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To improve soil health and to aid in climate change mitigation, the quantity of soil organic matter (SOM) should be maintained or increased over the long run. In doing so, not only the total quantity of SOC but also the stability of SOC must be considered. Stability of SOC increases as a function of resistance to microbial decomposition or microbial substrate use efficiency through chemical, biological, and physical mechanisms including humification, hydrophobic moieties, molecular diversity, and formation of macroaggregates. One of the mechanisms that enhance stability confers changes in the distribution of C functional groups of SOM. To better understand and quantify how these changes are influenced by agricultural management practices, we collected 670 pairwise data from the body of literature that has evaluated changes in the distribution of C functional groups of SOM measured by solid-state 13C NMR spectroscopy. The types of agricultural managements discussed herein include (1) fertilization, (2) tillage, (3) crop rotation, (4) grazing, and (5) liming practices. Our meta-analyses show that these practices modify the distribution of C functional groups of SOM. Fertilization practices were associated with increased O-alkyl groups. Tillage resulted in increases in the SOC consisted of aromatic and carbonyl groups. Crop rotations, especially legume-based rotations, were found to increase the proportion of aromatic groups. Although there are fewer publications on tillage and crop rotation than on fertilization practices, the distribution of C functional groups may be more influenced by crop rotation and tillage practices than fertilization management—and should be a focus of future research. Supplementary Information The online version contains supplementary material available at 10.1007/s00374-021-01580-2.

International audience; In situ synthesis of topologically modified linear polyethylenes (PE) using single-site polymerization catalysis is a challenging task, but it can enable the production of valuable advanced polymer materials with tailored properties. Described herein is an investigation aimed at the efficient generation of long-chain branches (LCB) in linear PEs using Al-alkenyl species, namely, iBuAl(oct-7-en-1-yl)2 (Al-1), in combination with homogeneous rac-{EBTHI}ZrCl2 (Zr-1)/MAO or heterogeneous MAO on silica-supported-rac-{EBTHI}ZrCl2 (supp-Zr-1)/TIBAL catalytic systems. As corroborated by extensive rheological studies and 13C NMR spectroscopy, the Al-alkenyl reagent was found to be quite efficient in the formation of LCB, via a mechanistic pathway involving both insertion and transmetallation reactions. Formation of LCB has been rationalized by density functional theory (DFT) computations carried out on the putative [rac-{EBTHI}Zr-R]+ (R = Me, nPr, and pentyl) cationic species and including a solvent model. Of the three possible isomers of Al/Zr heterobimetallic complexes derived from the cationic species [rac-{EBTHI}Zr-R]+ and Al-1, only one was identified, on kinetic and thermodynamic grounds, as the key intermediate. The DFT study also unveiled that (i) insertion of ethylene into the Zr-alkyl bond of the growing PE chain is accompanied by a reversible decoordination of the Al-vinyl transfer agent (AVTA), (ii) the vinyl 1,2-coordination/insertion of the alkenyl moieties of Al-1 into the Zr-alkyl bond, resulting in the formation of branching, is in direct kinetic competition with the insertion of ethylene, and (iii) the recoordination of the AVTA after either insertion step is thermodynamically favored and mostly responsible for the transmetallation phenomenon.

The new methyl [3-(4-chlorophenyl)-2-{[(2,4-dichloro-1,3-thiazol-5-yl)methylidene]hydrazinylidene}-4-oxo-1,3-thiazolidin-5-ylidene]acetate was synthesized from 4-(4-chlorophenyl)-1-(2,4-dichloro-1,3-thiazol-5-yl)methylidene-3-thiosemicarbazide using dimethyl acetylenedicarboxylate as thia-Michael reaction acceptor. New compounds (3 and 4) were characterized by IR, 1H and 13C NMR spectroscopy methods.

