Synthesis, characterization and study of the catalytic properties of Zn(II) camphor derived complexes

Fernandes, Tiago A.; Ferraria, Ana Maria; Galvão, Adelino M.; Rego, A.M. Botelho do; Suárez, Ana C.; Carvalho, M. Fernanda N. N.

doi:10.1016/j.jorganchem.2013.10.040

Cited by 13 publications

(16 citation statements)

References 32 publications

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“…The camphor derivatives were synthesized under air using conventional organic synthesis techniques. Complexes ( 4 – 8 ) [ 28 , 31 ] and ligands (L II , L IV -L VIII ) [ 32 , 33 ] were synthesized following published procedures. Camphor, camphorsulfonic acid and the appropriate amines were purchased from Sigma-Aldrich (St. Louis, MO, USA).…”

Section: Methodsmentioning

confidence: 99%

Ag(I) camphorimine complexes with antimicrobial activity towards clinically important bacteria and species of the Candida genus

et al. 2017

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The present work follows a previous report describing the antibacterial activity of silver camphorimine complexes of general formula [Ag(NO3)L]. The synthesis and demonstration of the antifungal and antibacterial activity of three novel [Ag(NO3)L] complexes (named 1, 2 and 3) is herein demonstrated. This work also shows for the first time that the previously studied complexes (named 4 to 8) also exert antifungal activity. The antibacterial activity of complexes was evaluated against Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia contaminans and Escherichia coli strains, while antifungal activity was tested against the Candida species C. albicans, C. glabrata, C. parapsilosis and C. tropicalis. The antimicrobial activity of the complexes ranged from very high (complex 4) to moderate (complex 6) or low (complex 8), depending on the structural and electronic characteristics of the camphorimine ligands. Notably, the highest antibacterial and anti-Candida activities do not coincide in the same complex and in some cases they were even opposite, as is the case of complex 4 which exhibits a high anti-bacterial and low antifungal activity. These distinct results suggest that the complexes may have different mechanisms against prokaryotic and eukaryotic cells. The antifungal activity of the Ag(I) camphorimine complexes (in particular of complex 1) was found to be very high (MIC = 2 μg/mL) against C. parapsilosis, being also registered a prominent activity against C. tropicalis and C. glabrata. None of the tested compounds inhibited C. albicans growth, being this attributed to the ability of these yeast cells to mediate the formation of less toxic Ag nanoparticles, as confirmed by Scanning Electron Microscopy images. The high antibacterial and anti-Candida activities of the here studied camphorimine complexes, especially of complexes 1 and 7, suggests a potential therapeutic application for these compounds.

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Section: Methodsmentioning

confidence: 99%

Ag(I) camphorimine complexes with antimicrobial activity towards clinically important bacteria and species of the Candida genus

et al. 2017

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“…). L1 (bi‐camphor) and L2 (camphorquinoxaline) were chosen because they can accommodate more than one metal per ligand and thus bridge or chelate metal sites.…”

Section: Resultsmentioning

confidence: 99%

“…This oligomer is representative of the structure of the coordination polymer, since extension to higher order calculations become computationally prohibitive. In the calculated structure ( 1 ), the bi‐camphor ligand adopts a trans geometry in contrast with the cis geometry found in the free ligand …”

Section: Resultsmentioning

confidence: 99%

Cu(I) camphor coordination polymers: Synthesis and study of the catalytic activity for cyclization of 4‐pentyn‐1‐oic acid

Fernandes

Galvão

Rego

et al. 2014

J. Polym. Sci. Part A: Polym. Chem.

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The number of CuCl units per camphor ligand in [{CuCl} 2 L] n was extended to three or four in [{CuCl} 3 L] n (2) or [{CuCl} 4 L] n (1). The Hartree-Fock ab initio calculations support the polymeric structure of 1 and 2 that catalyze the cyclization of 4-pentyn-1-oic acid (A) forming 5-methylenedihydrofuran-2(3H)-one (B) and/or 2-methyl-5-oxotetrahydrofuran-2-ylpent-4-ynoate (C). The catalytic activity of 1, 2 and other polynuclear Cu(I) complexes (3-5) was evaluated under solvent free conditions and/or solution. In the absence of solvent, catalyst 2 displays the highest activity and selectivity (75.8/23.1, C to B ratio, at 5.4% loading) while 4 reaches the highest level of A ! B conversion (97.5 %) in solution. Selected reactions were followed by NMR and the kinetic constants calculated. A mechanism is proposed based on the equations used for the calculations.

