NO is an important signaling molecule in human tissue. However, the mechanisms by which this molecule is controlled and directed are currently little understood. Nitrophorins (NPs) comprise a group of ferriheme proteins originating from blood-sucking insects that are tailored to protect and deliver NO via coordination to and release from ...

This paper reports a comprehensive phenomenological description and experimental infrared (IR) investigations of the soft-mode-driven lattice instabilities into various commensurately and incommensurately modulated phases of Cs(2)HgCl(4) crystals. Our theoretical analysis shows that the lattice instabilities along the a and c crystallographic directions are related to low-frequency transverse optical (TO) phonon ...

A nonporous neutral framework [CuCl(2)(m-bttmb)(2)](n) () was changed into a porous ionic {[Cu(m-bttmb)(2)(H(2)O)Cl]Cl(CH(3)CN)(0.5)(H(2)O)(2.75)}(n) () by simply increasing the amount of CH(3)CN in the mixed solvent (CH(3)CN and H(2)O) or temperature in the reactions of CuCl(2)·2H(2)O with 1,3-bis(triazol-1-ylmethyl)-2,4,6-trimethylbenzene (m-bttmb). undergoes transformation into when treated with CH(3)CN. Both and have 2D 4-connected ...

We report a theoretical analysis of a series of heteroleptic iridium(iii) complexes (dox)(2)Ir(acac) [dox = 2,5-diphenyl-1,3,4-oxadiazolato-N,C(2), acac = acetylacetonate] (), (fox)(2)Ir(acac) [fox = 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazolato-N,C(2)] (), (fox)(2)Ir(Et(2)dtc) [Et(2)dtc = N,N'-diethyldithiocarbamate] (), (fox)(2)Ir(Et(2)dtp) [Et(2)dtp = O,O'-diethyldithiophosphate] (), (pypz)(2)Ir(acac) [pypz = 3,5-di(2-pyridyl)pyrazole] (), (O-pypz)(2)Ir(acac) (), (S-pypz)(2)Ir(acac) () and (bptz)(2)Ir(acac) [bptz = 3-tert-butyl-5-(2-pyridyl)triazole] () ...

The new [N(CH(3))(4)][WSF(5)] salt was synthesized by two preparative methods: (a) by reaction of WSF(4) with [N(CH(3))(4)][F] in CH(3)CN and (b) directly from WF(6) using the new sulfide-transfer reagent [N(CH(3))(4)][SSi(CH(3))(3)]. The [N(CH(3))(4)][WSF(5)] salt was characterized by Raman, IR, and (19)F NMR spectroscopy and [N(CH(3))(4)][WSF(5)]·CH(3)CN by X-ray crystallography. The reaction of ...

Nickel pincer complexes of the type [2,6-(R(2)PO)(2)C(6)H(3)]NiH (R = (t)Bu, 1a; R = (i)Pr, 1b; R = (c)Pe, 1c) react with BH(3)·THF to produce borohydride complexes [2,6-(R(2)PO)(2)C(6)H(3)]Ni(η(2)-BH(4)) (2a-c), as confirmed by NMR and IR spectroscopy, X-ray crystallography, and elemental analysis. The reactions are irreversible at room temperature but reversible at ...

A new solid high-proton conductor, substituted heteropoly acid with Dawson structure H(7)[In(H(2)O)P(2)W(17)O(61)]·23H(2)O, has been synthesized by the degradation/ion exchange/freezing method. The pH of the synthesis reaction was given. The product was characterized by chemical analysis, IR, UV, XRD and TG-DTA. The determination of conductivity shows that H(7)[In(H(2)O)P(2)W(17)O(61)]·23H(2)O is an excellent ...

We have investigated the lowest triplet and singlet potential energy surfaces (PESs) for the reaction of Ga2 dimer with water. Under thermal conditions we predict formation of the triplet ground state addition complex Ga2…OH2(3B1) involving Ga…O…Ga bridge interaction. At the coupled cluster CCSD(T)/AE (CCSD(T)/ECP) levels, Ga2…OH2(3B1) is bound by 5.5 ...

