Dimensional 1H Research Articles

Preparation and structural characterization of a sulfated octasaccharide with heparin-like anticoagulant activity

Heparins are sulfated polysaccharides with a heterogeneous mixture derived from animal tissues, subject to supply limitations and the risk of animal virus residues. Patients using heparin also face the risks of spontaneous bleeding and thrombocytopenia. Here we reported an efficient riclinoctaose-based approach for rapid chemical synthesis of a structurally defined heparin-like anticoagulant sulfated octasaccharide (SRO). We used sulfur trioxide-pyridine, sulfur trioxide-trimethylamine, and sulfur trioxide-triethylamine complexes as solvents for one-pot O-sulfation and determined the optimal conditions for synthesizing SRO. Sulfur trioxide-trimethylamine provided reasonable control over the degree of substitution between 1.85 and 1.88, revealing a single molecule with a theoretical molecular weight of 2952.96 g/mol. The structural features of the SRO were carried out by Fourier transform infrared spectroscopy and one- and two- dimensional 1H and 13C NMR analysis, revealing sulfation repeatedly present at the fixed positions of C-6/C-2/C-3 and reducing terminals. The anticoagulant activity of SRO was demonstrated by efficiently blocking coagulation in the blood of mice and human. SRO dose-dependently decreased ferric chloride-induced experimental thrombosis in mice. Like heparin, SRO specifically inhibits coagulation factor Xa, but significantly reduces the risk of bleeding compared to heparin. Therefore, we named it octaparin. These results support that octaparin is expected to replace animal-sourced heparin.

Evaluation of polyanionic cyclodextrins as high affinity binding scaffolds for fentanyl

Cyclodextrins (CDs) have been previously shown to display modest equilibrium binding affinities (Ka ~ 100–200 M-1) for the synthetic opioid analgesic fentanyl. In this work, we describe the synthesis of new CDs possessing extended thioalkylcarboxyl or thioalkylhydroxyl moieties and assess their binding affinity towards fentanyl hydrochloride. The optimal CD studied displays a remarkable affinity for the opioid of Ka = 66,500 M−1, the largest value reported for such an inclusion complex to date. One dimensional 1H Nuclear Magnetic Resonance (NMR) as well as Rotational Frame Overhauser Spectroscopy (2D-ROESY) experiments supported by molecular dynamics (MD) simulations suggest an unexpected binding behavior, with fentanyl able to bind the CD interior in one of two distinct orientations. Binding energies derived from the MD simulations work correlate strongly with NMR-derived affinities highlighting its utility as a predictive tool for CD candidate optimization. The performance of these host molecules portends their utility as platforms for medical countermeasures for opioid exposure, as biosensors, and in other forensic science applications.

Isolation and identification of long -chain aliphatic compounds from Synadenium glaucescens

Purification of dichloromethane extract from root barks and leaves of Synadenium glaucescens extracts through chromatographic techniques resulted into the isolation of two compounds, namely erythrinacinate C and 1-octacosanol. Chemical structures were established mainly using both one and two dimensional 1H and 13C NMR data and by comparison of the current NMR data with those from literature. Mass spectrophotometry data were used for confirmation through molecular ion peak. Both compounds are known to have been isolated from other plant species but are being reported from this plant species for the first time.