In this study, we report the development of an efficient protocol in the preparation of linear arabino-oligosaccharides derived from sugar beet arabinan. By optimizing hydrolytic conditions and separation on tandem Bio-Gel P4 columns, we obtained arabino-oligosaccharides with various degrees of polymerization (DP) from 2 to 15. All of these α-1,5-linked arabino-oligosaccharides are highly pure (>95%) as determined by HPAEC, MALDI-TOF mass spectrometry and 13C NMR spectroscopy. Due to their purity, these oligosaccharides can be used as standards to identify other oligosaccharides and as substrates to characterize new arabinan-specific enzymes, as well as for the development of new functional oligosaccharides.

A library of 14 heterobis(carbene) complexes of the general formula [Au(iPr2-bimy)(ADC)]BF4 (7-20) containing the N-heterocyclic carbene reporter iPr2-bimy and various protic acyclic diaminocarbenes (ADCs) have been prepared to estimate their stereoelectronic properties by 13C NMR spectroscopy and percentage buried volume (%Vbur) determinations. Their preparation was achieved by nucleophilic attack of five secondary amines on six mixed NHC/isocyanide complexes of the type [Au(iPr2-bimy)(CN-R)]BF4 (1-6). Analyses of the iPr2-bimy carbene signals reveal that protic ADCs are stronger donors than classical and expanded-ring NHCs. On the other hand, they are weaker donating compared to NHCs with reduced-heteroatom stabilization. Moreover, stereoelectronic fine-tuning of these ligands is possible by a diverse range of substituents originating from the employed isocyanides and amines.

Whether chemists or biologists, researchers dealing with metabolomics require tools to decipher complex mixtures. As a part of metabolomics and initially dedicated to identifying bioactive natural ...

A series of novel Norcantharimide derivatives were synthesized and their structures were characterized by FTIR, 1H and 13C NMR spectroscopy as well as elemental analyses. The absorption, distribution, metabolism and excretion (ADME) properties of the synthesized molecules were investigated. The results obtained in silico demonstrated that these molecules can be considered as orally active drug candidates due to their physicochemical properties. Also, docking studies demonstrated that all derivatives exhibit a good theoretical affinity with MolDock Score in between 124–138 against the main protease of Coronavirus Disease 2019 (COVID‐19 Mpr°) that caused worldwide epidemics. We believe that newly synthesized norcantharimide derivatives can guide many future studies in organic synthesis, medicine and pharmaceutical applications., A series of new novel Norcantharimides have been synthesized and their absorption, distribution, metabolism and excretion (ADME) properties were investigated. The results obtained in silico showed that these molecules can be considered orally active drug candidates, taking into account their physicochemical properties. In addition, placement studies have shown that all derivatives exhibit good theoretical affinity with the 124–138 MolDock Score against the main protease of Coronavirus Disease 2019 (COVID‐19 Mpr°), which causes worldwide outbreaks.

In this study, 3,4,6-tri-O-acetyl-1,2-O-(1-tocopheroxyethylidene)-α-d-glucopyranose (sugar 1,2-orthoester) was synthesized with good and moderate yields in the presence of an N,N-diisopropylethylamine/tetrabutylammonium iodide system via a reaction of α-tocopherol with sugar halides. The utility of sugar α- and β-chlorides, α-bromides, and α-iodide in the synthesis of aryl (α-tocopherol, 2,2,5,7,8-pentamethylchroman-6-ol and 2,6-dimethylphenol) 1,2-orthoesters was investigated. The stereoselective formation of exo-1,2-orthoesters was confirmed using 1H and 13C NMR spectroscopy.

The identification and quantification of reaction intermediates and products in a time-resolved fashion is of great value for the understanding of mechanisms underlying the electro-catalytic oxidation of alcohols. Using a newly developed in situ cell, the identification of different intermediates, products, and side products became possible by monitoring the ethanol electro-oxidation in operando by 13C NMR spectroscopy.

