Five- and six-coordinated cobalt(II), nickel(II), copper(II), and zinc(II) complexes of the pentadentate Schiff base ligands N,N'-bis[(2-hydroxy-5-Y-phenyl)phenylmethylene]-4-azaheptane-1,7-diamine (Y = Cl or Ch3) and N,N'-bis[(5-chloro-2-hydroxyphenyl)phenylmethylene]-4-thiaheptane-1,7-diami

Boge, Edward M.; Freyberg, Derek P.; Kokot, E.; Mockler, Garry M.; Sinn, Ekkehard

doi:10.1021/ic50173a016

Cited by 23 publications

(3 citation statements)

References 2 publications

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“…The spectrum of X1[Cu] exhibits also a shoulder at 450 nm and a broad band at 734 nm, associated with d−d transitions. These values exclude the tetracoordination of the Cu(II) 30 and suggest a geometry intermediate between a square planar pyramid and a trigonal bipyramid. , Indeed, the UV−visible literature data in relation to crystallographic data associate a square planar pyramid with an absorption band in the vicinity of 550−670 nm whereas a trigonal bipyramid displays a band in the vicinity of 800−850 nm. , …”

Section: Resultsmentioning

confidence: 95%

Hybrid Materials Containing Metal(II) Schiff Base Complex Covalently Linked to the Silica Matrix by Two Si−C Bonds: Reaction with Dioxygen

et al. 2003

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A bis-silylated pentadentate Schiff base formed from substituted salicylaldehyde and bis(3-aminopropyl)amine has been prepared and isolated to give rise via the sol−gel process to hybrid materials containing metal Schiff base complexes covalently bonded to the silica matrix. For that purpose, two routes of complexation have been investigated: the first corresponds to the hydrolysis and polycondensation of the bis-silylated metal Schiff base complex (route A) and the second to the hydrolysis and polycondensation of the bis-silylated Schiff base followed by the complexation of organic moieties immobilized on silica (route B). We have shown that the geometry of metal Schiff base complexes immobilized on silica is a function on the route of preparation of materials. Furthermore, the study of the O2-binding capacity of these materials revealed that only the hybrid materials prepared under well-controlled experimental conditions via route A are able to bind notably dioxygen, showing thus the versatility of the sol−gel approach.

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Section: Resultsmentioning

confidence: 95%

Hybrid Materials Containing Metal(II) Schiff Base Complex Covalently Linked to the Silica Matrix by Two Si−C Bonds: Reaction with Dioxygen

et al. 2003

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“…The electronic spectra of the three compounds, recorded in acetonitrile, show absorption bands at 656, 638, and 676 nm for 1 , 2 , and 3 , respectively, which are associated to weaker ones centered at 961, 960, and 962 nm. The electronic spectrum for a five-coordinate nickel(II) compound with a square-pyramidal geometry is expected to exhibit absorption bands near 1150 (ν 1 ), 950 (ν 2 ), and 600 nm (ν 3 ), corresponding to the spin-allowed d–d transitions 3 A 2g → 3 T 2g ( F ) (ν 1 ), 3 A 2g → 3 T 1g ( F ) (ν 2 ) and 3 A 2g → 3 T 1g ( P ) (ν 3 ), respectively. In the present case, the ν 1 band cannot be located.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Crystal Structures, Magnetic Properties and Catecholase Activity of Double Phenoxido-Bridged Penta-Coordinated Dinuclear Nickel(II) Complexes Derived from Reduced Schiff-Base Ligands: Mechanistic Inference of Catecholase Activity

et al. 2012

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Three double phenoxido-bridged dinuclear nickel(II) complexes, namely [Ni(2)(L(1))(2)(NCS)(2)] (1), [Ni(2)(L(2))(2)(NCS)(2)] (2), and [Ni(2)(L(3))(2)(NCS)(2)] (3) have been synthesized using the reduced tridentate Schiff-base ligands 2-[1-(3-methylamino-propylamino)-ethyl]-phenol (HL(1)), 2-[1-(2-dimethylamino-ethylamino)-ethyl]-phenol (HL(2)), and 2-[1-(3-dimethylamino-propylamino)-ethyl]-phenol (HL(3)), respectively. The coordination compounds have been characterized by X-ray structural analyses, magnetic-susceptibility measurements, and various spectroscopic methods. In all complexes, the nickel(II) ions are penta-coordinated in a square-pyramidal environment, which is severely distorted in the case of 1 (Addison parameter τ = 0.47) and 3 (τ = 0.29), while it is almost perfect for 2 (τ = 0.03). This arrangement leads to relatively strong antiferromagnetic interactions between the Ni(II) (S = 1) metal centers as mediated by double phenoxido bridges (with J values of -23.32 (1), -35.45 (2), and -34.02 (3) cm(3) K mol(-1), in the convention H = -2JS(1)S(2)). The catalytic activity of these Ni compounds has been investigated for the aerial oxidation of 3,5-di-tert-butylcatechol. Kinetic data analysis following Michaelis-Menten treatment reveals that the catecholase activity of the complexes is influenced by the flexibility of the ligand and also by the geometry around the metal ion. Electrospray ionization mass spectroscopy (ESI-MS) studies (in the positive mode) have been performed for all the coordination compounds in the presence of 3,5-DTBC to characterize potential complex-substrate intermediates. The mass-spectrometry data, corroborated by electron paramagnetic resonance (EPR) measurements, suggest that the metal centers are involved in the catecholase activity exhibited by the complexes.

