Sema Caglar

Syntheses, crystallographic, mass-spectroscopic determination and antioxidant studies of Co(II), Ni(II) and Cu(II) complexes of a new imidazol based Schiff base

A new imidazole-based Schiff base, 2-((1H-imidazol-4-yl)methyleneamino)benzylalcohol (HL) and corresponding analogous bis(2-((1H-imidazol-4-yl)methyleneimino)benzylalcohol)metal(II) perchlorates (M: Co(1), Ni(2), Cu(3)) have prepared and characterized by elemental analyses, ESI-MS, IR, UV-Vis spectroscopies and conductivity measurements. X-ray single crystal structures of 1 and 2 have been also determined. Elemental analyses, spectroscopic and conductance data of 3 demonstrated similar structural features with these of crystallographically characterized complexes and based upon this relevances, HL ligands are neutrally coordinated to metal(II) ions in tridentate mode and all complexes are isostructural, dicathionic, contain perchlorate anions as complementary ions and, are in octahedral geometry with the formulae of [M(HL)2](ClO4)2 (for 3) and [M(HL)2](ClO4)2·H2O (for 1 and 2). Radical scavenging activities of the complexes have been evaluated by using DPPH, DMPD(+), and ABTS(+) assays. SC50 values (μg/mL) of the complexes and standards on DPPH, DMPD(+), ABTS(+) follow the sequences, BHA (9.06±0.33)>CMPD3 (15.62±0.52)>CMPD2 (17.43±0.29)>Rutin (21.65±0.60)>CMPD1 (25.67±0.51)>Trolox (28.57±0.37), Rutin>BHA>CMPD3>CMPD2>Trolox>CMPD1, and Trolox>BHA>CMPD3>CMPD2>Rutin>CMPD1 respectively.

Synthesis, crystal structures, thermal, and spectroscopic properties of four new metal(II) (M = Co, Ni, Cu, Hg) complexes of 2-benzoylbenzoate with 3-picoline

Four 2-benzoylbenzoate (bba) complexes, [Co(bba)2(H2O)2(3-pic)2] (1), [Ni(bba)2(H2O)2(3-pic)2] (2), [Cu(bba)2(3-pic)2] (3), and [Hg(bba)2(3-pic)2] (4), have been synthesized and characterized by IR spectra, thermal (TG, DTG, and DTA) analysis, and single crystal X-ray diffraction. All the complexes consist of neutral monomeric units with 1 and 2 crystallizing in the orthorhombic (P n a 21), 3 in triclinic (P 1), and 4 in monoclinic (P21/c) crystal systems. The metal(II) ions exhibit distorted octahedral coordination for 1, 2, and 3 and mercury(II) exhibits distorted trigonal prism coordination. In 1 and 2, bba is monodentate, whereas in 3 and 4 bba is bidentate. 3-Picoline (3-pic) is a classical N-monodentate ligand. Bba are coordinated to metal(II) with carboxylates and IR spectra of all complexes display characteristic absorptions of carboxylate {υ(OCO)asym and υ(OCO)sym}. Thermogravimetric (TG) analyses show that 1 and 2 are thermally stable (Tdecomp. > 60°C) and 3 and 4 are thermally stable (Tdecomp .  > 120°C).

Synthesis, thermal and spectroscopic properties, and crystal structures of [Co(bba)2(H2O)(phen)] and [Ni(bba)2(H2O)(butOH)(phen)] (bba = 2-benzoylbenzoate, phen = 1,10-phenanthroline, butOH = butanol)

Aquabis(2-benzoylbenzoato)(1,10-phenanthroline)cobalt(II) and aquabis(2-benzoylbenzoato)(butanol)(1,10-phenanthroline)nickel(II) have been prepared and characterized by elemental analyses, IR and electronic spectroscopy, magnetic measurements, and single-crystal X-ray diffraction. [Co(bba)2(H2O)(phen)] (1) and [Ni(bba)2(H2O)(butOH)(phen)] (2) consist of neutral monomeric units and crystallize in the monoclinic (P2(1)) and triclinic (P 1) crystal systems, respectively. The cobalt(II) and nickel(II) sit on inversion centres and exhibit distorted octahedral coordination. Phen is bidentate chelating. In 1, bba is both monodentate and bidentate, whereas in 2 bba is only monodentate. bba ligands are coordinated to metal(II) with carboxylates and IR spectra of both complexes display characteristic absorptions of carboxylate anions {ν(OCO)asym and ν(OCO)sym} of bba. Thermal analysis shows that mass losses of 1 from 105°C to 456°C correspond to decomposition of phen and bba, while for 2 these occur at 271–529°C.

