Tetrabenzo ,,, tetraazacyclohexadecine nickel II Perchlorate

BIS(ISOTHIOCY ANATO)(TETRABENZO[6,//n ][ 1,5,9,13 ] TETRA-AZACYCLOHEXADECINE)NICKEL(II) 

The red perchlorate complex is diamagnetic and the solid reflectance spectrum shows a band at 18.7 kK typical of square planar nickel(II). The isothiocya-nato complex is six-coordinate and high-spin (pgj-f = 3.21 and exhibits 

The complexes are extremely stable to boiling concentrated mineral acids but are sensitive to base (alkoxides or amines) producing, by way of nucleophilic attack on two of the azomethine linkages, neutral four-coordinate or five-coordinate complexes.  

Hydrogenation of the imine functions of the ligand has been achieved either with platinum oxide catalyst or by electrochemical means to produce a new series of fully saturated (excluding the benzene rings) nickel(II) complexes as well as species that appear to contain aromatic dianionic ligands. 

A solution of 2.9 g (0.024 mole) of freshly prepared o-aminobenzaldehyde in 40 mL of absolute ethanol is heated to reflux with stirring. Copper(II) nitrate trihydrate (1.45 g, 0.006 mole) in 30 mL of absolute ethanol is added. The solution immediately changes from pale yellow to red-brown. The solution is refluxed for 1 hour, cooled to room temperature, and filtered. The dark-green microcrystalline product is washed with absolute alcohol and ether before drying in vacuo over P4O10. The yield is 2.9 g (81%). Anal. Calcd. for C2gH2oN606Cu  

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