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Ultraviolet-induced photodissociation and photo-isomerization of the three most stable conformers (SSC, GAC, and AAT) of glycolic acid are investigated in a low-temperature solid argon matrix using FTIR spectroscopy and employing laser radiation with wavelengths of 212 nm, 226 nm, and 230 nm. The present work broadens the wavelength range of photochemical studies of glycolic acid, thus extending the understanding of the overall photochemistry of the compound. The proposed kinetic model for the photodissociation of glycolic acid proceeds from the lowest energy conformer (SSC). The model suggests that ultraviolet light induces isomerization only between the SSC and GAC conformers and between the SSC and AAT conformers. The relative reaction rate coefficients are reported for all proposed reactions. These results suggest that the direct photodissociation of GAC and AAT conformer does not occur in an argon matrix. The main photodissociation channel via the SSC conformer produces formaldehyde–water complexes. The proposed photodissociation mechanism emphasizes that the conformers’ relative abundancies can significantly affect the photodissociation rate of the molecule. For example, in the case of high relative GAC and AAT concentrations, the ultraviolet photodissociation of glycolic acid requires the proceeding photo-isomerization of GAC and AAT to SSC.

Organic semiconductors with distinct molecular properties and large carrier mobilities are constantly developed in attempt to produce highly-efficient electronic materials. Recently, designer molecules with unique structural modifications have been expressly developed to suppress molecular motions in the solid state that arise from low-energy phonon modes, which uniquely limit carrier mobilities through electron-phonon coupling. However, such low-frequency vibrational dynamics often involve complex molecular dynamics, making comprehension of the underlying electronic origins of electron-phonon coupling difficult. In this work, we first generate a mode-resolved picture of electron-phonon coupling in a series of materials that were specifically designed to suppress detrimental vibrational effects. From this foundation, we develop a method based on the crystalline orbital Hamiltonian population analyses to resolve the origins -- down to the single atomic-orbital scale -- of surprisingly large electron-phonon coupling constants of particular vibrations, explicitly detailing the manner in which the intermolecular wavefunction overlap is perturbed. Overall, this approach provides a comprehensive explanation into the unexpected effects of less-commonly studied molecular vibrations, revealing new aspects of molecular design that should be considered for creating improved organic semiconducting materials.

Journal of neurotrauma 39(11/12), 773-783 (2022). doi:10.1089/neu.2021.0410, Published by Liebert, Larchmont, NY

ACS applied materials & interfaces 14(23), 27040 - 27047 (2022). doi:10.1021/acsami.2c04712, The metal-organic framework MOF-808 contains Zr$_6$O$_8$ nodes with a high density of vacancy sites, which can incorporate carboxylate-containing functional groups to tune chemical reactivity. Although the postsynthetic methods to modify the chemistry of the Zr$_6$O$_8$ nodes in MOFs are well known, tackling these alterations from a structural perspective is still a challenge. We have combined infrared spectroscopy experiments and first-principles calculations to identify the presence of node vacancies accessible for chemical modifications within the MOF-808. We demonstrate the potential of our approach to assess the decoration of MOF-808 nodes with different catechol–benzoate ligands. Furthermore, we have applied advanced synchrotron characterization tools, such as pair distribution function analyses and X-ray absorption spectroscopy, to resolve the atomic structure of single metal sites incorporated into the catechol groups postsynthetically. Finally, we demonstrate the catalytic activity of these MOF-808 materials decorated with single copper sites for 1,3-dipolar cycloadditions., Published by ACS Publ., Washington, DC

In this study, micro-Raman spectroscopy technique in combination with multivariate statistical analysis was carried out to investigate the worn surfaces and metallurgical changes in the wear land of chemical vapor deposition-applied titanium carbonitride/aluminum oxide/titanium nitride-coated cutting inserts. To understand the wear process, detailed scanning electron microscopy analysis was also performed. The structural change at the molecular level of the coating due to the wear of the cutting-edge layers was investigated. Tool life was determined at 0.5 mm flank wear of the cutting tool. Thirty-four Raman spectra recorded from the different points of the worn parts of nine cutting inserts were investigated in comparison with the seven spectra of the different points of three unused cutting inserts. The principal component analysis followed by linear discriminant analysis performed on 41 Raman spectral data, clearly separated the samples as worn and unworn cutting inserts, and showed the wear effects. The comparison of the mean Raman spectrum of worn and unworn (unused) cutting inserts showed that the intensities of the aluminum oxide and titanium nitride bands were decreased, whereas the titanium carbide band at 672 cm(-1) was increased, as a result of the wear effect. Moreover, the relative intensity of disordered carbon (D band) band to the graphitic sp(2) bonded carbon (G band) band was found to increase, due to wear. Istanbul University

Heavy metal contamination due to industrial and agricultural waste represents a growing threat to water supplies. Frequent and widespread monitoring for toxic metals in drinking and agricultural water sources is necessary to prevent their accumulation in humans, plants, and animals, which results in disease and environmental damage. Here, the metabolic stress response of bacteria is used to report the presence of heavy metal ions in water by transducing ions into chemical signals that can be fingerprinted using machine learning analysis of vibrational spectra. Surface-enhanced Raman scattering surfaces amplify chemical signals from bacterial lysate and rapidly generate large, reproducible datasets needed for machine learning algorithms to decode the complex spectral data. Classification and regression algorithms achieve limits of detection of 0.5 pM for As 3+ and 6.8 pM for Cr 6+ , 100,000 times lower than the World Health Organization recommended limits, and accurately quantify concentrations of analytes across six orders of magnitude, enabling early warning of rising contaminant levels. Trained algorithms are generalizable across water samples with different impurities; water quality of tap water and wastewater was evaluated with 92% accuracy.

This review focuses on recent advances and future perspectives in the use of Raman spectroscopy for cervical cancer, a global women’s health issue. Cervical cancer is the fourth most common women’s cancer in the world, and unfortunately mainly affects younger women. However, when detected at the early precancer stage, it is highly treatable. High-quality cervical screening programmes and the introduction of the human papillomavirus (HPV) vaccine are reducing the incidence of cervical cancer in many countries, but screening is still essential for all women. Current gold standard methods include HPV testing and cytology for screening, followed by colposcopy and histopathology for diagnosis. However, these methods are limited in terms of sensitivity/specificity, cost, and time. New methods are required to aid clinicians in the early detection of cervical precancer. Over the past 20 years, the potential of Raman spectroscopy together with multivariate statistical analysis has been shown for the detection of cervical cancer. This review discusses the research to date on Raman spectroscopic approaches for cervical cancer using exfoliated cells, biofluid samples, and tissue ex vivo and in vivo.

