► Hollow rectangular-sectioned microtubes of PPy were deposited in salicylate solution. ► In a first step, crystallization of salicylic acid occurs on the electrode surface. ► These crystals ...constitute the building block for the formation of the PPy microtubes. ► PPy microtubes remain intact after extraction of the acid with ethanol.
Hollow rectangular-sectioned microtubes of polypyrrole were deposited on stainless steel by potentiostatic electropolymerization of pyrrole in the presence of an aqueous solution of salicylate. The formed films were characterized using AFM, SEM, EDS, UV and IR spectroscopies, XRD and XPS analysis methods. The initial crystallization of salicylic acid is considered to be responsible for the formation of these special morphological structures. The experimental results indicate a high content of salicylic acid and salicylate in the electrosynthesized film. The microtubes of the polymer doped with salicylate anions coexist with the acid. PPy microtubes remain on the electrode surface after extraction of the acid from the film with ethanol.
(Acetonitrile‐1κN)μ‐1H‐benzimidazole‐2(3H)‐thione‐1:2κ2S:S1H‐benzimidazole‐2(3H)‐thione‐2κSbis(μ‐1,1‐dioxo‐1λ6,2‐benzothiazole‐3‐thiolato)‐1:2κ2S3:N;1:2κ2S3:S3‐dicopper(I)(Cu—Cu), ...Cu2(C7H4NO2S2)2(C7H6N2S)2(CH3CN) or Cu2(tsac)2(Sbim)2(CH3CN) tsac is thiosaccharinate and Sbim is 1H‐benzimidazole‐2(3H)‐thione, (I), is a new copper(I) compound that consists of a triply bridged dinuclear Cu—Cu unit. In the complex molecule, two tsac anions and one neutral Sbim ligand bind the metals. One anion bridges via the endocyclic N and exocyclic S atoms (μ‐S:N). The other anion and one of the mercaptobenzimidazole molecules bridge the metals through their exocyclic S atoms (μ‐S:S). The second Sbim ligand coordinates in a monodentate fashion (κS) to one Cu atom, while an acetonitrile molecule coordinates to the other Cu atom. The CuI—CuI distance 2.6286 (6) Å can be considered a strong `cuprophilic' interaction. In the case of μ‐1H‐benzimidazole‐2(3H)‐thione‐1:2κ2S:Sbis1H‐benzimidazole‐2(3H)‐thione‐1κS;2κS‐bis(μ‐1,1‐dioxo‐1λ6,2‐benzothiazole‐3‐thiolato)‐1:2κ2S3:N;1:2κ2S3:S3‐dicopper(I)(Cu—Cu), Cu2(C7H4NO2S2)2(C7H6N2S)3 or Cu2(tsac)2(Sbim)3, (II), the acetonitrile molecule is substituted by an additional Sbim ligand, which binds one Cu atom via the exocylic S atom. In this case, the CuI—CuI distance is 2.6068 (11) Å.
Anti-inflammatory activity achieved for complexes under study and the corresponding uncomplexed parent drug in carrageenan induced paw oedema in mice. Display omitted
► Cu(II) complexes of Fenoprofen ...with imidazole and caffeine as therapeutic agents. ► Both complexes were characterized employing spectral and biological techniques. ► They present enhanced and lasting anti-inflammatory properties than the parent drug. ► Both complexes show potent superoxide dismutase activity acting as good antioxidants. ► The catechol oxidase activity revealed that they have moderate mimetic properties.
The copper(II) ternary complexes of the non-steroidal anti-inflammatory drug Fenoprofen (Hfen) and the biologically relevant molecules imidazole (im) and caffeine (caf) as auxiliary ligands were investigated as novel anti-inflammatory agents. The new copper(II) complexes with formula Cu(fen)2(im)2 (1) and Cu2(fen)4(caf)2 (2) were synthesized from the dinuclear complex Cu2(fen)4(dmf)2 and characterized by IR, UV–Vis, EPR spectral and elemental analysis. The molecular structure of complex 1 was determined by X-ray crystallography. Both complexes 1 and 2 present enhanced and prolongued anti-inflammatory properties against the parent drug calcium Fenoprofenate, Ca(fen)2·2H2O, with a better performance for complex 1. Ternary complexes are potential models for several mono and poly-nuclear metal enzymes. The measured superoxide dismutase (SOD) mimetic activities of the complexes indicated a higher SOD mimic activity for complex 2 (IC50 of 0.24μM) than complex 1 (IC50 of 0.70μM), and also than the native enzyme evaluated by the same method (IC50 of 0.480μM). The catecholase activity of the complexes toward the aerobic oxidation of 3,5-di-tert-butylcatechol (dtbc) onto 3,5-di-tert-butylquinone (dtbq) showed that both complexes have moderate catalytic oxidase activity.
