Ersin Temel

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

1-[(E)-(2-Phenoxy-anilino)methyl-ene]naphthalen-2(1H)-one.

The molecule of the title compound, C23H17NO2, a Schiff base derived from 2-hydroxy-1-naphthaldehyde, crystallizes in the keto–amine tautomeric form. The dihedral angle between the aniline and hydroxybenzene rings is 77.41 (17)°, whereas the planes of the naphthaldehyde and fused aniline benzene rings are nearly coplanar, making a dihedral angle of 8.29 (15)°. Intramolecular N—H⋯O hydrogen bonding, a characteristic hydrogen bond for Schiff bases, helps to stabilize the molecular structure. Weak intermolecular C—H⋯π interactions are present in the crystal structure.

(3aR*,6S*,7aR*)-7a-Chloro-6-methyl-2-(4-methyl­phenyl­sulfon­yl)-2,3,3a,6,7,7a-hexa­hydro-3a,6-ep­oxy-1H-isoindole

In the title compound, C16H18ClNO3S, the six-membered ring has a boat conformation. The two five-membered rings with the bridging O atom adopt envelope conformations, whereas the N-containing five-membered ring adopts a twisted conformation. In the crystal, C—H⋯O hydrogen bonds link the molecules into a three-dimensional network.

(3aR,6S,7aR)-7a-Bromo-2-methyl­sulfonyl-1,2,3,6,7,7a-hexa­hydro-3a,6-ep­oxy­isoindole

In the title compound, C9H12BrNO3S, the two tetrahydrofuran rings adopt envelope conformations, the pyrrolidine ring adopts a half-chair conformation and the six-membered ring is in a boat conformation. In the crystal, weak intermolecular C—H⋯O hydrogen bonds link the molecules into R 2 2(8) and R 2 2(14) rings along the b-axis direction.

Diaqua­bis(1,3-propane­diamine)nickel(II) squarate tetrahydrate

The asymmetric unit of the title compound, [Ni(C3H10N2)2(H2O)2](C4O4)·4H2O, contains one-half of the diaquabis(1,3-propanediamine)nickel(II) cation, one-half of the centrosymmetric squarate anion and two uncoordinated water molecules. In the cation, the NiII atom is located on a crystallographic inversion centre and has a slightly distorted octahedral coordination geometry. The six-membered chelate ring adopts a chair conformation. O—H⋯O hydrogen bonds link the cation and anion through the water molecule, while N—H⋯O hydrogen bonds link the cation and anion and cation and water molecules. In the crystal structure, intermolecular O—H⋯O and N—H⋯O hydrogen bonds link the molecules into a three-dimensional network structure.

CCDC 1440608: Experimental Crystal Structure Determination

Related Article: Sema Caglar, Esra Dilek, Bulent Caglar, Ekrem Adiguzel, Ersin Temel, Orhan Buyukgungor, Ahmet Tabak|2016|J.Coord.Chem.|69|3321|doi:10.1080/00958972.2016.1227802

Crystal structure, Hirshfeld surfaces and DFT computation of (E)-(5-methylfuran-2-yl) (morpholino) methanone oxime

Computational tools have found an increasing use throughout various topics and fields in chemistry. From the prediction of physicochemical properties1, reaction types and products2 or biological affinities towards macromolecules3 up to the high-dimensional problem of crystal structure prediction, so-called Machine Learning models experience a steady increase in application. Machine Learning models are considered a collection of algorithms that can be used to find regularities, irregularities and correlations in data sets independent of their dimensionality. The resulting mathematical constructs can then be used to predictively characterize previously unseen data. In crystallography, recent studies have set out to use such algorithms in order to predict general crystallinity of small molecules4, their crystallization propensity in different solvents5, or the crystallization conditions of proteins6. The most important prerequisite for a high-performing machine learning model is a sufficiently large data set of high integrity. Unfortunately, due to the lack of negative results in commonly used collections like the CSD, crystallization data suited for machine learning tasks is sparse. Therefore, several years back we set out to record both positive and negative results for every crystallization attempt made in the analytics group at the Novartis Institute for Biomedical Research. This data is stored in an SQL data base equipped with a touch-screen based graphical user interface, enabling easy access for both experimenter as well as programmer. Next to numerous statistical analyses, we set out to use machine learning for the prediction of suitable conditions to crystallize small, drug-like molecules. In particular, we focused on the prediction of organic solvents to crystallize a given compound in. While the individual performances of the first generation of machine learning models for this were rather frugal, a newly devised ensemble approach embodying additional data allows us to rationalize our crystallization experiments and thus significantly reduce the experimental effort required to yield crystalline materials. [1] Alzghuol A., et al. (2014) J Chem Inf Model 54, 3396-403 [2] Schneider N., et al. (2016) J Med Chem (10.1021/acs.jmedchem.6b00153) [3] Reker D., et al. (2014) PNAS 111, 4067-72 [4] Wicker J.P., Cooper R. (2015) CrystEngComm 17, 1927-34 [5] Hosokawa K., et al. (2005) ChemPharmBull 10, 1296-99 [6] Rupp B., Wang J. (2004) Methods 34, 390-407

XRD, FT-IR, and DFT study on a novel ethyl derivative of 3-hydroxy-2-quinoxalinecarboxylic acid

The novel ethyl derivative of 3-hydroxy-2-quinoxalinecarboxylic acid has been synthesized for the first time, characterized by FT-IR spectroscopy and single-crystal X-Ray diffraction. The crystal packing is achieved by inter-molecular C–H···N, C–H···O and N–H···O type hydrogen bonds, which play an important role in the formation of the 3D supramolecular network of the title compound. The geometries and vibrational frequencies of the title compound in monomer and dimer forms were investigated by density functional theory calculations employing the B3LYP hybrid functional. The calculation results are in accordance with the experimental data. In addition, the theoretical electronic properties like natural bond orbital (NBO) charges and frontier molecular orbitals were presented.

(3aR,6S,7aR)-7a-Chloro-2-[(4-nitro­phen­yl)sulfon­yl]-1,2,3,6,7,7a-hexa­hydro-3a,6-ep­oxy­iso­indole

In the title compound, C14H13ClN2O5S, the chlorine-substituted tetrahydrofuran ring adopts a twist conformation and the other tetrahydrofuran ring an envelope conformation with the O atom as the flap. The pyrrolidine ring adopts a twist conformation. In the crystal, C—H⋯O hydrogen bonds link the molecules into zigzag chains running along the b-axis direction.