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In the paper, a procedure was suggested for making plant oil blends of desirable physico-chemical and performance parameters. There was applied a rule of additivity of parameters of component oils in the blend to get oil products with modified nutritional characteristics. The other objective of the research study was to test the usefulness of the procedure when projecting thermal properties of the blends for deep frying. To make oil blends, plant oils were used that were produced by Oleofarm Ltd. The oil blends were analysed using chromatographic and spectroscopic methods. Their chemical parameters constituted an input dataset to make blends of expected performance properties. It was shown experimentally that it was possible to theoretically project physico-chemical and thermal parameters of the final oil blend. When knowing the chemical parameters of individual blend-forming oils, it is possible to employ them to determine the parameters of the final blend. There were suggested oil compositions for the preparation of advantageous blends to be used for deep frying and salad dressings. Thus there was confirmed the purposefulness of blending the oils in order to make a product the qualities of which could be geared to the specific utility purposes.

Two neodymium(III) six-coordinate complexes NdCl3(3-Br-4-CH3OC7H7NO)3 (Nd1) and Nd(C7H9NO)5(C4H8O2)(ClO4)3 (Nd2) have been synthesized and characterized. The FT-IR and FT-Raman data were acquired, and a complete vibrational assignment of the fundamental modes of the compounds was carried out. The frequencies calculated for the both ligands and scaled using the B3LYP approach with the 6-311G(2d,2p) basis set correspond very well to the experimental values. The XRD results, IR and Raman spectra were discussed in terms of a possible structure and composition of the studied compounds. The optical absorption and emission spectra were investigated at room temperature. The emission decay is mono exponential indicating that the energy transfer from the ligand occurs straight to the 4F3/2 level. The lifetime of this level is about 2.5 μs? A possibility of the energy transfer between the ligands under study and neodymium ions was considered. The calculations of the spin Hamiltonian parameters and EPR data simulation were performed using the electron paramagnetic resonance and nuclear magnetic resonance (EPR-NMR) program.

The crystal and molecular structure and physicochemical properties of 2-N-methylamino-3-methylpyridine N-oxide (MA3MPO) have been studied. MA3MPO was synthesized from 2-amino-3-methylpyridine by several steps to form colorless crystals suitable for crystallographic analysis. The data reveal that MA3MPO crystallizes in the monoclinic space group P21/n. The studied compound contains a nearly flat triply substituted pyridine skeleton whose structure is stabilized by an intramolecular N–H⋅⋅⋅O hydrogen bond. The N-oxide molecules are connected together by weak C–H⋯O hydrogen bonds, an acceptor of which is the oxygen atom from the N-oxide group. This leads to creation of two-dimensional network of hydrogen bonds. Its IR, Raman, UV–Vis and luminescence spectra have been measured and analyzed on the basis of DFT and NBO quantum chemical calculations in which the B3LYP/6-311++G(d,p) approach was applied. The distribution of the electron levels in the studied compound has been analyzed in terms of the possibility of its participation in the ligand-to-lanthanide ion energy transfer., Graphical abstract Image 10178, Highlights • The 2-N-methylamino-3-methylpyridine N-oxide (MA3MPO) was synthesized and characterized. • The studied compound structure is stabilized by an intramolecular N–H⋯O hydrogen bond. • The molecules are connected together by weak C–H⋯O hydrogen bonds. • The amino group plays the role of effective hydrogen-bond donor but the N-oxide group is a hydrogen-bond acceptor. • X-ray, IR, Raman and DFT methods recognized the existence of the intramolecular N–H⋯O hydrogen bond in the studied compound.

BackgroundIn contrast with the setting of acute myocardial infarction, there are limited data regarding the impact of diabetes mellitus on clinical outcomes in contemporary cohorts of patients with chronic coronary syndromes. We aimed to investigate the prevalence and prognostic impact of diabetes according to geographical regions and ethnicity.Methods and resultsCLARIFY is an observational registry of patients with chronic coronary syndromes, enrolled across 45 countries in Europe, Asia, America, Middle East, Australia, and Africa in 2009–2010, and followed up yearly for 5 years. Chronic coronary syndromes were defined by ≥1 of the following criteria: prior myocardial infarction, evidence of coronary stenosis >50%, proven symptomatic myocardial ischaemia, or prior revascularization procedure.Among 32 694 patients, 9502 (29%) had diabetes, with a regional prevalence ranging from below 20% in Northern Europe to ∼60% in the Gulf countries. In a multivariable-adjusted Cox proportional hazards model, diabetes was associated with increased risks for the primary outcome (cardiovascular death, myocardial infarction, or stroke) with an adjusted hazard ratio of 1.28 (95% confidence interval 1.18, 1.39) and for all secondary outcomes (all-cause and cardiovascular mortality, myocardial infarction, stroke, heart failure, and coronary revascularization). Differences on outcomes according to geography and ethnicity were modest.ConclusionIn patients with chronic coronary syndromes, diabetes is independently associated with mortality and cardiovascular events, including heart failure, which is not accounted by demographics, prior medical history, left ventricular ejection fraction, or use of secondary prevention medication. This is observed across multiple geographic regions and ethnicities, despite marked disparities in the prevalence of diabetes.ClinicalTrials identifierISRCTN43070564

