR spectra로부터 분자내에 존재하는 imino기와 carbonyl기가 상호수소결합하여 cyclic hydrogen bonded complex를 구성하고 있음을 밝힐 수 있었다. Aenine과 salicylie acid는 저농도에서 1:1 complex를 형성하며 고농도에 서는 1:2 complex를 형성한다. Aspirin의 경우도 salicylic acid와의 structural analogy에 의해 같은 양상임을 알았다. Salicylamide의 경우는 salicylie acid나 aspirin과 달리 그 결합이 약하며, 단지 1:1 complex만이 형성된다. 유사 화합물중 salicylic acid가 adenine과 가장 강한 complex를 형성하며 aspirin, salicylamide의 순으로 결합강도가 약화됨을 밝힐 수 있었다.
Spectroscopic investigation has been carried out to know the binding mechanism of 9-ethyladenine with salicylic acid derivatives, such as salicylic acid, aspirin and salicylamide in chloroform solution by using infrared and nuclear magnetic resonance spectra. Adenine and salicylic acid form a 1:1 cyclic hydrogen bonded dimer in low concentration, but form a 2:1 (salicylic acid:adenine:salicylic acid) complex in high concentration. The high concentration of the sample demanded by NMR measurement has enabled us to observe this trimer formation, whereas the dilution necessary for IR method yields a concentration of trimer too small to be observed. In the case of aspirin, it is expected that the similar mode of the interaction with salicylic acid may occur because of its structural analogy with SA. The association between adenine and salicylamide is very weak unlike salicylic acid or aspirin. So, we cannot observe that 2-salicylamide: 1-adenine complex is present. Adenine and salicylamide form a 1:1 cyclic hydrogen bonded dimer. It appeared that salicylic acid forms the strongest complex among them, aspirin is second and then sailcylamide is third.
