L-isoleucyl-L-asparagine 1.094-hydrate: a hybrid hydrogen-bonding pattern

The title compound, C(10)H(20)N(3)O(4) x 1.094 H(2)O, crystallizes with two dipeptide molecules in the asymmetric unit, each participating in two head-to-tail chains with hydrogen bonds between the terminal amino and carboxylate groups. As with many other dipeptides, the resulting structure is divided into distinct layers, but as the amide groups of the two peptide molecules participate in different types of interaction, the observed hydrogen bonds within a peptide main-chain layer (as distinct from the side-chain/solvent regions) cannot adapt to any of the four basic patterns observed previously for dipeptides. Instead, a rare hybrid pattern is formed.