Aggregation of imine-based metallo-supramolecular architectures through π–π interactions

Abstract

The design of supramolecular architectures based on isoquinoline-imine ligand systems is described. The isoquinoline affords an extended pi surface and the use of this surface to obtain self-recognition and consequent pi-pi aggregation is investigated. The approach is effective in that each of four complexes is observed to aggregate through these interactions. Other pi-pi interactions can interfere with the aggregation indicating that a larger pi-surface may be required to obtain complete control over the aggregation of the units.

Structural Diversity on Copper(I) Schiff Base Complexes

“…1 H-NMR spectra of copper(I) complex 37 have been recorded in CD 3 NO 2 and CD 3 CN solution. In CD 3 NO 2 solution at room temperature, two sets of resonance signals are observed consistent with the prersence of two solution species, the meso-and rac-isomers, and while in CD 3 CN solution at room temperature, a singlet set of resonance signals is observed because the ligands exchange is more rapid in this solvent [40]. www.intechopen.com…”

“…The basic bis-bidentate Schiff base ligands have two arms connected via a ring, or C-C bond, as for example, shown in Schemes 10 -14 [27][28][29][30]32,[35][36][37][38][39][40][66][67][68][69][70][71][72].…”

“…Until now, many examples of both single and double-stranded architectures have now been reported [92]. Studies on inorganic helical complexes containing transition metal ions have attracted much attention recently [27][28][29]40,[67][68][69][70][71][72]. In these supramolecular self-assembleies, the formation of the helicates can be described as the result of reading molecular information stored in the ligands by metal ions following the coordination algorithm such as tetrahedral.…”

“…Upon excitation at 360 or 470 nm, 35 display a single broad emission band with the maxima at 540 nm in methanol at room temperature [30]. In recent years, Hannon et al have systematically studied on helical metallo-supramolecular arrays with multidentate Schiff bas ligands L 47 -L 50 [27,28,40,71,72]. For this kind of compounds, the ligand must offer sufficient flexibility for multiple strands to wrap around two or more metal centers, and it should also be sufficiently rigid to impose the same stereochemistry as both metals [27,28].…”

Synthesis, characterization and molecular structures of Ni(II) complexes derived from Schiff base pyridylimine ligands

“…Other reports involve Schiff pyridylimine ligands in supramolecular chemistry to promote the formation of helicates [15] and mesocates [16].…”