Supramolecular Synthon Identification in Azelaic Acid – Isonicotinamide

Supramolecular synthons are the smallest structural units that contain the information inherent in building large molecular assemblies. Here, we apply solid-state NMR methods for the identification of the synthon in a cocrystal of Azelaic acid [(CH2)7(COOH)2]– Isonicotinamide [C6H6N2O]. It is observed that the spin-lattice relaxation time of protons in the cocrystal is long, implying that the choice of experiments, particularly those that involve low-sensitivity nuclei, could be time consuming. It is noticed that the two dimensional 1H double quantum (DQ) – 1H single quantum (SQ) correlation experiment at very fast MAS (60 kHz) is able to provide information on proton-proton proximities that leads to an understanding of the synthon structure. Experiments such as the CP-Reverse CP and 1H–13C HETCOR have been used to obtain spectral assignment which was additionally confirmed by first-principle GIPAW NMR chemical shift calculations. Present study indicates the basic unit to be a heterosynthon in Azelaic acid (AZA) – Isonicotinamide (INIC) cocrystal formed by two different modes of intermolecular connectivity, viz. acid–pyridine and acid–amide hydrogen bonding interactions. The presence of a CH…O type bond involving a hydrogen of INIC is also indicated from the observation of a larger chemical shift of the corresponding proton. The experimental protocol presented in this paper is expected to be a useful tool for the estimation of the basic structural arrangement of the synthons in a rapid fashion.

Stereodivergent Syntheses of All Stereoisomers of (−)‐Shikimic Acid: Development of a Chiral Pool for the Diverse Polyhydroxy‐cyclohexenoid (or ‐cyclohexanoid) Bioactive Molecules

AbstractNovel stereodivergent total syntheses of all the seven stereoisomers of (−)‐shikimic acid [(−)‐SA 1] have been systematically performed. (+)‐ent‐SA ent‐1 was synthesized from (−)‐SA 1 via 9 steps in 31 % overall yield; (−)‐3‐epi‐SA 2 was synthesized from (−)‐SA 1 via 5 steps in 66 % overall yield; (+)‐3‐epi‐ent‐SA ent‐2 was synthesized from (−)‐SA 1 via 7 steps in 43 % overall yield; (−)‐4‐epi‐SA 3 was synthesized from (−)‐SA 1 via 11 steps in 32 % overall yield; (+)‐4‐epi‐ent‐SA ent‐3 was synthesized from (−)‐SA 1 via 7 steps in 42 % overall yield; (−)‐5‐epi‐SA 4 was synthesized from (−)‐SA 1 via 6 steps in 56 % overall yield; and (+)‐5‐epi‐ent‐SA ent‐4 was synthesized from (−)‐SA 1 via 12 steps in 29 % overall yield. The stereochemistry of all the above seven stereoisomers of (−)‐SA 1 were further studied by two dimensional (2D) 1H NMR technique.

Two dimensional 1H magnetic resonance relaxometry-based analyses of Argonne premium coals

1H magnetic resonance (MR) is a useful technique for determining molecular structure of coals. Most previous MR studies were based on one-dimensional 1H magnetic resonance relaxometry. Two-dimensional (2D) 1H magnetic resonance relaxation correlation methods, T1–T2* and T1ρ–T2*, were used to evaluate Argonne premium coals, including Beulah-Zap (BZ), Wyodak-Anderson (WA), Pittsburgh #8 (PIT), Upper Freeport (UF), and Pochontas #3 (POC) coals as received. Samples were also measured after oxidization at low temperature (110 and 210 °C). From the 2D relaxation correlations, various hydrogen-containing components were distinguished and characterized. The change of hydrogen during low temperature oxidation was analyzed, and the hydrogen content estimated. The technique captured significant differences between low rank coals (BZ and WA) and high rank coals (PIT, UF, and POC). The order of T1/T2* ratios is aliphatic hydrogen > aromatic hydrogen > hydrogen- and oxygen-containing functional groups > moisture in BZ and WA coals. The PIT, UF, and POC coals mainly contain aromatic hydrogens. The T1–T2* and T1ρ–T2* spectra of BZ and WA coals change significantly during low temperature oxidation. Our new MR method provides new insight into coal behaviour.