Nanoconfined few-molecule water clusters are invaluable systems to study fundamental aspects of hydrogen bonding. Unfortunately, most experiments on water clusters must be performed at cryogenic temperatures. Probing water clusters in noncryogenic systems is however crucial to understand the behavior of confined water in atmospheric or biological settings, but such systems usually require either complex synthesis and/or introduce many confounding external bonds to the clusters. Here, we show that combining Raman spectroscopy with the molecular nanocapsule cucurbituril is a powerful technique to sequester and analyze water clusters in ambient conditions. We observe sharp peaks in vibrational spectra arising from a single rigid confined water dimer. The high resolution and rich information in these vibrational spectra allow us to track specific isotopic exchanges inside the water dimer, verified with density-functional theory and kinetic population modeling. We showcase the versatility of such molecular nanocapsules by tracking water cluster vibrations through systematic changes in confinement size, in temperatures up to 120° C, and in their chemical environment.

Di-p-tolyl disulfides (p-Tol2S2) are employed as load-carrying additives because of their anti-wear and extreme load-bearing qualities. External pressure triggers conformational up-conversion (leads to phase transition) in the molecules of p-Tol2S2, by compensating for the stress and absorbing its energy. These features make p-Tol2S2 a potential candidate for next-generation energy storage devices. Upon lithiation, MoS2 expands up to 103% which causes stress and affects battery stability and performance. Therefore, it is essential to study these materials under different physical conditions. In this work, we used density functional theory (DFT) at ωB97XD/6-31G* functional level, to calculate lattice parameters, Gibbs free energies, and vibrational spectra of three phases (i.e., α, β, and γ) of p-Tol2S2 under different pressure and temperature conditions. The phase transition between phases α and β occurred at a pressure and temperature of 0.65 GPa and 463 K, respectively. Furthermore, phase transition between phases α and γ was found at a pressure and temperature of 0.35 GPa and 400 K, respectively. Moreover, no phase transition was observed between phases β and γ under the pressure range studied (0 GPa to 5.5 GPa). We also computed and compared the FT–IR spectra of the three phases. These results can guide scientists and chemists in designing more stable battery materials.

The abstract is available here: https://uscholar.univie.ac.at/o:1649476

New spectroscopic experiments and state‐of‐the‐art quantum‐chemical computations of creatinine in different aggregation states unequivocally unveiled a significant tuning of tautomeric equilibrium by the environment: from the exclusive presence of the amine tautomer in the solid state and aqueous solution to a mixture of amine and imine tautomers in the gas phase. Quantum‐chemical calculations predict the amine species as the most stable tautomer by about 30 kJ mol−1 in condensed phases. On the contrary, moving to the isolated forms, both Z and E imine isomers become more stable by about 7 kJ mol−1. Since the imine isomers and one amine tautomer are separated by significant energy barriers, all of them should be present in the gas phase. This prediction has indeed been confirmed by high‐resolution rotational spectroscopy, which provides the first experimental characterization of the elusive imine tautomer. The interpretation of the complicated hyperfine structure of the rotational spectrum, originated by three 14N nuclei, makes it possible to use the spectral signatures as a sort of fingerprint for each individual tautomer in the complex sample., A journey among the aggregation states of a key biomolecule, creatinine, is reported, guided by state‐of‐the‐art quantum‐chemical computations and spectroscopic techniques. The fine tuning of the creatinine tautomeric equilibrium by different environments is unveiled and fully understood by vis‐à‐vis comparison between simulated and experimental signatures.

Current triage for women with post-menopausal bleeding (PMB) to diagnose endometrial cancer rely on specialist referral for intimate tests to sequentially image, visualise and sample the endometrium. A point-of-care non-invasive triage tool with an instant readout could provide immediate reassurance for low-risk symptomatic women, whilst fast-tracking high-risk women for urgent intrauterine investigations. This study assessed the potential for infrared (IR) spectroscopy and attenuated total reflection (ATR) technology coupled with chemometric analysis of the resulting spectra for endometrial cancer detection in urine samples. Standardised urine collection and processing protocols were developed to ensure spectroscopic differences between cases and controls reflected cancer status. Urine spectroscopy distinguished endometrial cancer (n = 109) from benign gynaecological conditions (n = 110) with a sensitivity of 98% and specificity of 97%. If confirmed in subsequent low prevalence studies embedded in PMB clinics, this novel endometrial cancer detection tool could transform clinical practice by accurately selecting women with malignant pathology for urgent diagnostic work up whilst safely reassuring those without.

Self-heating in organic electronics can lead to anomalous electrical performance and even accelerated degradation. However, in the case of disordered organic semiconductors, self-heating effects are difficult to quantify using electrical techniques alone due to complex transport properties. Therefore, more direct methods are needed to monitor the impact of self-heating on device performance. Here, self-heating in poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta [2,1-b;3,4-b′] dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) diodes is visualized using Raman spectroscopy, and thermal effects due to self-heating are quantified by exploiting temperature-dependent shifts in the polymer vibrational modes. The temperature increases due to self-heating are quantified by correlating the Raman shifts observed in electrically biased diodes with temperature-dependent Raman measurements. Temperature elevations up to 75 K are demonstrated in the PCPDTBT diodes at moderate power of about 2.6–3.3 W cm−2. Numerical modeling rationalizes the significant role of Joule and recombination heating on the diode current–voltage characteristics. This work demonstrates a facile approach for in situ monitoring of self-heating in organic semiconductors for a range of applications, from fundamental transport studies to thermal management in devices.

The goal set for the thesis was the application of low temperature matrix isolation method in combination with vibrational spectroscopy for the analysis of molecules possessing intramolecular hydrogen bond – malondialdehyde and acetylacetone derivatives, as well as acetylsalicylic and salicylic acids. Two methods were developed during the research – the sample preparation of the molecules with low vapor pressure and the combination of Raman spectroscopy with matrix isolation. Matrix isolation allows the observation of processes such as proton transfer and the formation of higher energy isomers. The studies presented in the dissertation proved that proton tunneling takes place in chloromalondialdehyde molecule isolated in a low-temperature matrix environment. It was shown that four out of eight open enol isomers of chloromalondialdehyde molecule can be produced in the matrix environment by exposure to ultraviolet laser radiation. It was proven for the first time that a higher-energy isomer of an asymmetric trifluoroacetylacetone molecule exists in low temperature matrices, and that its concentration depends on the environment surrounding the molecules. The analysis of the active substances of anti-inflammatory drugs was presented – showing the conformational diversity of acetylsalicylic and salicylic acid, and the complexes formed with water molecules in low temperature matrix environment.

