5-Carboxysalicylaldehyde (H2casal) formed two mixed-ligand complexes, [Cu(Hcasal)(bpy)]ClO4 (1) and [Cu(casal)-(bpy)]·2H2O (2) (bpy=2,2′-bipyridine) and the Schiff bases H2L1 and H2L2 derived by condensing H2casal with N2N-dimethylethylenediamine and bis(3-aminopropyl)amine, respectively, formed [Cu(L1)]·0.25H2O (3) and [Cu(L2)]·H2O (4), respectively. X-Ray crystallographic studies were done for 1, [Cu(casal)(bpy)(MeOH)] (2′), [Cu(L1)]·4H2O (3′) and 4. 1: Monoclinic, space group C2/c, a = 18.457(5), b = 19.215(5), c = 12.237(3) Å, α = 90, β = 121.76(2), γ = 90°, V = 3690(1) Å3, and Z = 8. It has a dimeric structure with a perchlorato bridge between two [Cu(Hcasal)(bpy)]+ moieties. In the bulk the dimeric units are assembled by interligand noncovalent interactions providing a pseudo 2-D sheet. 2′: Monoclinic, space group P21/m, a = 9.791(4), b = 6.850(4), c = 25.56(1) Å, α = 90, β = 98.99(3), γ = 90°,V = 1692(1) Å3, and Z = 4. The casal2- combines one copper at the mixed-ligand site and the carboxylato group unidentately coordinates to the adjacent molecule, providing a 1-D zipper-like chain. The 1-D chains are further assembled through the interchain bpy/bpy stacking to form a pseudo 2-D network extended on the bc plane. 3′: Tetragonal, space group I41/a, a = b = 16.006(3), c = 27.745(7) Å, α = β= γ = 90°, V = 7108(2) Å3, and Z = 16. It has a 1-D helical structure extended by Cu-NNO(spacer)OO-Cu linkages along c axis (Fig. 6): The nearest Cu-Cu separation in the chain is 9.60 Å. The four water molecules exist in the helical column but are readily removed in the air. 4: Monoclinic, space group P21/c, a = 9.149(6),b= 17.566(6), c= 11.004(6) Å, α = 90, β = 110.03(4), γ = 90°, V = 1661(1) A°3, and Z = 4. It has a 1-D zigzag chain structure extended by Cu-NNNO(spacer)O-Cu linkages. Further, the 1-D chains align through noncovalent interchain interaction to provide a pseudo 2-D sheet. The interplay of the two dissimilar metal-binding sites of H2casal and its Schiff bases and the intermolecular noncovalent interaction contributing to the network and bulk structures of the complexes are discussed.
!!!All Science Journal Classification (ASJC) codes
- 化学 (全般)