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“…Five and six-coordinated Co(II), Ni(II), Cu(II) and Zn(II) complexes of the pentadentate azomethine ligands. N,N-Bis [(2-hydroxy-5-Y-phenyl) phenylmethylene-4azoheptane-1,7-diamine (where Y=Chloro or methyl)] and N-N-Bis [5-chloro-2-hydroxyphenyl) phenylmethylene-4-thioheptane-1,7-diamine have been synthesized and characterized by Boge and co-workers 15 . Azomethine formed in the condensation reactions between unsymmetrical β-diketones and 1,2-diamino ethane and their transition complexes have also been reported in the literature 16 .…”

Section: Research Articlementioning

confidence: 99%

Synthesis, Spectral Studies of Binuclear Divalent Metal Chelates Derived from Benzofuron-2-carbo-hydrazide and 1-Chloro-4-isothiocyanatobenzene

2016

Chem Sci Trans

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The M(II) complex of benzofuron-2-carbohydrazide, 1-chloro-4-isothiocyanatobenzene and nitrophenol (2-nitrophenol, 2,3-dinitropheno, 2,3,4-trinitrophenol) with transition metal ion e.g. Cu(II), Ni(II) and Co(II) were prepared. All the complex have structure formula [Cu 2 (C 56 H 40 N 10 Cl 2 O 16 S 2)], [Ni 2 (C 56 H 40 N 10 Cl 2 O 16 S 2)], [Co 2 (C 56 H 40 N 10 Cl 2 O 16 S 2)], [Cu 2 (C 56 H 36 N 14 Cl 2 O 24 S 2)], [Ni 2 (C 56 H 36 N 14 Cl 2 O 24 S 2)], [Co 2 (C 56 H 36 N 14 Cl 2 O 24 S 2)], [Cu 2 (C 56 H 32 N 18 Cl 2 O 32 S 2)], [Ni 2 (C 56 H 32 N 18 Cl 2 O 32 S 2)] and [Co 2 (C 56 H 32 N 18 Cl 2 O 32 S 2)] characterized by the several analytical techniques including elemental analysis (C.H.N.), molar conductance measurements, magnetic measurements, electronic, FAB mass, IR, 1 H NMR and 13 C NMR spectral studies. Based on these studies six coordinated octahedral geometry for all the complexes was proposed.

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Five- and six-coordinated cobalt(II), nickel(II), copper(II), and zinc(II) complexes of the pentadentate Schiff base ligands N,N'-bis[(2-hydroxy-5-Y-phenyl)phenylmethylene]-4-azaheptane-1,7-diamine (Y = Cl or Ch3) and N,N'-bis[(5-chloro-2-hydroxyphenyl)phenylmethylene]-4-thiaheptane-1,7-diami

Cited by 23 publications

References 2 publications

Hybrid Materials Containing Metal(II) Schiff Base Complex Covalently Linked to the Silica Matrix by Two Si−C Bonds: Reaction with Dioxygen

Hybrid Materials Containing Metal(II) Schiff Base Complex Covalently Linked to the Silica Matrix by Two Si−C Bonds: Reaction with Dioxygen

Synthesis, Crystal Structures, Magnetic Properties and Catecholase Activity of Double Phenoxido-Bridged Penta-Coordinated Dinuclear Nickel(II) Complexes Derived from Reduced Schiff-Base Ligands: Mechanistic Inference of Catecholase Activity

Synthesis, Spectral Studies of Binuclear Divalent Metal Chelates Derived from Benzofuron-2-carbo-hydrazide and 1-Chloro-4-isothiocyanatobenzene

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