Intramolecular hydrogen bonding and tautomerism in Schiff bases. Part II. Structures of 1-[N-(2-pyridyl)aminomethylidene}-2(1H)-naphtalenone (1) and bis[2-hydroxy-κO–N-(2-pyridyl)-1-naphthaldiminato-κN]zinc(II) (2)
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Date
2000
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier Science Bv
Access Rights
info:eu-repo/semantics/closedAccess
Abstract
The Schiff base ligand (1) and its Zn(II) complex (2) have been synthesized and their crystal structures have been determined. Compound (1) crystallizes in the monoclinic space group C2/c with a = 26.993(2), b = 5.891(1), c = 16.000(2) W, P = 103.29(1)degrees, V = 2476.0(6) Angstrom(3), Z = 8 and D-x = 1.332 g cm(-3) Compound (2) crystallizes in the orthorhombic space group Pbca with a = 19.580(3), b = 9.416(2), c = 27.801(2) Angstrom, V = 5125.5(6) Angstrom(3), Z = 8 and D-x = 1.451g cm(-3) In the crystal structure of the free Schiff base ligand (1), the existence of a strong intramolecular N-H...O hydrogen bond INO = 2.572(4), N-H = 0.90(4), H...O = 1.759(4) Angstrom, N-H...O = 149.6(3)degrees] is observed. The C-N amine bond and C-N-C bond angle are 1.345(4)Angstrom and 124.4(3)degrees, respectively. The C3 = O1 and C4 = C5 bond lengths [1.274(4) and 1.351(5) Angstrom] are shortened by the pronounced quinoidal effect. In solution, compound (1) is in tautomeric equilibria (phenol-imine, O-H ... N keto-amine, O ... H-N forms), as supported by H-1 NMR and UV-visible data. In the crystal structure of the Zn(II) complex (2), zinc atom has a distorted tetrahedral coordination. One of the pyridine N atom of the ligands is in close contact with the Zn(II) atom [Zn1 ... N4 = 2.864(5) Angstrom].It is interesting that the C-N amine bond [1.345(4) Angstrom] in compound (1) changes to the imine bond [1.27(5) Angstrom] in the Zn(TI) complex (2). (C) 2000 Elsevier Science B.V. All rights reserved.
Description
Hokelek, Tuncer/0000-0002-8602-4382
Keywords
crystal structure of Schiff base ligand, tautomerism in Schiff bases, intramolecular hydrogen bond, synthesis of Schiff base ligands, spectroscopic studies of Schiff bases
Journal or Series
Journal Of Molecular Structure
WoS Q Value
Q3
Scopus Q Value
Q1
Volume
523
Issue
Citation
closedAccess
