Syntheses and solid state structures of cyclam-based copper and zinc compounds

Alves, Luís G.; Souto, Manuel; Madeira, Filipe; Adão, Pedro; Munhá, Rui F.; Martins, Ana M.

doi:10.1016/j.jorganchem.2013.11.015

Cited by 12 publications

(6 citation statements)

References 77 publications

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“…The [Zn( 13 )](ClO 4 ) 2 complex (Figure A) adopts a strained trigonal bipyramidal pentacoordinate geometry around the zinc(II) centre, typical of previously reported zinc(II) cyclams . The orientation of the macrocyclic N ‐substituents indicates that complex [Zn( 13 )](ClO 4 ) 2 adopts the trans ‐I configuration; this being the preferred stereochemistry of pentacoordinate cyclam complexes .…”

Section: Resultssupporting

confidence: 62%

Synthesis and Evaluation of 1,8‐Disubstituted‐Cyclam/Naphthalimide Conjugates as Probes for Metal Ions

Wong

Ast

et al. 2016

ChemistryOpen

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Fluorescent molecular probes for metal ions have a raft of potential applications in chemistry and biomedicine. We report the synthesis and photophysical characterisation of 1,8‐disubstituted‐cyclam/naphthalimide conjugates and their zinc complexes. An efficient synthesis of 1,8‐bis‐(2‐azidoethyl)cyclam has been developed and used to prepare 1,8‐disubstituted triazolyl‐cyclam systems, in which the pendant group is connected to triazole C4. UV/Vis and fluorescence emission spectra, zinc binding experiments, fluorescence quantum yield and lifetime measurements and pH titrations of the resultant bis‐naphthalimide ligand elucidate a complex pattern of photophysical behaviour. Important differences arise from the inclusion of two fluorophores in the one probe and from the variation of triazole substitution pattern (dye at C4 vs. N1). Introducing a second fluorophore greatly extends fluorescence lifetimes, whereas the altered substitution pattern at the cyclam amines exerts a major influence on fluorescence output and metal binding. Crystal structures of two key zinc complexes evidence variations in triazole coordination that mirror the solution‐phase behaviour of these systems.

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Section: Resultssupporting

confidence: 62%

Synthesis and Evaluation of 1,8‐Disubstituted‐Cyclam/Naphthalimide Conjugates as Probes for Metal Ions

Wong

Ast

et al. 2016

ChemistryOpen

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“…The structures of 4 are likely to be square pyramidal, as often observed for other pentacoordinated Cu II complexes supported by cyclam derivatives . However, one may not exclude the coordination of an additional oxygen atom of one CH 2 CH 2 CH 2 OH pendant arm of the cyclam ring, giving rise to a pseudo‐octahedral geometry, which was also observed for monocationic Cu II cyclam complexes …”

Section: Resultsmentioning

confidence: 89%

“…[37][38][39][40][41][42][43][44][45][46][47] However, one may not exclude the coordination of an additional oxygen atom of one CH 2 CH 2 CH 2 OH pendant arm of the cyclam ring, giving rise to ap seudo-octahedralg eometry, which was also observed for monocationicC u II cyclam complexes. [48] The IR spectra of complexes 5a and 5b show that the ligand framework bands are sensitivet om etal complexation and, as observed for complexes 4a and 4b,s hiftedt oh igher wavenumbers, in comparison with the free ligand (see Figures S5, S6, S11, and S12 in the Supporting Information). The spectra of 5a and 5b show broad intense vibrational bands due to the hydroxy groups of the CH 2 CH 2 CH 2 OH pendant arms at ñ = 3352 and 3412 cm À1 ,respectively.Inc omplex 5b,aband corresponding to the CF 3 group of the aromatic ring appears at ñ = 1327 cm À1 .T he presence of two bands at ñ = 870 and 922 cm À1 for 5a and at ñ = 764 and 858 cm À1 for 5b,w hich is attributed to the methylene vibration, are characteristico ft he cis isomer.…”