A new organometallic iodide cluster complex (Bu4N)2[W6I8(C≡C–C(O)OCH3)6] (I), analogous to the previously described (Bu4N)2[Mo6I8(C≡C–C(O)OCH3)6], was obtained by the reaction of (Bu4N)2[W6I14] with silver methyl propiolate AgC≡C–C(O)OCH3. The crystal structure was established for the tetraphenylphosphonium salt (Ph4P)2[W6I8(C≡C–C(O)OCH3)6] (II). According to X-ray diffraction (CIF file CCDC no. 1829205), tungsten atoms in II are coordinated by terminal carbon atoms of methyl propiolate ligands at W–C distances of 2.220(12)–2.268(14) A. The methyl propiolate complexes were characterized by electrospray mass spectrometry, 1H and 13C NMR spectroscopy, elemental analysis, and IR spectroscopy.

Five energetic compounds bearing the framework of methylenebis-(1,2,4-oxadiazole-3-yl) are developed. All chemical structures were confirmed using infrared spectroscopy (IR), 1H NMR and 13C NMR spectroscopy, HRMS, and single crystal X-ray diffraction for pivotal intermediate diethyl 2,2′-(methylenebis(1,2,4-oxadiazole-3,5-diyl))diacetate (2) and diammonium salt 5. Bis(5-(trinitromethyl)-1,2,4-oxadiazol-3-yl)methane (3) showed high performance (D = 9053.2 m s−1, P = 37.4 GPa) and relatively low sensitivity (IS = 12.5 J, FS = 72 J). All the others are less sensitive than TNT.

Exposure of bis-amidinate and -guanidinate supported thorium dialkyl complexes to dioxygen results in facile oxygen atom insertion and formation of the corresponding thorium bis(alkoxide) species. Preliminary mechanistic studies suggest a radical propagation mechanism is operative. All new complexes were fully characterized by 1H and 13C NMR spectroscopy, IR, EA and X-ray crystallography.

The synthesis of five new alkyl 2-azido-2,3-dideoxy-α-D-ribo-hexopyranoside (7a-d) from α,β-unsaturated sugar enones and sodium azide in the presence of acetic acid is described. One key intermediate, alkyl 2-azide-dideoxy-α-erythro-hexopyranosid-4-ulose (6a-d), was used to obtain compounds 7a-d. The compounds 7a-d were obtained in moderate yields. The structures of the synthesized compounds were elucidated using IR, 1H and 13C NMR spectroscopy and elemental analysis and their antiproliferative activities was evaluated against four different human cell lines that are also described in this paper.

Pure-silica-Nu-1 has been synthesized by a magadiite conversion method with the reactive gel composition SiO2 : 0.2 TMAOH : 5 H2O at 170 °C for 7 h. Its crystallization behaviors and the changes in its medium-range structure were discussed. The results demonstrate that part of the structure of magadiite decomposed. However, the 5-membered rings and 6-membered rings in magadiite were retained as SBUs in the system and participated in the formation of zeolite Nu-1, which accelerated the conversion. 4-Membered rings were present in the product after heating for 1 h, proving the formation of pure-silica-Nu-1. The conditions of the silicate species both in the solid product and in solution were investigated. Based on the results obtained from 13C NMR spectroscopy and TG/DTA, the state and amount of TMA+ in the solid product were examined. In addition, the influences of temperature, alkalinity and amount of TMA+ in the starting gels were studied.

Phenyl(chloro)dithioformate is treated with pyrazole derivatives and phenyl(Pz-1-carbodithioate) ligands (Pz = pyrazole (1), 3-methylpyrazole (2), and 3,5-dimethylpyrazole (3)) are obtained. These ligands are treated with PdCl2 in acetonitrile and complexes of the general formula Pd(L)Cl2 form in an essentially quantitative yield. The ligands are found to be N,S-bidentate linkers, and 5-membered palladacycles are obtained. Precursors 1–3 are oily materials and characterized by 1H and 13C NMR spectroscopy. Due to a partial solubility of Pd complexes, the complete set of NMR data cannot be collected. The structural elucidation is also accompanied by elemental and mass spectrometric analyses. Solid-state structures of complexes 5 and 6 are determined by X-ray diffraction. The data obtained for complexes 5 and 6 are also calculated by DFT using the TURBOMOLE program package. Experimental and calculated data sets are found to be in close agreement with each other.

