Applications Of Hydrazonic Moiety And Coordination Compounds

Hydrazones are widely used in organic synthose, neon technology, and medicinal chemistry. Due to presence of azomethine group hydrazones possess different type of functions.

Contribution of hydrazonic entities

Biological applicability of hydrazone is very popular due to diversity of functional groups. Hydrazones are used as antimicrobial, anti-fungal and anticancer material. In many cases it was observed that the metal complexes of hydrazones show relatively more valuable results then their related ligands. Broad spectrum bio activity is found in hydrazones due to polydented linkage sites along with synthose of stable complexes. In hydrazones, presence of sp2 hybridized lone pair of electron on nitrogen (azomethine) possess biological significance. Pinheiro et al.synthesiseda series of derivatives of hydrazones which show antitubercular activities. 2-quinoxalinone-3-hydrazone derivatives are reported as antibacterial and anti-fungal activities.

Hydrazones itself and their meal complexes are successfully tested as anti-cancer properties. In women breast cancer still remain a threat Lindgren et al. developed benzothiazoke hydrazones active against breast cancer. Cisplatina famous anticancer drug, its synthesis and success results are encourage new researchers. The iron metal complex of salicyladehydeisonicotinoyl hydrazones show remarkable activities to protect cardiac cells from cardio toxicity and catecholamine oxidation. Vanadium complex of hydrazones possess potential towards insulin mimetic compounds .there are large number of oxodivnadium complexes with hydrazones legends have been synthesized for such type of properties

Antimicrobial Activities of ligand and their complexes

Hydrazone and their transition metal complexes exibit good activities against bacteria. Anti-bacterial properties of acid hydrazone and its metal complex is screened against B. subtilis and E. coli microbs.A series of ligand have been synthesized from p-toluidene and furylglyoxal, exhibits antibacterial activity against S. aureus, E. coli, P. vulgaris and Bacillus subtilis. Tridentate ligands and their transition metal complexes also exhibits antibacterial activities against Saureus, E.Coli, S, B.pumpilis and B.Subtilis.

Thallium (I) hydrazone complexes of benzothiazolines exhibits antibacterial activity against pathogenic bacteria . There are some heterocyclic Schiff bases also have been screened as antibacterial drugs.

A shif base derived from Isatin show antibacterial activity along with anti-HIV activity. The presence of thiazole rings and cyclobutane enhance the antimicrobial activity of schiff base ligand. The metal complexes of ortho-phenylene diamine with pyrolidione, pyridine possess notable antibacterial activity

Antifungal Activities of ligand and their complexes

Benzothiazole and thiazole show effective Activity aganint fungi. Due to substituent naphthyl group and methoxy halogen fungicidal activity of lignds and their metal complexes towards carvularia, increased.

A series of quinazolinone Schiff base have been reported as excellent antifungal drugs against Trichophyton rubrum, A.niger candida albicans, etc. There are number of Schiff bases including their transition metal complexes prepared by furyl glycoxal and furan with different amines possess biological activity against C.capsic, syncephalosturum racemosus,and Helminthosporium, grameneum. Some ligands synthesized byo–dimethyl thiophosphoramide and sali cylaldehyde along with their transition metal complexes with Ni(II), Zn(II) and Cu(II) were reported as effective drugs. They are used to kill Tetranychus bimaculatus. Mo an Mn complex used in controlling of many disease caused by A.alternata. Benzoylpridine Complexes of Cu (II) possess antifungal activities.

Antitumor Activities of ligand and their complexes

Anti-ulcer activity of some Salicylidiene anthranilic acid derivatives also reported and it has been found that their metal complexes of Cu show more efficiency in ulcer. A series of Schiff base along with coordination compounds of Co,Ni,Cu and Zn were prepared by L-alanine and dihydroxy benzaldehyde glycine show antitumor inhibition . The reactivity order is reported as Ni>Cu>Zn>Co. Some heterocyclic and aromatic amines are repored as good anti-tumor agents.

Analytical Applications of Hydrazones

Hydrazones have great tendency to react with metal ions and form colored solutions according to central metal ion.

Analytical applications of hydrazones were reported by Jain and Singh. Chandrasekhar et al. reported the spectrophotometric determination of monoxime isonicotinoyl hydrazone complexes ofCu (II) and Ni(II). “Off-on” fluorescent chemo sensor for a rhodamine B-based hydrazones Cu2+complexes reported by Tong et al. (2006)[190]. Hydrazones are useful tool for the sensing applications for of fluoride ions and acetate due to the presence of acidic N-H gropu in hydrazone. With the help of Cinnammaldehyde-4-hydroxybenzoyl hydrazone, a simple and suitable spectrophotometric method for the determination of Cd (II) in biological material is reported by Krishna et al.

Hydrazones as catalyst

All nitrogen containing ligands possess catalytic properties .Due to the presence of nitrogen hydrazone metal complexes also play an important role in catalysis.

In peroxidative oxidationof cycolohexene to cyclohex-2-enol andcyclohex-2-inone Cu(II) complexes of aroylhydrazones obtained from β –diketones may useas a catalyst. Metalloproteins which catalyze some biochemical processes is a potential of modern coordination chemistry. Large number ofnickel complexes have long been known as special catalysts for reactions of alkenes and alkynes, such as oligomerization or reductive coupling. Ni quickly released-electrons to π-acceptors, so olefin bonding is strong.

β-Hydride elimination tends to be with little speed with Ni relative to Pd; specifically, the energy barrier to Ni–C bond rotation to form a β-agostic hydride complex is normally noticeable higher for comparable Ni than Pd.

Jarvo and coworkers (2011) disclosed the first stereo specific Ni-catalyzed alkyl–alkyl cross-coupling reaction.