The ‘complexes as metal’ strategy has been used to prepare new mixed ligand complexes containing Co(II), Ni(II) and Cu(II) terpyridine (terpy) with dithiooxamide (dto) and thiosemicarbazide (tsc). Characterization of the complexes has been accomplished by elemental analysis, molar conductance, thermal analysis, as well as electronic and IR spectral measurements. It is deduced that the coordination mode of the terpyridine is changed from tridentate in the binary complex to bidentate in the ternary one where the uncoordinated pyridine exists in the protonated form. The dto and tsc act as neutral bidentate ligands coordinating through either sulfur or sulfur and nitrogen atoms respectively, forming chelate ring systems

The ‘complexes as metal’ strategy has been used to prepare new mixed ligand complexes containing Co(II), Ni(II) and Cu(II) terpyridine (terpy) with dithiooxamide (dto) and thiosemicarbazide (tsc). Characterization of the complexes has been accomplished by elemental analysis, molar conductance, thermal analysis, as well as electronic and IR spectral measurements. It is deduced that the coordination mode of the terpyridine is changed from tridentate in the binary complex to bidentate in the ternary one where the uncoordinated pyridine exists in the protonated form. The dto and tsc act as neutral bidentate ligands coordinating through either sulfur or sulfur and nitrogen atoms respectively, forming chelate ring systems

The ‘complexes as metal’ strategy has been used to prepare new mixed ligand complexes containing Co(II), Ni(II) and Cu(II) terpyridine (terpy) with dithiooxamide (dto) and thiosemicarbazide (tsc). Characterization of the complexes has been accomplished by elemental analysis, molar conductance, thermal analysis, as well as electronic and IR spectral measurements. It is deduced that the coordination mode of the terpyridine is changed from tridentate in the binary complex to bidentate in the ternary one where the uncoordinated pyridine exists in the protonated form. The dto and tsc act as neutral bidentate ligands coordinating through either sulfur or sulfur and nitrogen atoms respectively, forming chelate ring systems

A series of novel dinuclear mixed-ligand complexes having the general formula [M2(tpt)(L)4]Cl4.nH2O where M = Ni(II), Co(II) or Cu(II); tpt = 2,4,6-tris(2-pyridyl)-1,3,5-triazine; L = dithiooxamide (dto) or thiosemicarbazide (tsc); n = 2 - 4, have been synthesized and characterized. The tpt molecule is flexidentate, where it can behave as di- or tridentate and either mono- or dinucleating ligand. The coordination mode of the tpt to the M(II) apparently occurs through pyridyl and a triazine nitrogen atoms. The binary complexes have the formulas [Co2(tpt)Cl4H2O].2H2O, [Ni(tpt)Cl]Cl.5.5H2O and [Cu(tpt)Cl2].3H2O. All the mixed-ligand complexes are dinuclear with bridging tpt molecule and having an octahedral structure. Binary Co(II) and Cu(II) complexes are probably penta coordinated. The complexes under study were characterized by chemical analysis, spectral, molar conductance and thermal studies

A series of novel dinuclear mixed-ligand complexes having the general formula [M2(tpt)(L)4]Cl4.nH2O where M = Ni(II), Co(II) or Cu(II); tpt = 2,4,6-tris(2-pyridyl)-1,3,5-triazine; L = dithiooxamide (dto) or thiosemicarbazide (tsc); n = 2 - 4, have been synthesized and characterized. The tpt molecule is flexidentate, where it can behave as di- or tridentate and either mono- or dinucleating ligand. The coordination mode of the tpt to the M(II) apparently occurs through pyridyl and a triazine nitrogen atoms. The binary complexes have the formulas [Co2(tpt)Cl4H2O].2H2O, [Ni(tpt)Cl]Cl.5.5H2O and [Cu(tpt)Cl2].3H2O. All the mixed-ligand complexes are dinuclear with bridging tpt molecule and having an octahedral structure. Binary Co(II) and Cu(II) complexes are probably penta coordinated. The complexes under study were characterized by chemical analysis, spectral, molar conductance and thermal studies