Four diclofenac complexes with cobalt(II) and nickel(II) ions: synthesis, spectroscopic properties, thermal decompositions, crystal structures, and carbonic anhydrase activities

Cobalt(II) and nickel(II) complexes with diclofenac (dicl) in the presence of nitrogen-donor 3-picoline (3-pic) and 1-(2-aminoethyl)pyrrolidine (2-aepyr), [Co(dicl)2(3-pic)2] (1), [Ni(dicl)2(3-pic)2(H2O)2] (2), [Co(dicl)2(2-aepyr)2] (3), and [Ni(dicl)2(2-aepyr)2] (4), have been synthesized and characterized by FT-IR, UV–Vis, elemental and thermal analysis. The crystal structures of 1 and 3 have been determined by single-crystal X-ray diffraction; phase purity of complexes has been proved by powder X-ray diffraction analysis. Structural analyses have demonstrated that 1 and 3 are mononuclear and Co(II) ions have distorted octahedral environments. In 1, dicl is bidentate, whereas in 2, 3, and 4 dicl is monodentate. Dicl ligands are coordinated to metal(II) ions with O of carboxylate. Therefore, IR spectra of all complexes display {ν(OCO)asym and ν(OCO)sym} of dicl. The calculated Δν(OCO) values are consistent with the presence of monodentate (>200) and bidentate (<200) carboxylate. Compounds 2, 3, and 4 exhibit inhibition effects on human carbonic anhydrase-I. Compounds 3 and 4 show high thermal stability compared with 1 and 2. Graphical Abstract

Mono and dinuclear copper(II) naproxenato complexes containing 3-picoline and 4-picoline: synthesis, structure, properties, catechol oxidase, and antimicrobial activities

Mononuclear and dinuclear copper(II) complexes [Cu2(μ-nap)4(3-pic)2] (1) and [Cu(nap)2(H2O)(4-pic)2] (2) have been synthesized in the presence of 3-picoline and 4-picoline. Two complexes were characterized by FT-IR, UV–vis spectroscopic methods and their thermal stabilities were determined by TG/DTA/DTG techniques. The crystal structures of 1 and 2 were established by X-ray analysis. X-ray structure analysis has shown that copper(II) has a distorted square-pyramidal geometry. Naproxenate is a bridging ligand in 1 and monodentate in 2. Two complexes have shown catalytic activity on oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone exhibiting saturation kinetics at high substrate concentrations. The complexes were also screened for antimicrobial activity against pathogenic bacteria and fungi. The complexes exhibited antimicrobial activity against Entrococcus faecalis and Candida albicans. Graphical Abstract

Synthesis, Characterization, and Crystal Structures of a Novel [Zn3(bba)6(3-pic)2] Complex (bba = 2-Benzoylbenzoat, 3-pic = 3-Picoline)

A novel trinuclear hekzakis(μ6-2-benzoylbenzoato-O,O′)-bis(3-picoline)-tri-zinc(II) complex, [Zn3(bba)6(3-pic)2] has been synthesized and characterized by elemental analysis, Fourier-transform infrared (FT-IR), ultraviolet/visible (UV/Vis), and mass spectroscopy, thermal methods, and single-crystal x-ray diffraction. The three Zn(II) centers are in two different coordination environments. The central Zn(II) is in a distorted octahedral geometry, while the two terminal Zn(II) centers adopt a distorted tetrahedral geometry. The central and the terminal metal centers are connected through tri μ-2-benzoylbenzoato-O,O′ bridges. The crystal packing of the trinuclear complex is stabilized by C–H···π interaction between bba ligands. The characteristics of the carboxylate anions with typical υ(OCO)asym and υ(OCO)sym values are 1594 and 1368 cm−1, respectively.

