A well-resolved uudd cyclic water tetramer was reported in the crystal host of [Cu(adipate)(4,4-bipyridine)].(H(2)O)(2), showing the contribution of the water cluster to the stability of the crystal host and the role of cooperative association of the water cluster and the crystal host in the formation of the water cluster.

Auf Biegen und Brechen: Ein Bruch der chiralen Symmetrie bei der Kristallisation intrinsisch chiraler, helicaler Koordinationspolymere gelingt durch die Einführung eines relativ stabilen Intermediats zur chemischen Steuerung der Keimbildungsgeschwindigkeit. Je weniger Kristallcluster gebildet werden, umso stärker ausgeprägt ist die Symmetriebrechung (siehe Bild).

The iminodiacetate dianion in diaquaiminodiacetato-nickel(II), [Ni(C4H5NO4)(H2O)(2)], chelates to the Ni atom through two carboxyl O and one imino N atoms; the six-fold coordination coordination environment comprises these three atoms, the water molecules and the carbonyl O atom of an adjacent dianionic group. The dative Ni<--O linkage leads to the formation of a helical chain running along the a axis of the orthorhombic crystal; adjacent chains are held in a network motif by hydrogen bonds