Ni[CH3(CH2)17PO3]·H2O was prepared and characterized by several techniques and the magnetic properties were measured by using a SQUID magnetometer. Preliminary refinement of the X-ray diffraction powder data by structure-less Le Bail fitting could be obtained and the compound was found to crystallise in the orthorhombic space group Pmn21 with a=5.478(7) Å, b=42.31(4) Å, c=4.725(3) Å. Ni(II)octadecyl phosphonate is lamellar and the structure consists of alternating inorganic and organic layers. The inorganic layers are interspersed by by-layers of the octadecyl substituent and van der Waals contacts are established between them. IR spectroscopy revealed all-trans configuration of the hydrocarbonic chain. A tilt angle of 48.2° between the chain axis and the (ac) plane could be estimated. The temperature dependence of the molar susceptibility plotted as 1/χ vs. T is linear above 100 K and it follows the Curie–Weiss law. The Curie, C, constant suggests the presence of Ni(II) ion in the S=1 spin state and the negative Weiss, θ, constant is indicative of antiferromagnetic nearest neighbour exchange interactions. Zero-field and field-cooled χ vs. T plots were then recorded. The plots show no overlap below 20 K, thus indicating that the compound is in an ordered magnetic state. The critical temperature has been located at the onset of the χ vs. T plot and was found to be TN=21 K. The magnetization vs. field plots, measured at different temperatures, provide the indication that the compound is a weak-ferromagnet below TN.

Ni[CH3(CH2)17PO3]·H2O was prepared and characterized by several techniques and the magnetic properties were measured by using a SQUID magnetometer. Preliminary refinement of the X-ray diffraction powder data by structure-less Le Bail fitting could be obtained and the compound was found to crystallise in the orthorhombic space group Pmn21 with a=5.478(7) Å, b=42.31(4) Å, c=4.725(3) Å. Ni(II)octadecyl phosphonate is lamellar and the structure consists of alternating inorganic and organic layers. The inorganic layers are interspersed by by-layers of the octadecyl substituent and van der Waals contacts are established between them. IR spectroscopy revealed all-trans configuration of the hydrocarbonic chain. A tilt angle of 48.2° between the chain axis and the (ac) plane could be estimated. The temperature dependence of the molar susceptibility plotted as 1/χ vs. T is linear above 100 K and it follows the Curie–Weiss law. The Curie, C, constant suggests the presence of Ni(II) ion in the S=1 spin state and the negative Weiss, θ, constant is indicative of antiferromagnetic nearest neighbour exchange interactions. Zero-field and field-cooled χ vs. T plots were then recorded. The plots show no overlap below 20 K, thus indicating that the compound is in an ordered magnetic state. The critical temperature has been located at the onset of the χ vs. T plot and was found to be TN=21 K. The magnetization vs. field plots, measured at different temperatures, provide the indication that the compound is a weak-ferromagnet below TN.

A series of novel dinuclear, mixed-ligand complexes having the general formula [M2(tpt)(L)4]Cl4 · nH2O where M=Ni(II), Co(II) or Cu(II); tpt = 2,4,6-tris(2-pyridyl)-1,3,5-triazine; L = dithiooxamide (dto) or thiosemicarbazide (tsc); n = 2-4, have been synthesized and characterized. The tpt molecule is flexidentate, where it can behave as di- or tridentate dinucleating ligand. The coordination mode of tpt to M(II) apparently occurs through the pyridyl and a triazine nitrogen atoms. All the mixed-ligand complexes are dinuclear with a bridging tpt molecule and having an octahedral structure. The complexes were characterized by chemical analyses, spectral, molar conductance and thermal studies.

The metal ion complexes [Co(II), Ni(II), Cu(II) and Cd(II)] of some azopyrazolopyrimidine derivatives have been prepared and characterized using elemental analyses, molar conductivity, electronic and IR spectra. The azopyrazolopyrimidines are characterized by a high tendency towards complex formation with the neutral molecules coordinating to the metal ion as bidentate ligands. It is concluded that the ligands are bonded to the metal ion through the - or β-nitrogen atom of the arylazo group and the carbonyl oxygen of the pyrazolone ring where six- or five-membered chelate rings are formed. The apparent formation constants of the complexes in solution have been determined.

Square-planar copper(II) and nickel(II) derivatives of the cis-dithiolate N2S2 ligand bis(N,N‘-2-mercapto-2-methylpropyl)-1,5-diazocyclooctane, (bme*daco)M, nucleate four CuICl moieties, forming MII2CuI4S4 clusters with unusual triply bridging thiolates, μ3-SR, in the topological form of adamantane. As determined by X-ray crystallography, the (bme*daco)M (M = Cu or Ni) metallothiolate serves as a bidentate ligand that bridges four CuI ions, utilizing all lone pairs on sulfurs. Further characterization by electrochemical and electronic spectral measurements suggests greater electron delocalization in the all-copper complex as compared to the NiCu heterometallic complex. Mass spectral data imply that the mixed-metal NiII2CuI4S4 is more stable toward CuCl loss than CuII2CuI4S4, a result that is corroborated by extraction of CuI by 1,2-bis(diphenylphosphino)ethane in the latter but not the former.