Silver phytate IP6, IP6Ag, IP6Ag2 and IP6Ag3 complexes in the solid state have been synthesized changing the phosphate to metal mole ratio. The obtained products have been characterized by means of chemical and spectroscopic studies. Attenuated total reflection Fourier transform infrared technique and Raman microscope were used in the measurements. These results were discussed in terms of DFT (Density Functional Theory) quantum chemical calculations using the B3LYP/6-31G(d,p) approach. The molecular structures of these compounds have been proposed on the basis of group theory and geometry optimization taking into account the shape and the number of the observed bands corresponding to the stretching and bending vibrations of the phosphate group and metal-oxygen polyhedron. The role of inter- and intra-hydrogen bonds in stabilization of the structure has been discussed. It was found that three types of hydrogen bonds appear in the studied compounds: terminal, and those engaged in the inter- and intra-molecular interactions. The Fermi resonance as a result of the strong intra-molecular O H⋯O hydrogen bonds was discovered. Electron absorption spectra have been measured to characterize the electron properties of the studied complexes and their local symmetry.

Attenuated total reflection Fourier transform infrared (ATR FT-IR) and confocal Raman microscopes were used to record horse fat depth profiles. The dependence of the unsaturation level and the iodi...

New europium and terbium [LnCl3L3(H2O)2] polycrystalline complexes were synthesized with the ligand L = 3-bromo-4-methylthio-2,6-lutidine N-oxide. IR, Raman, electron absorption UV-VIS and emission spectra measurements were carried out for these compounds. Re-crystallization of these materials led to formation of single crystals with another composition [LnL(H2O)7]Cl3∙L3, they were characterized by X-ray diffraction technique and spectroscopic measurements. Both types of the materials consist of eight coordinated LnCl3O3O’2 or LnOO’7 polyhedrons containing O - oxygen atoms of the N-oxide group, chlorine atoms or O’ - oxygen atoms of the water units. The crystal structure was solved for two complexes of the formula [Ln(L)(H2O)7]Cl3∙(L)3 where Ln = Eu and Tb. X-ray diffraction analysis reveals that these complexes are isostructural with P21/m space group. The optimization of the molecular system and frequency calculations were carried out using density functional theory (DFT). The DFT quantum chemical calculations of the vibrational wavenumbers were performed for the ligands used for the Eu3+ and Tb3+ ions complexation. The emission measurements were carried out with the femtosecond excitation. The effective ligand-to-metal energy transfer was discovered in the [LnCl3L3(H2O)2] complexes formed in the polycrystalline state.

The crystal and molecular structures of aquo 4,6-dimethyl- 5H -[1,2,3]triazolo[4,5- c ]pyridine in a zwitterionic form have been determined by X-ray diffraction and DFT quantum chemical calculations. The compound adopts a triclinic crystal structure, space group P-1 = C i 1 (No. 2) with Z = 2 and the unit cell parameters: a = 6.7452 A, b = 9.5292 A, c = 9.5554 A and α = 69.279°, β = 73.951°, γ = 74.242°. The temperature dependence of its IR and Raman spectra have been measured and discussed in terms of proton transfer dynamics. The molecular structure and simulated vibrational spectra of the studied compound have been determined using the DFT B3LYP/6-311G(2d,2p) approach. Vibrational characteristics of a triazolo-pyridinium system in the studied compound has been proposed. A role of water molecules in stabilization of the compound space structure has been considered.

The crystal and molecular structures of aquo 7-methyl-1H-[1,2,3]triazolo[4,5-c]pyridinium nitrate composite have been determined by X-ray diffraction and DFT quantum chemical calculations. The thermogravimetric and differential scanning calorimetric analyses were also performed. The compound crystallizes in a monoclinic structure, space group P21/n (No. 14) with Z = 4 and the unit cell parameters: a = 7.1392(3), b = 14.3163(5), c = 9.5900(4) and β = 107.330(4). The molecular structure and simulated vibrational spectra of the studied compound have been determined using B3LYP/6-311G(2d,2p) approach. The vibrational characteristics of the triazolo ring in the studied compound has been proposed. The role of the hydrogen bond in the formation of the salt composite has been discussed.