Protonation pathways of 2-amino-4-benzylsulfanyl-6-methylpyrimidines have been investigated by means of semiempirical PM3 quantum-chemical simulation, 13C NMR spectroscopy, and single-crystal diffractometry methods. In the gas phase and in the bipolar aprotic solvent, the protonation involves the N1 atom. The protonation in the crystalline state is characterized by the formation of a branched system of H-bonds, involving the protons of the amino group besides the mentioned nitrogen atom.

The five coumarin derivatives 3-(1-(2-hydroxypropylamino)ethylidene)-chroman-2,4-dione (L1), 3-(1-(phenylamino)ethylidene)-chroman-2,4-dione (L2), 3-(1-(o-toluidino)ethylidene)-chroman-2,4-dione (L3), 3-(1-(m-toluidino)ethylidene)-chroman-2,4-dione (L4), 3-(1-(2-mercaptoethylamino)ethylidene)-chroman-2,4-dione (L5) and its corresponding complexes 3-(1-(2-hydroxypropylamino)-ethylidene)-chroman-2,4-dione-palladium(II) (C1), 3-(1-(phenylamino)-ethylidene)-chroman-2,4-dione-palladium(II) (C2), 3-(1-(o-toluidino)-ethylidene)-chroman-2,4-dione-palladium(II) (C3), 3-(1-(m-toluidino)ethylidene)-chroman-2,4-dione-palladium(II) (C4), 3-(1-(2-mercaptoethylamino)ethylidene)-chroman-2,4-dione-palladium(II) (C5), were synthesized and characterized with microanalysis, infrared, 1H and 13C NMR spectroscopy. The proposed structures of ligands L3 and L4 were confirmed on the basis of the X-ray structural study. The ligands and their complexes were tested for their in vitro antimicrobial activity against 17 species of bacteria and fungi. Testing is performed by the microdilution method, with the minimum inhibitory concentration (MIC) and the minimum microbicidal concentration (MMC) being determined.

The O-polysaccharide (O-antigen) of Escherichia coli SDLZB008 was isolated from the lipopolysaccharide and studied by sugar analyses along with 1H and 13C NMR spectroscopy. The following structure of the branched pentasaccharide repeating unit was established, which is unique among the known structures of bacterial polysaccharides: The O-antigen gene cluster of E. coli SDLZB008 has been sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in full agreement with the O-polysaccharide structure.

Water-soluble organic matter (WSOM) in air particles has profound effects on climate and human health. At the heart of this environmental significance of WSOM lies a complex set of compounds, of which a major fraction still often remains undeciphered. Yet, not all environmental problems require delving into the molecular-level identification of WSOM constituents. Understanding the contribution of different functional groups to whole aerosol WSOM composition offers a highly important structural dataset that enables a better representation of WSOM in climate studies. For the first time, advanced solid-state 13C nuclear magnetic resonance (NMR) techniques, including nearly quantitative 13C multiple cross polarization/magic angle spinning (multiCP/MAS), multiCP/MAS with dipolar dephasing, multiCP/MAS with 13C chemical shift anisotropy filter, and two-dimensional 1H−13C heteronuclear correlation (2D HETCOR), are applied to acquire an accurate quantitative structural description of whole aerosol WSOM collected in an urban atmosphere. Two urban aerosol WSOM samples collected in two short periods of time, under different wintry weather conditions, were investigated. NMR data successfully pinpointed the variability of whole aerosol WSOM composition, allowing to suggest source-specific structural characteristics for each sample in two short periods of time. A new structural model of urban aerosol WSOM was build based on this compositional data, showing the presence of three independent classes of compounds that vary both in content and molecular diversity within short periods of time: heteroatom-rich aliphatic (either chain or branched), carbohydrate-like moieties, and highly substituted aromatic units. These findings establish advanced solid-state NMR as a promising tool for probing the chemical structures of inhomogeneous aerosol WSOM in rapidly changing atmospheric conditions, allowing to resolve discrepancies between modeled and measured aerosol WSOM. Fulbright Scholar Program; NSF (Award No. 1726346). published