Reaction of Ag
6(tsac)
6 (tsac
−
=
thiosaccharinate anion) with PPh
3 and 2,2′-bipyridine (bipy) ligands give rise to three new silver-thiosaccharinate complexes, Ag(tsac)(PPh
3)
3, Ag
4(tsac)
4(PPh
...3)
3 , and Ag
2(tsac)
2(bipy)
2. Their crystal structures established by single-crystal X-ray diffraction and IR spectroscopic characterizations are reported here. In each complex a singular coordination mode for the thiosaccharinate ligands is observed. The most important features of the different coordination modes of the thionates are discussed.
We report the synthesis, FTIR, Raman and NMR spectroscopic features of bis(triphenylphosphine)iminium and tetrabutylammonium thiosaccharinates, PNP(tsac) and NBu4(tsac) (tsac: thiosaccharinate anion, ...PNP: bis(triphenylphosphine)iminium). The molecular structure of the former compound was determined by X-ray diffraction methods. The salt crystallizes in the monoclinic P21/n space group with a = 9.6481(9), b = 29.258(3), c = 13.177(2) Å, β = 97.53(1)°, and Z = 4 molecules per unit cell. Slight but significant changes in the bonding structure of the thiosaccharinate anion as compared with those reported for the neutral molecule are observed.
Four new gold(I) complexes are reported. The metal atoms are coordinated by thiosaccharinate anions and by other ligands (PPh
3, dppm and dppe). The crystal structure of two of them, Au(tsac)(PPh
3) ...and Au
2(tsac)
2(dppm)·EtOH are solved applying single crystal X-ray diffraction and are studied using the density functional theory (DFT) formalism.
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► Four new binary and ternary gold(I) thiosaccharinates are described. ► The crystal structures of Au(tsac)(PPh
3) and Au
2(tsac)
2(dppm)·EtOH are presented. ► The complexes were theoretically studied applying DFT. ► The study indicates that an aurophilic interaction exists in Au
2(tsac)
2(dppm)·EtOH.
The reaction of gold with thiosaccharin ligand and additional phosphorous coligands is studied. Four new Au(I) complexes with thiosaccharinate as coordinating counteranion: Au(tsac)(PPh
3), Au
2(tsac)
2(dppm)·EtOH, Au
2(tsac)
2(dppe)·EtOH, and Au(tsac)(Htsac)
2·0.25 EtOH (tsac: thiosaccharinate, C
6H
4C(S)NSO
2
−, dppm: bis(diphenylphosphino)methane, dppe: bis(diphenylphosphino)ethane) were synthesized and characterized by means of spectroscopic techniques (IR, UV–Vis, and
1H,
13C and
13P NMR). The crystal structure of two of them, Au(tsac)(PPh
3) and Au
2(tsac)
2(dppm)·EtOH, were solved applying single crystal X-ray diffraction and studied using the density functional theory (DFT) formalism. In the latter, the aurophilic interaction between the two gold centers was analyzed and theoretically confirmed.
New ternary silver(I) thiosaccharinates with pyridine and 1,10-phenanthroline are prepared and structurally characterized. The pyridine derivative is a dinuclear silver complex, Ag
2(tsac)
2py, with ...argentophilic interaction and very unusual metal environments. One Ag(I) is coordinated by two S atoms and the other silver atom by three N atoms.
Treatment of Ag
6(tsac)
6 (tsac
=
thiosaccharinate anion) with pyridine (py) and 1,10-phenanthroline (
o-phen) each affords two novel silver(I)-thiosaccharinate complexes: dinuclear Ag
2(tsac)
2py (
1) and polynuclear Ag(tsac)(
o-phen)
n
(
2). Both crystal structures have been determined by X-ray diffraction and spectroscopic structural analysis (IR and Raman, UV–Vis,
1H and
13C NMR) have also been made for both compounds. Thermal stability analysis (TGA and DTA) of complex
1 are used to confirm the strength of the pyridine coordination to the silver ion. The molecular structure of complex
1 shows some astonishing characteristics. The two silver atoms are in different environments: one of them is surrounded by two S atoms, while the other completes its coordination sphere by three N atoms, two from the thiosaccharinate anions and the third from a pyridine molecule. The short Ag(1)–Ag(2) contact distance, 2.9681(8)
Å, indicates an interaction between the two silver metal atoms exists. Complex
2 shows a thiosaccharinate molecule bridging two silver atoms through the exocyclic S atom while the
o-phenanthroline ligand is coordinated as a bidentate
N,
N chelate, forming a polynuclear chain. Quantum chemical calculations confirm the argentophilic character of the Ag–Ag interaction in complex
1, and its structure and vibrational assignments were correlated and confirmed theoretically.
The title compound, Cu2(C15H13O3)4(C3H7NO)2, is formed by the chelate coordination of four racemic fenoprofenate (fenoprofenate is 2,3-phenoxyphenyl propionate) anions and two dimethylformamide ...molecules to two copper(II) ions, building a paddle-wheel dinuclear molecule. The distorted square-pyramidal coordination of each CuII atom is made up of four O atoms of the four fenoprofenate units and another O atom from a dimethylformamide molecule. The two enantiomeric forms of the fenoprofenate anions are present in the complex, in an optically inactive centrosymmetric arrangement.
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