Caralluma sinaica is sold on local markets of Saudi Arabia for various health benefits however no phytochemical study has specifically been performed on this species. NMR and UHPLC-ESI-TOF-MS profilings of the ethanolic extract of the whole plant reveal a very complex phytochemical composition dominated by pregnanes. Detailed information on its ...

A new three-dimensional alkaline-earth metal-organic framework (MOF) compound, [Mg(Pdc)(H(2)O)](n) () (H(2)Pdc = pyridine-2,5-dicarboxylic acid), has been synthesized and structurally characterized by single crystal X-ray diffraction analysis. Compound features a 3D porous framework afforded by the Mg(2)-diad centers through formation of interconnected chair like structural motifs. A nitrogen adsorption study confirms ...

A [C,N] cyclometalated Ir complex, [Ir(III)(Cp*)(4-(1H-pyrazol-1-yl-κN(2))benzoic acid-κC(3))(H(2)O)](2)SO(4) [1](2)•SO(4) was reduced by aliphatic alcohols to produce the corresponding hydride complex [Ir(III)(Cp*)(4-(1H-pyrazol-1-yl-κN(2))benzoate-κC(3))H](-) 4 at room temperature in a basic aqueous solution (pH 13.6). Formation of the hydride complex 4 was confirmed by (1)H and (13)C NMR, ESI MS, and UV-vis spectra. The ...

Six novel 2-(benzylcarbamoyl)phenyl derivatives were synthesized and characterized by (1) H-NMR, mass spectrometry, infrared spectra and elemental analysis. Their europium complexes were prepared and characterized by elemental analysis, EDTA titrimetric analysis, IR and UV spectra as well as molar conductivity measurements. The luminescence properties of these complexes were investigated and ...

Schiff base ligand (H(3)L) was prepared from the condensation reaction of protochatechualdehyde (3,4-dihydroxybenzaldhyde)with 2-amino phenol. From the direct reaction of the ligand (H(3)L) with Co(II), Ni(II) and Cu(II) chlorides, and Fe(III)and Zn(II)nitrates in 2 M/1 L molar ratio, the five new neutral complexes were prepared. The characterization of the newly formed compounds ...

Bahamaolides A and B (1 and 2), two new 36-membered macrocyclic lactones, were isolated from the culture of the marine actinomycete Streptomyces sp. derived from a sediment sample collected at North Cat Cay in the Bahamas. The planar structures of 1 and 2, bearing a hexaenone and nine consecutive skipped ...

To bridge or not to bridge depends on the size of the Lewis base in mixed sp(2) -sp(3) phosphine adducts of Br(2) B(2) Mes(2) . Whereas reaction with bulky PMeCy(2) induced a 1,2-rearrangement to afford the 1,1-dimesityl adduct as the major component, the "normal" 1,2-dimesityl adduct was favored for the ...

The effects of multivalent metal ions (Cu(2+)/Zn(2+)/Al(3+)) on the aggregation of salmon calcitonin (sCT)-a therapeutic peptide used worldwide in the treatment of osteoporosis and Paget's disease-have been studied in vitro using NMR (both solution state and solid state), TEM, ThT-fluorescence, and FT-IR spectroscopy. Overall, the various results indicated that the ...

C(60)-styryl Bodipy dyads that show strong absorption of visible light (ε = 64 600 M(-1) cm(-1) at 657 nm) and a long-lived triplet excited state (τ(T) = 123.2 μs) are prepared. The dyads were used as heavy-atom-free organic triplet photosensitizers for photooxidation of 1,5-dihydroxynaphthalene via the photosensitizing of singlet oxygen ((1)O(2)). ...

Aromatic trimeric interactions are extremely significant in the stabilization of the specific structures of the proteins as well as protein-protein, and protein-ligand interactions. Here we have reported a direct evidence of the observation of a cyclic asymmetric structure of indole[ellipsis (horizontal)](pyrrole)(2) trimer bound by three N-H[ellipsis (horizontal)]π hydrogen bonding interactions ...