Bacillus aryabhattai GYC2-3 strain, capable of synthesizing EPS, was isolated from the rhizosphere of Taraxacum spp. plant. The EPS was identified as levan by C-13 NMR spectroscopy and methylation analysis. The levan produced had a high weight average molecular weight of 5.317 x 10(7) Da and degree of branching 5.19%. Thin layer chromatography and high-performance anion-exchange chromatography revealed that it is capable of producing broad range of fructooligosaccharides (FOS) and higher levels of FOS synthesis were observed with increasing sucrose concentrations. The optimum temperature, initial pH and sucrose concentration for levan biosynthesis were studied to be 30 degrees C, 8.0 and 250 g/L, respectively. Levan production was increased by similar to 38% (26 g/L) when provided aeration as compare to static cultures. To the best of our knowledge, this is the first report on biosynthesis of levan and FOS by a B. aryabhattai strain.

Polar soils play a key role in global carbon circulation and stabilization as they contain maximum stocks of soil organic matter (SOM) within the whole pedosphere. Cold climate and active layer dynamics result in the stabilization of essential amounts of organic matter in soils, biosediments, and grounds of the polar biome. Chemical composition of soil organic carbon (SOC) determines its decomposability and may affect soil organic matter stabilization (SOM) rate (Beyer, 1995). This is quite important for understanding variability in SOC pools and stabilization rate in context of changes in plant cover or climate (Rossi et al. 2016). 13C nuclear magnetic resonance spectroscopy, which provides detailed information on diversity of structural composition of humic acids and SOM, may also be used to study the SOM dynamics under decomposition and humification proceses (Kogel-Knabner, 1997; Zech et al., 1997). This study aims to characterize molecular organization of the humic acids, isolated from various permafrost-affected soils of Yamal region and to assess the potential vulnerability of soils organic matter in context of possible mineralization processes. Organic carbon stocks for studied area were 7.85 ± 2.24 kg m-2 (for 0-10 cm layer), 14.97 ± 5.53 kg m-2 (for 0-30 cm), 23.99 ± 8.00 kg m-2 (for 0-100 cm). Results of solid-state 13C-NMR spectrometry showed low amounts of aromatic components in studied soils. All studied humic powders are characterized by predominance of aliphatic structures, and also carbohydrates, polysaccharides, ethers and amino acids. High content of aliphatic fragments in studied humic acids shows their similarity fulvic acids. Low level of aromaticity reflects the accumulation in soil of lowly decomposed organic matter due to cold temperatures. Our results provide further evidence of high vulnerability and sensitivity of permafrost-affected soils organic matter to Arctic warming. Consequently, these soils may play a crucial role in global carbon balance under effects of climate warming.

The reaction of 3-formylchromones and 4-((2-aminophenyl)imino)-2,6-di‑tert-butylcyclohexa-2,5-dienone gave a series of N-substituted benzimidazole derivatives, characterized by 1H and 13C NMR spectroscopy, mass spectrometry and elemental analysis. The molecular structures of compounds 1 and 4 were determined by single crystal X-ray diffraction studies. Compounds 1–8 exhibit cytotoxic activity against human colon cancer cells HCT116 and breast cancer cells MCF7 at submicromolar concentrations. Compound 6 is more active against tumor cells than non-malignant fibroblasts. Compounds 1, 3, 5 and 7 exhibit antioxidant activity comparable to the reference drug Trolox.

A two-stage scheme was proposed for the synthesis of alkoxy derivatives of the closo-decaborate anion [B10H9(OR)]2–, where R = C2H5, iso-C3H7, C4H9. At the first stage, the oxonium derivatives with the general formula [B10H9(OR2)]– were synthesized by the reaction between the [B10H11]–anion and acyclic ethers. At the second stage, the synthesized oxonium derivatives reacted with hydrazine hydrate to form the alkoxy derivatives with the general formula [B10H9(OR)]2–, where R = C2H5, iso-C3H7, C4H9. This approach appreciably increased the yield of target products and simplified their separation. The alkoxy derivatives were separated and characterized by IR and 1H, 11B, and 13C NMR spectroscopy.

