Neutral Ni(II) and Cu(II) complexes of tetraazatetraenemacrocyles

Grochala, Wojciech; Jagielska, Anna; niak, Krzysztof Wo; ckowska, Agnieszka Wi; Bilewicz, Renata; Korybut‐Daszkiewicz, Bohdan; Bukowska, J.; Piela, Lucjan

doi:10.1002/1099-1395(200102)14:2<63::aid-poc328>3.0.co;2-w

Cited by 23 publications

(12 citation statements)

References 15 publications

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“…This shift is not seen for the corresponding Ni II complexes (Figure 6) and reveals that the smaller ring in 4Cu has a more planar coordination environment of the copper centre, which allows reversible oxidation to the Cu III complex. We havenoted a similar dependence on the macrocycle size for other tetraazamacrocyclic complexes of copper 8. In these compounds a decrease of the Cu III reduction current was observed together with a shift to more positive potentials.…”

Section: Resultssupporting

confidence: 72%

“…The changes in the redox potential with increasing macrocycle size can be explained by assuming increased non‐planarity of the complex. The structures of the larger systems7,8 show deviations from planarity. On the other hand, in the case of 5Ni a diminished cathodic peak reveals an instability of Ni III and involvement of further chemical reactions.…”

Section: Resultsmentioning

confidence: 98%

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Tuning the Properties of Neutral Tetraazamacrocyclic Complexes of Copper(II) and Nickel(II) for Use as Host–Guest Compounds with Bismacrocyclic Transition Metal Cations

et al. 2006

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The synthesis and structural properties of tetraazamacrocyclic ligands and their neutral and protonated 14-, 15-and 16-membered complexes of Cu II and Ni II are described. Molecules of the free 14-membered ligands have a nonplanar, step-like structure of the central molecular fragments. Conformational changes are introduced upon protonation, with the protons pointing above and below the macrocycle plane. This prevents the formation of intramolecular N-H···N hydrogen bonds. On insertion of the transition metal ions a planar structure of the macrocycle is obtained, which has consequences for the electrochemical behaviour of the complexes. The deviations from planarity increase with increas-

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Section: Resultssupporting

confidence: 72%

Section: Resultsmentioning

confidence: 98%

Tuning the Properties of Neutral Tetraazamacrocyclic Complexes of Copper(II) and Nickel(II) for Use as Host–Guest Compounds with Bismacrocyclic Transition Metal Cations

et al. 2006

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“…One quasi-reversible oxidation wave was observed at E pa = 1.28 V can be assigned to the redox couple 27 of Ni(II)/Ni(III). The obtained redox behavior of the complex is similar to that of already reported NiN 4 complexes.…”

Section: 19mentioning

confidence: 99%

Structural, Electrochemical, DNA Binding and Cleavage Properties of Nickel(II) Complex [Ni(H₂biim)₂(H₂O)₂]²⁺of 2,2'-Biimidazole

Jayamani¹,

Thamilarasan²,

Ganesan³

et al. 2013

Bulletin of the Korean Chemical Society

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A nickel(II) complex [Ni(H 2 biim) 2 (H 2 O) 2 ](ClO 4 ) 2 ·H 2 O (1) of biimidazole ligand has been synthesized and characterized (Where H 2 biim = 2,2'-biimidazole). The single crystal X-ray diffraction of the complex shows a dimeric structure with six coordinated psudo-octahedral geometry. The cyclic voltammograms of complex exhibited one quasireversible reduction wave (E pc = −0.61 V) and an irreversible oxidation wave (E pa = 1.28 V) in DMF solution. The interaction of the complex with Calf-Thymus DNA (CT-DNA) has been investigated by absorption and fluorescence spectroscopy. The complex is an avid DNA binder with a binding constant value of 1.03 × 10 5 M −1. The results suggest that the nickel(II) complex bind to CT-DNA via intercalative mode and can quench the fluorescence intensity of EB bind to CT-DNA with K app value of 3.2 × 10 5 M −1. The complex also shown efficient oxidative cleavage of supercoiled pBR322 DNA in the presence of hydrogen peroxide as oxidizing agent. The DNA cleavage by complex in presence of quenchers; viz. DMSO, KI, NaN 3 and EDTA reveals that hydroxyl radical or singlet oxygen mechanism is involved. The complex showed invitro antimicrobial activity against four bacteria and two fungi. The antimicrobial activity was nearer to that of standard drugs and greater than that of the free ligand.

