Selective Synthesis of a New Macropolycycle Containing One N-CH₂-N Linkage
and Its Reaction with Cu²⁺ and Ni²⁺ Ions in Methanol

摘要

The reaction of 3,14-dimethyl-2,6,13,17-tetraazatetracyclo[16.4.0^1.18.0^7.12]docosane (L1) with formaldehyde in warm methanol yielded 3,14-dimethyl-2,6,13,17-tetraazatetracyclo[16.4.1^2.6.0^1.18.0^7.12]tricosane (L⁷) containing one 1,3-diazacyclohexane subunit. In methanol, L⁷ readily reacts with Cu²⁺ ion to form [CuL⁷(H₂O)]²⁺ which is extremely inert against methanolysis. In the solution containing Ni²⁺ ion, however, L⁷ reacts with methanol to yield [NiL³]²⁺ (L³ = 2-(methoxymethyl)-5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0^1.18.0^7.12]- docosane), in which one N-CH₂OCH₃ pendant arm is appended. The copper(II) complex [CuL⁷(H₂O)]- (ClO₄)₂·3H₂O (I·3H₂O) has a severely distorted trigonal bipyramidal coordination geometry with a 4-5-6-5 chelate ring sequence. The crystal structure of [NiL³](PF₆)₂·2H₂O (IIb) shows that the N-CH₂OCH₃ pendant arm is not coordinated to the metal ion in the solid state. In various solvents (S), however, the nickel(II) complex exists as a mixture of [NiL³(S)]²⁺, in which the N-CH₂OCH₃ group as well as S is coordinated to the metal ion, and [NiL³]²⁺.