Synthesis, characterization, and insecticidal activity of new tin (IV) complexes

GRAPHICAL ABSTRACT

ABSTRACT

A three-component reaction of dimethyltin dibromide with imidazo[1,2-a]pyridine, pyridine derivatives, or isoquinoline and allyl bromide in refluxing ethanol affords the ionic complex, bis(1-allylcycloiminium) dimethyltetrabromostannate (II). The reaction involves N-allylation of cycloimine accompanied by the coordination of two bromide ions with the tin atom of dimethyltin dibromide. The complexes have been characterized by infrared and ¹H NMR, ¹³C NMR, and ¹¹⁹Sn NMR studies. The X-ray crystal structure analysis of a complex reveals the tin atom to be hexacoordinated and the dimethyltetrabromostannate (II) anion having octahedral geometry. Some of the complexes tested for their insecticidal activity are found to exhibit strong activity against Tribolium castaneum insect with LC₅₀ ranging from 0.4 to 0.8 ppm.

KEYWORDS:

• Tin (IV) complexes
• N-heterocycles
• dimethyltetrabromostannate (II)
• ¹H- ¹¹⁹Sn-coupling
• ¹¹⁹Sn NMR
• insecticidal activity

Acknowledgments

We acknowledge the help from the DST for the crystallographic analysis of a sample at the University of Hyderabad, Hyderabad, India.