Metal-directed synthesis of a chiral acyclic pentaamine and pendant-arm macrocyclic hexaamine derived from an amino acid

Adsorption of Zn2+ and Cd2+ from Aqueous Solution onto a Carbon Sorbent Containing a Pyrimidine–Polyamine Conjugate as Ion Receptor

“…This accounts for the involvement of the deprotonated C(2)-NH group of the polyamine in metal coordination and confirms that L acts as a tetradentate N,N,N,N ligand. The complexation equilibria for HL/Cd II system are given in Table 2, with the speciation plots in Figure 4 ( 2+ complexes are similar to those of the analogous N,N bidentate 3-phenylpropane-1,2-diamine (log K = 4.1), pentane-1,2-diamine (log K = 5.5) and hexane-1,2-diamine (log K = 5.4) [14] and N,N,N tridentate, 1,4,7-triazaheptanediene (log K = 8.3) [15] ligands, respectively, thus indicating that the polyamine moiety acts either as a bidentate or tridentate chelating ligand, depending on the pH of the medium.…”

Mono- and Dinuclear Copper(II) Complexes of Pendant-Arm Macrocyclic Polyamines: Synthesis, Characterization and Investigation as Hydrolytic Cleavage Agents for DNA

“…This has been probed recently with examination of copper(II) complexes of acyclic polyamines where four nitrogen donors occupy the axial sites around the metal ion [62]. This has been probed recently with examination of copper(II) complexes of acyclic polyamines where four nitrogen donors occupy the axial sites around the metal ion [62].…”

Kinetics and Mechanism of the Ligand Exchange Reaction Between Tetraaza Macrocycle Ligand and Cu(II) Tetradentate Amine-Amide Complexes

“…Complexes with chelating ligands generally have increased stability relative to those of monodentate ligands, and even greater stability when the donor atoms are incorporated into a cyclic ligand that surrounds the metal ion, commonly referred to as a »macrocyclic effect«. [1][2][3] The chemistry of transition metal ion with macrocyclic ligands is an interesting field in chemistry and has been the subject of extensive research due to their potential applications in different fields, such as coordination chemistry, environmental chemistry and the role they play as models for metalloproteinase and enzymes binding sites in biological systems. [3][4][5][6][7][8][9][10][11] Macrocyclic ligands represent an interesting class of ligands in compared with acyclic multidentate ligands.…”

“…[9][10][11][12][13][14][15] Tetraaza macrocycles are coordinated by four donor atoms N to central ion, usually the central ion is coplanar with the four nitrogen atoms. 3,8,16 Our group has studied the ligand exchange of copper(II) and nickel(II) complexes by acyclic tetradentate ligands. [17][18][19] As an extension of our study, we have been interested in the possibility of ligand exchange reaction between Cu(bcen) 2+ and Cu(bctn) 2+ , where bcen and bctn are acyclic diamine-diamide tetradentate ligand, N,N'-bis(βcarbamoylethyl) ethylendiamine) and N,N'-bis(β-carbamoylethyl) propylendiamine), respectively, with tetraaza Vafazadeh and Zare-Sadrabadi: Kinetics and Mechanism of the Ligand Exchange Reaction ... macrocycles, teazma (5,7,7,12,14,14-hexamethyl-1,4,8, 11-tetraazacyclo tetradeca-4,11-diene dihydrogen perchlorate, Scheme 1) in order to gain better understanding of the kinetic and mechanistic behavior of multidentate ligand exchange processes.…”