62402-28-2Relevant academic research and scientific papers
A Barium Dithiocyanate Complex with an Unusual Macrocycle containing Pendant Arms, the Amine Precursor, and Related Copper(II) Diperchlorate Complexes: Synthesis and Structure
Tamburini, Sergio,Vigato, Pietro Alessandro,Casellato, Umberto,Graziani, Rodolfo
, p. 1993 - 2002 (2007/10/02)
The ligand 1-(p-nitrobenzylideneaminoethyl)-2-(p-nitrophenyl)imidazolidine (L1) was synthesized by condensation of p-nitrobenzaldehyde and diethylenetriamine.Reaction of L1 with 2-chloromethylpyridine yielded 1-(p-nitrobenzylideneaminoethyl)-2-(p-nitrophenyl)-3-(2'-pyridylmethyl)imidazolidine (L2), which by hydrolysis gave 7-(2'-pyridyl)-3,6-diazaheptylamine (L3).Crystals of L2 are monoclinic, space group P21/n, with a=21.050(5), b=7.935(6), c=13.529(6) Angstroem, and β=94.01(3)degree.The structure, determined by X-ray crystallography, was refined to a final R of 0.054 based on 2 646 observed reflections.The molecule shows the expected imidazolidine ring with normal bond lengths and angles.The behaviour in solution and the stereospecific assignments for the methylene protons of L2 were studied by (1)H n.m.r. spectroscopy.The reaction of the polyamine L3 with Cu(ClO4)2 produced 3(ClO4)2>.Crystals are orthorhombic, space group P212121, with a=14.295(6), b=13.143(6), and c=9.068(6) Angstroem.The structure was determined by X-ray crystallography and refined to a final R of 0.079 based on 1 068 observed reflections.The quadridentate ligand is equatorially bonded to Cu(2+) through the N atoms.Two axial Cu...O contacts with the ClO4(1-) anions complete the tetragonally elongated octahedral environment around the copper ion.Reaction of L3 with 4-chloro-2,6-diformylphenol in the presence of Ba(SCN)2 gave a macrocyclic complex 4(SCN)2>.Crystals are orthorhombic, space group Pbcn, with a=15.759(6), b=14.124(6), c=19.393(5) Angstroem.The structure was determined by X-ray crystallography and refined to a final R of 0.075 based on 1 270 observed reflections.The neutral macrocycle is co-ordinated to the Ba(2+) ion through four N and two O atoms.Two SCN(1-) ions complete the co-ordination polyhedron around the metal.The Ba(2+) ion lies on a crystallographic two-fold axis so that the molecular symmetry is C2.
