Novel sheet-like manganese(II) networks. Synthesis and structure of [Mn(bpe)(NCS)2(CH3OH)2] and [Mn(bpe)(NCS)2(CH3OH)2]·bpe [bpe = trans-1,2-bis(4-pyridyl)ethene]

Abstract

Two new manganese(II) compounds of formula [Mn(bpe)(NCS)₂(CH₃OH)₂] 1 and [Mn(bpe)(NCS)₂(CH₃OH)₂]·bpe 2 [bpe = trans-1-2-bis(4-pyridyl)ethene] have been synthesized and characterized by single-crystal X-ray diffraction. The structures of compounds 1 and 2 consist of neutral chains containing manganese(II) ions bridged by mutually trans bpe molecules, the substantial difference being the bpe crystallization molecules which are in 2 and not in 1. In both compounds the six-co-ordination of Mn²⁺ is achieved by means of two trans NCS^– ions and methanol molecules. In 1 adjacent chains are connected through weak hydrogen bonds in such a way to form a two-dimensional structure, in which rectangular holes are present. The Mn· · ·Mn distance through the bpe bridge is 14.06(1) Å whereas that through the thiocyanate–methanol bridge is 6.73(1) or 7.54(1) Å. In 2 adjacent chains are linked through hydrogen bonds involving two nitrogen atoms of the solvate bpe molecule and two hydroxo groups from two methanol molecules in order to form layers. In each of these, four Mn²⁺ ions occupy the corners of a rectangle, which is constituted by four metal ions, four bpe and four methanol molecules. The Mn· · ·Mn distances through co-ordinated and hydrogen-bonded bpe are 13.93(1) and 17.10(1) Å. Adjacent sheets are shifted in such a way that metal ions of the first approximately correspond to the center of the hole of the second one and vice versa.