Four unprecedented 2D trinuclear Mn(II)-complexes with adenine nucleobase controlled by solvent or co-ligand: Hydrothermal synthesis, crystal structure and magnetic behaviour

Four unique infinite 2D Mn(II) aggregates, [Mn-3(mu(3)-ade)2(OAc)(4)X]. (X = DMF for 1, DMA for 2 and C2H5O- for 3), [Mn-3(mu(3)-ade)(2)(ap)(2)DMF](n) (4) (Hade = adenine; DMF = N,N-dimethylformamide; DMA = N,N-dimethylacetamide, OAc- = acetate ion, H(2)ap adipic acid) with trinuclear Mn(II) as secondary building units (SBUs), have been successfully synthesized by the assembly of Hade nucleobase and manganese acetate under solvothermal conditions. The resultant complexes can be applied to explore the influence of solvent or co-ligands on the self-assembly and properties of metal complexes based on adenine. The Hade represent tridentate mu(3)-N3, N7, N9 bridging coordination modes. The acetate anions exhibit mu(2)-eta(1):eta(1) bidentate, mu(2)-eta(1):eta(2) tridentate mode, and mu(2)-eta(0):eta(2) bidentate mode. The adipate anions in complex 4 adopt two coordination modes: one is mu(4)-eta(2):eta(1):eta(1):eta(1) pentadentate mode, the other one is mu(3)-eta(1):eta(2):eta(2):eta(1) hexadentate mode. Their magnetic behaviors exhibit interesting variations, in which the local net magnetization at low temperature increases from 1 to 3. The Mn(II)3 SBUs in 1-3 are symmetric with an inversion center, whereas that in 4 has three crystallographically independent Me atoms. Thus, the magnetic behaviors of 4 are different from complex 1-3. (C) 2017 Elsevier B.V. All rights reserved.