Thirteen edible oils: sunflower, avocado, hemp, high-linolenic flax, low-linolenic flax, safflower, walnut, roasted sesame, rice, corn, rapeseed, pumpkin seed, and hazel were studied in this work. Their fatty acid composition, iodine, acidic, peroxide, and saponification values were determined. Infrared and Raman spectra of the oils were recorded in the range 400–3200 cm−1. The integral intensities of the bands at about 1655 and 2852 cm−1 corresponding to ν(C=C) and ν(CH2) vibrations were evaluated and used to construct a relationship between the spectroscopic data and the iodine value. The following linear dependencies were obtained: Iν(C=C)/Iν(CH2) = 7.449 × 10−4 × iodine value – 0.0339 and Iν(C=C)/Iν(CH2) = 9.299 × 10−4 × iodine value – 0.023 for the infrared and Raman spectra with a correlation coefficient 0.988 and 0.976, respectively. These calibration lines can be used to determine the iodine value for oils with unknown unsaturation level, and may be applied for margarines and other fatty m...

Syntheses of 5-nitro-2-(2-phenylhydrazinyl)pyridine (5-nitro-2-phenylhydrazopyridine), 3-methyl-5-nitro-2-(2-phenylhydrazinyl)pyridine (3-methyl-5-nitro-2-phenylhydrazopyridine), 4-methyl-5-nitro-2-(2-phenylhydrazinyl)pyridine (4-methyl-5-nitro-2-phenylhydrazopyridine) and 6-methyl-5-nitro-2-(2-phenylhydrazinyl)pyridine (6-methyl-5-nitro-2-phenylhydrazo-pyridine) have been described. Electronic absorption and emission spectra of the compounds in the solid state and in various solvents have been measured at room temperature and discussed in terms of DFT quantum chemical calculations. The molecular structures and energy sequences of the singlet and triplet states have been determined in the B3LYP/6-311G(2d,2p) approximations. The Mulliken analysis and non-bonding orbital approach have been used in characterization of the studied compounds. It has been shown that the HOMO-LUMO transition of the studied compounds is observed in the range 23,900 ÷ 29,300 cm −1 and in this excitation the π-electrons of phenyl ring are transferred to nitro group of pyridine ring. In such a transition the hydrazo-bridge should take part as a mediator. The luminescence of the studied hydrazo-compounds is weak, not measureable in the solid state but measureable in solution.

Time-dependent changes of chicken meat were studied using Fourier transform IR and Raman techniques. Small pieces of intact chicken breast muscle (pectoralis major) were used in the investigations. They were stored in air at 22 °C up to 10 days and their IR and Raman spectra were measured successfully. Analysis of the obtained spectra was performed using a deconvolution of the experimental bands into Lorentz components. All integral intensities of the observed bands were standardized using the statistical R2 coefficient of determination. The R2 values were automatically created as the output of the Origin software. The time-dependent changes of the spectra were used for meat spoilage detection. The analytical relationships between the integral intensities of selected bands have been derived indicating an increase of free amino acids content as the main effect of the chicken breast muscle spoilage.

The crystal and molecular structures of 6,6′-dimethyl-3,3′,5,5′-tetranitro-2,2′-hydrazobipyridine have been determined by X-ray diffraction and DFT quantum chemical methods. The B3LYP/6-311G(2d,2p) approach has been used in the theoretical calculations. The studied compound crystallizes in the monoclinic P21/n space group (Z = 2) with one-half molecule in the asymmetric unit. In the molecular structure of the studied compound the intramolecular N H⋯O hydrogen bonds play a crucial role. These molecules also interact in the unit cell by means of weak intermolecular C H⋯O contacts. IR and Raman spectra have been measured and simulated from the optimized geometry. In the calculations the monomeric unit has been taken into account because the intermolecular interactions between the components of the unit cell are weak and the factor group splitting is not observed in the experimental spectra. The structural and vibrational properties of the hydrazo bonds have been described with their relation to the intramolecular N H⋯O interaction existing in the structure of the monomeric form.

The species Lathecla carolyna Busby, 2015 described recently from Ecuador is reported to occur also in Venezu- ela and Colombia. An additional Peruvian occurrence of L. mimula (Draudt, 1920) is also documented.

[Ln2(2-hydroxy-5-methyl-nicotinic acid)6(H2O)4] and Ln2(5-methyl-nicotinic acid)6(H2O)4] complexes (Ln = Gd, Tb) have been synthesized and characterized by means of powder X-ray diffraction, IR, Raman, electron UV–Vis and emission measurements. The luminescence and dynamics of the excited states depopulation have been studied using femtosecond laser excitation. The singlet and triplet states of nicotinic acid were localized using DFT quantum chemical calculations. The energy transfer mechanism between the electron levels of the ligands and Tb3+ ion have been proposed.

The copper phytate IP6Cu, IP6Cu2 and IP6Cu3 complexes were synthesized changing the phytate to metal mole ratio. The obtained products have been characterized by means of chemical and spectroscopic studies. Spectroscopic ATR/IR, FT-Raman, UV–Vis, EPR and magnetic measurements were carried out. The structures of these compounds have been proposed on the basis of the group theory and geometry optimization taking into account the shape and number of the bands corresponding to the stretching and bending vibrations of the phosphate group and metal–oxygen polyhedron. The role of the inter- and intra-hydrogen bonds in stabilization of the structure has been discussed. EPR studies showed that a local rhombic symmetry of copper ions appears in the studied phytates. Dominant interactions show antiferromagnetic properties depending on the content of paramagnetic ions. Electronic supplementary material The online version of this article (10.1007/s00775-018-1622-0) contains supplementary material, which is available to authorized users.

