577960-99-7Relevant academic research and scientific papers
Ring-ring or nitro-ring π,π-interactions in N-(p-nitrobenzyl)iminodiacetic acid (H2NBIDA) and mixed-ligand copper(II) complexes of NBIDA and imidazole (Him), 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen). Crystal structures of H2NBIDA, [Cu(NBIDA)(Him)(H2O)], [Cu(NBIDA)(bipy)] · 3H2O and [Cu(NBIDA)(phen)]-2H2O
Sánchez-Moreno,Choquesillo-Lazarte, Duane,González-Pérez, Josefa M.,Carballo, Rosa,Martín-Ramos, José D.,Casti?eiras, Alfonso,Niclós-Gutiérrez, Juan
, p. 1039 - 1049 (2003)
N-(p-nitrobenzyl)iminodiacetic acid (H2NBIDA) and the mixed-ligand copper(II) complexes with NBIDA and imidazole (Him), 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen) were prepared and characterised by thermal, spectral, magnetic and X-ray diffraction methods. Our aim is to study various possibilities of the N-(p-nitrobenzyl) arm in the iminodiacetate(2-) ion (IDA) skeleton to be involved in π,π-interactions which contribute to molecular recognition processes and crystal building. Analysis of the shortest aromatic ring-ring interactions were carried out with PLATON program and let us conclude that in free H2NBIDA acid (1) and [Cu(NBIDA)(Him)(H2O)] (2) only inter-molecular benzyl-benzyl π,π-stacks occur, whereas in [Cu(NBIDA)(bipy)] · 3H2O (3) and [Cu(NBIDA)(phen)] · 2H2O (4) there are both inter-molecular nitro-benzyl π,π-interactions (instead of benzyl-benzyl π,π-stacks) and α,α′-diimine-α,α′-diimine ring-ring π,π-interactions. In compound 2 NBIDA ligand has a typical mer-NO2 tridentate conformation, whereas in 3 or 4 it exhibits an unusual fac - O2 + N(apical) conformation. The molecular recognition pathway in 3 and 4 is discussed on a structural basis, considering a variety of interligand interactions involved in molecular recognition processes to build these and closely related crystals. We conclude that both the presence of a non-coordinating N-substituent in the IDA-like ligand and the chelation of Cu(II) by an aromatic α,α′-diimine (bipy or phen) display active roles for promote a fac-O2 + N(apical) conformation and various modes of interligand π,π-stacking interactions.