Blood is the most common and relevant bodily fluid that can be found in crime scenes. It is critical to correctly identify it, and to be able to differentiate it from other substances that may also appear at the crime scene. In this work, several stains of blood, chocolate, ketchup, and tomato sauce on five different substrates (plywood, metal, gauze, denim, and glass) were analysed by ATR FTIR spectroscopy assisted with orthogonal partial least square discriminant analysis (OPLS-DA) models. It was possible to differentiate blood from the environmental interfering substances independently of the substrate they were on, and to differentiate bloodstains according to the substrate they were deposited on. These results represent a proof-of-concept that open new horizons to differentiate bloodstains from other interfering substances on common substrates present in crime scenes.

Vibrational spectroscopic techniques, both infrared absorption and Raman scattering, are high precision, label free analytical techniques which have found applications in fields as diverse as analytical chemistry, pharmacology, forensics and archeometrics and, in recent times, have attracted increasing attention for biomedical applications. As analytical techniques, they have been applied to the characterisation of viruses as early as the 1970s, and, in the context of the coronavirus disease 2019 (COVID-19) pandemic, have been explored in response to the World Health Organisation as novel methodologies to aid in the global efforts to implement and improve rapid screening of viral infection. This review considers the history of the application of vibrational spectroscopic techniques to the characterisation of the morphology and chemical compositions of viruses, their attachment to, uptake by and replication in cells, and their potential for the detection of viruses in population screening, and in infection response monitoring applications. Particular consideration is devoted to recent efforts in the detection of severe acute respiratory syndrome coronavirus 2, and monitoring COVID-19.

Chiral molecular propeller conformations have been induced to various triaryl structures including trityl derivatives and triaryl boranes. For borane–amine adducts, such induced propeller chirality has not been reported yet due to the low energy barrier for racemization in common triarylboranes such as B(C6H5)3 or B(C6F5)3. Herein, we demonstrate that point chirality in side chains of chiral triarylborane–ammonia adducts, which feature intramolecular hydrogen bonds in addition to the dative N→B bond, can efficiently be transferred to triarylborane propeller chirality. Employing X‐ray crystallography and ECD/VCD spectroscopy for structural characterizations, we investigate three examples with different steric demands of the incorporated chiral alkoxy side groups. We elucidate the conformational preferences of the molecular propellers. Furthermore, we show that computationally predicted conformational preferences obtained for the isolated, only implicitly solvated molecules are actually opposite to the experimentally observed ones., Using VCD spectroscopy as key analytical tool, it was found that point chirality in side chains of chiral triarylborane–ammonia adducts, which feature intramolecular hydrogen bonds in addition to the dative N→B bond, can efficiently be transferred to triarylborane propeller chirality.

Pistachio is one of the most expensive nuts with having high economic importance in Turkey. It has become more prone to adulteration because of its high commodity value. Peanut with color additives and green pea are generally used to adulterate ground pistachio. Vibrational spectroscopy is a potential technique to detect adulterations in pistachio. The objective of this study was to generate a non-targeted method for portable FT-IR and UV–Vis spectrometers to authenticate pistachio and detect green pea and peanut adulterations. Pistachio granules were adulterated with green pea and peanut at different concentrations (5 to 40% w/w). Spectra were collected by a portable FT-IR spectrometer and by a conventional UV–Vis spectrometer and analyzed by Soft Independent Modeling of Class Analogy (SIMCA) to generate classification algorithms to authenticate pistachio, and Partial Least Square Regression (PLSR) to predict the concentrations of adulterants. SIMCA showed very distinct clusters for pure samples. Moreover, adulterated pistachio samples were discriminated by SIMCA even in low levels of adulteration (5%). Portable FTIR showed excellent performance (rval > 0.93) of predicting the adulterant levels with a standard error of prediction (SEP) 0.66% and 0.80% for green pea and peanut, respectively. Similarly, UV–VIS predicted (rval > 0.93) the adulterant levels with SEP 0.58% and 0.14% for green pea and peanut, respectively. The results supported that portable FT-IR, and UV–Vis units present great potential for real-time surveillance of green pea and peanut adulteration in pistachio.

Optical spectroscopy is a powerful tool to interrogate quantum states of matter. We present simulation results for the cross-polarized two-dimensional electronic spectra of the light-harvesting system LH2 of purple bacteria. We identify a spectral feature on the diagonal, which we assign to ultrafast coherence transfer between degenerate states. The implication for the interpretation of previous experiments on different systems and the potential use of this feature are discussed. In particular, we foresee that this kind of feature will be useful for identifying mixed degenerate states and for identifying the origin of symmetry breaking disorder in systems like LH2. Furthermore, this may help identify both vibrational and electronic states in biological systems such as proteins and solid-state materials such as hybrid perovskites.

Spectroscopic characterizations of key reaction intermediates are often considered the final confirmation of a reaction mechanism. This proof‐of‐principle study showcases the application of vibrational circular dichroism (VCD) spectroscopy for the characterization of in situ generated reaction intermediates using the key intermediates of enamine catalysis of Jørgensen–Hayashi‐type prolinol ether catalysts as model system. By comparison of experimental and computed spectra, the enamines are shown to preferentially adopt an anti‐conformation with E‐configured C=C bond. For the parent prolinol catalyst, the structure and stereochemistry of the oxazolidine side product is determined as well. This study thus demonstrates that VCD spectra can provide insights into structural preferences of organocatalysts that utilize a covalent activation mechanism. Thereby it outlines new fields of applications for VCD spectroscopy and finally adds the technique to the toolbox of physical organic chemistry for in‐depth mechanistic studies., Before it reacts: The enamine and oxazolidine intermediates are characterized by in situ IR and VCD spectroscopy. The study demonstrates the proof‐of‐principle for such analysis of asymmetric catalysts employing a covalent substrate activation mechanism by VCD spectroscopy.Stereochemistry of the reaction intermediates of prolinol ether catalyzed reactions characterized by vibrational circular dichroism spectroscopy (Merten and Golub @MertenLab @ruhrunibochum)

Structure and hydrogen bonding interactions of bioactive oxazolidinones have been studied by means of NMR and vibrational spectroscopies and quantum chemical calculations. We have demonstrated that oxazolidinone derivatives form hydrogen bonds in solution and solid state. Conformational space search has revealed predominant conformations in solution. In low polarity solvents, such as chloroform, dimers are formed presumably by intermolecular hydrogen bonds between two oxazolidinone molecules forming the most stable complexes, which has also been found in the solid state by IR spectroscopy and crystallography. In solvents of higher polarities, like methanol and dimethylsulfoxide, intermolecular interactions with solvent molecules and in dimers are present. As expected, raising the temperature broke hydrogen bonds, which was reflected in down-field chemical shifts of corresponding resonances. On the other hand, raising the solution concentration considerably affected oxazolidinone resonances only in chloroform, corroborating the formation of oxazolidinone dimers. These results may help in better understanding oxazolidinone structure, properties and interactions when designing new bioactive compounds and pharmaceutical products.

