Akademik Veri Yönetim Sistemi
SIGMA JOURNAL OF ENGINEERING AND NATURAL SCIENCES, cilt.25, sa.4, ss.359-366, 2007 (Scopus)
Dazomet (DTTT), (tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione) is soil fumigant used to control
weeds, soil fungicide, insects and nematodes. DTTT was synthesized and purified according to literature. The
protonation constant of DTTT in water-ethanol 70:30(v%) solution was determined by potentiometric
titration at constant temperature, t = (25±0.10
C) and 0.06 M NaClO4 as ionic background. The formation
constants of DTTT with Cu(II), Ni(II), Co(II), Zn(II), and Fe(III) were determined at the same conditions.
Purified nitrogen gas bubbled through the titrated solution to ensure stirring and neutral inert atmosphere.
Furthermore, the solution was stirred magnetically. The solutions were titrated with 5.10-3 M NaOH in
increments of 0.1 mL. The corresponding change in the pH value of the solution was measured. The
stochiometric protonation constants of the ligand were calculated using software called TITFIT developed by
Zuberbühler and Kaden(1). The formation constant of DTTT complexes with Cu(II), Ni(II), Co(II), Zn(II),
Fe(III) and species distribution curves were calculated and plotted using TITFIT computer program. The
values of the protonation constants for the ligand are log β1 = 9.49 (∆=2.36.10-2) and log β2= 13.50
(∆=2.38.10-2). The order of the stability constants of ML complexes with DTTT is Fe>Cu>Co>Ni>Zn and
that of MLH complexes is Co>Cu>Fe>Ni>Zn.