Synthesis, characterization, and applications of novel Co(II)‐pyridoxalphosphate‐Schiffbase/SBA‐15 as a nanocatalyst for the green synthesis of benzothiazole heterocycles

Abstract

Mesoporous heterogeneous santa barbara amorphous (SBA)‐15‐supported cobalt complex, as a novel nanocatalyst containing N–O chelating Schiff‐base ligand was successfully synthesized by the reaction of SBA‐15 and Cobalt(II)‐Schiff‐base complex. The Co(II)‐Schiff base complex also was prepared for the first time, by the reaction of pyridoxal 5′‐phosphate or PLP (biological active form of vitamin B6), 3‐(aminopropyl)‐triethoxysilane in methanol that complexation with CoCl2. The subsequent grafting of entitled complex to SBA‐15 afforded Co(II)‐PLP‐Schiff base/SBA‐15 mesoporous catalyst. Characterization of the product was carried out with powder X‐ray diffraction, Brunauer–Emmett–Teller nitrogen adsorption–desorption, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, atomic absorption spectroscopy, and inductively coupled plasma, Fourier‐transform infrared spectroscopy. The results revealed the retention of the textural properties and hexagonally uniform structures of SBA‐15 during the grafting procedure. This nanocatalyst was applied successfully for one‐pot synthesis of various benzothiazole heterocycles under green conditions. This catalyst is an active, reusable, and stable nanomaterial with no leaching of metal ions to the reaction medium. It was used for the synthesis of desired benzothiazole heterocycles by the cyclo‐condensation of aryl‐aldehydes with 2‐aminothiophenol with good to excellent yields and under green conditions.

Synthesis, structural elucidation, biological screening, and density functional theory calculations of Cu(II), Ni(II), Mn(II), and Co(II) complexes of 20 Z‐N‐((Z)‐2‐(6‐nitrobenzo[d]thiazol‐2‐ylimino)‐1,2‐diphenylethylidene)‐5‐nitrobenzo[d]thiazol‐2‐amine Schiff base ligand

“…The escalation in multidrug-resistant infections and cancer among development of civilization is a major altercation. In this study, the ligand and metal complexes have been synthesized and characterized by employing elemental analysis, 1 H and 13 C NMR spectroscopy, mass spectroscopy, and FTIR analysis. The HL2 ligand moiety suggests the structural donor atoms as N and S to the metal center.…”

“…The ligand field stabilization energy (LFSE) can be calculated through the following equation. [11][12][13][14][15][16][17] LFSEco 2þ oct: ð Þ¼8 Dq=83:6:…”

“…The derivatives of benzothiazole have attained significant attention nowadays owing to their antibacterial, antiviral, antipyretic, antiinflammatory, analgesic, anesthetic, and anticonvulsant properties. [9][10][11][12][13] The production of novel biologically active molecular hybrids dotted with remarkable chemotherapeutic properties make them ideal pharmaceutical candidates. A heterocyclic compound benzothiazole exhibits different electronic, liquid, and optical properties.…”

“…Herein, novel Schiff base N,N 0 -[(1Z,2Z)-1,2-diphenylethane-1,2-diylidene]bis(6-nitro-1,3-thiazol-2-amine) and corresponding Cu(II), Ni(II), Mn(II), and Co(II) metal complexes were successfully synthesized and characterized. The characterization of ligand and corresponding metal complexes was carried out by employing elemental analysis, 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy, mass spectroscopy, Fourier transform infrared spectroscopy (FTIR) analysis, molar conductance, magnetic susceptibility measurements, electronic spectra, electronic paramagnetic resonance (EPR) and density functional theory (DFT) studies. DFT calculations at B3LYP/6-311+G** level of theory have been executed to examine the equilibrium geometry of the ligand and metal complexes.…”

Ternary complexes of vanadium(IV) and titanium(IV) of Schiff bases as primary ligand: Synthesis, spectral characterization, biomedical applications, and molecular docking withSARS‐CoV‐2 Mpro

“…[ 11–13 ] Bhave et al synthesized single crystal of oxovanadium(IV)‐2‐hydroxybenzylidene amino)acetate using microwave as the source of energy. [ 14 ] Synthesis, characterization, and biological applications of metal complexes of pyridoxal phosphate [ 15 ] and 2‐hydroxyphenoxymethylfuran‐5‐carbaldehyde [ 16 ] Schiff base have been described. The antimicrobial activity of nine Ln(III) complexes of the Schiff base derived from the condensation of 2‐hydroxy‐1‐naphthaldehyde with 1,6‐hexanediamine was explored by Ajlouni et al [ 17 ] The structure of Mn(II), Fe(III), Co(II), Ni(II), and Zn(II) complexes of Schiff base obtained from 1,6‐hexanediamine and salicylaldehyde was described.…”