Three-dimensional H-bonded supramolecular complexes. Synthesis and crystal structures of [Mn(μ-bpe)(H2O)4](ClO4)2·4(bpe)·2H2O and [M(μ-bpe)(bpe)2(H2O)2](ClO4)2·bpe·H2O, where M = Zn, Ni and bpe = 1,2-bis(4-pyridyl)ethane

Abstract

The reaction of Mn(II), Zn(II), and Ni(II) perchlorate with 1,2-bis(4-pyridyl)ethane (bpe) was studied and the products were characterized by IR spectroscopy and X-ray diffraction methods. The zinc and nickel compounds are isomorphous with a metal-bpe molar ratio of 1:4, while the manganese compound is quite different with a Mn-bpe ratio of 1:5. [Mn(μ-bpe)(H2O)4](ClO4)2·4(bpe)·2H2O (1) is monoclinic, C2/c, with a = 30.141(7), b = 13.993(4), c = 19.765(4) Å, β = 129.41(1)°, and R = 0.059. The Mn atom is located on an inversion centre and forms an infinite chain with the bridged bpe ligand. The four other bpe molecules are hydrogen-bonded to the aqua ligands and form an extensive H-bonded interpenetrating 3D network. The bonds Mn-N = 2.316(3) Å and Mn-OH2 = 2.148(4) and 2.178(3) Å. [Zn(μ-bpe)(bpe)2(H2O)2](ClO4)2·bpe·H2O (2) crystallized in the P21/c space group, with a = 14.609(4), b = 21.164(5), c = 16.482(5) Å, β = 114.69(2)°, and R = 0.058. For [Ni(μ-bpe)(bpe)2(H2O)2](ClO4)2·bpe·H2O (3), a = 14.511(6), b = 21.216(7), c = 16.467(7) Å, β = 114.76(3)°, and R = 0.065. The aqua ligands are located trans to each other. The bridged bpe ligands form an infinite chain with the metal atoms. Two other terminal bpe ligands are coordinated to the metal in trans positions to each other. These ligands form H-bonds with the aqua ligands of other chains resulting in an H-bonded 3D network. The Zn-N distances vary from 2.151(3) to 2.185(4) Å while the Ni-N bonds are between 2.098(10) and 2.126(11) Å. The bonds Zn-OH2 = 2.125(4), 2.161(4) Å and Ni-OH2 = 2.077(11), 2.110(11) Å. Key words: crystal structure, manganese complex, zinc complex, nickel complex, 1,2-bis(4-pyridyl)ethane.