In this series, six new 2-substituted 5-arylsulfonyl-1,3-oxazole-4-carbonitriles were synthesized and characterized by IR, 1H NMR, 13C NMR spectroscopy, elemental analysis and chromato-mass-spectrometry. The anticancer activities of the compounds were evaluated via single high dose (10−5M) against 60 cancer cell lines by the National Cancer Institute according to its own screening protocol. In the next phase, the compounds have been selected for five-dose assay. All synthesized compounds displayed growth inhibitory (GI50) and cytostatic activities (TGI) against the most sensitive cell lines at submicromolar (0.2–0.6 μM) and micromolar concentrations (1–3 μM), respectively. Cytotoxic activity (LC50) of these compounds, with the exception of 4d, against the most sensitive cell lines was also high (5–6 μM). All compounds exhibit high selectivity towards leukemia cell lines, and among them, 4e and 4f showed the best antiproliferative and cytostatic selectivity. Compounds 4c and 4f displayed considerable cytotoxic selectivity towards the renal and breast cancer subpanels. Our results provided evidence for anticancer activities of novel 2-substituted 5-arylsulfonyl-1,3-oxazole-4-carbonitriles which could be useful for developing new anticancer drugs. These substances could also be used as an excellent framework in anticancer research that may lead to discovery of potent antitumor agents.

Structure of the O-polysaccharide (O-antigen) of Escherichia coli O60 was studied by sugar analysis, partial solvolysis with CF3CO2H, and 1D and 2D 1H and 13C NMR spectroscopy. The O-polysaccharide was found to consist of D-galactose and L-rhamnose. The structure of its branched tetrasaccharide repeating unit was established, which is unique among known bacterial polysaccharide structures.

Recent global demand of polyethylene was 187 billion pounds with 23% being low density polyethylene (LDPE). LDPE is used in a variety of applications including liners, consumer bags, heavy duty sac...

A capsular polysaccharide (CPS) was isolated from strain MAR13-1452 of an emerging pathogen Acinetobacter baumannii and assigned type K125. The following structure of the CPS was established by sugar analysis, Smith degradation, and 1D and 2D 1H and 13C NMR spectroscopy: Proteins encoded by the KL125 gene cluster in the genome of MAR13-1452, including three glycosyltransferases, were assigned roles in the biosynthesis of the K125 CPS.

New Mannich bases were synthesized by reacting bicyclo[2.2.1]hept-5-en-2-ylmethanol with secondary amines and formaldehyde. Physicochemical characteristics, composition and structure of the synthesized compounds were determined by elemental analysis, IR, 1H, 13C NMR spectroscopy and mass spectrometry.

The leaves and stem of Zanthoxylum lepreurii were collected in two localities of Cote d’Ivoire, namely San-Pedro (South-east) and Adzope (South). The collects were submitted to hydrodistillation with the Clevenger apparatus. The oils obtained were investigated by 13C NMR spectroscopy, GC (RI) and GC-MS. Thus, twenty-eight components accounting for 90.9-96.8% were identified. Essential oils from leaves and stem bark of Z. leprieurii exhibited the predominance of two acyclic ketones. Undecan-2-one and tridecan-2-one have been identified as the main components. Undecan-2-one was found in abundance in the stem (30.3%) and the leaves (10.0%) respectively in Adzope and San-Pedro, while tridecan-2-one characterized all the samples (15.5%-77.2%). In addition with monoterpenoids and sesquiterpenoids identified as major components led to the new chemotypes of Z. leprieurii essential oil.

Analysis of carbonyl and β-CH2 signals in the 100 MHz 13C NMR spectra of poly(methyl methacrylate-co-n-propyl acrylate) (PMMA/nPrA), provided distribution of configurational-compositional s...