The study of the intra- and intermolecular interactions in the solid state of four related fluorine-containing 1,2,3-triazole derivatives (1: R = –H, 2: R = –NO2, 3: R = –CH3, 4: R = –Cl) was carried out using quantum chemical calculations, vibrational (IR and Raman) and solid phase UV-vis spectroscopy, and single-crystal X-ray diffraction methods. The enol–keto/keto–enol tautomerism on the o-hydroxyacetophenone moiety was analyzed in terms of the synergy between O–H⋯O intramolecular hydrogen bond strengthening and the enhancement of π delocalization within the pseudo ring. The preference of the enol–keto form was attributed to the aromatic stabilization energy. The proton in the triazole ring was located on the intermediate nitrogen atom, with no evidence of prototropy in the studied series. Compounds 1 and 4 have similar structural motifs with N–H⋯O hydrogen bonds connecting amino and carbonyl groups of neighboring molecules in a chain along the a-axis. For 2, it was found that both oxygen atoms of the nitro substituent participate as acceptors, connecting adjacent molecules by hydrogen bonds through the N–H and O–H groups. In compound 3, the crystallization water molecule dominates the hydrogen bonding interactions, which associates three molecules of 3, giving rise to a three-dimensional H-bonding network. These intra and intermolecular interactions, which affect the absorption band locations of the involved groups, were also detected in the vibrational spectra of the studied triazoles., Centro de Química Inorgánica

Raman spectroscopy is used in a wide variety of fields, and in a plethora of different configurations. Raman spectra of simple analytes can often be analyzed using univariate approaches and interpreted in a straightforward manner. For more complex spetral data such as time series or line profiles (1D), Raman maps (2D), or even volumes (3D), multivariate data analysis (MVDA) becomes a requirement. Even though there are some existing standards for creation, implementation, and validation of methods and models employed in industry and academics, further research and development in the field must contribute to their improvement. This review will cover, in broad terms, existing techniques as well as new developments for MVDA for Raman spectroscopic data, and in particular the use associated with instrumentation and data calibration. Chemometric models are often generated via fusion of analytical data from different sources, which enhances model discrimination and prediction abilities as compared to models derived from a single data source. For Raman spectroscopy, raw or unprocessed data is rarely ever used. Instead, spectra are usually corrected and manipulated,1 often by case-specific rather than universal methods. Calibration models can be used to characterize qualitatively and/or quantitatively samples measured with the same instrumentation that was used to create the model. However, regular validation is required to ensure that aging or incorrect maintenance of the instrument does not alter the model’s predictions, particularly when applied in regulated fields such as pharmaceuticals. Furthermore, a model transfer may be required for different reasons, such as replacement or significant repair of the instrumentation. Modeling can also be used to consistently harmonize Raman spectroscopic data across several instrumental designs, accounting for variations in the resulting spectrum induced by different components. Data for Raman harmonization models should be processed in a protocolled manner, and the original data accessible to allow for model reconstruction or transfer when new data is added. Important processing steps will be the calibration of the spectral axes and instrument dependent effects, such as spectral resolution. In addition, data fusion and model transfer are essential for allowing new instrumentation to build on existing models to harmonize their own data. Ideally, an open access database would be created and maintained, for the purpose of allowing for continued harmonization of new Raman instruments using an outlined and accepted protocol

Ezetimibe (EZT) being an anticholesterol drug is frequently used for the reduction of elevated blood cholesterol levels. With the purpose of improving the physicochemical properties of EZT, in the present study, cocrystals of ezetimibe with L-proline have been studied. Theoretical geometry optimization of EZT-L-proline cocrystal, energies, and structure–activity relationship was carried out at the DFT level of theory using B3LYP functional complemented by 6-311++G(d,p) basis set. To better understand the role of hydrogen bonding, two different models (EZT + L-proline and EZT + 2L-proline) of EZT-L-proline cocrystal were studied. Spectral techniques (FTIR and FT-Raman) combined with quantum chemical methodologies were successfully implemented for the detailed vibrational assignment of fundamental modes. It is a zwitterionic cocrystal hydrogen bonded with the OH group of EZT and the COO− group of L-proline. The existence and strength of hydrogen bonds were examined by a natural bond orbital analysis (NBO) supported by the quantum theory of atoms in molecule (QTAIM). Chemical reactivity was reflected by the HOMO–LUMO analysis. A smaller energy gap in the cocrystal in comparison to API shows that a cocrystal is softer and chemically more reactive. MEPS and Fukui functions revealed the reactive sites of cocrystals. The calculated binding energy of the cocrystal from counterpoise method was −11.44 kcal/mol (EZT + L-proline) and −26.19 kcal/mol (EZT + 2L-proline). The comparative study between EZT-L-proline and EZT suggest that cocrystals can be better used as an alternative to comprehend the effect of hydrogen bonding in biomolecules and enhance the pharmacological properties of active pharmaceutical ingredients (APIs).

The research activity of the R&D Group Molecular Physical-Chemistry of the University of Coimbra, Portugal (http://www.ci.uc.pt/qfm/ ), is focused on studies of biosystems by vibrational spectroscopy, from optical methods (Raman and infrared) to neutron scattering techniques (inelastic and quasi-elastic) – to yield both structural/conformational and dynamical information. The present lecture reports results on: (i) the impact of novel Pt- and Pd-anticancer agents on human cancer cells – aiming at evaluating their efficacy and identifying new therapeutic targets (ii) the normal-to-cancer transition, probing tissues resected from human patients (both tumour and non-malignant) – in order to allow a more accurate and early cancer diagnosis (iii) the effect of heat on human bones – for future applications in Forensic Science and Archaeology Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.

Se van a descibir los avances de los estudios basados en la dispersión inlástica de neutrones (INS) sobre la estructuración de polímeros bio-compatibles y disolventes eutécticos. La técnica INS permite obtener una información complementaria a los resultados de las espectroscopías vibracionales convencionales, Infrarroja y Raman, especialmente en relación con el empaquetamiento de estos sistemas y su grado de cristalinidad. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.

