Strength vs. Accessibility: unraveling the patterns of self-recognition in a conformationally locked amino alcohol

Abstract

Unlike the self-assembly of aminols studied till date, that of the conformationally locked, trans-amino alcohol under study is unique in having the amino protons serving as mere spectators in the crystal packing. The principal non-covalent interactions, holding the molecules in the crystal lattice, are O-H···N hydrogen bonds, and the rarely encountered π-π stacking interactions between the isolated double bonds. Experimental charge density analyses have been carried out on the amino alcohol not only to characterize the non-covalent interactions existing in the supramolecular assembly in terms of the topological features of electron density at their bond critical points, but also to elucidate the apparent presence of the "spectator" amino hydrogen atoms beyond the criteria of mere geometry.