The four isostructural compounds Li(2)In(2)MQ(6) (M = Si, Ge; Q = S, Se) have been synthesized for the first time. They crystallize in the noncentrosymmetric monoclinic space group Cc with the three-dimensional framework composed of corner-sharing LiQ(4), InQ(4), and MQ(4) tetrahedra. The second-harmonic-generation signal intensities of the two sulfides and ...

Reactions between 2,2'-dipyridylketone () and different amines gave a series of iminic ligands, and their chemical reductions produced the related amines. The organic ligands were employed in the syntheses of the corresponding new phosphorescent six-member ring bis-cyclometalated heteroleptic iridium(iii) complexes of general formula [Ir(ppy)(2)(L)](+) (ppy = 2-phenylpyridine), namely . The ...

The adsorption and desorption of hydrogen on Ir/SiO(2) catalyst were studied by using in situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) combined with curve-fitting analysis. The results indicate that there are three different surface species formed on the catalyst that correspond to the peaks at 1950, 2010, and 2035 ...

A chemical investigation on the aerial parts of Hypericum scabrum L. resulted in the isolation of three new phloroglucinol derivatives, hyperscabrins A (1), B (2), and C (3), together with one known compound, (2R,3R,4S,6R)-3-methyl-4,6-di(3-methyl-2-butenyl)-2-(2-methyl-1-oxopropyl)-3-(4-methyl-3-pentenyl)-cyclohexanone (4). The structures were elucidated by means of spectroscopic methods, including MS, IR, 1D NMR, and ...

Setting up spatially separated HOMO and LUMO regions in a non-Kekulé structured trinuclear Ir(iii)-Ru(ii)-Ir(iii) system and using oxidative-reduction electrochemiluminescence leads to emissions that are not detected in photoluminescence. Moreover, the new design allows tuning of the wavelength of emission in a stepless fashion as a function of the selected potential ...

The structures of the complex of 2,2'-(methylimino)bis(N,N-dioctylacetamide) (MIDOA) with M(VII)O(4)(-) (M = Re and Tc), which were prepared by liquid-liquid solvent extraction, were investigated by using (1)H nuclear magnetic resonance (NMR), extended X-ray absorption fine structure (EXAFS), and infrared (IR) spectroscopy. The (1)H NMR spectra of the complex of MIDOA ...

A novel secondary metabolite, N-trans-cinnamoyl 2-amino-3a,4,5,6,7,8,9,10,11,12,13,13a-dodecahydrocyclododeca[d]oxazole (1), was isolated from Streptomyces spp. CIBYL1, along with five known compounds, pimprinine (2), (3R,4S,5R,6R)-3,4,5,6-tetrahydro-4-hydroxy-3,5,6-trimethyl-2H-pyran-2-one (3), indolyl-3-carboxylic acid (4), 2-phenylacetamide (5) and di(1H-pyrrol-2-yl)methanone (6). The structures of these metabolites were elucidated on the basis of extensive analysis of spectroscopic data, including OR, IR, HRMS, ...

Stearate@Cu/ZnO nanocomposite particles with molar ratios of ZnO ∶ Cu = 2 and 5 are synthesized by reduction of the metal-organic Cu precursor [Cu{(OCH(CH(3))CH(2)N(CH(3))(2))}(2)] in the presence of stearate@ZnO nanoparticles. In the case of ZnO ∶ Cu = 5, high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) combined with electron-energy-loss-spectroscopy (EELS) as well as ...

The present study comprehensively explores diverse mechanistic pathways for intramolecular hydroamination of prototype 2,2-dimethyl-4-penten-1-amine by Cp*Ir chloropyrazole (1; Cp*=pentamethylcyclopentadienyl) in the presence of KOtBu base with the aid of density functional theory (DFT) calculations. The most accessible mechanistic pathway for catalytic turnover commences from Cp*Ir pyrazolato (Pz) substrate adduct 2⋅S, ...

