One-Pot Reaction Involving Two Different Amines and Formaldehyde Leading to the Formation of Poly(Macrocyclic) Cu(II) Complexes

Abstract

2n have been prepared by the one-pot reaction of formaldehyde with ethylenediamine and 1,2-bis(2-aminoethoxy)ethane, 1,3-diaminopropane, or 1,6-diaminohexane in the presence of the metal ion. The polymer complexes contain fully saturated 14-membered hexaaza macrocyclic units (1,3,6,8,10,13-hexaazacyclotetradecane) pendant arms has also been prepared by the metal-directed reaction of ethylenediamine, 1,2-bis(2-aminoethoxy)ethane, and formaldehyde. The polymer complexes were characterized employing elemental analyses, FT-IR and electronic absorption spectra, molar conductance, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron micrograph (SEM). Electronic absorption spectra of the complexes show that each macrocyclic unit of them has squareplanar coordination geometry with a 5-6-5-6 chelate ring sequence. The polymer complexes as well as4+ are quite stable even in concentrated HClO 4 solutions. Synthesis and characterization of the polynuclear and mononuclear copper(II) complexes are reported.

Synthesis, Crystal Structure, and Spectroscopic Properties of Cu(II) Complex with 14-Membered Hexaazamacrocyclic Ligands

“…Macrocyclic complexes are best prepared with the aid of metal ion as template to direct the condensation reaction which ultimately ends with ring closure [20]. In addition, formaldehyde can serve as a link for two amine moieties and, therefore, metal-directed reaction of coordinated amines and formaldehyde is useful for the preparation of various types of fully saturated hexaazamacrocyclic complexes containing N-CH 2 -N linkings [21]. Typical examples of primary amines side chain, the ''pendant arm'', that have been used so far include propylamine [22,23], ethanolamine [24,25], 1,4-phenylenediamine [26], hydrazine [27], 2-thiophenemethylamine [28], nicotinamide [5], 4-aminobutyric acid [29,30], ethylamine [31], (R)-(?…”