Section: Chemical Studiesmentioning

confidence: 75%

New Cyclams and Their Copper(II) and Iron(III) Complexes: Synthesis and Potential Application as Anticancer Agents

et al. 2019

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New cyclam derivatives (HOCH2CH2CH2)2(PhCH2)2Cyclam and (HOCH2CH2CH2)2(4-CF3 PhCH2)2Cyclam, as well as their CuII and FeIII complexes, were synthesized and characterized and their stability in cellular media was assessed. The cytotoxic effect of all compounds was examined on human cervical cancer (HeLa) cells, revealing strong anticancer activity. After 24 h, only complexes with the (HOCH2CH2CH2)2(4-CF3 PhCH2)2Cyclam ligand are cytotoxic, whereas after incubation for 72 h all compounds show significant antiproliferative effects. Notably, compounds containing 4-CF3 PhCH2 pendant arms on the cyclam ring revealed the most activity, with cytotoxicity values up to 12 times higher than those of cisplatin. All metal complexes seem to induce cell death through the formation of reactive oxygen species.

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“…The capability of py‐cyclam‐pyr to act as a recognition element for Cu 2+ ions was first studied by preparing the py‐cyclam‐pyr‐Cu species on a preparative scale, according to a literature procedure …”

Section: Resultsmentioning

confidence: 99%

A Cyclam‐Based Fluorescent Ligand as a Molecular Beacon for Cu²⁺ and H₂S Detection

2017

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A pentadentate cage‐like cyclam‐based fluorescent ligand has been designed, synthesized, and characterized by 1D and 2D NMR spectroscopic analysis. To further characterize the title ligand, ESI‐MS, UV/Vis spectroscopy, and fluorescence experiments have been also performed. Its suitability as a chemosensor for the detection of Cu2+ ions has been successfully explored with a variety of spectroscopic techniques (i.e., ESI‐MS, UV/Vis, and fluorescence). A Job's plot experiment, together with ESI‐MS experiments, indicate a 1:1 stoichiometry for the binding of Cu2+ to the cyclam‐based ligand. Fluorescence experiments corroborate this hypothesis. The resulting system is selective in the recognition of copper and is stable for a week, as assessed by fluorescence spectroscopy. The CuII complex has been isolated and tested as a fluorescent probe for the detection of H2S. NMR spectroscopy and ESI‐MS investigations have provided evidence that H2S recognition occurs through a copper‐displacement mechanism, as reported in the literature for different copper complexes. The system functions with a selective response to HS–, harnessing a concentration‐dependent “turn‐on” of the initial fluorescence intensity.

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Syntheses and solid state structures of cyclam-based copper and zinc compounds

Cited by 12 publications

References 77 publications

Synthesis and Evaluation of 1,8‐Disubstituted‐Cyclam/Naphthalimide Conjugates as Probes for Metal Ions

Synthesis and Evaluation of 1,8‐Disubstituted‐Cyclam/Naphthalimide Conjugates as Probes for Metal Ions

New Cyclams and Their Copper(II) and Iron(III) Complexes: Synthesis and Potential Application as Anticancer Agents

A Cyclam‐Based Fluorescent Ligand as a Molecular Beacon for Cu²⁺ and H₂S Detection

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Syntheses and solid state structures of cyclam-based copper and zinc compounds

Cited by 12 publications

References 77 publications

Synthesis and Evaluation of 1,8‐Disubstituted‐Cyclam/Naphthalimide Conjugates as Probes for Metal Ions

Synthesis and Evaluation of 1,8‐Disubstituted‐Cyclam/Naphthalimide Conjugates as Probes for Metal Ions

New Cyclams and Their Copper(II) and Iron(III) Complexes: Synthesis and Potential Application as Anticancer Agents

A Cyclam‐Based Fluorescent Ligand as a Molecular Beacon for Cu2+ and H2S Detection

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A Cyclam‐Based Fluorescent Ligand as a Molecular Beacon for Cu²⁺ and H₂S Detection