Paper Title
Studies on New Schiff Base and Legend MO(VI) Complexes with Anchored Type Ligand: Tailored Synthesis, Spectroscopic Characterization, DFT, and Anti-Corrosion Activity

Abstract
This paper deals with The reaction of new Schiff base ligand was synthesized bythe condensation of the 2-hydroxy-1-naphtheldehyde and phenyl hydrazine Schiff base 1-((E)-(p- phenyl)hydrazine)naphthalen-2-ol , 4 nitro phenyl hydrazine Schiff base 1-((E)-(p-nitro- phenyl)hydrazine)naphthalen-2-ol for complex of the composition [Mo(1-((E)-(p- phenyl)hydrazine)naphthalen-2-ol)2], [Mo(1-((E)-(p- phenyl)hydrazine)naphthalen-2-ol)(2 amino pyridine)] [Mo(1-((E)-(p-nitro-phenyl)hydrazine)naphthalen-2-ol)2], [Mo(1-((E)-(p-nitro-phenyl)hydrazine)naphthalen-2-ol)(2 amino pyridine)] have been synthesized of dioxomolybdenum (VI) complexes. These complexes are novel due to the presence of newly synthesized bidented type legend and anchored with 2 amino pyridine as a co-legend. The structure of ligand and complex 1-4 has been discussed in the light of molar conductance, electronic spectra, FT-IR, 1H-NMR, 13C-NMR and ESI-MS analysis. DFT was employed for geometry optimization of ligand and complexes. The FT-IR data have suggested that ligand is coordinated with metal through azomethine-N and phenolic-O. Correlation coefficients value between 0.995 - 0.993 shows satisfactory agreement in 1H-NMR and 13C-NMR. Synthesized complexes were screened for catalytic activity.The prepared ligands and their metal complexes have been assayed for their antimicrobial activity against fungi as well as Gram-positive and Gram-negative bacteria. The resulting data indicate the ability of the investigated compounds to inhibit the growth of micro-organismsin whichcomplex 1 manifested the highest activity among all the compounds. Minimum inhibitory concentration (MIC) of complex 1 against the growth of five micro-organisms wasdetermined which gives better response against As per gillusfumigatus and Bacillissubtilis in comparison to some selected standard drugs. Molybdenum and Tungsten are essential trace elements present in the human body, animals and plants. Metalloenzymes containing molybdenum and tungsten centers are present in almost all life forms. There are more than fifty enzymes are known in nature containing molybdenum. Some known enzymes have important functions in living systems, which is mainly characterized by oxygen transfer processes. Tungsten is found almost exclusively in archaea, an ancient form of unicellular life forms. Molybdenum, instead, is found widely in all biological systems. Both molybdenum and tungsten have a chemical versatility that is useful to biological systems: they are redox-active under physiological conditions ranging between oxidation states VI to IV. Oxidation state V is also reachable, so these systems can act as transductors between bielectronic and mono electronic systems. The majority of molybdenum and tungsten enzymes are oxotransferasesthat catalyze the transfer of an oxygen atom to a substrate, using O2 or H2O as source of oxygen. These reactions involve a proton-coupled electron transfer (PCET) between the substrate and a Fe-S cluster, a heme group or a flavine.Molybdenum complexes are also known as the one of the best homogeneous catalysts for epoxidation with alkyl or aryl hydroperoxides as well as with other oxygen donors like H2O2, NaClO, PhIO, or KHSO5. Many of the molybdenum compounds catalyzed the epoxidaton of alkene in high yields. The yields of by-products are also lower compared to those from other metal complexes. In some reaction tungsten complexes also found displaying varying degree of catalytic activity. Schiff base are a class of ligands which are a center of attraction for researcher since last twenty five years, due to their coordinating ability, synthetic flexibility and a number of biological, anticorrosive and catalytic activity. Therefore, in view of above facts it will be interesting to synthesize some new Schiff base derivatives of molybdenum and tungsten and to explore their structure, reactivity and biological activity. Literature survey reveals that Schiff base ligands and their complexes with transition metals are area of intense research during last 25 years. Complexes of molybdenum and tungsten have exhibited good biological catalytic and biomimetic properties. Therefore in our opinion such a study will be illuminating not only due to chemical reactivity of the complexes formed but also due to their biological activity. These complexes may possess pharmacological propertywhich would be a boon to the pharmaceutical industries and by which they may develop new medicine against diseases which have no cure yet so far.