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“…[20] The 14-membered cyclidene units are relatively easy to obtain [21][22][23] and able to coordinate various transition metal ions, such as copper(II), nickel(II), but also iron(II), cobalt(II, III), palladium(II) and platinum(II, IV). [13,23] The rings are π-electron rich and almost ideally planar.…”

Section: Introductionmentioning

confidence: 99%

“…The dissociation to metal cation and free tetraaza [14]macrocyclic ligand was never observed in nickel(II) and copper(II) cyclidenes, as confirmed many times using NMR and mass spectrometry. [14][15][16][17][18][19][20][21][22] The removal of the metal ion can only occur in the presence of strong acids in dry solvents. Moreover, a large number of heterodinuclear bismacrocyclic complexes, containing both copper and nickel ion in one molecule have been previously obtained and neither the presence of free ligand in solution nor metal scrambling was observed.…”

Section: Introductionmentioning

confidence: 99%

Tetraaza[14]macrocyclic Transition Metal Complexes as DNA Intercalators

2015

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Six tetraazamacrocyclic copper(II) and nickel(II) complexes have been synthesised and their interactions with double‐stranded DNA (calf thymus DNA) have been studied using circular and linear dichroism, as well as other spectroscopic methods. The ability of these complexes to intercalate between DNA base pairs has been demonstrated qualitatively and confirmed by determining the stoichiometry and association constant values; these were found to range from 8.5 × 103 – 2.8 × 104 L mol–1. The nickel(II) complexes, being more electron‐deficient, seem to have higher binding abilities than guests containing the copper ion. It has also been shown that not only CD, but also linear dichroism, can be a very useful tool for carrying out qualitative DNA interaction studies.

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Neutral Ni(II) and Cu(II) complexes of tetraazatetraenemacrocyles

Cited by 23 publications

References 15 publications

Tuning the Properties of Neutral Tetraazamacrocyclic Complexes of Copper(II) and Nickel(II) for Use as Host–Guest Compounds with Bismacrocyclic Transition Metal Cations

Tuning the Properties of Neutral Tetraazamacrocyclic Complexes of Copper(II) and Nickel(II) for Use as Host–Guest Compounds with Bismacrocyclic Transition Metal Cations

Structural, Electrochemical, DNA Binding and Cleavage Properties of Nickel(II) Complex [Ni(H₂biim)₂(H₂O)₂]²⁺of 2,2'-Biimidazole

Tetraaza[14]macrocyclic Transition Metal Complexes as DNA Intercalators

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Neutral Ni(II) and Cu(II) complexes of tetraazatetraenemacrocyles

Cited by 23 publications

References 15 publications

Tuning the Properties of Neutral Tetraazamacrocyclic Complexes of Copper(II) and Nickel(II) for Use as Host–Guest Compounds with Bismacrocyclic Transition Metal Cations

Tuning the Properties of Neutral Tetraazamacrocyclic Complexes of Copper(II) and Nickel(II) for Use as Host–Guest Compounds with Bismacrocyclic Transition Metal Cations

Structural, Electrochemical, DNA Binding and Cleavage Properties of Nickel(II) Complex [Ni(H2biim)2(H2O)2]2+of 2,2'-Biimidazole

Tetraaza[14]macrocyclic Transition Metal Complexes as DNA Intercalators

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Structural, Electrochemical, DNA Binding and Cleavage Properties of Nickel(II) Complex [Ni(H₂biim)₂(H₂O)₂]²⁺of 2,2'-Biimidazole