1H NMR lanthanide-induced Shift investigations of highly flexible molecules III: Applications to alcohols,aldehydes, esters,and amines

Summary Two new methods (RANDOM-LIS and STEED-LIS) with random selection of up to ten dihedral angles were applied for the determination of preferred conformers of flexible molecules (alcohols, aldehydes, esters, and amines, respectively, with only one coordination site) by LIS studies. The results proved to be useful. The preferred complexation conformation was detected only in cases where conformational changes of the substrate took place to improve complexation to the LIS reagent. Force field calculations (RANDOM-PIMM) and Simple Hard Sphere Model calculations (RANDOM-SHSM and STEED-SHSM), using the same algorithm of randomly varying the dihedral angles, support the results obtained.For parts I and II, see Refs. 1] and 2]