Abstract
Tetrachlorocyclodiphosph(V)azane of thiazole, H
2
L (1,3-diphenyl -2,4-bis(3-phenyl-2-iminothiazole)-2,2,4,4-tetrachlorocyclodiphos(V)azane, reacts with stoichiometric amounts of transition metal salts such as Co(II), Ni(II), and Cu(II) to afford colored complexes in a moderate to high yield. The structure of the isolated complexes was suggested based on elemental analyses, IR, molar conductance, UV-Vis,
1
H and
31
P NMR, mass spectra, solid reflectance, magnetic susceptibility measurements and dark electrical conductivity of solid state from room temperature up to 450 k. The data obtained obeyed the relation σ = σ ° exp (−E/2kT) over the temperature range 30-150°C. The observed conductivities of the different complexes follow the order Co < Ni < Cu. It is clear that this trend is depending on the decreasing of the ionic radii and the increasing stability of metal complexes. The calculated mobility of charge carriers is ranged from 10
−5
to 10
−9
cm
2
/V s suggesting that the conduction of the studied complexes takes place by hopping mechanism. The solid-state electrical conductivity obtained reveals that the metal complexes behave as semiconducting materials. The powder XRD studies confirm the amorphous nature of the complexes. From the elemental analyses data, 1: 2 (H
2
L: M) ratio is suggested and the complexes are found to have the general formula [(MX
2
)
2
(H
2
L)(H
2
O)
m
]. nH
2
O where M = Co(II) (X = SCN, n = 2, m = 0), Ni(II) (X = Cl, n = 4, m = 4), and Cu(II) (X = Cl, n = 2, m = 0). The complexes have been investigated in solution by the spectrophotometric molar ratio and conductometric methods. IR spectra show that the ligand is coordinated to the metal ions in a bidentate manner with NN donor sites of the imine NH and thiazole N. The UV-Vis, solid reflectance, and magnetic-moment data have shown that the ligand is coordinated to the metal ions in an octahedral, tetrahedral, or square planar manner. The molar conductance data show that the complexes are nonelectrolytes. The prepared complexes showed high to moderate bactericidal activity compared with the ligand.