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The crystal X-ray structure of 3-(pyrrolidine-1-carbonyl)-2H-chromen-2-one (1) has been presented. The compound crystallizes in the triclinic space group with two molecules in the unit cell characterized by unit cell parameters a = 7.8547(5) Å, b = 9.0159(5) Å, c = 9.1516(5) Ǻ, α = 76.623(2)°, β = 89.546(3)° and γ = 67.626(2)°. The experimental bond lengths and bond angles have been compared with DFT computed results. The Hirshfeld surface analysis of the compound has been presented. [ABSTRACT FROM AUTHOR]

The DFT computational studies, crystal structures and Hirshfeld surface analysis of (E)-4-(2-chlorostyryl)-2,2-dimethyl-2,3-dihydro-1H-benzo[b][1,4]diazepine (1) and (E)-4-(2-(2,2-dimethyl-2,3-dihydro-1H-benzo[b][1,4]diazepin-4-yl)vinyl)phenol (2) have been presented. The compounds crystallized in the monoclinic space group P21/c with 4 molecules in their unit cells each. The experimental and computed bond lengths and bond angles deviated from each other to some extent but also showed good agreement with each other in some cases. Hirshfeld surface analysis of the compounds provided further information about the structural properties of the compounds. [ABSTRACT FROM AUTHOR]

Herein we report the zwitterionic pentagonal bipyramidal oxidorhenium(V) complex trans-[ReOI2(bpp)] where bpp is (1E,3E)-1,3-bis(pyrimidin-2-ylimino)propan-2-ide anion. The complex trans-[ReOI2(bpp)] was unusually formed from the reaction of trans-[ReOI2(OEt)(PPh3)3] with 2-aminopyrimidine in propan-2-ol in the presence of triethylamine (Et3N). The anionic ligand bpp was formed by oxidorhenium(V)-catalysed dehydroxylation of propane-2-ol followed by condensation with 2-aminopyrimidine, and coordinates to the [ReO]3+ core as tetradentate N-donor chelate. A few numbers of pentagonal bipyramidal complexes are known for oxidorhenium(V), and the complex trans-[ReOI2(bpp)] is another example. The complex was analyzed by 1H NMR, IR, UV-visible and single crystal X-ray crystallography. In addition, density functional theory (DFT) was also studied. [ABSTRACT FROM AUTHOR]

Zn(II) Bis(N-ethyl-N-ethanol dithiocarbamate) (1) and its heteroleptic complexes derived from 2,2′-bipyridine (2) and 1,10-phenanthroline (3) are synthesized. Their spectroscopic and structural characterization is carried out using FTIR, 1H, 13C NMR, and the single crystals X-ray analysis. The interatomic data obtained from the structural studies show that the parent complex possesses a distorted trigonal bipyramidal geometry about the Zn metal, which changes to a distorted octahedral geometry upon increased coordination about the metal centre due to the addition of N-donor ligands. This addition also causes a change in Zn–S, C–S, and C–N bond lengths within the adduct complexes. [ABSTRACT FROM AUTHOR]

The reaction of 5-phenyl-1,3,4-oxadiazole-2-thiol with mercury(II) acetate in ethanol led to the isolation of the complex [Hg(L)2] (1). Further reaction of 1 with a twofold molar excess of triphenylphosphine led to the isolation of [Hg(L)2(PPh3)2] (2). The complex 2 was characterized by infrared, ultraviolet–visible and nuclear magnetic resonance spectroscopy techniques, as well as by X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

N-[(9E)-8,10,17-Triazatetracyclo[8.7.0.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaen-9-ylidene] benzamide (I) is synthesized and characterized by spectroscopy, microanalysis, and single crystal X-ray diffractometry. Compound I crystallizes in the monoclinic space group P21/c with a = 15.8980(7) Å, b = 4.8067(2) Å, c = 21.0455(10) Å, β = 101.153(2)°, and Z = 4. The experimental bond lengths and bond angles are contrasted with computed bond lengths and bond angles. [ABSTRACT FROM AUTHOR]

2-(Benzamido)thiazolylbenzoate is synthesized via a novel method. It is characterized by spectroscopy, micranalysis, and GC-MS. It crystallizes in the monoclinic space group P21/n with a = 19.8990(5), b = 7.3680(2), c = 22.3845(6) Å, β = 113.799(1)°, V = 3002.85(14) Å3Z = 8. The HOMO-LUMO of the reactants and products are considered. [ABSTRACT FROM AUTHOR]