The electron absorption and emission spectra were measured for the pyramidal LnPc(OAc) complexes in the solid state and co-doped in silica glass, where Ln=Er, Eu and Ho. The theoretical electron spectra were determined from the quantum chemical DFT calculation using four approximations CAM-B3LYP/LANL2DZ, CAM-B3LYP/CC-PVDZ, B3LYP/LANL2DZ and B3LYP/CC-PVDZ. It was shown that the best agreement between the calculated and experimental structural parameters and spectroscopic data was reached for the CAM-B3LYP/LANL2DZ model. The emission spectra were measured using the excitations both in the ligand and lanthanide absorption ranges. The possibility of energy transfer between the phthalocyanine ligand and excited states of lanthanide ions was discussed. It was shown that the back energy transfer from metal states to phthalocyanine state is responsible for the observed emission of the studied complexes both in the polycrystalline state and silica glass.

The crystal and molecular structures of 6-methyl-3,5-dinitro-2-[(E)-phenyldiazenyl]pyridine have been determined by X-ray diffraction and quantum chemical DFT calculations. The crystal is monoclinic, space group Cc (No. 9) with Z = 4 with the unit cell parameters: a = 12.083(7), b = 12.881(6), c = 8.134(3) A and β = 97.09(5)°. The azo-bridge appears in the trans conformation in which C2-N2-N2′-C1′ torsion angle takes a value − 178.6(3)°, whereas the dihedral angle between the planes of the phenyl and pyridine rings is 3.5(2)°. The IR and Raman spectra measured in the temperature range 80–350 K and quantum chemical calculations with the use of B3LYP/6-311G(2d,2p) approach confirmed the trans configuration of the azo-bridge as the most stable energetically and allowed determination of the energy other virtual structures. The observed effects were used in the discussion of vibrational dynamics of the studied compound. The energy gap between cis and trans conformers equals to 1.054 eV (0.03873 Hartree). The electron absorption and emission spectra have been measured and analyzed on the basis of DFT calculations. The life time of the excited state is 12 μs and the Stokes shift is close to 5470 cm− 1.

Fourier transform IR and Raman spectra, XRD studies and DFT quantum chemical calculations have been used to characterize the structural and vibrational properties of 2-hydroxy-5-methylpyridine-3-carboxylic acid. In the unit-cell of this compound two molecules related by the inversion center interact via O H⋯N hydrogen bonds. The double hydrogen bridge system is spaced parallel to the (1 0 2) crystallographic plane forming eight-membered arrangement characteristic for pyridine derivatives. The six-membered ring is the second characteristic unit formed via the intramolecular O H⋯O hydrogen bond. The geometry optimization of the monomer and dimer have been performed applying the Gaussian03 program package. All calculations were performed in the B3LYP/6-31G(d,p) basis set using the XRD data as input parameters. The relation between the molecular and crystal structures has been discussed in terms of the hydrogen bonds formed in the unit cell. The vibrations of the dimer have been discussed in terms of the resonance inside the system built of five rings coupled via hydrogen bonds.

Syntheses of 5-nitro-2-(2-phenylhydrazinyl)pyridine (5-nitro-2-phenylhydrazopyridine), 3-methyl-5-nitro-2-(2-phenylhydrazinyl)pyridine (3-methyl-5-nitro-2-phenylhydrazopyridine), 4-methyl-5-nitro-2-(2-phenylhydrazinyl)pyridine (4-methyl-5-nitro-2-phenylhydrazopyridine) and 6-methyl-5-nitro-2-(2-phenylhydrazinyl)pyridine (6-methyl-5-nitro-2-phenylhydrazopyridine) have been described. Their IR and Raman spectra have been measured and analyzed in terms of DFT quantum chemical calculations. The 6-311G(2d,2p) basis set with the B3LYP functional has been used to discuss the optimized structure and vibrational spectra. The vibrational characteristics of the hydrazo-bond have been reported with their relation to the inter- and intra-molecular hydrogen bonds formed in the studied systems. The role and influence of substitution position of the methyl chromophore on the structure and vibrational data have been discussed.

The molecular structure of 2-N-ethylamino-5-methyl-4-nitropyridine (EN5MP) and its vibrational spectra have been analyzed in terms of quantum chemical DFT calculations (B3LYP/6-311++G(d,p) approaches) and related to the XRD data. The EN5MP crystal is triclinic and centrosymmetric and its unit-cell is built by asymmetric units consisting of two parallelly arranged formula units, 2[C8H11N3O2], of different conformations. In each of the two subunits the methyl carbons and N-atoms of the nitro group are coplanar with the pyridine ring, but the O-atoms are inclined from this plane in the opposite directions. Dimers are linked by intermolecular NH⋯N hydrogen bonds system. Properties of the NA H⋯NP interactions between the hydrogen atom of the pyridine ring NP and the hydrogen atom of the amino group NA have been characterized. Additionally the crystal structure is stabilized by a set of weak intermolecular C H⋯O interactions.

