Synthesis, Crystal Structure and Spectroscopic Studies of 2-{(E)-[2-Hydroxyphenyl)imino]methyl} Phenol Schiff Base Molecule

Abstract

A new Schiff-base complex 2-{(E)-[2-hydroxyphenyl)imino]methyl}phenol has been synthesized and characterized by elemental analyses, UV-VIS and IR spectroscopy and single crystal X-ray determination. The structure comprises two independent and similar molecules. The two independent molecules in the asymmetric unit are hydrogen bonded and have different conformations. In each molecule, C 13 H 11 NO 2 , adopt an E configuration about the azomethine C-N double bond. The complex crystallized in the triclinic space group P-1. Two benzene rings and azomethine group are practically coplanar, as a result of intramolecular hydrogen bonds involving the hydroxy O atom and azomethine N atom. Also hydroxy group of the molecule is the presence intermolecular O-HÁÁÁO hydrogen bonds with the hydroxy group of the other molecule.

Characterization of Schiff bases derived from 3,4-dimethoxybenzaldehyde: The crystal structure of N,N′-bis(3,4-dimethoxy-benzylidene)-2,2-dimethylpropane-1,3-diamine hydrate

“…In the crystal structure of 1, the water molecule is connected to the Schiff base by two O-H⋯N hydrogen bonds. The molecule adopts an E configuration about the N1=C7 and N2=C13 bonds with the azomethine nitrogen atoms [18]. The bond lengths and angles of 1 are very close to the corresponding ones found in Cambridge Structural Database [11][12][13][14]19].…”

Zero Field SMM Behavior and Magnetic Refrigeration in Rare Heterometallic Double Stranded Helicates of Cu2Ln2 (Ln = Dy, Tb, Gd)

“…Materials and Methods: Succinic dihydrazide, 3‐ethoxysalisaldehyde, salicylaldehyde, 2‐aminophenol and metal salts [DyCl 3 · 6H 2 O, GdCl 3 · 6H 2 O, TbCl 3 · 6H 2 O, Cu(NO 3 ) 2 · 2.5H 2 O and Cu(SO 4 ) 2 · 5H 2 O] were purchased from Sigma Aldrich. Ligands H 4 L 1 and H 2 L 2 were prepared by previously reported methods , . The elemental analyses were performed on Elemental Microvario Cube Elemental Analyser.…”

Eight Schiff bases derived from various salicylaldehydes: phenol–imine and keto–amine forms, conformational disorder, and supramolecular assembly in one and two dimensions

“…(VII), consistent with the presence of the 5-fluoro substituent in (VI). A very simple example of a Schiff base derived from unsubstituted salicylaldehyde is compound (VIII) and two polymorphs of this compound have been reported: one, crystallized from dioxane solution, is monoclinic in the C2/c space group, with Z 0 = 2 (Elerman et al, 1995), while the other, crystallized from a mixture of ethanol and chloroform, is triclinic P1, also with Z 0 = 2 (Tunç et al, 2009). In the monoclinic polymorph, one of the molecules is disordered, such that each ring adopts two orientations relative to the central spacer and, in each case, related to one another by a 180 rotation about the exocyclic C-C or C-N bonds.…”

“…With these considerations in mind and as part of a wider structural study of Schiff bases (Girisha, Yathirajan et al, 2017Girisha, Sagar et al, 2018), we have now investigated five newly synthesized Schiff bases of this type, compounds (I)-(IV) and (VI) (Scheme 2), whose structures are reported here, and we have also re-investigated three further examples, i.e. compounds (V) (Chattopadhyay et al, 2009), (VII) (Kaur et al, 2014) and (VIII) (Maciejewska et al, 1999;Tunç et al, 2009); of these, the structures reported for compounds (V) and (VIII) leave room for uncertainty about their constitutions, while that for (VII) overlooked the possibility of conformational disorder. All of (I)-(VIII) are derived from salicylic acid or one of its C-substituted analogues, and the new examples were all prepared by acid-catalyzed condensation between the salicylic acid precursor and an appropriately substituted aniline or, in the case of compounds (VI) and (VII), a 2-aminobenzothiophene.…”

“…480-485 K for (III) and 347-350 K for (IV)]. The preparations of compounds (V), (VII) and (VIII) have been described previously (Chattopadhyay et al, 2009;Kaur et al, 2014;Tunç et al, 2009); compound (VI) was prepared exactly as for (VII) (Kaur et al, 2014), except that 5-fluorosalicylaldehyde was used in place of unsubstituted salicylaldehyde, and crystallization was from acetonitrile rather than from the dichloromethane used for (VII) [m.p. 413-418 K for (VI)].…”