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.

Keywords:

• Mixed-ligand complex Cd(II)
• 1,1-Dicyanoethylene-2,2-dithiolate
• 1,3-Diaminopropane
• X-ray diffraction
• 2D chain structure
• antifungal activity

Acknowledgments

The corresponding author, Dr. Arijit Das (Principal Investigator, SERB, DST Project, New Delhi), Department of Chemistry, Ramthakur College, Agartala, Tripura, India is grateful to SERB, DST, Govt. of India, New Delhi for their financial assistance (Sanction no. – SERB/F/5537/2013-14 dated 27/11/2013 and D.O. No. SB/EMEQ – 014/2013). The author is also grateful to the Head, RSIC, NEHU, Shillong for microanalysis and IIT, Guwahati for doing NMR spectroscopy.

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

This work was supported by the Science and Engineering Research Board [grant number SB/EMEQ – 014/2013], [grant number SERB/F/5537/2013-14 27/11/2013]. The authors wish to acknowledge the assistance of Dr. Matthias Zeller in the data collection and NSF [grant number 0087210], Ohio Board of Regents [grant number CAP-491], and Youngstown State University for funds to purchase the diffractometer.