Structure of [2,6-bis(2-benzimidazolyl)pyridine]dichlorocopper(II) dimethylformamide

Bérnardinelli, Gerald; Hopfgartner, Gérard; Williams, Alan F.

doi:10.1107/s0108270189014368

Cited by 16 publications

(7 citation statements)

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“…The copper-nitrogen (pyridine) (2.062 Å) and copper-nitrogen (thiazole) (1.972 Å) distances are similar to those found in other iminopyridine copper com plexes. [12][13][14] Electrochemical study. Free ligand 1 and complexes 2-5 were studied by cyclic voltammetry (CV) and rotat ing disk electrode (RDE) voltammetry at glassy car bon (GC), Pt, and Au electrodes in anhydrous DMF in the presence of a 0.05 M Bu 4 NClO 4 solution as the sup porting electrolyte.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and electrochemical study of 2-(2-pyridyl)benzothiazole complexes with transition metals (CoII, NiII, and CuII). Molecular structure of aquabis[2-(2-pyridyl)benzothiazole]copper(II) diperchlorate

et al. 2006

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The reactions of 2 (2 pyridyl)benzothiazole (1) with MХ 2 •nH 2 O salts (M = Ni II , Co II , or Cu II ; X = Cl or ClO 4 ; n = 0-2) in EtOH afforded the corresponding complexes. Depending on the nature of the counterion in the starting metal salt, the reactions give compounds of composition M(1)Cl 2 •nH 2 O or Cu(1) 2 (ClO 4 ) 2 •H 2 O. The molecular and crystal structure of the Cu II (1) 2 (ClO 4 ) 2 •H 2 O complex was established by X ray diffraction. The copper atom in this complex has a distorted tetragonal pyramidal ligand environment and is coordinated by four nitrogen atoms of two ligand molecules and one water molecule. Electrochemical study of the ligand and the resulting complexes by cyclic voltammetry and at a rotating disk electrode demonstrated that ligand 1 stabilizes reduced forms of complexes containing Ni, Co, or Cu atoms in the oxidation state +1.Nickel(II) and copper(II) complexes with organic S,N containing ligands can be reversibly reduced to metal(I) complexes; they have attracted attention as func tional models of metalloenzymes and electroactive cata lysts. From this point of view, 2 (2 pyridyl)benzothiazole (1), which contains electron donating nitrogen and sul fur atoms and is capable of forming chelate five mem bered metallacycles upon complexation, is of consider able interest. In the present study, we synthesized Co II , Ni II , and Cu II complexes with 2 (2 pyridyl)benzothiazole.To use the resulting metal complexes as potential electroactive catalysts, it is necessary that oxidation and reduction or at least their initial steps be electrochemi cally reversible or quasireversible. Hence, we also studied the electrochemical behavior of the resulting complexes.Complexes of 2 (2 pyridyl)benzothiazole with transi tion metal ions are few in number (Pt II , 1 Sn II , 2 Ru III , 3,4 and Re V complexes 5-7 ). Ligand 1 can exist in two differ ent conformations (N-S and N-N) and form complexes with one or two ligand molecules. However, all structur ally characterized complexes contain only one molecule 1 adopting an N-N conformation, i.e., the metal atom is coordinated through the lone pairs of two nitrogen atoms of the pyridine and benzothiazole fragments. It should be noted that free ligand 1 has an N-S conformation in the crystalline state. 2

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Section: Resultsmentioning

confidence: 99%

Synthesis and electrochemical study of 2-(2-pyridyl)benzothiazole complexes with transition metals (CoII, NiII, and CuII). Molecular structure of aquabis[2-(2-pyridyl)benzothiazole]copper(II) diperchlorate

et al. 2006

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“…-Two themes of current interest in coordination chemistry are the synthetic modification of multidentate ligands in such a way as to vary in a predictable fashion the properties of their complexes, and the linking of multidentate ligands together in such a way as to favour the formation of structured polynuclear complexes. We have recently been studying the complexes of the ligand 2,6-bis( 1 -methyl-benzimidazol-2-yl)pyridine (L'), a rigid tridentate ligand which is structurally [l] [2] and chemically [l] [3] analogous to 2,2':6',2"-terpyridine (terpy). L' forms a double-stranded helicate with Cu' [4], and two L' units may be linked together to give a bis-tridentate ligand which forms a triple-stranded helicate with Eu"' [5].…”