IR and Raman spectra of Ca 2 MgSi 2 O 7 , Ca 2 ZnSi 2 O 7 and Sr 2 MgSi 2 O 7 oriented single crystals and powders have been measured. The temperature dependence of phonons has been established in the 4–650 K range. Discussion of the results has been performed on the basis of factor group approach for the tetragonal P 42 1 m (D 2d 3 ) space group with Z =2. The assignment of the bands observed to the internal and external modes has been made on their polarization behaviour, phonon energy calculations and literature data. The evidences of the LO–TO splitting and commensurate (C) to incommensurate (IC) as well as incommensurate (IC) to normal (N) phase transitions have been found. As a representative example, the results obtained for the spontaneous Raman scattering have also been used in the discussion of the stimulated Raman spectra of Ca 2 ZnSi 2 O 7 .

X-ray crystal structures of two isomers C 8 H 11 N 3 O 3 , i.e. 2-N-ethylamino-5-methyl-4-nitropyridine N-oxide (EN5MPO) and 2-N-ethylamino-3-methyl-4-nitropyridine N-oxide (EN3MPO) have been determined. The different substitutions of the CH 3 groups lead to change of the unit-cell structure, molecular and intermolecular arrangement. Both structures are monoclinic, space group P 2 1 / c and P 2 1 / n with a parallel and antiparallel orientation along the a -axis, respectively. In each of the two subunits, the methyl carbons and N-atoms of the nitro group are almost coplanar with the pyridine ring, but the N-oxide bonds are inclined from this plane. The crystal structures are stabilized by a set of the weak inter- and intramolecular hydrogen bonds of the N H⋯O type. The structures of both isomers have been confirmed by the results of IR and Raman spectra measurements, quantum chemical calculations and potential energy distribution (PED). The role of methyl group introduced in 3 or 5 position of 2-N-ethylamino-4-nitropyridine N-oxide has been analysed.

The molecular structures, vibrational energy levels and potential energy distribution of 4-methyl-imidazo[4,5-c]pyridine (4MIPc) and 7-methyl-imidazo[4,5-c]pyridine (7MIPc) are derived from the quantum chemical calculations and compared to the experimental results obtained from the X-ray diffraction (XRD), IR and Raman studies. The B3LYP/6-311G(2d,2p) quantum model and PED contributions have been applied for the assignment of the vibrational modes. 4MIPc crystallizes in an orthorhombic structure, space group Pna 2 1 and Z = 4 and 7MIPc crystallizes in a triclinic structure, space group P −1 and Z = 4. The almost planar conformation of the molecules and presence of the N–H⋯N hydrogen bonds formed with the pyridine and imidazole nitrogen atoms was found to be characteristic for the studied systems. The presence of hydrogen bonds is also confirmed by the results of IR studies.

The 1 H and 13 C NMR spectra of the 4,4′(or 6,6′)-dimethyl-3,3′-dinitro-2,2′-azo- and hydrazo-pyridine have been measured in the solid state and solution. The spectral data have been analyzed on the basis of DFT quantum chemical calculations using the B3LYP/6-311G, 6-311++G and 6-311G ∗∗ approaches. The structures of all molecules have been optimized starting from trans and cis molecular geometry and additionally from diimino form for hydrazoderivatives and compared to the XRD data. The optimization process always led to the trans – isomers. The influence of the azo-bond on the electronic properties of the whole system was analyzed. The role of the hydrogen bond in the structure stabilization of the hydrazo-derivatives has been discussed.

Infrared and Raman spectra of the polycrystalline samples and single crystals of Sr2ZnGe2O7, Ba2ZnGe2O7, Ba2MgGe2O7 and Sr2MgGe2O7 were measured. The temperature dependence of phonons was studied in the range 4–295 K. The discussion of the results is based on the factor group approach for the tetragonal space group with Z = 2. The discussion of the internal vibrations of the Ge2O7 unit and external modes is made on the basis of the literature data and phonon calculations. The results obtained for the spontaneous Raman scattering were used in the discussion of the stimulated Raman spectra of the studied materials. Copyright © 2010 John Wiley & Sons, Ltd.

New organic–organic salt, 2-amino-4-methyl-3-nitropyridinium trifluoroacetate, has been synthesised and characterised by FT-IR, FT-Raman, DSC and single crystal X-ray crystallography. The 2-amino-4-methyl-3-nitropyridinium trifluoroacetate undergoes a reversible phase transition at ∼162 K. The X-ray structures, vibrational spectra and quantum chemical DFT calculations (B3LYP/6-31G(d,p) approach) have been analysed for high-temperature and low-temperature modifications of the compound, which both crystallize in orthorhombic space group Pbca with two non-equivalent cations and two anions in the asymmetric unit. Their crystal and molecular structures have been compared and the role of the intermolecular interactions in these crystals has been analysed. The mechanisms of the phase transition have been proposed.

