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Updated: Jul 15, 2026
Hydrolysis of a Ni-Schiff-Base Complex Using Conditions Suitable for Retention of Acid-labile Protecting Groups
Published on: April 6, 2017
Isomeric Schiff bases related by dual imino-group reversals
William H Ojala1, Trina M Arola, Nell Herrera
1Department of Chemistry, University of St Thomas, St Paul, MN 55105, USA. whojala@stthomas.edu
Abstract:
Two isomeric pairs of Schiff bases, N,N'-bis(2-methoxybenzylidene)-p-phenylenediamine, C(22)H(20)N(2)O(2), (I), and 2,2'-dimethoxy-N,N-(p-phenylenedimethylene)dianiline, C(22)H(20)N(2)O(2), (II), and (E,E)-1,4-bis(3-iodophenyl)-2,3-diazabuta-1,3-diene (alternative name: 3-iodobenzaldehyde azine), C(14)H(10)I(2)N(2), (III), and N,N'-bis(3-iodophenyl)ethylenediimine, C(14)H(10)I(2)N(2) [JAYFEV; Cho, Moore & Wilson (2005). Acta Cryst. E61, o3773-o3774], differ pairwise only in the orientation of their imino linkages and in all four individual cases occupy inversion centers in the crystal, yet all four compounds are found to assume unique packing arrangements. Compounds (I) and (II) differ substantially in molecular conformation, possessing angles between their ring planes of 12.10 (15) and 46.29 (9) degrees , respectively. Compound (III) and JAYFEV are similar to each other in conformation, with angles between their imino linkages and benzene rings of 11.57 (15) and 7.4 (3) degrees , respectively. The crystal structures are distinguished from each other by different packing motifs involving the functional groups. Intermolecular contacts between methoxy groups define an R(2)(2)(6) motif in (I) but a C(3) motif in (II). Intermolecular contacts are of the I...I type in (III), but they are of the N...I type in JAYFEV.
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