Durant aquestes darreres dècades, l'espectroscòpia vibracional ha captat l'atenció dins el camp de la ciència dels aliments, ja que proporciona maneres senzilles i ràpides d'analitzar i de caracteritzar una àmplia gamma de productes agroalimentaris. A més, la seva rendibilitat, reproductibilitat i sensibilitat han estat extensament provades. Recentment, amb l'aparició dels sistemes nanoelectromecànics, l'espectroscòpia vibracional ha experimentat un gran desenvolupament respecte a la seva miniaturització, aconseguint en alguns equips mides tan petites com la del palmell d'una mà. Els dispositius espectroscòpics miniaturitzats obren noves possibilitats respecte a les aplicacions in situ de la tècnica per al control no destructiu de la qualitat dels aliments. El propòsit de la present tesi doctoral ha estat avaluar la viabilitat dels espectròmetres portables Raman, d'infraroig mitjà i infraroig proper combinats amb potents algorismes quimiomètrics per a aplicacions alimentàries que engloben l'estudi de paràmetres químics (seguiment de la reacció de Maillard o discriminació de pols d'insecte comestibles per espècie), físics (predicció de les força d'extracció en taps de suro) i microbiològics (discriminació de soques de bacteris i llevats d'interès alimentari). Durante estas últimas décadas, la espectroscopia vibracional ha captado la atención dentro del campo de la ciencia de los alimentos, ya que proporciona maneras sencillas y rápidas de analizar y caracterizar una amplia gama de productos agroalimentarios. Además, su rentabilidad, reproducibilidad y sensibilidad han sido extensamente probadas. Recientemente, con la aparición de los sistemas nanoelectromecánicos, la espectroscopia vibracional ha experimentado un gran desarrollo respecto a su miniaturización, alcanzando en algunos equipos tamaños tan pequeños como el de la palma de una mano. Los dispositivos espectroscópicos miniaturizados abren nuevas posibilidades respecto a las aplicaciones in situ de la técnica para el control no destructivo de la calidad de los alimentos. El propósito de la presente tesis doctoral ha sido evaluar la viabilidad de los espectrómetros portables Raman, de infrarrojo medio e infrarrojo cercano combinados con potentes algoritmos quimiométricos para aplicaciones alimentarias que engloban el estudio de parámetros químicos (seguimiento de la reacción de Maillard o discriminación de polvos de insecto comestibles por especie), físicos (predicción de las fuerza de extracción en tapones de corcho) y microbiológicos (discriminación de cepas de bacterias y levaduras de interés alimentario). During these last decades, vibrational spectroscopy has gathered attention in the food science field because it provides ways of analyzing and characterizing a wide range of food commodities in a fast and simple manner. Moreover, their cost-effectiveness, reproducibility, and sensitivity have also been proved. Recently, with the advent of nanoelectromechanical systems, vibrational spectroscopy has experienced a breakthrough regarding its miniaturization, achieving in certain equipment sizes as small as a palm. Miniaturized spectroscopic devices open new possibilities towards the applications of vibrational spectroscopy for the in-situ analysis of several quality control parameters without altering the sample. The objective of this doctoral thesis was to evaluate the feasibility of portable Raman, mid-infrared and near-infrared spectrometers combined with powerful chemometric algorithms for food applications comprising studies of chemical (Maillard reaction monitoring or edible insect powder discrimination), physical (extraction force prediction in cork stoppers), and microbiological (discrimination of bacterial and yeast strains

Background The dynamics of the cellular glycolysis pathway underpin cellular function and dysfunction, and therefore ultimately health, disease, diagnostic and therapeutic strategies. Evolving our understanding of this fundamental process and its dynamics remains critical. Scope of review This paper reviews the medical relevance of glycolytic pathway in depth and explores the current state of the art for monitoring and modelling the dynamics of the process. The future perspectives of label free, vibrational microspectroscopic techniques to overcome the limitations of the current approaches are considered. Major conclusions Vibrational microspectroscopic techniques can potentially operate in the niche area of limitations of other omics technologies for non-destructive, real-time, in vivo label-free monitoring of glycolysis dynamics at a cellular and subcellular level.

In recent years, the disease burden of hyperuricemia has been increasing, especially in high-income countries and the economically developing world with a Western lifestyle. Abnormal levels of uric acid and hypoxanthine are associated with many diseases, and therefore, to demonstrate improved methods of uric acid and hypoxanthine detection, three different bodily fluids were analysed using surface-enhanced Raman spectroscopy (SERS) and high-performance liquid chromatography (HPLC). Gold nanostar suspensions were mixed with series dilutions of uric acid and hypoxanthine, 3 kDa centrifugally filtered human blood serum, urine and saliva. The results show that gold nanostars enable the quantitative detection of the concentration of uric acid and hypoxanthine in the range 5–50 μg/mL and 50–250 ng/mL, respectively. The peak areas of HPLC and maximum peak intensity of SERS have strongly correlated, notably with the peaks of uric acid and hypoxanthine at 1000 and 640 cm−1, respectively. The r2 is 0.975 and 0.959 for uric acid and hypoxanthine, respectively. Each of the three body fluids has a number of spectral features in common with uric acid and hypoxanthine. The large overlap of the spectral bands of the SERS of uric acid against three body fluids at spectra peaks were at 442, 712, 802, 1000, 1086, 1206, 1343, 1436 and 1560 cm−1. The features at 560, 640, 803, 1206, 1290 and 1620 cm−1 from hypoxanthine were common to serum, saliva and urine. There is no statistical difference between HPLC and SERS for determination of the concentration of uric acid and hypoxanthine (p > 0.05). For clinical applications, 3 kDa centrifugal filtration followed by SERS can be used for uric acid and hypoxanthine screening is, which can be used to reveal the subtle abnormalities enhancing the great potential of vibrational spectroscopy as an analytical tool. Our work supports the hypnosis that it is possible to obtain the specific concentration of uric acid and hypoxanthine by comparing the SER signals of serum, saliva and urine. In the future, the analysis of other biofluids can be employed to detect biomarkers for the diagnosis of systemic pathologies.

Current assays for acrylamide screening rely heavily on LC-MS/MS or GC-MS, techniques that are not suitable to support point of manufacturing verification because it can take several weeks to receive results from a laboratory. A portable sensor that can detect acrylamide levels in real-time would enable in-house testing to safeguard both the safety of the consumer and the economic security of the agricultural supplier. Our objective was to develop a rapid, accurate, and real-time screening technique to detect the acrylamide content in par-fried frozen French fries based on a portable infrared device. Par-fried French fries (n = 70) were manufactured at times ranging from 1 to 5.5 min at 180 °C to yield a wide range of acrylamide levels. Spectra of samples were collected using a portable FT-IR device operating from 4000 to 700 cm−1. Acrylamide was extracted using QuEChERS and quantified using uHPLC-MS/MS. Predictive algorithms were generated using partial least squares regression (PLSR). Acrylamide levels in French fries ranged from 52.0 to 812.8 µg/kg. The best performance of the prediction algorithms required transformation of the acrylamide levels using a logarithm function with models giving a coefficient of correlation (Rcv) of 0.93 and RPD as 3.8, which means the mid-IR model can be used for process control applications. Our data corroborate the potential of portable infrared devices for acrylamide screening of high-risk foods.

