Two genuine Co(II) supramolecular isomers, a two-dimensional (2-D) rhombus grid 1 and a one-dimensional (1-D) ribbon 2, that have the same metal fragment and ligand conformations, were crystallized from the same reaction bath under hydro(solvo)thermal conditions. The formation of supramolecular isomers in this system is dominated by the bridging orientation of InMe-4-py ligands, which is mainly influenced by reaction temperature but also weakly swayed by pH value, reaction time, and counteranion. The major rhombus grid 1 is the thermodynamically favored product, and the minor ribbon 2 is the kinetically favored product under controlled conditions, as supported by their relative abundances in functions of temperature and time. Both polymeric networks of supramolecular isomers 1 and 2 display a high thermal stability over 350 °C. Magnetic studies of 1 and 2 indicate that the Co(II) centers in the 2-D and 1-D networks are essentially magnetically insulated. The magnetic behavior demonstrates depopulation of higher energy Kramers doublets to the ground state, which results from a spin−orbit contribution, of the highspin Co(II) center in O h configuration upon a decrease of temperature.
Three unsymmetrical semirigid ligands, HInMe-n-py (n = 2, 3, 4), showing positional isomerism have assembled with ZnCl 2 and CdCl 2 to yield supramolecular coordination assemblies. Compoundhas a two-dimensional rhombus gridlike (4,4) layer structure constructed from the dinuclear paddlewheel [Zn 2 (O 2 C) 4 N 2 ] units with two pendant side-arms. Compound [Zn 2 Cl 2 (InMe-3-py) 2 (HInMe-3-py) 2 ] (2) forms a discrete armed M 2 L 2 macrocycle, which connects with others by intermolecular O-H⋯O and C-H⋯Cl hydrogen bonds to give rise to a decorated three-dimensional supramolecular pcu net. Compound [Zn(InMe-4-py) 2 ]•1/2H 2 O (3) adopts a two-dimensional chiral wavy (4,4) square grid. Opposite-handedness chiral wavy grids are stacked in an ABAB type of sequence that has small voids accommodating lattice water molecules. Compound [CdCl(InMe-3-py)] (4) displays a two-dimensional achiral meso layer in which the opposite-handedness Cd-L helical chains are interconnected by the Cd-O bridging bonds and stitched by zigzag Cd-Cl chains. Compound [Cd(InMe-4-py) 2 (H 2 O) 2 ] (5) features a two-dimensional rhombus gridlike (4,4)-net.Through the connections of net-to-net O-H⋯O hydrogen bonds, the grids are offset-stacked to be a hydrogen-bonded three-dimensional oblique pcu net. The structural diversity and complexity in these supramolecular coordination architectures are most likely attributed to the various coordination modes adopted by these N-and O-donor ligands of different substituent position and the coordination preference exhibited by the metal ions. Thermogravimetric (TG) analyses showed that all the frameworks of compounds 1-5 exhibit a thermal stability higher than 300 °C. In addition, the solid-state photoluminescent properties of compounds 1-5 were investigated.
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