POTENTIAL ANTIFOULING AGENTS: COPPER, COBALT, AND NICKEL COMPLEXES OF 3-(2-ACETYL PYRIDYLIDENE) HYDRAZINO-5, 6-DIPHENYL-1,2,4-TRIAZINE

POTENTIAL ANTIFOULING AGENTS: COPPER, COBALT, AND
NICKEL COMPLEXES OF 3-(2-ACETYL PYRIDYLIDENE)
HYDRAZINO-5, 6-DIPHENYL-1,2,4-TRIAZINE
HEMAIDA H.A.E.*, DISSOUKY ALI A.EL** AND SADEK S.M.M.**
*National Institute of Oceanography and Fisheries, Alexandria, Egypt
** Faculty of Science, Alexandria University, Alexandria, Egypt
Key words: Antifouling, hydrazone, 1, 2, 4-triazine, metal complexes, toxicity, barnacle larvae.
ABSTRACT
Several copper, cobalt and nickel complexes of 3-(2-acetyl pyridylidene) hydrazino5,6-diphenyl-1,2,4-triazine (L) were prepared and their structure assigned through IR,
electronic spectra and magnetic moments at room temperature. The IR data suggested that
the ligand (L) acts as a neutral tridentate chelating agent in [LCoCl2
], [L2Co] Ac2.4H2O,
[L2 Co] (ClO4) 2
.2H2O, [L Cu Cl2
].2H2O and [L2Cu (H2O)] (ClO4
)2 complexes, but as a
neutral bidentate chelating agent in [L2 Ni] Ac2
.H2O, [LCuCl2
], [L2 Cu] Ac2
.2H2O and [L2
Cu] (ClO4
)2
. The electronic spectra and room temperature magnetic moments of the
complexes indicate a distorted triagonal bipyramidal structure for [LCoCl2
], [L Cu
Cl2
].2H2O and [L2Cu(H2O)](ClO4
)2
; and the existence of high spin-low spin cobalt(II),
while electronic and ESR spectra of [L2Co]Ac2
.4H2O and [L2 Co] (ClO4) 2
.2H2O indicate a
distorted octahedral. In case of [L2 Ni] Ac2
.H2O complex, the room temperature magnetic
moment indicates that there is equilibrium between square planar and tetrahedral
configurations and the percent of the tetrahedral geometry was estimated and found to be
30.4%. This geometry was changed into distorted octahedron if the electronic spectra was
recorded in pyridine or
- picoline. The electronic and ESR spectra of the two complexes
[L2 Cu] Ac2
.2H2O and [L2 Cu] (ClO4
)2 confirmed the presence of distorted tetrahedral
copper(II)complexes with d y- x
2- 2
as a ground state. Finally, upon heating the green
complex [L Cu Cl2
] .2H2O, the square planar brown compound [L Cu Cl2
] was obtained.
Some compounds were tested for their antifouling activity by measuring their toxicity
against barnacle’s larvae.