A comparative study of steric effects of nickel(II) complexes containing 12-membered macrocyclic ligands

Smierciak, R. C.; Passariello, J. V.; Blinn, Elliott L.

doi:10.1021/ic50176a046

Cited by 33 publications

(11 citation statements)

References 2 publications

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“…The large band located at 2,923 cm -1 can be assigned to asymmetric stretching of CH 2 groups [57] while the shift at 2,959 cm -1 is attributed to vibrations of CH 2 groups [58]. N-H stretching mode are characterized by the vibrational features observed around 3,250 cm -1 , but the splitting on the corresponding band in two components (3,230 cm -1 and 3,260 cm -1 ) is an indication of non equivalency between the local environment of the bonded hydrogen atoms [59]. A tentative explanation for such splitting can be suggested from the computational work performed on cyclam-Ni molecules reported in Table 1.…”

Section: Methodsmentioning

confidence: 98%

Mesoporous Silica Functionalized by Cyclam–Metal Groups: Spectroscopic Studies and Numerical Modeling

Makowska‐Janusik

Kassiba

Errien

et al. 2010

J Inorg Organomet Polym

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Mesoporous silica functionalized by cyclammetal molecules were investigated by spectroscopic methods including Raman, IR, UV-VIS absorption and EPR technique. To analyse quantitatively the physical features, numerical models were developed using the density functional theory method. Thus, the construction of molecular geometries and their optimisation analysis were achieved on the cyclam-metal molecules in vacuum as well as constrained by the host mesoporous silica matrixes. In this context and with regard to the paramagnetic nature of the metals chelated by cyclam molecules, EPR technique allows probing the metal environments which can be compared to theoretical results inferred from numerical models. The vibrational and optical properties were exhaustively investigated and the assignment of the main features was quantitatively discussed thanks to the carried out numerical analyses. The developed approach point out the possibility to define a targeted application of such functional materials based on the possibility to fine tune the absorption features in a wide wavelength range by stabilizing defined configurations of the cyclam-metal groups.

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Section: Methodsmentioning

confidence: 98%

Mesoporous Silica Functionalized by Cyclam–Metal Groups: Spectroscopic Studies and Numerical Modeling

Makowska‐Janusik

Kassiba

Errien

et al. 2010

J Inorg Organomet Polym

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“…For example, other transition metal cations such as Ni 2+ or Mn 2+ did not produce any enhancement of the emission of either QD 620 -cyclam or QD 620 -cyclen, even though it is known that complexes of cyclam and cyclen with those metals are easily formed in solution. 48,49 On the other hand, Cu 2+ , Fe 3+ , Fe 2+ , and Co 2+ produced the quenching of QD-azamacrocycle conjugate luminescence, but also the quenching of QD-MPA at the same rate. It is known that redox-active transition metals (such as Cu, Fe, and Co) when bound to the receptor can quench the fluorescence of a nearby fluorophore through an electron-transfer mechanism.…”

Section: Scheme 1 Photogenerated Hole-transfermentioning

confidence: 99%

Azamacrocycle Activated Quantum Dot for Zinc Ion Detection

2008

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A new fluorescent nanosensor family for Zn (2+) determination is reported based on azamacrocycle derivatization of CdSe/ZnS core/shell quantum dot nanoparticles. They are the first zinc ion sensors using QD nanoparticles in a host-guest and receptor-fluorophore system. Three azamacrocycles are demonstrated as receptors: TACN (1,4,7-triazacyclononane), cyclen (1,4,7,10-tetraazacyclododecane), and cyclam (1,4,8,11-tetraazacyclotetradecane). Azamacrocycles conjugated to QDs via an amide link interact directly with one of the photoinduced QD charge carriers, probably transferring the hole in the QD to the azamacrocycle, thereby disrupting the radiative recombination process. When zinc ion enters the aza-crown, the lone pair electrons of the nitrogen atom become involved in the coordination and the energy level is no longer available for the hole-transfer mechanism, switching on the QD emission and a dramatic increase of the fluorescence intensity results, allowing the detection of low concentrations of zinc ions. Using this operating principle, three zinc ion sensors based on CdSe-ZnS core-shell QD nanoparticles showed a very good linearity in the range 5-500 microM, with detection limits lower than 2.4 microM and RSDs approximately 3% ( n = 10). In addition, the versatility of the sensors was demonstrated, since different sizes (and colors) of QDs can be employed and will respond to zinc in a similar way. In a study of interferences, the zinc-sensitive QDs showed good selectivity in comparison with other physiologically important cations and other transition metals tested. The results from fetal calf serum and samples mimicking physiological conditions suggested very good applicability in the determination of zinc ion in physiological samples.

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“…The cyclen ring is too small to accommodate nickel(II), copper(II), or zinc(II) ions within the ring plane. [30,31] Thus, its stabilizing macrocyclic effect is lower than that of cyclam.…”

Section: Discussionmentioning

confidence: 99%

“…Cyclen (cyclen ϭ 1,4,7,10-tetraazacyclododecane) is too small to accommodate divalent metal ions such as Ni 2ϩ , Cu 2ϩ , or Zn 2ϩ within the ring plane. [30,31] Conjugates of cyclen with naphthyl [32,33] and dansyl [34] chromophores have been synthesized as receptors for divalent metal ions such as Zn 2ϩ and Cd 2ϩ . Its zinc(II) complexes have also been described as recognition units for nucleobases [35,36] and phenothiazine.…”

Section: Introductionmentioning

confidence: 99%

Selective Recognition of Copper(II) by a Water-Soluble, Emitter-Receptor Conjugate Containing a Ruthenium Chromophore, a Lysine Bridge, and a Cyclen Unit

Geißer

König

Alsfasser

2001

Eur. J. Inorg. Chem.

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Keywords: Bioinorganic chemistry / Amino acids / Luminescence / Macrocyclic ligands / Copper / Ruthenium / Molecular recognitionThe amino acid derivative [H-Lys{Ru(bipy) 2 m}-cyclenH 2 ](PF 6 ) 5 (7; Lys = lysine, bipy = 2,2Ј-bipyridyl, m = 4-carbonyl-4Ј-methyl-2,2Ј-bipyridyl, cyclen = 1,4,7,10-tetraazacyclododecane) has been synthesized. A modular approach was taken which involves only standard amide-coupling methods well-known from peptide synthesis. Compound 7 is readily soluble in water. It contains a luminescent ruthenium chromophore and a cyclen ligand which serves as a binding site for metal ions. The emission of 7 is pH-independent but

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A comparative study of steric effects of nickel(II) complexes containing 12-membered macrocyclic ligands

Abstract: Substitution on the nitrogen atoms on a polyamine ligand has been shown to have a major effect on the stoichiometry, the geometry, and the electronic configuration of nickel(II) complexes.1•2 For example, by employing diamine ligands, one

Cited by 33 publications

References 2 publications

Mesoporous Silica Functionalized by Cyclam–Metal Groups: Spectroscopic Studies and Numerical Modeling

Mesoporous Silica Functionalized by Cyclam–Metal Groups: Spectroscopic Studies and Numerical Modeling

Azamacrocycle Activated Quantum Dot for Zinc Ion Detection

Selective Recognition of Copper(II) by a Water-Soluble, Emitter-Receptor Conjugate Containing a Ruthenium Chromophore, a Lysine Bridge, and a Cyclen Unit

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