Toxoplasma gondii (T. gondii) is an opportunistic protozoan that can cause brain infection and other serious health consequences in immuno-compromised individuals. This parasite has a remarkable ability to cross biological barriers and exploit the host cell microenvironment to support its own survival and growth. Recent advances in label-free spectroscopic imaging techniques have made it possible to study biological systems at a high spatial resolution. In this study, we used conventional Fourier-transform infrared (FTIR) microspectroscopy and synchrotron-based FTIR microspectroscopy to analyze the chemical changes that are associated with infection of human brain microvascular endothelial cells (hBMECs) by T. gondii (RH) tachyzoites. Both FTIR microspectroscopic methods showed utility in revealing the chemical alterations in the infected hBMECs. Using a ZnS hemisphere device, to increase the numerical aperture, and the synchrotron source to increase the brightness, we obtained spatially resolved spectra from within a single cell. The spectra extracted from the nucleus and cytosol containing the tachyzoites were clearly distinguished. RNA sequencing analysis of T. gondii-infected and uninfected hBMECs revealed significant changes in the expression of host cell genes and pathways in response to T. gondii infection. These FTIR spectroscopic and transcriptomic findings provide significant insight into the molecular changes that occur in hBMECs during T. gondii infection.

Weak complexes of isocyanic acid (HNCO) with nitrogen were studied computationally employing MP2, B2PLYPD3 and B3LYPD3 methods and experimentally by FTIR matrix isolation technique. The results show that HNCO interacts specifically with N2. For the 1:1 stoichiometry, three stable minima were located on the potential energy surface. The most stable of them involves a weak, almost linear hydrogen bond from the NH group of the acid molecule to nitrogen molecule lone pair. Two other structures are bound by van der Waals interactions of N⋯N and C⋯N types. The 1:2 and 2:1 HNCO complexes with nitrogen were computationally tracked as well. Similar types of interactions as in the 1:1 complexes were found in the case of the higher stoichiometry complexes. Analysis of the HNCO/N2/Ar spectra after deposition indicates that the 1:1 hydrogen-bonded complex is prevalent in argon matrices with a small amount of the van der Waals structures also present. Upon annealing, complexes of the 1:2 and 2:1 stoichiometry were detected as well.

Rotational microwave jet spectroscopy studies of the monoterpenol α-fenchol have so far failed to identify its second most stable torsional conformer, despite computational predictions that it is only very slightly higher in energy than the global minimum. Vibrational FTIR and Raman jet spectroscopy investigations reveal unusually complex OH and OD stretching spectra compared to other alcohols. Via modeling of the torsional states, observed spectral splittings are explained by delocalization of the hydroxy hydrogen atom through quantum tunneling between the two non-equivalent but accidentally near-degenerate conformers separated by a low and narrow barrier. The energy differences between the torsional states are determined to be only 16(1) and 7(1) cm−1hc for the protiated and deuterated alcohol, respectively, which further shrink to 9(1) and 3(1) cm−1hc upon OH or OD stretch excitation. Comparisons are made with the more strongly asymmetric monoterpenols borneol and isopinocampheol as well as with the symmetric, rapidly tunneling propargyl alcohol. In addition, the third—in contrast localized—torsional conformer and the most stable dimer are assigned for α-fenchol, as well as the two most stable dimers for propargyl alcohol.

Influence of the cation–anion interaction (expressed as internal hydrogen bonds) on the nonlinear optical properties (dipole moment, polarizability, anisotropy of polarizability and first-order hyperpolarizability) for the ionic liquids pyridinium hydrogen sulfate (PHS) and pyridinium bis(dihydrogen phosphate) (P2HP) was investigated in this paper. It was achieved analyzing vibrational modes (FT-IR) and electronic transitions (UV–vis) in PHS and P2HP. Molecular geometry of the title compounds was optimized by means of density functional theory calculations at B3LYP/6–311++G(2d,2p) level. Structural analysis exposed stronger internal hydrogen bonds (H7···O3 and H18···O4) between cationic and anionic fragments in the pyridinium hydrogen sulfate than these (H26···O4 and H25···O12) in pyridinium bis(dihydrogen phosphate). These observations are confirmed by FT-IR and UV–vis methods, where: (i) the infrared bands due to H···O and N–C interactions in P2HP appear at lower frequencies than the same ones in the spectrum of PHS and (ii) the n → π* electron transitions in PHS are more pronounced in comparison with these in P2HP. Based on the weaker cation–anion interaction in P2HP with respect to PHS, the former one is characterized with a remarkably higher first-order hyperpolarizability value. Hence, the ionic liquid P2HP was referred as a better nonlinear optical material than PHS.

We examine the role of nuclear quantum statistical effects in the vibrational spectroscopy of molecular systems at finite temperatures. Our starting point is Matsubara dynamics, which rigorously combines quantum Boltzmann statistics with classical real-time trajectories, by filtering out the high-frequency components of the imaginary-time Feynman paths that are responsible for quantum coherence. Using a simple model of perturbed harmonic oscillators, it is shown that most of the intensity differences between quantum and classical non-fundamental (overtone, combination, and difference) bands can be accounted for by the anharmonic coupling between the imaginary-time path centroid and the fluctuations around it. This coupling causes the amplitudes of the relevant centroid vibrations to be ‘Matsubara heated’ to an effective temperature that is consistent with the underlying quantum distribution. Quantum coherence thus appears to play no major role in describing such features, contrary to what has sometimes been assumed in the literature. Practical path-integral methods for calculating vibrational spectra, such as centroid and thermostatted ring-polymer molecular dynamics, faithfully capture the harmonic behaviour of the centroid but make drastic approximations to the fluctuation dynamics. We explain how these approximations render such methods incapable of predicting non-fundamental bands with significantly more accuracy than classical mechanics. This is borne out by illustrative simulations of water in its gas, liquid, and ice phases; the linearised semiclassical initial value representation is shown to be the only established trajectory-based approach that reproduces most non-fundamental bands with qualitative accuracy, even though it suffers severe zero-point energy leakage on a sub-picosecond timescale. However, a simple quantum–classical correction formula (derived from first-order perturbation theory) is shown to bring the predictions of path-integral methods into much closer agreement with exact quantum results. Finally, a simple model of the carbon dioxide molecule is studied numerically to establish that ‘Matsubara heating’ accounts for the quantum (temperature quasi-independent) behaviour of the Fermi resonance splitting, which is underestimated by path-integral methods analogously to overtone band intensities.

