High yield synthesis of oxo-tungsten(V) porphyrin: Structural characterization of the hydrolyzed products

•Solid phase synthesis of oxo-tungsten(V) porphyrins.•Methodology developed gives almost quantitative yield of the desired complex.•On chromatographic purification hydrolyzed to monomeric species.•Structural characterization of the hydrolyzed products.•Spectral, electrochemical and DFT studies.

Thermal reaction of [W(NO)2(py)2(Cl)2] and TTPH2 in 1:1 stoichiometric ratio in the solid matrix of 4-chlorobenzoic acid resulted the formation of complex [WVO(TTP)((4-ClBZ)] (1) (where 4-ClBz = 4-chlorobenzoate ion and TTP = dianion of 5,10,15,20-meso-tetratolyporphyrin) in almost quantitative yield. The synthesized complex is characterized by different spectroscopic techniques like UV–Vis, FT-IR, ESR, ESI mass and by electrochemical studies. 1 on chromatographic purification stage using alumina column is hydrolyzed in the presence of traces of moisture present in the DCM/ethyl acetate and DCM/methanol used as the eluting solvent mixture leading to the formation of trans oxo-hydroxo and oxo-methoxo complexes respectively. The hydrolyzed complexes show varied electrochemical behavior compared to 1.

Graphical abstractSynthesis of 4-chlorobenzoato-(5,10,15,20-meso-tetratolylporphyrinato)-oxo-tungsten(V) is made by using [W(NO)2py2Cl2] as the metal source and porphyrin under thermal condition in the solid matrix of aromatic organic acid in almost quantitative yield. The product has been characterized by several spectral, electrochemical and by DFT studies. Its chromatographic purification yields newer hydrolyzed products. These are characterized by spectral and crystal structure analysis.Figure optionsDownload full-size imageDownload as PowerPoint slide