Supramolecular manganese(II) compounds influenced by conformational flexibility and rigidity of bis(4-pyridyl) containing bridging ligands

A covalent-bonded one-dimensional (1D) chain, [Mn(bpe)2(SCN)2]n (1) [bpe=1,2-bis(4-pyridyl)ethane], and a hydrogen-bonded two-dimensional (2D) sheet, [Mn(tbp)2(H2O)2(SCN)2] (2) [tbp=trans-1,2-bis(4-pyridyl)ethylene], have been prepared. Complex 1 can be viewed as a purely coordinative-bonded 1D motif doubly bridged by the bpe ligand that is a gauche conformational isomer with a large dihedral angle of 73.9°. The two bridging bpe ligands feature a shape of square with a dimension of 10.064 Å × 9.776 Å. The compound 2 possesses non-covalent bonding forces of hydrogen bonds and π–π interactions responsible for the fabrication of the 2D architecture. Magnetic susceptibility data for 1 were fitted by employing the infinite chain model (H=−J∑Si·Si+1) to give parameters of J=−0.052 cm−1 and g=2.00, indicating the presence of a weak anti-ferromagnetic coupling.