Deep learning can accelerate and quantify simulated localized correlated spectroscopy

Nuclear magnetic resonance spectroscopy (MRS) allows for the determination of atomic structures and concentrations of different chemicals in a biochemical sample of interest. MRS is used in vivo clinically to aid in the diagnosis of several pathologies that affect metabolic pathways in the body. Typically, this experiment produces a one dimensional (1D) 1H spectrum containing several peaks that are well associated with biochemicals, or metabolites. However, since many of these peaks overlap, distinguishing chemicals with similar atomic structures becomes much more challenging. One technique capable of overcoming this issue is the localized correlated spectroscopy (L-COSY) experiment, which acquires a second spectral dimension and spreads overlapping signal across this second dimension. Unfortunately, the acquisition of a two dimensional (2D) spectroscopy experiment is extremely time consuming. Furthermore, quantitation of a 2D spectrum is more complex. Recently, artificial intelligence has emerged in the field of medicine as a powerful force capable of diagnosing disease, aiding in treatment, and even predicting treatment outcome. In this study, we utilize deep learning to: (1) accelerate the L-COSY experiment and (2) quantify L-COSY spectra. All training and testing samples were produced using simulated metabolite spectra for chemicals found in the human body. We demonstrate that our deep learning model greatly outperforms compressed sensing based reconstruction of L-COSY spectra at higher acceleration factors. Specifically, at four-fold acceleration, our method has less than 5% normalized mean squared error, whereas compressed sensing yields 20% normalized mean squared error. We also show that at low SNR (25% noise compared to maximum signal), our deep learning model has less than 8% normalized mean squared error for quantitation of L-COSY spectra. These pilot simulation results appear promising and may help improve the efficiency and accuracy of L-COSY experiments in the future.

Aqueous N-H acid bis(trifluoromethylsulfonyl) imide Solution - [C4mim][Tf2N] Ionic Liquid Biphasic System: an Original Investigation by Diffusion Ordered Spectroscopy Nuclear Magnetic Resonance

Transfers of solutes from an aqueous solution to an ionic liquid and vice versa has been well studied for years. On the other hand, influence of transferred solutes on the ionic liquid's network is not yet evaluated. Therefore, we focus on the aqueous - ionic liquid biphasic system composed of two immiscible solutions containing N-H acid bis(trifluoromethylsulfonyl) imide and [C4mim][Tf2N] ionic liquid. After mixing and separation of the two phases, a part of water, H3O+, [Tf2N−] and H[Tf2N] anions are transferred into [C4mim][Tf2N] ionic liquid because H[Tf2N] has a salting in effect. The presence of this solutes might modify the local structure of [C4mim][Tf2N] ionic liquid. So far, our goal is to evaluate this structural change using several tools. For this, one dimensional 1H, 19F and Diffusion Ordered Spectroscopy Nuclear Magnetic Resonance were carried out on [C4mim][Tf2N] ionic liquid. We observed that some of water molecules are free and formed local microstructure as water pocket inside the ionic liquid network. The others are hydrogen bonded to [Tf2N−] anions as Tf2N−….H-O-D….Tf2N− for example. As long as the mole fraction of water in the ionic liquid remains less than or equal to that of [C4mim+] or [Tf2N−] the structure of the network is maintained. Free water moves at its own speed and bound water is an inclusion in the [C4mim][Tf2N] network. As soon as the mole fraction of the water is greater than that of [C4mim+] or [Tf2N−], the network of [C4mim][Tf2N] ionic liquid is gradually dislocated. Charged clusters composed with [C4mim+], [Tf2N−] and bond water are build and free water flow between them.

Metabolic profiling of historical and modern wheat cultivars using proton nuclear magnetic resonance spectroscopy

To determine changes in the grain components between historical and modern wheat (Triticum aestivum L.) cultivars, wholemeal flours from 19 wheat cultivars and 2 landraces released or introduced between 1870 and 2013 and grown over two crop years were extracted using hydroalcoholic solution and analyzed using one dimensional 1H NMR spectral profiling. Grain yield, grain volume weight (GVW), and grain protein concentration were also measured. Grain yield increased while protein concentration decreased by release year (p < 0.001). Increasing trends (p < 0.01) were observed for tryptophan, sum of the measured amino acids, chlorogenic acid, ferulic acid, vanillic acid, and sum of the measured phenolic acids. Grain yield, phenolic acids, and tryptophan were mainly associated with modern cultivars, whereas grain protein concentration and GVW were associated with historical cultivars. The findings from this study showed changes in concentration of grain components over a century of breeding that may have implications for grain quality and human health.

