(Pyrazole-κN²)[N-salicylidene-κO-(S)-alaninato-κ²N,O]copper(II) Dihydrate and (Pyrazole-κN²)[N-salicylidene-κO-(R,S)-alaninato-κ²N,O]copper(II) Pyrazole Solvate

In both {N-[(2-hydroxyphenyl)methylene]-(S)-alaninato-O,N,O′}(pyrazole-N²)copper(II) dihydrate, [Cu(C₁₀H₉NO₃)(C₃H₄N₂)].2H₂O, (I), and {N-[(2-hydroxyphenyl)methylene]-(R,S)-alaninato-O,N,O′}(pyrazole-N²)copper(II) pyrazole solvate, [[Cu(C₁₀H₉NO₃)(C₃H₄N₂)].C₃H₄N₂, (II), the Cu^IIion adopts a similar axially distorted square-pyramidal coordination. The basal plane is formed by the tridentate Schiff base N-salicylidenealaninato dianion (TSB²⁻) and the pyrazole ligand. The apex of the pyramid is occupied by a carboxylic O atom from the neighbouring chelate. The cooperative ordering and the apical distance [2.978 (3) Å in (I) compared with 2.366 (3) Å in (II)] are the two main differences between the two complexes. The stacked Cu(TSB) complexes within (I) form polymeric chains by translation parallel to [100]. The apically bridged Cu(TSB) complexes of (II) form zigzag chains parallel to [010] via the 2₁ operator. The influence of the configuration at the chiral C atoms as well as the effect of uncoordinated water and pyrazole molecules on the cooperative ordering are discussed.

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