Mn₂(H₂O)[O₂C(CH₂)_nCO₂]₂ (n = 3−12): Replication of an Inorganic Monolayer in Three-Dimensional (Dicarboxylato)manganese(II)

A series of novel manganese α,ω-dicarboxylates, Mn 2 (H 2 O)[O 2 C(CH 2 ) n CO 2 ] 2 ( n = 3−12), were synthesized as single crystals or polycrystallines by the hydrothermal reaction of MnCl 2 with the corresponding dicarboxylic acid in the presence of base. Mn 2 (H 2 O)[O 2 C(CH 2 ) 3 CO 2 ] 2 and Mn 2 (H 2 O)[O 2 C(CH 2 ) 5 CO 2 ] 2 ( n = 3 and 5) crystallized in the orthorhombic space group Pbcm (No. 15), with a = 7.6701(6) Å, b = 9.1156(4) Å, c = 17.975(1) Å, and Z = 4 and with a = 7.6089(8) Å, b = 9.167(2) Å, c = 23.070(3) Å, and Z = 4, respectively. Using various α,ω-dicarboxylates with different numbers of carbons in alkyl chains, the interlayer spacings of the manganese(II) compounds have been varied from 8.99 to 20.42 Å. Their organic chains between two terminal carboxylates are close-packed and self-assembled between Mn−O layers. The relative conformations of two terminal carboxylate groups determine the spacing groups of crystal structures. All the prepared manganese dicarboxylate compounds involve the replication of the local crystal structure in the Mn−O monolayer to present an antiferromagnetic interaction.