N-[(9E)-8,0 10,0 17-triazatetracyclo[8.7.0.02,7.011,18]heptadeca-1(17),2(7),3,5,11,13,15-heptaen-9-ylidene] acetamide (I) is synthesized and characterized by spectroscopy, microanalysis, and single crystal X-ray diffractometry. Compound 1 crystallizes in the monoclinic space group P21/n with a = 17.5552(17) Å, b = 4.6163(4) Å, c = 17.7662(17) Å, β = 115.953(3)°, and Z = 4. The bond angles and bond lengths of the compound are computed using the density functional theory with B3LYP, BPW91, and wB97XD functionals and the 6-31G++(d,p) basis set. The frontier orbitals that contribute to the reactivity of triazatetracyclics are discussed. [ABSTRACT FROM AUTHOR]

A novel co-crystal of 2-aminobenzimidazole and 2-[(benzoylcarbamothioyl)amino] propanoic acid is synthesized and characterized by spectroscopy, elemental analysis, GC-MS, and single crystal XRD. A computation of the structures involved in the formation of the co-crystal are carried out and their contribution to reactivity is explained. [ABSTRACT FROM AUTHOR]

This study investigated the solid-state physical stabilities of azithromycin dihydrate (AZM-DH), thermally prepared anhydrate and hemihydrate modifications. Programmed thermal treatment of AZM-DH in DSC yielded the formation of anhydrate amorphs (I, II), crystalline AZM anhydrate and hemihydrate phases. The formation of the anhydrate amorphs, I and II, respectively, involved different transformation pathways of solid-liquid-solid (melting and supercooling) and solid-solid (378 K for 24 h.). Both amorph phases exhibit hygroscopic behaviour, producing non-stoichiometric hydrates, with extent of moisture absorption increasing with increased storage humidity (0-96% RH/313 K). TG analysis after controlled storage (4 days at 96% RH/313 K) detected absorbed waters of hydration up to 5.9 and 5.3% for amorphs I and II, respectively. The crystal anhydrate and hemihydrate phases were hygroscopic and readily converted to the stoichiometric dihydrate form, which was compositionally stable in RH ranges from 11 to 96% at 313 K. Solubility studies, performed in distilled water at 310 K, showed an at least 1.5 fold solubility improvement for both amorph forms relative to crystalline AZM-DH, but with some evidence of solvent-mediated phase transformation after 20 min. Structural characterization by single-crystal XRD concluded that thermally stimulated amorphization required energy to disrupt intermolecular hydrogen bond interactions by bridging water molecules in addition to hydrogen bond interactions between neighbouring AZM molecules in unit cell. [ABSTRACT FROM AUTHOR]

The relative accuracies of approximation-based integral versus differential isoconversional approaches for 'actual' E determination were investigated on experimental dehydration data of roxithromycin monohydrate from thermogravimetric (TG) analysis. The dehydration kinetic parameters and the relationship to the structural characteristics of the monohydrate and anhydrate forms from differential scanning calorimetry (DSC) and single-crystal X-ray diffractometry (SC-XRD) are also reported. Integral methods versus the differential Friedman isoconversional method evaluated E correspondences in both iso- and non-isothermal TG methods. The reliability in E from Friedman approached that of estimates from current most accepted integral isoconversional methods and was even superior to methods (for non-isothermal studies) that employ an approximation to the temperature integral (modified Kissinger-Akahira-Sunose, Senum-Yang fourth degree). Structural characterization (DSC, SC-XRD) and kinetic analysis from generalized kinetic master plots concluded that coordinated water occupied interlinked voids in crystal structure which may have facilitated the multidimensional diffusional loss of water upon heating without disruption of the crystal structure. [ABSTRACT FROM AUTHOR]

A novel Mannich base is synthesized by the condensation of 4-methylacetophenone and dimethylamine hydrochloride in the presence of formaldehyde. The molecular and crystal structure of the title compound is confirmed by 1H, 13C NMR and IR spectroscopy, and single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