A framework for automated structure elucidation from routine NMR spectra.

Methods to automate structure elucidation that can be applied broadly across chemical structure space have the potential to greatly accelerate chemical discovery. NMR spectroscopy is the most widely used and arguably the most powerful method for elucidating structures of organic molecules. Here we introduce a machine learning (ML) framework that provides a quantitative probabilistic ranking of the most likely structural connectivity of an unknown compound when given routine, experimental one dimensional 1H and/or 13C NMR spectra. In particular, our ML-based algorithm takes input NMR spectra and (i) predicts the presence of specific substructures out of hundreds of substructures it has learned to identify; (ii) annotates the spectrum to label peaks with predicted substructures; and (iii) uses the substructures to construct candidate constitutional isomers and assign to them a probabilistic ranking. Using experimental spectra and molecular formulae for molecules containing up to 10 non-hydrogen atoms, the correct constitutional isomer was the highest-ranking prediction made by our model in 67.4% of the cases and one of the top-ten predictions in 95.8% of the cases. This advance will aid in solving the structure of unknown compounds, and thus further the development of automated structure elucidation tools that could enable the creation of fully autonomous reaction discovery platforms.

NMR spectroscopic investigation of benzothiazolylacetonitrile azo dyes: CR7 substitution effect and semiempirical study

Ebead et al. had reported in the synthesis and the UV–Visible solvatochromism combined with semiempirical calculations to study the tautomerism of 1,3-benzothiazol-2-ylacetonitrile azo dyes [1]. In this study, 1,3-benzothiazol-2-ylacetonitrile azo dyes (1–6) have been resynthesized, one and two dimensional 1H and 13C NMR, as well as absorption and emission spectra, were collected and interpreted. The obtained results were used to clarify the tautomerization phenomenon of these dyes. Predominantly, these dyes exist in Z-hydrazone form reinforced through intramolecular hydrogen bonding in deuterated chloroform. Substituents (R) in carbon7 (CR7) are the key player of the changes in 1H and 13C NMR chemical shifts, also in the absorption and emission wavelengths of benzothiazole azo dyes. Also, the relative photoluminescence quantum yields (PL QY) of these dyes (1–6) were estimated and related to the nature of substituents. Finally, PM6 semiempirical calculations were employed to confirm the preferred geometric structure and experimental NMR, absorption, and emission results.

Metabolomic and antioxidant properties of different varieties and origins of Dragon fruit

Dragon fruit has appealed much concern from consumers as a novelty fruit with potent nutritional and medicinal benefits. Dragon fruit quality warrants comprehensive evaluation, based on the contents of pigments and health-promoting natural compounds in different varieties. This study was aimed to evaluate the differences among dragon fruitvarieties extracted with methanol–water (CD3OD-D2O) and methanol (CD3OD) by proton nuclear magnetic resonance (1H NMR)-based metabolomics approach. The variation features of the metabolite profiles were studied between varieties and origins of dragon fruit, considering the differences in principal component analysis (PCA). The hierarchical clustering analysis (HCA) based on score values of PCA model was also performed to analyze the distance between samples based on metabolites contents. The results of 1H NMR spectra showed that the CD3OD-D2O extracts quantitatively differ from CD3OD ones. In dragon fruit extracts, 36 metabolites were identified. The results demonstrated that the methanol and methanol/water extracted similar compounds with higher intensity in methanol. The metabolic differences among varieties were also shown for CD3OD extracts by comparing both Pareto and UV scaling methods. The big size red fleshed dragon fruit (samples 2 and 3), growing in Israel were clustered similar to that growing in Thailand with the abundance of phenolic compounds. Glucose and fructose were more prominent in the yellow and white fleshed fruit (samples 4 and 5) growing in Israel. To support the obtained results two dimensional 1H–1H J-resolved and UHPLC-MS measurements were carried out. This research gain novel insights into the field as the first NMR metabolites fingerprinting of the major dragon fruit varieties. The correlations between DPPH, CUPRAC, antioxidant and metabolomic properties were also evaluated. The chemical markers associated with varieties of dragon fruit quality and their appearances were identified and can be utilized for the basis of authentication purpose of this fruit.