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confidence: 99%

“…[2][3][4][5] complexes (1.0-1.3 and 0.5 ppm, respectively). Similar upfield shifts have been observed for the H6 protons of terpyridine in [Fe(terpy),]'+[21] and Mg(ter~y)~]*+[23], and are ascribed to the shielding experienced by these protons lying above the plane of the central pyridine ring of the second ligand as a result of the perpendicular arrangement of the two tridentate donors around the pseudo-octahedral metal ion.…”

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confidence: 99%

Synthesis and Electronic Properties of Intensely Coloured Iron(II) complexes with new 4‐substituted planar tridentate nitrogen ligands analogous to 2, 2′: 6′, 2″‐terpyridine

Bochet

Piguet

Williams

1993

Helvetica Chimica Acta

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The para -substituted tridentate ligands 2,6-bis[l-(3,5-dimethoxybenzyl)benzimidazol-2-yl]-4-(4'-X~phenyl)-pyridine (X = H: L3; X = NO,: L4; X = NEt,: L') have been synthesized in six steps using Krohnke reactions. Spectroscopic results show that the electronic properties of the ligands are strongly influenced by the nature of the substituent bound to the pyridine ring and extended Huckel calculations performed on 4-(X-phenyl)pyridine fragments give a qualitative insight into the factors responsible for the striking differences observed in the absorption spectra. Upon complexation to Fe", the ligands L2-Ls give intensely coloured pseudo-octahedral low spin [Fe(L")2]2' (n = 2-5) complexes in acetonitrile solution. Electrochemical and spectroscopic measurements show that the particular electronic characteristics associated with each substituent strongly influence the properties of the resulting Fe'' complexes as demonstrated by the very intense MLCT transition (E > 50000 M-I cm-') observed in the green complex [Fe(L5),I2'.

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“…The base of the pyramid is formed by two N-atoms of benzimidazoles and two bridging phenolate functions; the apex of the pyramid is formed by the O-atom of a coordinated DMF molecule. The CuÀN bond distances of 1.952(4) and 1.951(4) are slightly shorter than the CuÀbenzimidazole distances observed for another square pyramidal copper(II) complex (2.04 [22]), but longer than the bonds to two-coordinate copper(I) in [Cu 2 (1) 2 ] 2+ (1.89 ) [19]. The copper-phenolate distances of 1.974(3) and 2.009(3) are slightly longer than those observed by Karlin et al [4] and Casella et al [8] [19].…”

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confidence: 49%

A Minimalist Approach to CH Activation by Copper

Kuebel-Pollak

Rüttimann

Dunn

et al. 2006

Helvetica Chimica Acta

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The complex [Cu2(1)2]2+ (1 = 1,3‐bis(1‐methyl‐1H‐benzimidazol‐2‐yl)benzene) undergoes slow oxidation by dioxygen in DMF solution to give the hydroxylated product [Cu2(2‐H)2]2+ (2 = 2,6‐bis(1‐methyl‐1H‐benzimidazol‐2‐yl)phenol) characterized by an X‐ray crystal‐structure analysis. The oxidation occurs much faster when CuII is mixed with 1 in the presence of H2O2, with 80% hydroxylation observed within a few minutes. The mononuclear complex formed with 1‐methyl‐2‐phenyl‐1H‐benzimidazole (3) shows no hydroxylation under these conditions. It is concluded that the hydroxylation requires the presence of a ligand capable of stabilizing a binuclear species, but no special coordinative activation of the copper is required.

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Structure of [2,6-bis(2-benzimidazolyl)pyridine]dichlorocopper(II) dimethylformamide

Cited by 16 publications

References 3 publications

Synthesis and electrochemical study of 2-(2-pyridyl)benzothiazole complexes with transition metals (CoII, NiII, and CuII). Molecular structure of aquabis[2-(2-pyridyl)benzothiazole]copper(II) diperchlorate

Synthesis and electrochemical study of 2-(2-pyridyl)benzothiazole complexes with transition metals (CoII, NiII, and CuII). Molecular structure of aquabis[2-(2-pyridyl)benzothiazole]copper(II) diperchlorate

Synthesis and Electronic Properties of Intensely Coloured Iron(II) complexes with new 4‐substituted planar tridentate nitrogen ligands analogous to 2, 2′: 6′, 2″‐terpyridine

A Minimalist Approach to CH Activation by Copper

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