Shin-Geol Kang, Jang-Sik Choi, Kwanghee Nam
Jul 5, 2004
Citations
0
Influential Citations
9
Citations
Journal
Inorganica Chimica Acta
Abstract
New structurally constrained tetraaza macrocycles 2,3-dimethyl-1,5,12,16-tetraazapentacyclo[14.6.3.3 5 , 1 2 ,0 6 , 1 1 ,0 1 7 , 2 2 ]octacosane (L 6 ) and 2,2,4,10,12,18,20-octamethyl-1,5,9,13-tetraazatricyclo[11.3.2.2 5 , 9 ]eicosane (L 7 ) have been prepared in high yield by direct reaction of 1,3-dibromopropane with 3,14-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.0 7 . 1 2 ]docosane (L 3 ) or 2,5,5,7,9,12,12,14-octamethyl-1,4,8,11-tetraazacyclodecane (L 5 ). The macrocycle L 6 readily reacts with anhydrous copper(II) ion to yield [CuL 6 ] 2 + in dry methanol but does not react with nickel(II) ion, showing a high copper(II) ion selectivity. On the other hand, neither of the metal ions is inserted into the cavity of L 7 in similar conditions. The copper(II) complex [CuL 6 ](ClO 4 ) 2 has a severely distorted square-planar coordination polyhedron with a rarely observed trans-IV type N-conformation. The visible absorption spectrum of [CuL 6 ] 2 + shows the d-d transition band at 490 nm (e = 690 M - 1 cm - 1 ); the wavelength is quite similar to that of [CuL 3 ] 2 + , but the molar absorption coefficient is extraordinarily larger than those of [CuL 3 ] 2 + and other related tetraaza macrocyclic copper(II) complexes.