Effect of extraction procedures on the chemical structure, antitumor and anticoagulant properties of ulvan from Ulva lactuca of Tunisia coast

The effect of extraction procedures on chemical composition, structural, antitumor and anticoagulant properties of the sulphated polysaccharide ‘ulvan’ from the green seaweed Ulva lactuca were investigated. The structural features of ulvans were carried out by FTIR and by one- and two- dimensional 1H and 13C NMR spectroscopic. The ulvans were mainly composed of rhamnose, xylose, and uronic acid. Chemical and spectroscopic analyses demonstrated that ulvans were constituted of (1→4)-β-glucuronic acid, (1→3,4)-α-L-rhamnose-3-sulphate and (1→4)-α-xylose.The extraction procedures effect were observed in chemical structure, Mw and biological activities. Cytotoxic activity of enzymatic-chemical extract on cervical cancer cells (HeLa) (IC50 = 1000 μg/mL) was higher than on normal peripheral blood lymphocytes cells (PBL). Acid extracts promoted to reduce HeLa cells and to grow PBL cells. At high concentrations, acid extracts showed the highest APTT and TT clotting time. Antitumoral and anticoagulant activities of ulvans from Ulva lactuca promote their use as effective therapeutic agent.

Aqueous photo-degradation of Flupyradifurone (FPD) in presence of a natural Humic Acid (HA): A quantitative solution state NMR analysis

The present study aims to characterize the molecular interaction and photo-degradation behaviour of halogen (F and Cl) containing novel insecticide, flupyradifurone, (FPD) in the presence of humic acid (KHA), isolated from Karwar, western Rajasthan, India. Time-dependent photo-degradation kinetics of UV-exposed FPD is quantified in the absence and presence of KHA employing one dimensional 1H and 19F solution-state NMR. The pseudo first-order photo-degradation rate constant quantified for FPD showed a significant decrease in the presence of KHA. Interestingly, variable degradation rates are found from 1H and 19F NMR spectral changes indicating chemical moiety wise degradation of FPD. Further, NMR saturation transfer difference (STD), relaxation, and diffusion experiments have been employed for the complete evaluation of binding interactions of KHA with FPD and its major degradation product difluoroacetic acid (DFA). STD experiments revealed that FPD binds to KHA through the chlorinated pyridine ring while the –F containing moiety of FPD does not show any detectable interaction. Relevant kinetic parameters, namely association constants and Gibbs free energy of interaction are quantified at neutral pH conditions by diffusion experiments depicting a stronger and more spontaneous association of FPD with KHA (KA = 55.55 M−1) compared to that of DFA-KHA (KA = 10.90 M−1). Both FPD and DFA bind with KHA through weak non-covalent interaction indicating the encapsulation of these molecules within KHA hindering the photo-degradation process of FPD. Concomitantly, it is also envisaged that FPD will be more persistent in soil compared to DFA that may leach out to groundwater.

Determination of the Geographical Origin of Maltese Honey Using 1H NMR Fingerprinting.

