Syntheses and properties of mixed dinuclear copper(II) complexes with heterocyclic dithiocarbamates and a cyclic octadentate tertiary amine

Abstract

Five new Cu II complexes of general formula [Cu 2 (Rdtc)tpmc](ClO 4 ) 3 , (1)-(5), where tpmc and Rdtc ) refer to N,N¢,N¢¢,N¢¢¢-tetrakis(2-pyridylmethyl)-1,4,8,11-teraazacyclotetradecane and piperidine-(Pipdtc), 4-morpholine-(Morphdtc), 4-thiomorpholine-(Timdtc), piperazine-(Pzdtc) or N-methylpiperazine-(N-Mepzdtc) dithiocarbamates, respectively, have been prepared. Elemental analyses, conductometric and magnetic measurements, u.v./vis, i.r., e.p.r. and mass spectroscopy have been employed to characterize them. The complexes adopt an exo coordination of Cu II ions and tpmc. The dithiocarbamate ion joins both the sulphur and the copper atoms acting as a bridging ligand The presence of different heteroatoms in the piperidine ring influences the m(C'N) and m(C'S) vibrations which decrease in the order of the complexes: Pipdtc > N-Mepipdtc > Pzdtc > Morphdtc > Timdtc ligands. Attention has been paid to the detailed mechanism of the mass spectral fragmentation of the complexes. The g eff factors of the complexes have been also estimated by e.p.r. spectra. Finally, the complexes obtained demonstrate microbiologycal activity against some bacteria.

Antimicrobial and toxicological studies of some metal complexes of 4-methylpiperazine-1-carbodithioate and phenanthroline mixed ligands

“…Metal dithiocarbamates are now available for medicinal or for diagnostic use as radiopharmaceuticals and for diagnostic kit (17). Number of reports on antifungal (5,21), antibacterial (4,22,24,27,28), antialkylation (9,19), anticancer and apoptosis inducing activity (1) of the metal dithiocarbamate complexes of the mixed ligands …”

Spectroscopic properties and antimicrobial activity of dioxomolybdenum(VI) complexes with heterocyclic S,S’-ligands

“…The 950-1100 cm -1 region is associated with ν(CSS) vibrations and has been effectively used to differentiate between monodentate and bidentate Rdtcligands. 9,14 In the IR spectra of the obtained complexes, the presence of only one strong band in this region supports a symmetrical bidentate coordination of the dithio ligands, while a doublet expected in the case of monodentate coordination 9 was absent. New absorption bands in the 420-440 cm -1 region, absent in the spectra of the free Rdtc -ligands, are in good agreement with the available literature data.…”

“…The 1390-1430 cm -1 region is associated primarily with the thioureide vibration and is attributed to the ν(C N) vibrations of the S 2 C NR 2 bond 12,14 (Table I). This indicates a significant increase in double bond character of the C N bond, resulting in higher frequencies compared with the free Rdtc -ligands.…”

“…3,4 Moreover, dithiocarbamato (Rdtc -) ligands are known to form stable complexes with many transition metals. [5][6][7][8][9][10][11][12][13][14] Interest in dithiocarbamate complexes arises because of their versatile structures, depending on the manner of coordination, [15][16][17][18][19] and the type of their biological activity. [20][21][22][23][24] Additionally, these coordination compounds have intriguing properties, being good corrosion inhibitors in acidic media.…”

A Copper(II) Ion‐Selective Potentiometric Sensor Based on N,N′,N″,N′′′‐Tetrakis(2‐pyridylmethyl)‐1,4,8,11‐tetraazacyclotetradecane in PVC Matrix

“…Contrary to other cations (Ni 2þ , Co 2þ ), which need an additional bidentate ligand (dithiocarbamate orb-diketones) forming a bridge between the two metal atoms only Cu(II) is capable to form very stable complex with tpmc without any other ligands, too [35]. In that respect, its structure has the advantage of being relatively less rigid and thus gives structurally well-defined moiety [22,36], which delineates the preference of a certain ion. It seems to be a good explanation for sensor behavior and high selectivity of proposed electrode to copper(II) ions over other metal ions except Ag þ and Fe 2þ cations.…”