Tris(2-succin­imido­ethyl)­amine hydrate (1/0.075)

The title compound, C₁₈H₂₄N₄O₆·0.075H₂O, (I), was prepared as part of a research programme to prepare and identify new tripodal ligands which exhibit instability at low pH, thereby releasing coordinated metal cations under such conditions. Each mol­ecule lies on a crystallographic threefold axis with the three arms arranged in the form of a claw. Angles within the five-membered succin­imide ring, where the r.m.s. deviation of the five atoms from the least-squares ring plane is only 0.004 Å, vary from 104.8 (3)° at a methyl­ene C atom to 112.7 (3)° at the formally sp² N atom. The structure contains a partially occupied disordered water mol­ecule, the source of which is presumably the water produced as a by-product of the synthetic reaction.