Cobalt(II) complexes with aromatic carboxylates and N-functionalized cyclam bearing 2-pyridylmethyl pendant arms

Vučković, Gordana; Stanić, Vojislav; Sovilj, P Sofija; Antonijević-Nikolić, Mirjana; Mrozynski, J.

doi:10.2298/jsc0509121v

Cited by 19 publications

(17 citation statements)

References 25 publications

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“…The strongest interaction between the divalent metal(II) ion and the oxygen atoms of deprotonated carboxylic acid groups is reflected in the shortest distances for M-O bonds of 2.047(3) and 2.057(3) Å (2a), and of 2.109 and 2.116 Å (2b), respectively (Table 2). These metal-oxygen bond length distances are in accordance with the literature data of similar O-containing mononuclear Co(II) and Mn(II) complexes[48][49][50][51][52][53][54][55][56][57]. The O-donor atoms of both Monensin molecules occupy the equatorial plane of M 2+ with a deviation of ca.…”

supporting

confidence: 90%

First Divalent Metal Complexes of the Polyether Ionophore Monensin A:X-Ray Structures of [Co(Mon)2(H2O)2] and [Mn(Mon)2(H2O)2] and their Bactericidal Properties

Pantcheva

Mitewa²,

Sheldrick³

et al. 2008

CDDT

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The complexation of carboxylic acid Monensin A (MonH, 1a) with CoCl2.6H2O and MnCl2.4H2O leads to the formation of mononuclear complexes [Co(Mon)2(H2O)2], 2a and [Mn(Mon)2(H2O)2], 2b, respectively. The unique crystal structures of 2a and 2b were determined by X-ray crystallography. The complexes crystallize in the monoclinic space group P2 1 with an octahedrally coordinated transition metal center forming the crystallographically centrosymmetric chromophore CoO6 or MnO6, respectively. Two molecules of Monensin A act bidentately through their carboxylate moiety and a hydroxyl group, and two water molecules are additionally trans-coordinated. Although the transition metal ions are not bound into the cavity of the ligand, the unusual bidentate coordination mode of the ionophore induces its "pseudo-cyclization" forming 22-membered cycles further stabilized by a number of H-bonds. The complexes are the first example of divalent metal complexes of the monovalent polyether ionophore. The parallel study on the complexation ability of the potassium complex of Monensin A (MonK, 1b) towards Co(II) and Mn(II) showed the formation of the isostructural complexes 2a and 2b accompanied by loss of the potassium ion due to the new coordination mode of the ligand. The biological tests performed with the antibiotic MonH and the corresponding metal(II) complexes show greatly enhanced antimicrobial activity of complexes 2a-b against Gram(+)-bacteria.

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supporting

confidence: 90%

First Divalent Metal Complexes of the Polyether Ionophore Monensin A:X-Ray Structures of [Co(Mon)2(H2O)2] and [Mn(Mon)2(H2O)2] and their Bactericidal Properties

Pantcheva

Mitewa²,

Sheldrick³

et al. 2008

CDDT

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“…In contrast, a broad band at 540 nm (e = 18 M À1 cm À1 ) was observed in the spectrum of 3 in MeOH solution. The position of the band and lower molecular absorbance of the complex in polar solvents are in agreement with an additional coordination of H 2 O or MeOH molecules, changing the tetrahedral environment around Co(II) ion to an octahedral one [51,59].…”

Section: Spectroscopic Characterization Ofmentioning

confidence: 54%

“…The unidentate coordination of carboxylate ion to Mn(II) is confirmed by appearance of asymmetric m(CO 2 ) asym at 1600 cm À1 and symmetric m(CO 2 ) sym at 1400 cm À1 (Dm = 200 cm À1 , Dm = m(CO 2 ) asym À m(CO 2 ) sym ). In the case of a non-deprotonated carboxyl group (1a) m(CO) is observed at 1700 cm À1 , while the deprotonated carboxyl group of 1b, engaged in H-bond formation, absorbs at 1540 cm À1 and 1390 cm À1 , respectively [41,[49][50][51].…”

Section: Spectroscopic Characterization Ofmentioning

confidence: 99%

Synthesis, structure and antimicrobial activity of manganese(II) and cobalt(II) complexes of the polyether ionophore antibiotic Sodium Monensin A

Dorkov

Pantcheva

Sheldrick

et al. 2008

Journal of Inorganic Biochemistry

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“…The values of the molar conductivities for complexes 1 and 2 (Table I) corresponded to a 1:2 type of electrolyte. 26 The absorption maxima and intensities of peaks in the Vis spectra of the complexes 1-6 (Table II) 27 were similar and corresponded to d-d transitions in high-spin Co(II) complexes of low symmetry. 28 The ε values for complex 2 containing CH 3 COO − are larger than those for the complex 1 containing HCOO − (Table II).…”

Section: Resultsmentioning

confidence: 86%

High-spin binuclear Co(II) complexes with a pendant octaazamaclocycle and carboxylates

Vučković¹,

Tanasković²,

Miodragović³

et al. 2007

JSCS

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Three new binuclear Co(II) mixed-ligand complexes with N,N′,N′′,N′′′-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane (tpmc) and mono-or dicarboxylate ligands were prepared and some of their physical properties were determined. The general formulas: [Co 2 (HCOO) 2 tpmc](ClO 4 ) 2 ·4H 2 O, [Co 2 (CH 3 COO) 2 tpmc](ClO 4 ) 2 and [Co 2 (tpht)tpmc](ClO 4 ) 2 ·4H 2 O (tphtH 2 = terephthalic acid) were proposed on the basis of elemental analyses (C,H,N) and molar conductivity. UV/Vis absorption and IR spectra, magnetic and CV measurements were used to study their geometries and properties. For the monocarboxylate complexes, an exo coordination of Co(II) with four nitrogens from tpmc and bis-bidentate bonded HCOO -/CH 3 COO -in the trans position is assumed. Tpmc adopts the chair conformation. For the dicarboxylate complex, it is supposed that a terephthalate dianion, as well as methylene chains from cyclam bridge two Co(II) atoms, while tpmc is in the boat conformation. The complexes were stable against chemical and electrochemical oxidation of Co(II) to Co(III). The data are compared with those for the previously published Cu(II) complexes containing the corresponding ligands and mutual similarities or differences were considered. Finally, some antibacterial activity of the complexes was found.

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Cobalt(II) complexes with aromatic carboxylates and N-functionalized cyclam bearing 2-pyridylmethyl pendant arms

Cited by 19 publications

References 25 publications

First Divalent Metal Complexes of the Polyether Ionophore Monensin A:X-Ray Structures of [Co(Mon)2(H2O)2] and [Mn(Mon)2(H2O)2] and their Bactericidal Properties

First Divalent Metal Complexes of the Polyether Ionophore Monensin A:X-Ray Structures of [Co(Mon)2(H2O)2] and [Mn(Mon)2(H2O)2] and their Bactericidal Properties

Synthesis, structure and antimicrobial activity of manganese(II) and cobalt(II) complexes of the polyether ionophore antibiotic Sodium Monensin A

High-spin binuclear Co(II) complexes with a pendant octaazamaclocycle and carboxylates

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