The price of honey, as a highly consumed natural product, depends on its botanical source and its production environment, causing honey to be vulnerable to adulteration through mislabeling and inappropriate, fraudulent production. In this study, a fast and simple approach is proposed to tackle this issue through non-target one dimensional zg30 and noesypr1d 1H NMR fingerprint analysis, in combination with multivariate data analysis. Results suggest that composition differences in sugars, amino acids, and carboxylic acid were sufficient to discriminate between the tested honey of Maltese origin and that of non-local origin. Indeed, all chemometric models based on noesypr1d analysis of the whole fraction honey showed better prediction in geographical discrimination. The possibility of discrimination was further investigated through analysis of the honey’s phenolic extract composition. The partial least squares models were deemed unsuccessful to discriminate, however, some of the linear discriminant analysis models achieved a prediction accuracy of 100%. Lastly, the best performing models of both the whole fraction and the phenolic extracts were tested on five samples of unknown geographic for market surveillance, which attained a high agreement within the models. Thus, suggesting the use of non-target 1H NMR coupled with the multivariate-data analysis and machine learning as a potential alternative to the current time-consuming analytical methods.

Sample Preparation and Data Analysis for NMR-Based Metabolomics.

NMR spectroscopy has become one of the preferred analytical techniques for metabolomics studies due to its inherent nondestructive nature, ability to identify and quantify metabolites simultaneously in a complex mixture, minimal sample preparation requirement, and high degree of experimental reproducibility. NMR-based metabolomics studies involve the measurement and multivariate statistical analysis of metabolites present in biological samples such as biofluids, stool/feces, intestinal content, tissue, and cell extracts by high-resolution NMR spectroscopy-the goal then is to identify and quantify metabolites and evaluate changes of metabolite concentrations in response to some perturbation. Here we describe methodologies for NMR sample preparation of biofluids (serum, saliva, and urine) and stool/feces, intestinal content, and tissues for NMR experiments including extraction of polar metabolites and application of NMR in metabolomics studies. One dimensional (1D) 1H NMR experiments with different variations such as pre-saturation, relaxation-edited, and diffusion-edited are routinely acquired for profiling and metabolite identification and quantification. 2D homonuclear 1H-1H TOCSY and COSY, 2D J-resolved, and heteronuclear 1H-13C HSQC and HMBC are also performed to assist with metabolite identification and quantification. The NMR data are then subjected to targeted and/or untargeted multivariate statistical analysis for biomarker discovery, clinical diagnosis, toxicological studies, molecular phenotyping, and functional genomics.

A green cascade polymerization method for the facile synthesis of sustainable poly(butylene-co-decylene terephthalate) copolymers

Typical semicrystalline aromatic polyesters are synthesized via the condensation polymerization of aromatic diacids with excess diols in vacuum. We demonstrate here a green cascade polycondensation-coupling ring-opening polymerization (PROP) method for the facile incorporation of diols into polyesters in N2, utilizing cyclic oligo(butylene terephthlate)s as monomer and bio-based 1,10-decanediol as initiator. Poly(butylene-co-decylene terephthalate) (PBDT) copolyesters are synthesized with high atom economy (87–99%), and their structures are characterized and confirmed by the 1H quantitative NMR, two dimensional 1H–1H gCOSY and DOSY NMR spectra. Property investigations reveal that with the increment of decanediol content, the glass transition temperature, melting temperature, storage modulus and Young's modulus for PBDT copolyesters decrease, while the toughness increases, respectively. Our results provide a high atom economy PROP method for the synthesis of sustainable PBDT copolyesters, which have lower processing temperatures and improved ductility than poly(butylene terephthalate) (PBT) homopolymers, and could draw attentions for further investigations on the green synthesis of other copolyesters.

New approaches to identification and characterization of tioconazole in raw material and in pharmaceutical dosage forms

