Water of Hydration in 2:1 Hydrogen-Bonded Complexes between 1,5,7-Triazabicyclo[4.4.0]dec-5-ene and Dicarboxylic Acids

Crystalline (2:1)
complexes between a basic bicyclic guanidine
derivative and four dicarboxylic acids have been prepared and characterized
by single-crystal X-ray diffraction methods. Classical R22(8) hydrogen-bonded
ring motifs involving charge-assisted +N–H···O– interactions occur in three of these crystals. The
high affinity toward water molecules is manifested by cocrystallization
of water in three structures of which two display distinct hydrophilic
channels with extensive hydrogen bonding in intricate hydrogen-bonded
water tapes.