The association process between the tetracycline (TC) antibiotic molecule and Keplerate-type nanocluster polyoxometalate (POM) {Mo72Fe30} was studied in aqueous solution. The novel supramolecular ensemble {Mo72Fe30}@TC12.5 was produced, its composition and structure were revealed by means of elemental analysis (C, N, H) and vibrational spectroscopy (IR and Raman). Based on the spectral data, the POM structure’s integrity was confirmed and binding sites of TC with the Keplerate {Mo72Fe30} surface were found. Due to thermogravimetric analysis (TG) and in-situ Raman spectroscopy during the process of {Mo72Fe30}@TC12.5 thermal destruction, we showed a significant change in the phase composition of POM’s destruction products after association with TC. The antibacterial activity of the obtained complex {Mo72Fe30}@TC12.5 was examined. The experimental results allowed us to note the partial inhibition of TC’s antibacterial activity owing to the coordination of TC to FeIII centers, in turn, which hinders the participation of TC in coordination via Mg2+ of ribosomal subunits 30S in bacteria.

Cistus is a plant that has been used in natural medicine for hundreds of years; it works primarily as an antioxidant and cleansing agent. Cistus × incanus leaves or herb can be an attractive source of polyphenols and flavonoids. The official protocols of active compound analysis relies on the extraction of compounds of interest from plant matter, which makes their determination long and costly. An analysis of plant material in its native state can be performed using vibrational spectroscopy. This paper presents a comparison of Raman spectroscopy, attenuated total reflection in mid-infrared and diffuse reflectance technique in the near-infrared region for the simultaneous quantification of total polyphenols (TPC) and flavonoids (TF) content, as well as the determination of FRAP antioxidant activity of C. incanus material. Utilizing vibrational spectra and using partial least squares algorithm, TPC and TF were quantified with the RSEPVAL errors in the 2.7–5.4% range, while FRAP antioxidant activity for validation sets was determined with relative errors ranged from 5.2 to 9.3%. For the analyzed parameters, the lowest errors of predictions were computed for models constructed using Raman data. The developed models allow for fast and precise quantification of the studied active compounds in C. incanus material without any chemical sample treatment.

Hormones regulate metabolic homeostasis through interlinked dynamic networks of proteins and small molecular weight metabolites and state-of-the-art chemical technologies have been developed to decipher these complex pathways. Stable-isotope tracers have largely replaced radiotracers to measure flux in humans, building on advances in nuclear magnetic resonance spectroscopy and mass spectrometry. These technologies are now being applied to localise molecules within tissues. Radiotracers are still highly valuable both preclinically and in 3D imaging by positron emission tomography. The coming of age of vibrational spectroscopy in conjunction with stable-isotope tracing offers detailed cellular insights to map complex biological processes. Together with computational modelling, these approaches are poised to coalesce into multi-modal platforms to provide hitherto inaccessible dynamic and spatial insights into endocrine signalling.

FTIR spectroscopy was combined with the matrix isolation technique and quantum chemical calculations with the aim of studying complexes of isocyanic acid with sulfur dioxide. The structures of the HNCO⋯SO2 complexes of 1:1, 1:2 and 2:1 stoichiometry were optimized at the MP2, B3LYPD3, B2PLYPD3 levels of theory with the 6-311++G(3df,3pd) basis set. Five stable 1:1 HNCO⋯SO2 complexes were found. Three of them contain a weak N-H⋯O hydrogen bond, whereas two other structures are stabilized by van der Waals interactions. The analysis of the HNCO/SO2/Ar spectra after deposition indicates that mostly the 1:1 hydrogen-bonded complexes are present in argon matrices, with a small amount of the van der Waals structures. Upon annealing, complexes of the 1:2 stoichiometry were detected, as well.

Proteins play an important role in biological and biochemical processes taking place in the living system. To uncover these fundamental processes of the living system, it is an absolutely necessary task to understand the structure and dynamics of the protein. Vibrational spectroscopy is an established tool to explore protein structure and dynamics. In particular, two-dimensional infrared (2DIR) spectroscopy has already proven its versatility to explore the protein structure and its ultrafast dynamics, and it has essentially unprecedented time resolutions to observe the vibrational dynamics of the protein. Providing several examples from our theoretical and experimental efforts, it is established here that two-dimensional vibrational spectroscopy provides exceptionally more information than one-dimensional vibrational spectroscopy. The structural information of the protein is encoded in the position, shape, and strength of the peak in 2DIR spectra. The time evolution of the 2DIR spectra allows for the visualisation of molecular motions.

The chemical composition of recent and fossil organic-walled dinoflagellate cyst walls and its diversity is poorly understood and analyses on single microscopic specimens are rare. A series of infrared spectroscopic experiments resulted in the proposition of a standardized attenuated total reflection micro-Fourier transform infrared-based method that allows the collection of robust data sets consisting of spectra from individual dinocysts. These data sets are largely devoid of nonchemical artifacts inherent to other infrared spectrochemical methods, which have typically been used to study similar specimens in the past. The influence of sample preparation, specimen morphology and size and spectral data processing steps is also assessed within this methodological framework. As a result, several guidelines are proposed which facilitate the collection and qualitative interpretation of highly reproducible and repeatable spectrochemical data. These, in turn, pave the way for a systematic exploration of dinocyst chemistry and its assessment as a chemotaxonomical tool or proxy.

Textile waste presents a major burden on the environment, contributing to climate change and chemical pollution as toxic dyes and finishing chemicals enter the environment through landfill leachate. Moreover, the majority of textile waste reaching landfills is discarded clothing, which could be reused or recycled. Here we investigate environmentally benign morphology changing of cotton textiles as a precursor for reintegration into a circular materials economy. At 50 °C using low concentrations of acids and bases, the interfiber structures of woven cotton were successfully degraded when treated with the following sequence of chemical treatment: citric acid, urea, sodium hydroxide, ammonium hydroxide, and sodium nitrate. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) reveal separation of the constituent fibers without depolymerization of the cellulose structure, and streaming potential measurements indicate that surface charge effects play a key role in facilitating degradation. The proposed reaction procedures show feasibility of effective waste-fabric recycling processes without chemically intensive processes, in which staple fibers are recovered and can be re-spun into new textiles.

[NiFe] hydrogenases are complex model enzymes for the reversible cleavage of dihydrogen (H2). However, structural determinants of efficient H2 binding to their [NiFe] active site are not properly understood. Here, we present crystallographic and vibrational‐spectroscopic insights into the unexplored structure of the H2‐binding [NiFe] intermediate. Using an F420‐reducing [NiFe]‐hydrogenase from Methanosarcina barkeri as a model enzyme, we show that the protein backbone provides a strained chelating scaffold that tunes the [NiFe] active site for efficient H2 binding and conversion. The protein matrix also directs H2 diffusion to the [NiFe] site via two gas channels and allows the distribution of electrons between functional protomers through a subunit‐bridging FeS cluster. Our findings emphasize the relevance of an atypical Ni coordination, thereby providing a blueprint for the design of bio‐inspired H2‐conversion catalysts., Where does the H2 go? Using an F420‐reducing [NiFe]‐hydrogenase from Methanosarcina barkeri as a model enzyme, it is shown that the protein backbone provides a strained chelating scaffold that tunes the [NiFe] active site for efficient H2 binding and conversion. The protein matrix also directs H2 diffusion to the [NiFe] site via two gas channels and allows the distribution of electrons between functional protomers through a subunit‐bridging FeS cluster.

