Synthesis and Characterization of Bis(Macrocyclic) Nickel(II) Complexes Containing Aromatic Nitrogen–Nitrogen Linkers Produced by Template Condensation

Abstract

Bis(macrocyclic)dinickel(II) complexes containing phenylene bridges between 16-membered pentaaza macrocyclic subunits have been synthesized via one-pot template condensation of nitrogen-nitrogen linker (1,4-phenylenediamine; benzidine; 4,4¢-diaminodiphenylmethane; 4,4¢-diaminodiphenylether; 4,4¢-diaminodiphenylsulfone), formaldehyde, 1,3-diaminopropane, nickel(II) and 2,4-pentanedione in a 1:4:4:2:2 molar ratio. Elemental analyses, i.r., u.v.-vis, H-n.m.r. spectroscopy, cyclic voltametry, conductometric and magnetic measurements have been used to characterize the new complexes.

Characterization and crystal structure of a 17-membered macrocyclic Schiff base compound MeO-sal-pn-bn

“…and for their role in host-guest and supramolecular chemistry [8][9][10]. Macrocycles containing imine groups can form mono-, di-, and polynuclear transition metal complexes with various applications [11][12][13][14]. Among them a wide Schiff base macrocycles based on 2,6-diacetylpyridine and 2,6-diformylpyridine as building blocks evolved from the early studies [15].…”

Characterization and Crystal Structures of New Schiff Base Macrocyclic Compounds

“…Schiff base compounds are widely used ligands due to the ease of preparation and remarkable versatility. The ability to form stable complexes designates Schiff bases to play an important role in the development of transition metal coordination chemistry [1][2][3][4][5][6][7][8][9][10]. The research field on Schiff base complexes is very broad because of their structural diversity and many potential applications [1][2][3][4][5][6][7][8][9][10].…”

“…They can be prepared by condensation of different dicarbonyl groups with a wide range of different diamines [11][12][13][14][15][16][17][18][19][20][21]. The direct preparation of free macrocyclic Schiff bases is sometimes complicated, and in such cases they must be prepared by the template effect [ 1,3 ]. Nevertheless, in recent years, considerable effort has been made to avoid the template effect in the preparation of macrocyclic Schiff bases [11][12][13][14][15][16], because the template effect has two substantial disadvantages.…”