Coordination Networks from Zero-Dimensional Metallomacrocycle, One-Dimensional Chain to Two-Dimensional Sheet Based on a Ditopic Diiminopyridine Ligand and Group 12 Metals

Abstract

The reaction of a ditopic diiminopyridine ligand 2,6-bis (1-(2,6-diisopropyl-4-(pyridin-3-yl)phenylimino)ethyl)pyridine (L) with group 12 metal salts in various solvent systems afforded 12 metal-organic coordination complexes, including zero-dimensional (0D) metallomacrocycle, one-dimensional (1D) chain, and two-dimensional (2D) network structures:In these complexes, the semirigid ligand L exhibits four kinds of coordination modes [(syn, syn, syn), (syn, syn, anti), (anti, anti, syn), (anti, anti, anti)], leading to the formation of various supramolecular structures. Complex 1a is a tetranuclear metallomacrocycle. 1b contains 1D zigzag chains propagating along two different directions, which further pack into a noninterpenetrated three-dimensional (3D) framework by hydrogen-bonding interactions. Complexes 1c, 2, 3, 9, and 10 exhibit a 1D helical chain structure, while 4, 5, 6, and 7 are 1D looped-chain coordination polymers. Complex 8 displays an unprecedented pentanuclear Hg(II)-based 2D network with both HgCl 2 and Hg 2 Cl 2 bridges. It is noteworthy that 1a and 1b are supramolecular isomers formed in different solvent systems. The effects of the solvent, metal center, and anion on the different conformations adopted by the ligand and the structure of the products have been discussed. Additionally, the luminescent properties of the complexes have been investigated in the solid state, which display increased ligand-based fluorescence emission at room temperature.

Solid-state inclusion of C60and C70in a co-polymer induced by metal–ligand coordination of a Zn–porphyrin cage with a bis-pyridyl perylene derivative

“…[16][17][18][19] It is possible to modify and tune the properties of MOFs by simply using different ligands, metal centres and counter ions. [20][21][22][23] Fullerenes are valuable spherical molecules that exhibit low reduction potentials and strong electron acceptor properties. [24][25][26][27][28] The molecular recognition process between fullerenes and porphyrins is an interesting supramolecular recognition element 29 and its use in supramolecular chemistry is convenient not only for the affinity that exists between the flat tetrapyrrole ring and the curved surface of the fullerene, 30,31 but also for the capability that the fullerene/porphyrin assemblies generate photo-induced charge-separated species mimicking the natural photosynthesis processes.…”

Two Cd(II) complexes derived from mercapto-triazole ligands: syntheses, crystal structures, and luminescent properties

“…Metal-organic frameworks (MOFs) display fascinating structures [1][2][3][4][5] and usefiil properties in photoelectrical [6,7], magnetic [8], catalytic [9], and porous materials [10]. Although some results have been achieved [11][12][13], it is still a challenge to rationally and predictably assemble MOFs.…”

From discrete to infinite 3D coordination polymer: Sonochemical syntheses and structural characterization of a new nano flower lead (II) coordination compound

“…Organic aromatic ligands are good candidates for spacer part of organic-inorganic materials, because not only they can act as hydrogen-bonding acceptors or donors, but also can provide recognition sites for p-p stacking interactions to form interesting supramolecular structures when coordinating to metal ions. Polynuclear d 10 metal complexes and coordination polymers have attracted extensive interest in recent years, since they exhibit appealing structures [12][13][14][15]. In the field of crystal engineering, the anions not only balancing the charges of cationic species but also impart their influence on the structure of a given supramolecular system through coordinative bonding to metal ions or through weak interaction with organic ligands [16].…”