Dibenzo-tetraaza annulene

Cataldi, T.R.I., E. Desimoni, G. Ricciardi, and F. Lelj (1995). Study of the nickel-based chemically modified electrode obtained by electrochemical deposition of an Ni -tetramethyl-dibenzo-tetraaza[14] annulene complex. Redox catalysis of carbohydrates in alkaline solutions. II. Electroanalysis 7(5), 435-441. 

A logical extension of the condensation reactions which yield multidentate nitrogen donors is the formation of macrocyclic ligands. The preference of palladium for square planar coordination makes it an ideal metal for the formation of complexes of these ligands. Thus palladium porphyrins are very stable and resistant to demetallation.281 Both 14- and 16-atom macrocycles have been used to form complexes. The ligand l,8-dihydro-5,7,12,14-tetramethyl-dibenzo[b,i][l,4,8,ll]tetraaza[14]annulene reacts with [PdCl2(PhCN)2] to yield the complex (46). 

Veber and co-workers have investigated the mesomorphic behavior of a related family of nickelfll) complexes of dibenzo[Z), ] [1,4,8,ll]tetraaza[14]annulenes (35), bearing four, six, and eight peripheral chains. The disk-like nickel complexes were prepared by a template reaction... 

As specified above, it has also been shown that tetraaza[14]annulene 74 (5,7,12,14-tetramethyl-dibenzo-l,4,8,ll-tetraaza[14]annulene) can be electrode-posited on common conducting substrates and electrochemically treated so as to display a nickel-based catalytic deposit towards the oxidation of carbohydrates in alkaline solutions which shows strong similarities to the nickel hydroxide electrode. Similar observations were reported for Ni complex 75 although they were rather oriented towards the oxidation of hydrogen peroxide " and for Ni curcumin films towards the electrocatalytic oxidation of aliphatic alcohols. ... 

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