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“…Camphorquinone (CQ) is an α‐dicarbonyl compound which does not contain a planar six‐membered ring but gains stability through the rigid bicyclic ring system [16] . Coupling of two CQ entities by a p ‐phenylenediimino bridge to yield bis‐imines such as bcqb has been observed early [17] but a coordination compound was reported only much later with redox‐inactive zinc and without structural characterization [18] . The following presents two electron transfer‐active homodinuclear complexes of bcqb, the structurally characterized dicopper system 1 n which is capped by ferrocene entities, and the diruthenium species 2 n .…”

Section: Introductionmentioning

confidence: 99%

Homodinuclear Complexes of [Cu(dppf)]⁺ or [Ru(bpy)₂]²⁺ with 1,4‐Bis(camphorquinoneimino)benzene (bcqb) as a Redox‐Active Bridging Ligand

et al. 2021

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The product μ‐bcqb from the reaction between p‐phenylenediamine and two equivalents of camphorquinone has been used as a potentially conjugated molecular bridge between two complex fragments [Cu(dppf)]+, dppf=1,1‘‐bis(diphenylphosphino)ferrocene, to yield 12+, and between two [Ru(bpy)2]2+ moieties, resulting in 24+. The molecular structure of 1(BF4)2 shows an intramolecular Cu−Cu distance of 8.04 Å and a torsionally twisted conformation of the bridge, while cyclic voltammetry, EPR, IR and UV‐vis‐NIR spectroelectrochemistry reveal two closely spaced one‐electron reductions and a ferrocene‐based two‐electron oxidation. Compound 2(PF6)4 exhibits at least three one‐electron reduction waves and one 2e‐oxidation, the former attributed to μ‐bcqb and the latter assigned to metal‐based processes showing no evidence for a Ru−Ru mixed‐valent intermediate. However, intra‐ligand based mixed valency with intense LLIVCT absorptions in the near infrared was observed for the metal coordinated μ‐bcqb.− and μ‐bcqb.3− bridges. The two examples 1n+ and 2n+ illustrate that a combination of physical methods is advantageous to analyze and define the correct electronic structures in complexes involving several metal centers and noninnocent ligand components.

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Synthesis, characterization and study of the catalytic properties of Zn(II) camphor derived complexes

Cited by 13 publications

References 32 publications

Ag(I) camphorimine complexes with antimicrobial activity towards clinically important bacteria and species of the Candida genus

Ag(I) camphorimine complexes with antimicrobial activity towards clinically important bacteria and species of the Candida genus

Cu(I) camphor coordination polymers: Synthesis and study of the catalytic activity for cyclization of 4‐pentyn‐1‐oic acid

Homodinuclear Complexes of [Cu(dppf)]⁺ or [Ru(bpy)₂]²⁺ with 1,4‐Bis(camphorquinoneimino)benzene (bcqb) as a Redox‐Active Bridging Ligand

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Synthesis, characterization and study of the catalytic properties of Zn(II) camphor derived complexes

Cited by 13 publications

References 32 publications

Ag(I) camphorimine complexes with antimicrobial activity towards clinically important bacteria and species of the Candida genus

Ag(I) camphorimine complexes with antimicrobial activity towards clinically important bacteria and species of the Candida genus

Cu(I) camphor coordination polymers: Synthesis and study of the catalytic activity for cyclization of 4‐pentyn‐1‐oic acid

Homodinuclear Complexes of [Cu(dppf)]+ or [Ru(bpy)2]2+ with 1,4‐Bis(camphorquinoneimino)benzene (bcqb) as a Redox‐Active Bridging Ligand

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Homodinuclear Complexes of [Cu(dppf)]⁺ or [Ru(bpy)₂]²⁺ with 1,4‐Bis(camphorquinoneimino)benzene (bcqb) as a Redox‐Active Bridging Ligand