A pyrazoline based ligand; (5-(4-chlorophenyl)-3-phenyl-4, 5-dihydro-1H-pyrazole-1-carbothioamide) has been synthesized by Claisen-Schmidt condensation of acetophenone with p-chlorobenzaldehyde, followed by sodium hydroxide assisted cyclization of the resulting chalcone with thiosemicarbazide. Metal ion complexes of the synthesized ligand were prepared with Cu(II) and Ni(II) metal ions, separately and respectively. Ligand and the metal complexes ...

Despite the wide-ranging applications of binary Rh and Ir oxides, their stability and trends in Rh and Ir oxidation states are not fully understood. Using first-principles electronic structure calculations, we demonstrate that the origin of the categorical stability of Ir(4+) is the relativistic contraction of the 6s orbital and, consequently, ...

The reaction between the oxometallic complexes Cp*(2)M(2)O(5) and Na(2)M'O(4) (M, M' = Mo, W) in a 1:10 molar ratio in an acidic aqueous medium constitutes a mild and selective entry into the anionic Lindqvist-type hexametallic organometallic mixed oxides [Cp*Mo(x)W(6-x)O(18)](-) [x = 6 (1), 5 (2), 1 (3), 0 (4)]. All ...

Lattice dynamics and stability of four fcc crystals (Al, Ir, Pt and Au) under isotropic (hydrostatic) tensile loading are studied from first principles using the linear response method and the harmonic approximation. The results reveal that, contrary to former expectations, strengths of all the studied crystals are limited by instabilities ...

First principles calculations based on spin-polarized density functional theory were used to identify metallic adatoms that would strengthen the Pt(111)/graphene interface (with a low work of separation of 0.009 J m(-2)), when the adatom was placed between the Pt(111) and the graphene. It was shown that the strength of the Pt-adatom bond, ...

In this study we introduce a series of monodentate pyridine-based ligands for which the phosphorus coordination mode to rhodium can be controlled by the binding of Zn(II) -templates to the pyridyl group. A series of monodentate phosphoroamidite and phosphite ligands have been prepared and studied under hydroformylation conditions by in ...

Singly and triply charged cationic clusters of aluminium and the protected amino acid AcPheOMe are investigated in a supersonic beam by using a combination of a thermic and a laser ablation ion source. For the singly charged species UV- and IR photodissociation spectroscopy is applied. In the case of the ...

In this study, (E)-2-[(4-bromophenylimino)methyl]-5-(diethylamino)phenol compound was investigated by mainly focusing on conformational isomerism. For this purpose, molecular structure and spectroscopic properties of the compound were experimentally characterized by X-ray diffraction, FT-IR and UV-Vis spectroscopic techniques, and computationally by DFT method. The X-ray diffraction analysis of the compound shows the formation ...

A series of 2-naphthyl pyrazolines were synthesized by the cyclization of 2-naphthyl chalcones and phenylhydrazine hydrochloride in the presence of sodium acetate. The yields of pyrazoline derivatives are more than 80%. The synthesized pyrazolines were characterized by their physical constants, IR, (1)H, (13)C and MS spectra. From the IR and ...

An interesting series of heterocyclic mixed ligand of oxovanadium(IV) complexes have been synthesized by the reaction of vanadium(IV) sulfate with rhodanine azo (HL(n)) in the presence of β-diketon (LH). The elemental analysis, magnetic moments, spectral (UV-Vis, IR, (1)HNMR and ESR) with thermal studies were used to characterize the isolated complexes. ...

The metal complexes [M{HB(hpp)}(2)(CO)(4)] (M = Cr, Mo or W) and [M(cod){HB(hpp)}(2)Cl] (M = Rh or Ir) of the doubly-base stabilized diborane(4) ligand [HB(hpp)](2) were fully characterized and their bonding nature was investigated in detail. While bonding in the group 6 complexes predominantly occurs through the hydrogen atoms, the metal-ligand ...

The preparation, structures, and magnetic properties of a series of metal formate perovskites [CH(3) NH(3) ][Mn(x) Zn(1-x) (HCOO)(3) ] were investigated. The isostructural solid solution can be prepared in the complete range of x=0-1. The metal-organic perovskite structures consist of an anionic NaCl type [Mn(x) Zn(1-x) (HCOO)(3) (-) ] framework ...