The paper presents the molecular and XRD structures as well as room temperature IR and Raman studies of 2-hydroxy-3-cyano-4-methylpyridine. The nature and assignment of the vibrational modes have been discussed on the basis of the quantum chemical calculations performed with the use of B3LYP/6-311G(d,p) basis set. The role of the hydrogen bonds in the stabilization of the structure has been analyzed. The quantum chemical calculations have been performed for the monomer as well as for the dimer coupled via the hydrogen bonds. A possible application of this compound in the hybrid formation technology is discussed.

Polarised IR and Raman spectra of Na3Li(MoO4)2· 6H2O single crystal were measured. Discussion of the results is based on the factor group approach for the trigonal R 3c(C3v6) space group with Z = 2. The assignment of the observed bands was performed on the basis of their polarisation behaviour and literature data. The obtained results for the spontaneous Raman scattering were used in the analysis of the stimulated Raman spectra of the material studied—a new Raman laser crystal. The promoting modes of the stimulated effect were identified. Copyright © 2009 John Wiley & Sons, Ltd.

This paper reports on room-temperature infrared (IR) and Raman studies and vibrational characteristics of amide and thiocyano groups of R-NH-CO-CH2-SCN n-alkylamides of thiocyanoacetic acid (R = C8H17, C9H19, C12H25 and C14H29). Their molecular structure has been proposed on the basis of optimization process. The experimental wavenumbers have been compared to those obtained from discrete Fourier transform (DFT) quantum chemical calculations performed with the use of B3LYP/6–31G(d,p) approximation. The role of the hydrogen bonds in the stabilization of the structure has been analyzed. It was found that the hydrogen bonding and strong dynamic interactions between the unit cell components are responsible for the deviation of several theoretical wavenumbers from the experimental ones. Copyright © 2009 John Wiley & Sons, Ltd.

X-ray diffraction (XRD) studies have shown that 2-piperidyl-5-nitro-6-methylpyridine, C11H15N3O2, undergoes a structural phase transition at T = 240 K. The room temperature structure is tetragonal, space group I41/a, with the unit-cell dimensions a = 13.993(2) and c = 23.585(5) A. The pyridine ring takes trans conformation with respect to the piperidine unit. While pyridine is well ordered, the piperidine moiety shows apparent disorder resulting from a libration about the linking NC bond. The low-temperature phase is monoclinic, space group I2/a. Contraction of the unit-cell volume by 2.3% at 170 K enables the CH···O linkage between the molecules of the neighbouring stacks. As result, the asymmetric unit becomes bi-molecular. The thermal librations of the piperidine and methyl groups become considerably reduced at 170 K and nearly fully reduced at about 100 K. The IR spectra and polarised Raman spectra agree with the X-ray structure and confirm the disorder effect on the piperidine ring. The assignment of the bands observed was made on the basis of DFT chemical quantum calculations. Copyright © 2008 John Wiley & Sons, Ltd.

Seven 3-substituted (alkylamino, alkylnitramino and alkylnitrosoamino) derivatives of pyridine N-oxide have been prepared and their 1H, 13C and 15N NMR chemical shifts assigned based on PFG 1H, 13C HMQC and PFG 1H, X (X = 13C or 15N) HMBC experiments. In the sterically most crowded congener, 3-ethylnitramino-4-nitropyridine N-oxide, chemical non-equivalence or diastereotopicity of the N–CH2 protons was observed probably due to the chirality of the adjacent amino nitrogen caused by its restricted inversion. The coalescence temperature for the 1H NMR chemical shifts of these geminal protons has been determined and the corresponding ΔG∗ for the energy barrier of the dynamic process has been estimated.

IR and Raman spectra (RS) of polycrystalline 3-(or 4 or 6)-methyl-5-nitro-2-pyridinethione have been measured and analyzed by means of density functional theory (DFT) quantum chemical calculations. The B3LYP/6-311G(2d,2p) approach has been applied for both the thiol and thione tautomers due to the possibility of the formation of these two thiole forms. Molecular structures of these compounds have been optimized starting from different molecular geometries of the thiol group and thione group. Two conformations of the 2-mercaptopyridine, trans and cis, have been taken into account. It was shown that the studied compounds appear in the solid state in the thione form. The effect of the hydrogen-bond formation in the studied compounds has been considered. Copyright © 2008 John Wiley & Sons, Ltd.

Polarized Raman and IR spectra of a PbB4O7 single crystal were measured. The obtained spectra are discussed within the factor group approach for the orthorhombic P21nm(C2v7) space group with Z = 2 assuming that the crystal structure is built up of the (B4O7)∞2− framework and Pb2+ ions. It has been shown that vibrations of borate and Pb2+ units are observed above 240 and below 160 cm−1, respectively. The results obtained for the spontaneous Raman scattering have also been used in the discussion of the stimulated Raman spectra of the material studied—a new Raman-laser crystal. The obtained results revealed that mainly translational motions of Pb2+ ions participate efficiently in the SRS effect. Copyright © 2008 John Wiley & Sons, Ltd.

