L. Fabbrizzi, Maurizio Licchellia, A. Poggi
May 1, 1996
Citations
0
Influential Citations
13
Citations
Journal
Inorganica Chimica Acta
Abstract
Abstract Diethylmalonate acts as an efficient locking fragment in the Cu II directed synthesis of 14-membered tetra-aza-macrocycles. In the reaction of [Cu II (en) 2+ (en = 1,2-diaminoethane) with 2 equiv. of diethylmalonate in the presence of formaldehyde and triethylamine the 1,4,8,11-tetraazacyclotetradecane-6,6,13,13-tetracarboxylic acid tetraethyl ester copper(II) diperchlorate complex salt is formed: monoclinic, space group C 2/ c with a = 12.201(5) A , b = 12.464(5) A , c = 21.353(22) A , α = 90°, β = 91.30(6)°, γ = 90°, V = 3247(4) A 3 , and Z = 4 ( R = 0.072, R w = 0.072). The formaldehyde building block can be replaced by benzaldehyde in the same type of template procedure if the two en fragments are replaced by the tetra-amine 2.3.2-tet ( N/N′ -bis-(2-amino-ethyl)-propane-1,3-diamine) and if the synthesis is carried out under strictly anhydrous conditions. The 5,7-diphenyl-1,4,8,11-tetraazacyclotetradecane-6,6-dicarboxylic acid diethyl ester copper(II) diperchlorate complex is obtained in good yield and exhibits a regular square coordination which is not disturbed by the bulky phenyl substituents: triclinic, space group P 1 with a = 11.742(5) A , β = 16.949(8) A , c = 8.718(4) A , α = 101.15(4)°, β = 105.92(4)°, γ = 96.21(4)°, V = 1613(1) A 3 , and Z = 2 (R = 0.047, R w = 0.051) .