Nickel(II) complexes prepared from NNN type ligands and pseudohalogens : Synthesis, structure and thermal decomposition

Six nickel(II) complexes, using azide and thiocyanate ions, have been synthesized from bis-2,6(pyrazol-1-yl)pyridine (pp) and some methyl derivatives, 2-(3,5-dimethyl(pyrazol-1-yl)-6-(pyrazol-1-yl)pyridine (app) and bis-2,6(3,5-dimethyl(pyrazol-1-yl) pyridine (dmpp) in non-aqueous media. The complex structures were analyzed using elemental analysis, IR spectroscopy and thermogravimetry. Appropriate crystals of complex, containing azide [Nipp(N3)2]·MeOH (I) and thiocyanate [Nidmpp(SCN)2·MeOH] (VI) were prepared and the molecular structures determined using X-ray diffraction. Complex I was seen to be dinuclear as stated in literature, space group P21/n, monoclinic, a=10.503, b=10.681, c=13.291 Å, β=106.56° and Z=2 whereas complex VI was found to be mononuclear, space group P21/n, monoclinic,...

Two non-linear azide containing heteronuclear complexes: crystal structure and thermal decomposition

Bis-N,N'(salicylidene)-2,2'-dimethyl-1,3-propanediamine (LDMH2) has a high tendency to form polynuclear complexes. Two trinuclear complexes were obtained using this ligand and azide ions; (CuLDM)(2) center dot A Mn(N-3)(2) center dot A (DMF)(2), [(C19H20N2O2Cu)(2) center dot A Mn(N-3)(2) center dot A (C3H7NO)(2)] and (CuLDM)(2) center dot A Cd(N-3)(2) center dot A (DMF)(2), [(C19H20N2O2Cu)(2) center dot A Cd(N-3)(2) center dot A (C3H7NO)(2)]. The structures were identified with X-ray methods. TG and DSC methods were also employed to these complexes. Studies showed the (CuLDM)(2) center dot A Mn(N-3)(2) center dot A (DMF)(2) and (CuLDM)(2) center dot A Cd(N-3)(2) center dot A (DMF)(2) to be non-linear. Also mu-bridges were not encountered for the azide ions but were seen to form b...

Comparison of hydride generation atomic absorption and electrothermal atomic absorption techniques for determination of lead in blood

In this study, hydride generation atomic absorption and Zeeman background corrected electrothermal atomic absorption techniques was compared for determination of lead in blood. Blood samples were digested by microwave acid digestion and then Pb(IV) formation was realized by using (NH4)(2)Cr2O7 in 0.72 mol/l HNO3. To increase the stability of Pb(IV) different chelating agents were added. Malic acid was a more suitable chelating agent than lactic, tartaric and salicylic acids. After PbH4 was formed, NaBH4 was swept with argon into the heated quartz tube for atomization. (NH4)(2)Cr2O7 + HNO3 + malic acid medium was chosen as the most suitable medium. After these conditions were fulfilled, Pb levels of the samples were measured first by hydride generation atomic absorption and then by Zeeman b...

Synthesis, crystal structure, thermal decomposition, and XPS studies of homo and heterotrinuclear Cu(II)–Cu(II)–Cu(II) and Cu(II)–Ni(II)–Cu(II) complexes obtained from salpn type ligands

In this study, a mononuclear CuL complex was prepared by the use of bis-N,N′-(salicylidene)-1, 3-propanediamine (LH2) and Cu2+ ion. NiCl2 and NiBr2 salt were treated with this complex in dioxanewater medium and two new complexes [(CuL)2NiCl2(H2O)2] and [(CuL)2NiBr2(H2O)2)] with Cu(II)–Ni(II)–Cu(II) nucleus structure were obtained. In addition to this bis-N,N′-(2-hydroxybenzyl)-1,3-diaminopropane (LHH2) was prepared by the reduction of LH2 with NaBH4 in MeOH medium. The treatment of this reduced complex with Cu2+ ion resulted a complex [(CuLH)2CuCl2] with a structure of Cu(II)–Cu(II)–Cu(II). The complexes prepared were characterized by the use of elemental analysis, IR spectroscopy, thermogravimetric and X-ray diffraction methods. The crystal structures of [(CuL)2NiBr2(H2O)2] (СIF file CCDC...

Enrichment of copper and nickel with solid phase extraction using multiwalled carbon nanotubes modified with Schiff bases

Dogan Calhan, Selda

The behaviour of some Schiff bases in the presence of metal ions is very selective in complex formation. In this study, new, selective and easily prepared adsorbent materials have been developed. Multiwalled carbon nanotubes (MWCNTs) are quite suitable as supporting material for preparation of new solid phase adsorbents modified with Schiff bases due to their selective nature. Different Schiff bases were designed and synthesised as adsorbent agents for Ni(II) and Cu(II) ions, according to the literature, and MWCNTs were modified with these Schiff bases. The modification of CNTs was performed by adsorption from the alcoholic solution of Schiff base. The measurements of Ni(II) and Cu(II) ions were carried out using ICP-MS. Different parameters such as pH, model and eluent solution flow rates...

Two new mononuclear Ni(II) complexes with reduced ONNO type Schiff base

N, N′-bis (salicylidene)-1, 3-propanediamine (LH 2) and N, N′-bis (salicylidene)-2, 2′-dimethyl-1, 3-propanediamine (DMLH 2) were reduced to phenolic amines by using NaBH 4. Mononuclear complexes were obtained with Ni (II) in a N 3 O 6 coordination sphere with these amines and N 3–ions, in DMF media. It was established with the XRD studies that the coordination spheres were distorted octahedral and the complex obtained with LH 2 formed dimeric structures via phenolic OH bonds. The other complex was seen to have monomeric structure. The complexes were characterized by X-ray diffraction, elemental analysis, termogravimetry, IR spectroscopy and simple magnetic susceptibility (Gouy method). In addition, cyclic voltammetric studies have been performed.