Bijaya Paul

Six-coordinate cadmium(II) complex containing a bridging dithiolate ligand: synthesis, crystal structure and antifungal activity study

Abstract A mixed-ligand polymeric metal complex of Cd(II) has been prepared by reactions of Cd(NO3)2·4H2O with 1,3-diaminopropane (tn) and potassium salt of 1,1-dicyanoethylene-2,2-dithiolate and characterized on the basis of spectroscopy and single-crystal X-ray diffraction analysis. Single-crystal X-ray diffraction analysis reveals that the Cd(II) complex crystallizes in monoclinic space group P21/n with distorted octahedral coordination geometry. The Cd(II) complex was screened in vitro against fungal pathogens such as Synchytrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans (ATCC10231), and Trichophyton mentagrophytes by the disk diffusion method. The biological testing data of the primary ligand K2i-MNT·H2O and [Cd(tn)(i-MNT)]n indicate that the complex exhibits fungistatic antifungal activity, whereas K2i-MNT·H2O has no activity. The fungicidal properties of [Cd(tn)(i-MNT)]n showed that the cadmium complex was more bioactive than the parent ligand.

Cd(II) complexation with 1,1-dithiolate and nitrogen donors: synthesis, luminescence, crystal structure, and antifungal activity study

A new luminescent complex of Cd(II) with 1,1-dicyanoethylene-2,2-dithiolate [i-MNT2− = {S2C : C(CN)2}2−] with 1,3-diaminopropane (tn) and 4-methyl pyridine (γ-picoline) as secondary ligands has been synthesized and characterized on the basis of spectroscopy and single-crystal X-ray diffraction analysis. Single-crystal X-ray diffraction analysis reveals that cadmium(II) is five coordinate in a 1-D polymer. Biological screening effects in vitro of the synthesized complex has been tested against five fungi Synchytrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans (ATCC10231), and Trichophyton mentagrophytes by the disk diffusion method. A comparative study of inhibition zone values of K2i-MNT·H2O and {[Cd(tn)(iMNT)(4-MePy)]·4H2O}n (1) indicates that the complex exhibits antifungal activity, whereas K2i-MNT·H2O became silent on S. endobioticum, P. oryzae, H. oryzae, C. albicans (ATCC10231), and T. mentagrophytes. Graphical abstract A new luminescent complex of Cd(II) with 1,1-dicyanoethylene-2,2-dithiolate [i-MNT2− = {S2C:C(CN)2}2−] has been synthesized and characterized on the basis of spectroscopy and single-crystal X-ray diffraction analysis. Single-crystal X-ray diffraction analysis reveals that the cadmium(II) complex is five coordinate in a 1-D polymer. Biological screening in vitro of the complex has been tested against five fungi Synchytrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans (ATCC10231), and Trichophyton mentagrophytes by the disk diffusion method. The antifungal activity of the complex of Cd(II) is significant compared to K2iMNT on S. endobioticum, P. oryzae, H. oryzae, and T. mentagrophytes and proved to be crucial for the growth-inhibitor effect.

Synthesis and characterization of mixed ligand complexes of cobalt(II) with some nitrogen and sulfur donors

Mixed ligand complexes of Co(II) with nitrogen and sulfur donors, Co(OPD)(S–S) · 2H2O and Co(OPD)(S–S)L2 [OPD = o-phenylenediamine; S–S = 1,1-dicyanoethylene-2,2-dithiolate (i-MNT2−) or 1-cyano-1-carboethoxyethylene-2,2-dithiolate (CED2−); L = pyridine (py), α-picoline (α-pic), β-picoline (β-pic), or γ-picoline (γ-pic)], have been isolated and characterized by analytical data, molar conductance, magnetic susceptibility, electronic, and infrared spectral studies. The molar conductance data reveal non-electrolytes in DMF. Magnetic moment values suggest low-spin and high-spin complexes. The electronic spectral studies suggest distorted octahedral stereochemistry around Co(II) in these complexes. Infrared spectral studies suggest bidentate chelating behavior of i-MNT2−, CED2−, or OPD while other ligands are unidentate in their complexes.

Synthesis, crystal structure, and antifungal activity of a newly synthesized polymeric mixed ligand complex of Zn(II) with 1,1-dithiolate and nitrogen donors

A new mixed ligand complex of Zn(II) with 1,1-dicyanoethylene-2,2-dithiolate [i-MNT2− = {S2C:C(CN)2}2−] and 1,3-diaminopropane as ligands has been synthesized and characterized on the basis of spectroscopy and single-crystal X-ray diffraction analysis. Spectroscopic studies and single-crystal X-ray diffraction analysis reveal that the zinc(II) complex is tetrahedral and adopts a 1,3-diaminopropane-assisted linear polymeric assembly. The molar conductance data of the complex in DMF solution show non-electrolytic nature. Biological screening effects of the complex in vitro have been tested against five fungi Synchitrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans (ATCC10231), and Trichophyton mentagrophytes by the disk diffusion method. A comparative study of inhibition zone values of the primary ligand K2i-MNT·H2O and its synthesized complex indicates that the complex exhibits a fungistatic antifungal activity whereas K2i-MNT·H2O does not affect P. oryzae. Graphical Abstract Complex of Zn(II) with 1,1-dicyanoethylene-2,2-dithiolate [i-MNT2− = {S2C:C(CN)2}2−] and 1,3-diaminopropane.

Time Economic Innovative Methodology on the Prediction of Hybridization State of Heterocyclic Compounds

Context based learning approaches have been presented in this article as a way to enhance students interest in, as well as time economic learning outcomes from chemical education. In this article state of s-p hybridization of hetero atoms in heterocyclic compounds is empirically calculate from the number of bonds and delocalized lone pair of electrons associated with it. The article explores the results and gives implications for context-based teaching, learning and assessment.