We have synthesized a series of ligands (1, 3, 4, 6 and 7) and some of their complexes with Ni(II), Cu(II) and Pt(II) (2, 5, 8 and 9). These compounds were studied and characterized by elemental analysis, IR and UV-Vis spectra, conductivity measurements in solution, FAB+/MS, 1H and 13C NMR, ESR, etc. Compound 7 crystallized in the orthorhombic space group P2(1)2(1)2(1), with Z = 4. Unit cell parameters were as follows: a = 21.307(2) A, alpha = 90 degrees, b = 12.498(1) A, beta = 90 degrees, c = 7.7232(4) A, gamma = 90 degrees. For seven of these compounds, the antifungal activity of a major pathogen responsible for important crop damage was studied. In general, inhibition by the ligands was higher than that of the complexes. When the thiourea was linked to some diethyl groups, the compounds showed higher antifungal activity than the morpholine groups. Compound 3 achieved total inhibition (100%).