<span style="font-size:12.0pt;font-family:"Times New Roman","serif"; mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language: EN-IN;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">Synthesis and charaterisation of cobalt complexes of salicylaldehyde 4-methoxybenzoyl hydrazone (H₂ smbhon)</span>

Abstract

A number of mononuclear and dinuclear cobalt(II) and cobalt(III) complexes have been isolated by reacting salicylaldehyde 4- methoxybenzoyl hydrazone (H₂smbhon) with CoCI₂.6H₂O, CO(NO₃)₂6H₂O, Co(CH₃COO)₂.4H₂O and Co(acac)₃ under varied reaction

conditions. [Co^II(smbhon)(H₂O)₃], isolated in this study, further reacts with pyridine (Py) dipyridine (dip) and triphenylphosphine (Ph₃P) in presence of NaCIO₄ to form new cobalt(III) complexes. Equimolar mixtures of [Co^II(smbhon)(H₂O)₃] and the ligands like

acetylacetone (Hacac), glycine (Hgly), N,N-bisethyleneacteophenoneimine (bape),N-phenylsalicylaldimine (Haslan), N-phenylorthohydroxyacetophenoneimine

(Hohapan), N-hydroxymethylsalicylaldimine (H₂salgly), N-2-hydroxyphenylsalicylaldimine (H₂saloap) or N-2-carboxyphenylsalicylaldimine (H₂salana) on refluxing in methanol-acetonitrile in the presence of oxygen at <i style="mso-bidi-font-style:normal">p</i>H ~ 9 afford coloured heterochelates of cobalt (III) in high yields. Structures of the complexes have been assigned on the basis of elemental analyses, molecular weights, molar conductances, magnetic moments and spectral (UV -vis and IR) studies. The physico-chemical data suggest that H₂smbhon can behave as a dibasic tridentate (ONO) donor, monobasic tridentate (ONO) (keto form) donor and monobasic bidentate (NO) donor depending on the reaction conditions.