Molecular structure, vibrational energy levels and potential energy distribution of 1H-imidazo[4,5-b]pyridine, 3H-imidazo[4,5-b]pyridine, 5-methyl-1H-imidazo[4,5-b]pyridine, 6-methyl-1H-imidazo[4,5-b]pyridine and 7-methyl-3H-imidazo[4,5-b]pyridine were determined using density functional theory (DFT) at the B3LYP/6-31G(d,p) level. The optimised bond lengths and bond angles are in good agreement with the X-ray data of 5-methyl-1H-imidazo[4,5-b]pyridine obtained in the present work (Pbca space group; a = 8.660(2), b = 11.078(2), c = 11.078(3) A, Z = 8). The N+H group plays the role of a proton donor in a medium strong hydrogen bond of the type NH…N, linking the N-atom of the pyridine with the adjacent molecule related by the symmetry operation: 1/2 − x, y − 1/2, z(N…N = 2.869(25) A). The presence of hydrogen bond is confirmed by appearance in the IR spectra of a very broad and strong contour in the 2000–3100 cm−1 range. The place of substitution of the methyl group at the pyridine ring influences the proton position of the NH group at the imidazole unit. Copyright © 2007 John Wiley & Sons, Ltd.

A new organic–organic salt, 2-aminopyridinium-4-hydroxybenzenosulfonate, has been synthesised and characterised by means of FT-IR and FT-Raman spectroscopies, differential scanning calorimetry (DSC) and single crystal X-ray crystallography. Its vibrational spectra have been discussed on the basis of quantum chemical density functional theory (DFT) calculations using the B3LYP/6-31G(d,p) approach. The role of the intermolecular interactions in this crystal is analysed. The N–H ··· O interactions between the hydrogen atoms of the pyridinium cation and oxygen atoms of hydroxybenzenosulfonate anion built the supramolecular arrangement in three-dimensional space. Copyright  2008 John Wiley & Sons, Ltd.

Molecular structure, vibrational energy levels and potential energy distribution of 1H-1,2,3-triazolo[4,5- b ]pyridine and 3H-1,2,3-triazolo[4,5- b ]pyridine as well as 1H- and 3H-tautomers of 5-methyl-1,2,3-triazolo[4,5- b ]pyridine, 6-methyl-1,2,3-triazolo[4,5- b ]pyridine and 7-methyl-1,2,3-triazolo[4,5- b ]pyridine have been determined using density functional theory (DFT) at the B3LYP/6-31G(d,p) level. In order to obtain good fitting with the experimental values the calculated frequencies have been scaled using the scaling factors 0.96 and 0.975 in the 2800–3500 and 1000–1700 cm −1 region, respectively. The role of the hydrogen bond formation in the stabilization of the structure of the studied triazolo[4,5- b ]pyridines has been discussed. The substitution place of the methyl group at the pyridine ring influences the proton position of the NH group at the triazole unit. The 5- and 7-methyl substitution leads to the 3H-tautomeric form whereas the 6-methyl substitution gives the mixture of 1H- and 3H-tautomers.

The 1 H, 13 C and 15 N NMR chemical shifts of seven 2-alkylnitrosoamino-4-nitropyridines and seven 2-alkylnitrosoamino-4-nitropyridine N -oxides have been assigned. The GIAO/DFT 13 C chemical shifts of energetically optimized structures have been calculated. The results were compared to the chemical shifts of previously studied 2-alkylamino and 2-alkylnitramino derivatives of 4-nitropyridine and 4-nitropyridine N -oxide. In sterically crowded ortho -substituted congener (2-ethylnitrosoamino-3-methyl-4-nitropyridine N -oxide) restricted inversion of pyramidal amino nitrogen forms a chiral center in the molecule and makes the geminal protons of N–CH 2 -moiety diastereotopic. In 5- and 6-CH 3 -substituted derivatives this diastereotopism disappears, but the rotation around N–CH 2 sigma bond in all congeners is so slow in NMR time scale, that 1 H, 13 C and 15 N NMR chemical shifts could be detected for two conformers. In 4-nitropyridine and 4-nitropyridine N -oxide derivatives the shielding of aromatic nitrogen is very sensitive to the ring substituents. 2-Alkylnitrosoamino group produces a significant shielding based on conjugation between the ring and the nitrosoamino group.

Electronic absorption spectra of 2-(N-methylamino)-3-methyl-4-nitropyridine (M3M4NP), 2-(N-methylamino)-5-methyl-4-nitropyridine (M5M4NP), 2-(N-methylamino)-3-methyl-5-nitropyridine (M3M5NP) and 2-(N-methylamino)-5-methyl-3-nitropyridine (M5M3NP) in the ethyl alcohol, acetonitrile and n-heptane solution as well as solid state have been measured at room temperature. The influence of the solvent and substitution on polar and non-polar properties has been discussed. The results obtained by the ab initio TD DFT quantum calculations using MPW1PW91 and B3LYP functional and 6-31G(d,p) basis have been compared with that of experimental values.

