Attempted functionalisation of a mononuclear barium complex of a 24-membered bibracchial tetraimine Schiff-base macrocycle derived from tris(2-aminoethyl)amine using salicylaldehyde

Tris(μ-phenoxo) bridged Cd(II) polymer synthesised from a symmetrical tripodal ligand: A novel observation for heptadentate monocapped trigonal antiprismatic Schiff base complex

“…Calc. for C 64 H 68 Cd 4 N 16 2 ] À values of the free dicyanamide ligand (2287, 2229 and 2181 cm À1 ), those of the reported complex show higher frequency shifts due to the end-to-end bridging coordination mode of dicyanamide in the complex [14].…”

“…The polyaza macrocyclic ligands also have these properties and have attracted much attention earlier [16][17][18]. Cadmium is an environmental pollutant which inhibits RNA polymerase activity in vivo [19,20] and reacts readily with proteins and other biological molecules.…”

Synthesis and Characterization of Some Metal Complexes with New Nitrogen–Oxygen Donor Macrocyclic Ligands – X-ray Crystal Structures of a 26-Membered Reduced Monoprotonated Macrocycle and a 20-Membered Pendant-Arm Schiff-Base Macrocyclic Cadmium(II) Complex

“…The complex nature of these signals could stem from the presence of related conformers in solution or from the magnetic inequivalence of the geminal hydrogen pairs caused by restricted rotation about the C-C bond. [38,39] In the pendant arm, this restriction could possibly be due to hydrogen-bonding effects. The broad singlet at δ ϭ 1.84-1.95 may be assigned to the NH 2 by changing the experimental conditions were unsuccessful and it was possible to identify complexes derived from the precursor amine as the major components of the products.…”

Synthesis, X-ray characterization, NMR and ab initio molecular-orbital studies of some cadmium(II) macrocyclic Schiff-base complexes with two 2-aminoethyl pendant arms

“…A broad singlet at 1.85 ppm is assigned to the NH 2 groups on the basis of the deuterium exchange noted when D 2 O was added to the CD 3 CN solution. The complex nature of the resonances arising from the aliphatic regions of the molecules most likely stems from magnetic inequivalence of the geminal hydrogen pairs caused by restricted rotation about the C-C bonds, which strongly suggests that coordination of the primary amine nitrogen atoms to the Cd(II) ion is retained in solution [26,27].…”