Synthesis, characterization, catalytic, electrochemical and thermal properties of tetradentate Schiff base complexes

Abstract

In this study, the Schiff base ligands H 2 L 1 -H 2 L 3 and their Cu II , Co II , Ni II , Fe III Ru III and VO IV complexes have been prepared and characterized by spectroscopic and analytical techniques. All the complexes are mononuclear. Keto-enol tautomeric forms of the ligands have been investigated in polar and apolar solvents. The ligands favor the keto-form in the C 7 H 8 and C 6 H 14 . The C-C coupling reaction of the 2,6-di-t-butylphenol has been investigated by the Co II and Cu II complexes. Thermal properties of the complexes have been assessed using thermal techniques and similar properties were found. In the Fe III and Ru III complexes, firstly, the coordinated water molecule is lost from the complex; in the second step, the chloride ion leaves the molecule in the 300-350°C temperature range. Finally, the complexes decompose to the appropriate metal oxide at the higher temperature ranges. The electrochemical properties of the complexes have been studied in the two different solvents (DMF and CH 3 CN).

Synthesis, characterization of palladium hydroxysalen complex and its application in the coupling reaction of arylboronic acids: Mizoroki–Heck type reaction and decarboxylative couplings

“…Herein, we report the synthesis of a palladium salen complex and its application as a catalyst in the Mizoroki-Heck type and the decarboxylative coupling reactions. The salen-OH ligand was prepared by the procedure reported in a previous article [40]. (Salen-OH)Pd (1, salen-OH_N,N′-bis(3,5-dihydroxysalicylidene)-ethylenediamine) was prepared by the reaction of the salen-OH ligand with PdCl 2 (CH 3 CN) 2 in ethanol for 12 h at 50°C (Scheme 1).…”

Crystal Structure and Thermal Decomposition Studies on Cobalt (II) Complex of 4-Chloro-2-((E)-(Isopropylimino)methyl)phenol

“…7 A wide variety of cobalt(II) complexes had been studied as model compounds for natural oxygen carriers and for their use in O 2 storage. 8 Even though many Schiff bases using 5-Chlorosalicy-laldehyde and amines had been studied, [9][10][11][12] as ligands, no work had been done with 5-chlorosalicylaldehyde and isopropylamine as the basic nucleus of Schiff bases. In addition, the thermal behaviour of this type of complex is almost unknown, because systematic thermal analysis has not been carried out.…”

“…This is true of the corresponding planes which were generated by symmetry. Bond angles also show that the coordination geometry about the cobalt atom is a distorted tetrahedral structure, with O1Co1N1, N1Co1N1A and O1Co1O1A angles of 96.39(11), 117.75 (17) …”

Synthesis, characterization and catalytic activity of Fe(III) complexes containing Schiff base and triphenylphosphine ligands

“…Among them, less explored iron based Schiff base complexes possess many advantages over traditional catalyst due to iron's copious, non-toxic, and inexpensive nature [12]. In this context, we present the synthesis of a series of novel Schiff base transition metal complexes of iron and their use as potential catalysts for the oxidation of allylic and benzylic alcohols under mild conditions using H 5 IO 6 as oxidant.…”

“…Indeed, there are numerous reports where these catalysts have been employed as part of a long synthetic strategy [3,4]. Recently, extensive research efforts have been invested in the development of catalysts based on the Schiff base transition metal complexes of Ru [5-7], Co [8,9], Cu [10], Ni [11] for the oxidation of alcohols to carbonyls.Among them, less explored iron based Schiff base complexes possess many advantages over traditional catalyst due to iron's copious, non-toxic, and inexpensive nature [12]. In this context, we present the synthesis of a series of novel Schiff base transition metal complexes of iron and their use as potential catalysts for the oxidation of allylic and benzylic alcohols under mild conditions using H 5 IO 6 as oxidant.…”