Synthesis, Characteristic Spectral Studies, and In Vitro Antimicrobial Activity of Organosilicon(IV) Derivatives of N‐Benzoylamino Acids

Abstract

Some organosilicon(IV) complexes of the formulae Me₂SiL₂ and R₃SiL (where L = monoanoion of N‐benzoylamino acids: hippuric acid [HL¹], N‐benzoyl‐DL‐alanine [HL²], N‐benzoyl‐DL‐valine [HL³] and N‐benzoyl‐DL‐leucine[HL⁴]; R = Me or Ph) have been synthesized and characterized by elemental analyses, molar conductance, electronic, infrared, ¹H and ¹³C NMR spectral studies. On the basis of the spectral studies a distorted trigonal‐bipyramidal and a distorted octahedral geometries around the central silicon atom have been suggested for all of the triorganosilicon(IV) compounds and dimethylsilicon(IV) compounds, respectively. The in vitro antimicrobial activity of the dimethyl‐ and trimethylsilicon(IV) complexes has also been screened against bacteria, such as Escherichia coli, Pseudomonas putida‐2252, Aeromonas formicans, Staphylococcus aureus‐740, and fungi, viz. Aspergillus niger ORS‐4, Aureobasidium pullulans‐1991, Verticillium dahliae‐2063 and Penicillium notatum‐1348. The thermal behaviour of some complexes using TGA (thermogravimetric analysis), DTA (differential temperature analysis) and DTG (derivative thermogravimetric) techniques is also discussed.

Keywords:

• Organosilicon(IV) derivatives
• N‐benzoylamino acids
• Antimicrobial activity
• Synthesis
• Characterization

Acknowledgments

We are thankful to the Head, Regional Sophisticated Instrumental Centre (RSIC), Central Drug Research Institute (CDRI), Lucknow for providing CHN analyses, and ¹H and ¹³C NMR spectra of the samples. Our sincere thanks are offered to Dr. R. P. Singh and the Head, Biosciences and Biotechnology Department, Indian Institute of Technology Roorkee (formerely University of Roorkee), for providing laboratory facilities for screening the antimicrobial activity of the samples.