Tioconazole (TCZ), a broad-spectrum antifungal agent, has significant activity against Candida albicans and other Candida species, and therefore, it is indicated for the topical treatment of superficial mycoses. The main goal of this work is to report an exhaustive identification and characterization procedure to improve and facilitate the online quality control and continuous process monitoring of TCZ in bulk material and loaded in two different dosage forms: ovules and nail lacquer. The methodologies were based on thermal (differential scanning calorimetry (DSC), melting point, and thermogravimetry (TG)), spectroscopic (ultraviolet (UV), Raman, near infrared (NIR), infrared spectroscopy coupled to attenuated total reflectance (FTIR-ATR), and nuclear magnetic resonance (NMR)), microscopic and X-ray diffraction (XRD). The TCZ bulk powder showed a high crystallinity, as observed by XRD, with a particles size distribution (3–95 µm) resolved by microscopic measurements. TCZ melting point (82.8 °C) and a degradation peak centered at 297.8 °C were obtained by DSC and DTG, respectively. An unambiguous structure elucidation of TCZ was obtained by mono- and two- dimensional 1H and 13C NMR spectral data analysis. The FTIR-ATR, Raman and NIR spectra of both the raw material and the commercial products were analyzed and their characteristic bands were tabulated. The best methods for TCZ identification in ovules were DSC, TG, XRD, NIR and Raman, while NIR and FTIR-ATR were the most appropriate techniques to analyze it in the nail lacquer. DSC, TG, DRX, Raman, FTIR-ATR and NIR spectroscopy are effective techniques to be used in online process analysis, because they do not require sample preparation, and they are considerably sensitive to analyze complex samples.

NMR spectroscopic, linear and non-linear optical properties of 1,3-benzothiazol-2-yl-(phenylhydrazono)acetonitrile (BTPA) azo dye

The azo dye 1,3-benzothiazol-2-yl-(phenylhydrazono)acetonitrile (BTPA) was synthesized and structurally characterized by different spectroscopic techniques, including two dimensional 1H and 13C NMR as well as optical absorption and emission spectra. The obtained spectroscopic results and semiempirical PM6 calculations allowed to clarify the tautomerization phenomenon of this azo dye. Predominantly, this compound exists in Z-hydrazone form, reinforced through intramolecular hydrogen bonding, in chloroform. The X-Ray Diffraction (XRD) measurements revealed that the BTPA powder is crystallized in monoclinic system structure with the space group P1. BTPA/ITO thin film was prepared by the spin coating technique. The results of XRD for the powder and BTPA/ITO thin films confirmed the existence of nanostructural features. Analysis of the absorption edges for BTPA/ITO thin film gives direct optical band gap (2.6 eV). Lastly, the third order nonlinear susceptibility χ(3) and nonlinear refractive index n(2) were calculated in the wavelengths range 300–2500 nm. These attractive ÷(3) and n(2) results indicated that BTPA has potential applications in optoelectronics and photonics.

Aqueous acidic solution - ionic liquid biphasic system: An original investigation by diffusion ordered spectroscopy nuclear magnetic resonance

Transfers of solutes from an aqueous phase to an ionic liquid phase and vice versa has been well studied for years. On the other hand, influence of the transferred solutes on the structure of the ionic liquid phase is not yet evaluated. Therefore, we focus on the aqueous - ionic liquid biphasic system composed of two immiscible phase containing nitric or hydrochloric acid and the [C4mim][Tf2N] ionic liquid. They have been yet examined in terms of water and acid solubility in the ionic liquid rich phase. After mixing and separation of the two phases, a part of water, H3O+ and nitrates species were transferred into the [C4mim][Tf2N] ionic liquid phase, but not chloride anions. The presence of the solutes water, H3O+ and nitrates in [C4mim][Tf2N] ionic liquid phase could modify local structure of [C4mim][Tf2N] ionic liquid. So far, our goal is to evaluate this structural change using several tools. For this, one dimensional 1H, 19F and 15N Nuclear Magnetic Resonance, Nuclear Overhauser effect and Diffusion Ordered Spectroscopy Nuclear Magnetic Resonance were carried out on the [C4mim][Tf2N] liquid ionic phase. We observed that some of water molecules were free and formed local microstructure as water pocket inside the ionic liquid frame. The others were hydrogen bonded to [Tf2N−] anions via theirs oxygen atoms from sulfonyl groups. The free water fraction decreased as the concentration of [HNO3]aq, init increased. In case of [C4mim][Tf2N] ionic liquid mixed with hydrochloric acid, the fraction of hydrogen bonded water molecules was more important than with nitric acid.