Two Schiff Base Ligands Derived from 1,2-Diaminoethane

Cocrystallization of two tautomers: 4-(1-{[4-(dimethylamino)benzylidene]hydrazono}ethyl)benzene-1,3-diol and 6-[(E)-1-{[4-(dimethylamino)benzylidene]hydrazino}ethylidene]-3-hydroxycyclohexa-2,4-dien-1-one (1/1)

“…A concomitant decrease in the C-O distance is also noted [C5-O1 = 1.344 (3) Å versus C22-O3 = 1.316 (2) Å ]. The C7-N2 and C5-O1 distances are similar to the corresponding distances in 2,2 0 -(azinodimethylene)diphenol [1.285 (7) and 1.364 (8) Å ; Xu et al, 1994] and 2,2 0 -[(1,2ethanediyl)bis(nitrilopropylidyne)]bisphenol [1.295 (3) and 1.351 (3) Å ; Corden et al, 1997], which both exist in the phenol-imine tautomeric form. Likewise, the C24-N4 and C22-O3 bond lengths are similar to the corresponding distances in 2-{[tris(hydroxymethyl)methyl]aminomethylene}cyclohexa-3,5-dien-1(2H)-one [1.2952 18and 1.3025 (18) Å , respectively; Odabaşog lu et al, 2003] and 3-[(2-oxo-1naphthylidene)methylamino]benzoic acid [1.319 (3) and 1.290 (2) Å ; Pavlović & Sosa, 2000], which both show the keto-amine tautomeric form.…”

The Preparation of Dicompartmental Multifunctional Group Ligands

“…This phenomenon has been observed in similar systems 17 and was also confirmed by single crystal X-ray diffraction. 18 It can be concluded that the dissimilar two compartmental ligands 3 were prepared in satisfactory yields by a simple and convenient multistep method.…”

Solvent Extraction Studies on Copper(II) and Silver(I) Complexes of Bis(4-hydroxypent-2-ylidene)diaminoethane: Composition of Extracted Copper(II) Species

“…(H 2 B = BHPDE and X = NO 3 , Cl, or ½SO 4 ) The determined extraction constant, Kex, from equation 7as depicted in Figure 2 is 10 15.9 . The ligand behaves as a weak acid and in high pH media 13,14 formation of a chelate will probably be according to equation (8).…”

“…Bis(4-hydroxypent-2-ylidene)diaminoethane (BHPDE) has been synthesised and characterized via UV-Vis 1,2 , FTIR [3][4][5] and NMR 6,7 . Through these means it was established to exist in three tautomeric forms 8 . The coordination chemistry of BHPDE with divalent metal ions and the potentials of BHPDE as a photometric reagent and as extractant for Cu(II) and many other metal ions have been documented [9][10][11][12] .…”