New metal complexes with diclofenac containing 2-pyridineethanol or 2-pyridinepropanol: synthesis, structural, spectroscopic, thermal properties, catechol oxidase and carbonic anhydrase activities

Abstract Four new neutral diclofenac-based complexes, [Co(dicl)2(2-pyet)2] 1, [Ni(dicl)2(2-pyet)2] 2, [Cu2(dicl)2(2-pyet)2] 3, and [Cu2(dicl)2(2-pypr)2] 4 have been synthesized and characterized by elemental analysis, FT-IR, thermal analysis. Complexes 1, 3, and 4 have also been characterized by X-ray single-crystal structural analysis. The compounds of Co(II) and Ni(II) have octahedral geometry with two diclofenac and two 2-pyridineethanol ligands in the coordination sphere. The compounds of Cu(II) have square-pyramidal geometry and Cu(II) ions are linked via oxygens to the bridging 2-pyridineethanol or 2-pyridinepropanol ligands. The Δν values acquired by FT-IR are in agreement with the single XRD data. Studies on the thermal properties are reported and the complexes are stable to 196, 216, 215, and 201 °C in air, respectively. Two dinuclear Cu(II) complexes have demonstrated catalytic activity on oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone showing saturation kinetics at high substrate concentrations. The diclofenac complexes are investigated as inhibitors of the human cytosolic isoforms hCA I and II. The complexes are good as hCA I inhibitors (Kis of 1.52–55.06 μM) but only moderately efficient as hCA II inhibitors (Kis of 0.23–5.61 μM).

Copper(II) 2-Benzoylbenzoate Complexes Containing 2-Pyridilmethanol and 2-Pyridilethanol: Synthesis, Crystal Structures, Spectroscopic, and Thermal Properties

Two new copper(II) complexes, [Cu(bba)2(pymet)2] 1 and [Cu(bba)2(pyet)2] 2, have been synthesized and characterized by elemental analysis, thermal analysis, UV-Vis, and IR spectroscopic techniques. Single-crystal X-ray analysis of 1 and 2 revealed that the geometries are octahedral. 1 crystallizes in the monoclinic crystal system with space group P21/n, while 2 crystallizes in the triclinic crystal system with the space group P-1. 2-benzoylbenzoic acid ligand behaves as a monodentate, while 2-pyridilmethanol and 2-pyridilethanol ligands act as a bidentate in two complexes. Thermal analysis show that two decomposition stages of the investigated complex 1 and 2, stable up to ∼160°C.

Structural, thermal and morphological properties of a novel poly(acrylamide-co-methacrylic acid)/organoclay nanocomposite

ABSTRACT A novel poly(acrylamide-co-methacrylic acid)/organoclay nanocomposite was prepared and its structural, thermal, and morphological properties were investigated by various techniques. The absence of diffraction peaks for the organomodified-smectite nanocomposite showed that dispersion of the clay nanolayers within the polymer matrix was in the form of an exfoliated nanostructure. Morphological studies confirmed that organomodified-clay dispersed homogeneously in the polymer matrix. Infrared spectroscopy results indicated that the organosmectite is physically dispersed in the polymer network without forming any chemical bonds. The thermal analysis data revealed that there are significant increases in temperatures of decomposition and softening points of polymer with addition of organoclay.

Synthesis and characterization of four novel palladium(II) and platinum(II) complexes with 1-(2-aminoethyl)pyrrolidine, diclofenac and mefenamic acid: In vitro effect of these complexes on human serum paraoxanase1 activity

In this study, the effects of four novel mononuclear palladium(II) and platinum(II) complexes on the activity of human serum paraoxanase1 were examined. First, four novel mononuclear palladium(II) and platinum(II) complexes were synthesized with a nitrogen donor ligand 1‐(2‐aminoethyl)pyrrolidine and nonsteroidal anti‐inflammatory drugs diclofenac, mefenamic acid. These complexes were characterized by spectroscopic, thermal, and elemental analyses. The crystal structures of complex [Pd(2‐amepyr)2](dicl)2 1 and [Pd(2‐amepyr)2](mef)2 3 were determined by X‐ray crystallography. Then, paraoxonase1 enzyme was purified from human serum. The effects of these complexes on enzyme were evaluated in vitro. The complexes consist of the cationic unit and the counterions. The diclofenac and mefenamic acid acted as a counterion in the complexes. It was observed that all the complexes were stable up to high temperatures. These complexes, even at low doses, inhibited the activity of the enzyme with different inhibition mechanisms.