The mechanism of ligated transition metal MH+ (M = Os, Ir and Pt) catalyzed methane activation has been computed at the B3LYP level of density functional theory. The B3LYP energies of important species on the potential energy surface are compared to CCSD(T) single point energy calculations. Newer kinetic and dispersion-corrected ...

A new discrete [V(16)O(38)(CN)](9-) cluster, which displays the hitherto unknown 8- charge on the cluster shell and is the first to encapsulate the cyanide anion, has been synthesized and characterized by IR and UV/vis/near-IR spectroscopy, electrochemistry, and magnetic susceptibility measurements. Bond valence sum calculations conducted on the basis of the ...

We use protonated benzene (C(6)H(7) (+)) and cyclohexadienyl radical (c-C(6)H(7)) to demonstrate a new method that has some advantages over other methods currently used. C(6)H(7) (+) and c-C(6)H(7) were produced on electron bombardment of a mixture of benzene (C(6)H(6)) and para-hydrogen during deposition onto a target at 3.2 K. Infrared ...

We combined experimental vibrational spectroscopy (FTIR-Raman) and ab-initio calculations based on the density functional theory (DFT) to predict the structural and vibrational properties of sodium saccharinate in the solid and aqueous solution phases. The structural properties for the saccharinate ion and its dimer, such as the bond order, possible charge-transfer ...

A series of bis(2-phenylbenzothiozolato-N,C(2'))iridium(acetylacetonate) [(bt)(2)Ir(acac)] derivatives, , were synthesized. Different substituents (CF(3), F, CH(3), OCH(3)) were introduced in the benzothiazole ring to study the substituent effect on the photophysical, electrochemical properties and electroluminescent performance of the complexes, and finally to select high-performance phosphors for use in organic light-emitting diodes (OLEDs). ...

Semisynthetic zinc chlorins are shown for the first time to self-assemble in the absence of an intrinsic hydroxy group, which is always present in the chlorosomal bacteriochlorophylls (BChl's) c, d and e. Instead, the presently studied compounds have carbonyl groups. These cannot function as hydrogen bond donating groups. However due ...

Two new Co(II) coordination polymers with a pyridinedicarboxylate ligand, {[Co()(H(2)O)]·H(2)O}(n) () and [Co(3)(HCOO)(2)()(2)(H(2)O)(2)](n) () (H(2) = 5-(pyridin-4-yl)isophthalic acid), have been synthesized and structurally characterized by elemental analysis, IR, XRPD, and single-crystal X-ray diffraction. Structure analyses show that complex has a two-dimensional (2D) double-layered structure with a (3,6)-connected kgd topology based ...

A family of ligands derived from bis(amino amides) containing aliphatic spacers has been prepared, and their protonation and stability constants for the formation of Cu(2+) complexes have been determined potentiometrically. Important differences are associated to both the length of the aliphatic spacer and the nature of the side chains derived ...

As indicated by nearly perfect XRD data, but challenged by a two-signal IR spectrum of CO guest molecules, it is confirmed by computer simulations and XPS experiments that the most defect-free SURMOFs contain about 4 % defective Cu sites.

The Ir(i) complexes of chiral spiro phosphino-oxazoline ligands (SpinPhox) have demonstrated good to excellent enantioselectivity in the asymmetric hydrogenation (AH) of a variety of (E)-β,β-disubstituted α,β-unsaturated N-methoxy-N-methylamides, affording the corresponding optically active Weinreb amides with up to 97% ee.

The novel terthiophene (3T) oligomer 6 and a series of cationic Ir(III) bis-cyclometalates [Ir(C(∧)N)(2)(N(∧)N)]PF(6)9-12 were prepared. The synthesis, characterization, electrochemical, and photophysical properties are reported. The cyclometalating ligands (C(∧)N) are 2-phenylpyridinato (ppy) or the 3T oligomer (3T-ppy), asymmetrically capped in the 5 and 5″ positions with the ppy and mesityl ...