Unusual isomorphism in crystals of organic solvates with hydrazine and water

Abstract

An unusual isomorphism of 18-crown-6 hydrazine disolvate C₁₂H₂₄O₆·2N₂H₄ (1) and 18-crown-6 tetrahydrate (2) is observed. The isomorphous substitution of hydrazine by water molecules is found for the first time in the structures of tetrabutylammonium acetate hydrazine solvates hydrous Bu₄N⁺AcO⁻·0.9(N₂H₄)·0.1(H₂O) (3) and anhydrous Bu₄N⁺AcO⁻·N₂H₄ (4). Surprisingly, the nature of these isomorphous relationships is completely different from the well-known isostructurality of organic hydrogen peroxide/water solvates.