SPECTRAL AND BIOLOGICAL STUDIES OF COPPER(II) COMPLEXES OF 2-ACETYLPYRIDINE THIOSEMICARBAZONES WITH BULKY N-4-SUBSTITUENTS

Copper(II) complexes of a large number of 2-acetylpyridine N-4-alkylth iosemicarbazones were prepared and characterized. I.r., electronic and e.s.r. spectra of the complexes, as well as H-1 and C-13 n.m.r. spect ra of the thiosemicarbazones, were obtained. Both the thiosemicarbazon es and their complexes show either modest or no growth inhibitory acti vity against Aspergillus niger, but many have considerable activity ag ainst Paecilomyces variotii. There is a relationship between the antif ungal activity and size of the N-4-substituent for both the thiosemica rbazones and their copper(II) complexes.