WOS: 000471652700051 The structural, spectroscopic and electronic features of the 6-(Chloromethyl)uracil (6CMU) have been characterized by using single crystal X-ray diffraction (XRD), H-1 and C-13 NMR, UV-Vis. and vibrational (FT-IR and Raman) spectroscopies. The classical geometry analyses of intermolecular interactions, which were performed on the basis of experimental crystal structure, have been supported by Hirshfeld surface analysis. Theoretical molecular geometry optimization parameters (bond lengths and angles), vibrational wavenumbers, proton and carbon NMR chemical shifts, UV-Vis. parameters (wavelengths, excitation energies, oscillator strength) and the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies have been calculated using density functional theory (DFT/B3LYP) quantum chemical method with 6-311++G (d,p) basis set to compare with the experimental results. Assignments of the vibrational wavenumbers have been carried out by Potential Energy Distribution (PED) analyses by using VEDA 4 software. UV-Vis. electronic absorption parameters, HOMO-LUMO analyses, Natural Bond Orbital (NBO) results and Molecular Electrostatic Potential (MEP) surface of 6CMU have been studied to explicate electronic transitions, intramolecular charge transfer and interaction sites in the molecule. The computed vibrational wavenumbers, NMR chemical shifts and UV-Vis. parameters have been in good agreement with the corresponding experimental data and literature. (C) 2019 Elsevier B.V. All rights reserved.

Vibrational strong coupling (VSC) has recently emerged as a completely new tool for influencing chemical reactivity. It harnesses electromagnetic vacuum fluctuations through the creation of hybrid states of light and matter, called polaritonic states, in an optical cavity resonant to a molecular absorption band. Here, we investigate the effect of vibrational strong coupling of water on the enzymatic activity of pepsin, where a water molecule is directly involved in the enzyme's chemical mechanism. We observe an approximately 4.5‐fold decrease of the apparent second‐order rate constant kcat/Km when coupling the water stretching vibration, whereas no effect was detected for the strong coupling of the bending vibration. The possibility of modifying enzymatic activity by coupling water demonstrates the potential of VSC as a new tool to study biochemical reactivity., Angewandte Chemie. International Edition, 58 (43), ISSN:1433-7851, ISSN:1521-3773, ISSN:0570-0833

Carboxylic-acid adsorption on anatase TiO2 is a relevant process in many technological applications. Yet, despite several decades of investigations, the acid-proton localization-either on the molecule or on the surface-is still an open issue. By modeling the adsorption of formic acid on top of anatase(101) surfaces, we highlight the formation of a short strong hydrogen bond. In the 0 K limit, the acid-proton behavior is ruled by quantum delocalization effects in a single potential well, while at ambient conditions, the proton undergoes a rapid classical shuttling in a shallow two-well free-energy profile. This picture, supported by agreement with available experiments, shows that the anatase surface acts like a protecting group for the carboxylic acid functionality. Such a new conceptual insight might help rationalize chemical processes involving carboxylic acids on oxide surfaces.

Bone crystallite chemistry and structure change during bone maturation. However, these properties of bone can also be affected by limited uptake of the chemical constituents of the mineral by the animal. This makes probing the effect of bone-mineralization-related diseases a complicated task. Here it is shown that the combination of vibrational spectroscopy with two-dimensional X-ray diffraction can provide unparalleled information on the changes in bone chemistry and structure associated with different bone pathologies (phosphate deficiency) and/or health conditions (pregnancy, lactation). Using a synergistic analytical approach, it was possible to trace the effect that changes in the remodelling regime have on the bone mineral chemistry and structure in normal and mineral-deficient (hypophosphatemic) mice. The results indicate that hypophosphatemic mice have increased bone remodelling, increased carbonate content and decreased crystallinity of the bone mineral, as well as increased misalignment of crystallites within the bone tissue. Pregnant and lactating mice that are normal and hypophosphatemic showed changes in the chemistry and misalignment of the apatite crystals that can be related to changes in remodelling rates associated with different calcium demand during pregnancy and lactation., The following funding is acknowledged: European Commission Seventh Framework Programme (grant No. 2012-328731 to HEK); Universidad de Granada (grant Nos. CGL2015- 64683-P and UCE PP 2016.05 to ABRN).

Wood is an important source of phenolic compounds, which can be transferred to wine during aging process, improving its properties, from an organoleptic point of view. Therefore, understanding and optimizing the extractability of phenolic compounds from wood are crucial in the oenological field. The structural composition of oak wood samples has been evaluated using Raman and attenuated total reflectance Fourier transform infrared (ATR–FTIR) spectroscopies, and their main spectral features have been linked to phenolic compound extractabilities, as measured by classic chemical analyses. To support the analysis, microscopic images of the samples were also recorded using scanning electron microscopy (SEM). The applied methodology is shown to be useful to relate the wood cell wall structure to phenolic extractability levels of wood samples. It could assist in selecting oak wood suited for improving wine quality with regard to its color or/and stability through the addiction of external copigments to wine.

The virtual multifrequency spectrometer (VMS) integrates state-of-the-art computational implementations of different spectroscopies with a powerful graphical user interface, which offers an invaluable aid in preorganizing and displaying the computed spectroscopic information. This chapter provides an overview of the VMS software, thus focusing on its peculiarities and unique features. It presents a short introduction of the theoretical background for the selected spectroscopies and of the corresponding quantum chemical requirements. The chapter also presents the current status of VMS in some detail with specific reference to rotational, vibrational, vibronic, and magnetic spectroscopy. To address the great potentialities of the VMS software, various case studies have been selected. The choice has been made in order not only to point out the ability of VMS in dealing with different spectroscopic techniques and thus providing an exhaustive characterization but also to demonstrate the scientific impact of VMS in the field.

International audience; On the grounds of a hybrid CCSD(T)/B3LYP/aug-cc-pVTZ anharmonic potential and the use of a variational and variational-perturbational methods, the IR spectra of dicyanodiacetylene C6N2 is revisited in the mid-infrared region up to 4500 cm−1. A position and intensity analysis of our theoretical results allow us to assign the fundamental bands together with their combinations and overtones, in the aforementioned range of frequencies. The pure theoretical results are discussed in relation with the pure experimental data. The main objective of this paper is to give an ‘a priori’ complete IR spectrum of C6N2 which can be used as a guide of the low-intensity bands in areas not completely assigned so far.