Four Cu(II) complexes [Cu(HL-LH)Cl].HO ( 1), [Cu(L-L)Cl] ( 2), [Cu(LH)]0.5HO ( 3) and [CuL] ( 4) derived from a disulfide Schiff base ligand N, N′-(1,1′-dithio-bis(phenylene))-bis(salicylideneimine) ( HL- LH) were synthesized under different reaction conditions in the absence and presence of N-donor ligands and characterized by spectral, elemental, magnetic and thermal studies. A single-crystal X-ray analysis of 4 revealed that the Cu atom is in a square planar geometry, coordinated to phenolic oxygen, azomethine nitrogen and two sulfur atoms with cleavage of the S-S bond in HL- LH. Complexes 1- 4 were found to be better antioxidants than HL- LH. Complexes 1 and 3, possessing free OH groups, showed higher antioxidant potentials. The interactions of the Schiff base Cu(II) complexes with DNA were investigated by UV-visible and fluorescence spectroscopies and agarose gel electrophoresis. The binding constants were in the order 10-10 M suggesting moderate binding affinity of the complexes toward CT-DNA, with complex 1 showing the maximum binding affinity. In competitive binding experiments with ethidium bromide, complex 1 displayed the highest quenching constant, consistent with the UV binding results. Complexes 1- 4 were found to cleave DNA efficiently in its nicked or linear forms. [ABSTRACT FROM AUTHOR]

The reaction of cis-[ReO2I(PPh3)2] with tert-butyl isocyanide in benzene led to the isolation of the complex [ReI3(CN-t-Bu)3(PPh3)] (1). The complex is unusual since it contains bulky ligands with large cone angles, i.e. three iodides, three isocyanides with tert-butyl groups and a triphenylphosphine as ligands in a seven-coordinate geometry around the rhenium(III) metal ion. [ABSTRACT FROM AUTHOR]

A series of cyanohydrines derived from cyclic aliphatic ketones was synthesized by acid-catalyzed nucleophilic addition reaction under the action of potassium cyanide. The products were characterized by means of multi-nuclear NMR spectroscopy (H, C, N, N), mass spectrometry, elemental analysis, UV-Vis spectroscopy, refraction index measurements as well as vibrational spectroscopy. The structure of the cyanohydrine of cyclohexanone was elucidated by means of single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

The reactions of trans-[ReOX 3(PPh 3) 2] (X = Cl, Br) with 4-aminoantipyrine (H 2pap) were studied, and the complexes cis-[ReX 2(pap)(H 2pap)(PPh 3)](ReO 4) (X = Cl ( 1), Br ( 2)) were isolated. The crystal structure of 2 was determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2 1 with a = 11.5145(6) Å, b = 11.5330(5) Å, c = 17.5492(9) Å, β = 105.322(2)°, V = 2247.6(2) Å 3, Z = 2, C 40H 39N 6O 6PBr 2Re 2, Mr = 1262.97, Dc = 1.866 g cm −3, F(000) = 1208 and μ(Mo Kα) = 7.244 mm −1, the final R = 0.0545 and wR = 0.1314. The ligand pap is coordinated through the doubly deprotonated amino nitrogen as an imide, and H 2pap acts as a neutral bidentate chelate, with coordination through the neutral amino nitrogen and the ketonic oxygen. Graphical Abstract: The synthesis and crystal structure of the complex cis-[ReBr 2(pap)(H 2pap)(PPh 3)](ReO 4), prepared from the reaction of trans-[ReOBr 3(PPh 3) 2] with 4-aminoantipyrine (H 2pap), is described. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

An unusual mixed crystal of a square-pyramidal oxorhenium(V), [ReOCl(Hdua)], and an octahedral imidorhenium(V) complex, [Re(dua)Cl2(PPh3)], was prepared from the reaction of trans-[ReOCl3(PPh3)2] and (6Z)-6-(2-aminobenzylideneamino)- 5-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione (H3dua) in ethanol. Characterization was performed by single crystal X-ray structure determination and IR spectroscopy. The chelate Hdua is coordinated as a tridentate diamido-imine, and dua is chelated as an imido-imino-amide. [ABSTRACT FROM AUTHOR]

In the original publication there was a typo in the title of the article. The correct title of the article is SYNTHESIS, CHARACTERIZATION, AND COMPUTATIONAL STUDIES OF TRIAZATETRACYCLO ACETAMIDE. [ABSTRACT FROM AUTHOR]

The rhenium(I) compound fac-[Re(CO)3(daa)].Hpab.H2O (Hpab = N,N'-(1,2-phenylene)bis(2′-aminobenzamide); Hdaa = 2- amino-N-(2-aminophenyl)benzamide) was synthesized from the reaction of [Re(CO)5Br] with two equivalent of Hpab in toluene. The monoanionic tridentate ligand daa was formed by the rhenium-mediated cleavage of an amido N-C bond of the potentially tetradentate ligand Hpab. The compound was characterized by IR spectroscopy and X-ray crystallography, and daa is coordinated as a diaminoamide via three nitrogen-donor atoms. [ABSTRACT FROM AUTHOR]