Linear Metal(II)-4,4′-Bipyridine (4,4′-bpy) Chains Organized into Two-Dimensional Rhombic Networks by Hydrogen Bonding. Crystal Structures of [Co(4,4′-bpy)(H2O)4] (ClO4)2.(4,4′-bpy)2.2H2O and [Zn(4,4′-bpy)(H2O)3(ClO4)] (ClO4).(4,4′-bpy)1·5.H20

Abstract

Two substances with extended two-dimensional networks through hydrogen-bond cross linkages, namely, [Co(4,4′-bpy)(H₂O₄] (ClO₄)₂.(4,4′-bpy)₂.2H₂O and [Zn(4,4′-bpy)(H₂O)₃(ClO₄)] (ClO₄).(4,4′- bpy)_1·5.H₂O, were synthesized, in EtOH/H₂O solution. The cobalt complex crystallizes in the triclinic space group P^-1 with a 9·113(2), b 11· 093(2), c 11·394(2) Å, α 64·04(3), β 70·18(3), γ 66·91(3)°, V 932·9(3) ų. The crystal structure contains 4,4′-bpy-bridged linear polymeric [Co(4,4′-bpy)(H₂O)₄]_n chains, where the cobalt(II) is coordinated in a slightly distorted octahedral environment by four water molecules (Co-O 2·088(2)-2·101(2) Å) at the equatorial positions and two nitrogen atoms of the bridging 4,4′-bpy ligands (Co–N 2·149(2) Å) at the axial positions. The chains are interconnected into a two-dimensional rhombic network by double hydrogen-bond bridges of the type Co–H₂O · · · bpy · · · H₂O–Co. The zinc complex also crystallizes in the triclinic space group P^-1 with a 9·0230(11), b 11·299(2), c 16·397(2) Å, α 74·429(11), β 83·132(9), γ 70·654(12)°, V 1518·5(3) ų. The crystal structure contains 4,4′-bpy-bridged linear polymeric [Zn(4,4′-bpy)(H₂O)₃(ClO₄)]_n chains, where the zinc atom is coordinated in a distorted octahedral environment by two nitrogen atoms of the bridging 4,4′-bpy ligands (Z–N 2·104(2)–2·117(2) Å), three water molecules (Zn–O 2·068(2)–2·091(2) Å) and one monodentate ClO₄- anion (Zn–O 2·320(2) Å). The chains are interconnected into a rhombic network alternately by single or double hydrogen-bond bridges of the type Zn–H₂O · · · 4,4′-bpy · · · H₂O–Zn.