Polycrystalline infrared and polarized FT-Raman spectra have been measured for 2-adamantylamino-5-nitropyridine, a novel organic material for laser Raman converters. The assignment of IR and Raman bands is given on the basis of DFT calculations. The spectroscopic studies have not indicated the presence of any significant intermolecular interactions in the crystal structure of this compound. The lines observed in the stimulated Raman spectrum of this crystal are assigned to the respective molecular vibrations.

Electronic absorption spectra of 2-methylamino-, 2-ethylamino-3-methyl-4-nitropyridine and 2-ethylamino-, 2-methylamino-5-methyl-4-nitropyridine in the solid state and ethyl alcohol solution have been measured at room temperature. Their luminescence spectra and life times have been recorded at room and liquid helium temperatures. The energy sequence of the singlet and triplet states has been calculated for optimised geometry of the molecules and compared to the experimental values. The results of ab initio TD DFT quantum calculations using MPW1PW91 density functional 6-31G(d,p) basis set have been analysed.

Polarized IR and Raman scattering spectra of an oriented salol (benzoic acid 2-hydroxyphenylester) crystal have been measured at 295 K. The nature and assignment of the vibrational modes have been discussed on the basis of the quantum chemical calculations. The 6-31G and 6-31G(d,p) bases, and B3LYP and MPW1PW91 hybrid functionals have been applied. The role of the anharmonic effects has been analyzed and the scaling factors of the vibrational frequencies have been determined.

Excavation, in particular, trenching, presents a hazardous working environment for workers. Many deadly accidents still occur even though the Occupational Safety and Health Administration has increased its training for safe trenching. The work presented in this paper originated with the belief that the best approach to remedy this problem is technology. Its premise is the need to remove the workers from this deadly trap and replace them with a mechanical device capable of doing the work necessary to lay pipes accurately. Presented is the result of a comparative field evaluation designed to prove that such a technology is not only technically feasible, but also cost-effective. For this purpose, a tele-operated pipe manipulator was built, capable of being easily attached to an excavator bucket and controllable from the safety of an operator cabin. The new technology was subsequently evaluated during field tests using both qualitative and quantitative performance criteria. Data from the study clearly demonstrate that this technological intervention not only works as intended, but also promises to reduce the cost of installing pipes, especially with increasing trench depths.

Electronic absorption spectra of 2-ethylamino-3-methyl-4-nitropyridine and 2-ethylamino-5-methyl-4-nitropyridine in the solid state and ethyl alcohol solution have been measured at room temperature. Their luminescence spectra and life times have been recorded at room and liquid helium temperatures. The energy sequence of the singlet and triplet states has been calculated for optimised geometries of both molecules and compared to the experimental values. The usefulness of the semi-empirical ZINDO as well as ab initio with DFT with B3LYP and MPW1PW91 density functionals within the 6-31G and Huzinaga basis set have been analysed.

“Ergonomics” is derived from the Greek words “ergon”, meaning work, and “nomos”, meaning natural laws. Thus, one can interpret ergonomics as the “natural laws of work.” As documented in the literature, ergonomics has long been ignored by management and workers in construction alike. Unfortunately, a sore back in the evening is not always the effect of healthy hard work at the jobsite, made apparent by the staggering cost of workers’ compensation. Occupational back injuries result in more lost workdays than any other illness, second only to the common cold. In addition, manufacturers of construction tools have started to redesign their products because of liability concerns. This paper describes an effort that considers the health epidemic of back injuries as an opportunity. The basic premise is to apply the “natural laws of work” in a scientific manner to reach and treat the root of the problem and not its symptoms. Pneumatic nailing of subfloors is used to explain that back pain and the risk of back injuries for the average construction worker can be decreased while, at the same time, maintaining short-term productivity and increasing long-term productivity.

We have studied charmless hadronic decays of B mesons into two-body final states with kaons and pions and observe three new processes with the following branching fractions: B(B{yields}{pi}{sup +}{pi}{sup -})=(4.3{sup +1.6}{sub -1.4}{+-}0.5)x10{sup -6} , B(B{yields}K{sup 0}{pi}{sup 0}) =(14.6{sup +5.9+2.4}{sub -5.1-3.3})x 10{sup -6} , and B(B{yields}K{sup {+-}}{pi}{sup 0} )=(11.6{sup +3.0+1.4}{sub -2.7-1.3}) x10{sup -6} . We also update our previous measurements for the decays B{yields}K{sup {+-}}{pi}{sup {+-}} and B{sup {+-}}{yields}K{sup 0}{pi}{sup {+-}} . (c) 2000 The American Physical Society.