Alternating chains with the new J1J2J3J1⋯ sequence in a three-dimensional MnII complex

•A three-dimensional carboxylate-bridged MnII compound containing unique manganese chains has been synthesized.•Alternating Mn chain was arranged as unprecedented J1J2J3J1⋯ mode.•Magnetic susceptibility measurement reveals an antiferromagnetism behavior derived from the topology of the chain.

A three-dimensional carboxylate-bridged MnII compound [Mn6(tci)4(H2O)3]·7H2O}n (1) (tci = tris(2-carboxyethyl) isocyanurate) have been synthesized. The structure contains unique manganese chains in which the MnII ions are alternatively bridged by carboxylate groups in different coordination modes. The first example of such alternating Mn chain shows Mn1–(COO)3–Mn2–(COO)2–Mn3–(COO)3–Mn1–(COO)3–Mn2-sequence arranged as J1J2J3J1S⋯ mode. Magnetic susceptibility measurement reveals an antiferromagnetism behavior derived from the topology of the chain. There is no suitable analytical expression for determining the exchange parameters in a 1-D Heisenberg ferrimagnet consisting of alternating interactions J1J2J3J1⋯. The best way to fit the magnetic behavior of these complexes is to proceed by using a Hamiltonian that corresponds to a 12-membered of S = 5/2 with 4 fragments repeating the sequence J1J2J3. The fit was performed by means of the computer program MAGPACK. The fitting for the observed magnetic data gives J1 = − 2.31 cm− 1, J2 = − 1.60 cm− 1, J3 = − 3.10 cm− 1, zJ′ = − 0.03 cm− 1 and g = 1.98, with R = 7.2 × 10− 3.

Graphical abstractA three-dimensional carboxylate-bridged MnII compound [Mn6(tci)4(H2O)3]·7H2O}n (1) containing unique manganese chains have been synthesized. The first example of such alternating Mn chain was arranged as J1J2J3J1⋯ mode. Magnetic susceptibility measurement reveals an antiferromagnetism behavior derived from the topology of the chain.Figure optionsDownload full-size imageDownload as PowerPoint slide