Design, synthesis and photoelectrochemical properties of hexagonal metallomacrocycles based on triphenylamine: [M-6(4,4 '-bis(2,2 ': 6 ',2 ''-terpyridinyl)triphenylamine)(6)(X)(12)]; [M = Fe(II), PF6- and Zn(II), BF4-]

摘要

Synthesis of a novel bis(terpyridine) ligand, 4,4'-bis( 2,2': 6',2 ''-terpyridinyl) triphenylamine, utilizing triphenylamine, as a specific angle controller, has led to the self-assembly of a unique hexagonal metallomacrocycle family, [Fe-6(2)(6)(PF6)(12)] and [Zn-6(2)(6)(BF4)(12)], utilizing terpyridine -metal(II) - terpyridine connectivity. The crystal structure of the novel ligand shows that the angle between the two terpyridinyl moieties is 119.69 degrees, which enabled the formation of the hexagonal-shaped macrocycles. The crystal packing architectures of this starting ligand revealed channels induced by solvent encapsulation. Following complexation of this ligand with transition metals [ Fe( II) or Zn(II)] in a one-pot reaction, the resultant structures were characterized by H-1 and C-13 NMR, UV/Vis and mass spectroscopies. The expected metal-to-ligand charge transfer (MLCT; lambda(max) = 582 nm) and emission (lambda(em) = 575 nm) characteristics were exhibited by both [Fe-6(2)(6)(PF6)(12)] and [Zn-6(2)(6)(BF4)(12)]. The photoelectrochemical characteristics of these hexagonal metallomacrocycles demonstrate that they can be used as sensitizers in dye-sensitized solar cells.