A series of indole-containing γ-aminobutyric acids (GABA) were synthesized via alkaline hydrolysis of 4-(indol-3-yl)-2-pyrrolidones. Their structures were confirmed by IR, PMR, and 13C NMR spectroscopy. Studies of the pharmacological properties of 4-amino-3-indolylbutanoic acids (GABA derivatives) showed that they possessed neuropsychotropic activity, the spectrum of which depended on the acid molecular structure. Nootropic properties prevailed for 4-amino-3-(indol-3-yl)butanoic acid; anxiolytic activity, for 4-amino-3-(1-benzylindol-3-yl)butanoic acid.

Studying C functional group distributions in decomposing litterfall samples is one of the common methods of studying litterfall decomposition processes. However, the methods of studying the C functional group distributions, such as 13C NMR spectroscopy, are expensive and time consuming and new rapid and inexpensive technologies should be sought. Therefore, this study examined whether laboratory-based hyperspectral image analysis can be used to predict C functional group distributions in decomposing litterfall samples. Hyperspectral images were captured from ground decomposing litterfall samples in the visible to near infrared (VNIR) spectral range of 400–1000 nm. Partial least-square regression (PLSR) and artificial neural network (ANN) models were used to correlate the VNIR reflectance data measured from the litterfall samples with their C functional group distributions determined using 13C NMR spectroscopy. The results showed that alkyl-C, O,N-alkyl-C, di-O-alkyl-C1, di-O-alkyl-C2, aryl-C1, aryl-C2 and carboxyl derivatives could be acceptably predicted using the PLSR model, with R2 values of 0.72, 0.73, 0.71, 0.74, 0.76, 0.75 and 0.63 and ratio of prediction to deviation (RPD) values of 1.86, 1.82, 1.78, 1.71, 1.90, 1.76 and 1.43, respectively. Predicted O,N-alkyl-C, di-O-alkyl-C1, di-O-alkyl-C2, aryl-C1 and aryl-C2 using the ANN model provided R2 values of 0.62, 0.68, 0.69, 0.82 and 0.67 and the RPDs of 1.54, 1.76, 1.52, 2.10 and 1.72, respectively. With the exception of aryl-C1, the PLSR model was more reliable than the ANN model for predicting C functional group distributions given limited amount of training data. Neither the PLSR nor the ANN model could predict the carbohydrate-C and O-aryl-C acceptably. Overall, laboratory-based hyperspectral imaging in combination with the PLSR modelling can be recommended for the analysis of C functional group distribution in the decomposing forest litterfall samples.

A novel functional [2]rotaxane containing two alkenyl bonds was designed, synthesized and characterized by 1H, 13C NMR spectroscopy and HRESI mass spectrometry. The introduction of alkenyl bonds endowed the [2]rotaxane a fascinating ability to react with versatile functional groups such as alkenyl and thiol functional groups. The reversible shuttling movement of the macrocycle between two different recognition sites on the molecular thread can be driven by external acid and base. This kind of rotaxane bearing functional groups provides a powerful platform for preparing stimuli-responsive polymers.

Thermolysis of mono metal carbonyl fragment, [M′(CO)5·thf, M′ = Mo and W, thf = tetrahydrofuran] with an in situ generated intermediate, obtained from the reaction of [Cp*MCl4] (M = Mo and W, Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl) with [LiBH4·thf], yielded dimetallaboranes, 1 and 2. Isolations of [{Cp*M(CO)}2B4H6] (M = Mo (1) and W(2)) provide direct evidence for the existence of saturated molybdaborane and tungstaborane clusters, [(Cp*M)2B4H10]. Our extensive theoretical studies together with the experimental observation suggests that the intermediate may be a saturated cluster [(Cp#M)2B4H10], not unsaturated [(Cp#M)2B4H8] (Cp# = Cp or Cp*), which was proposed earlier by Fehlner. Furthermore, in order to concrete our findings, we isolated and structurally characterized analogous clusters [(Cp*Mo)2(CO)(μ-Cl)B3H4W(CO)4] (3) and [(Cp*WCO)2(μ-H)2B3H3W(CO)4] (4). All the compounds have been characterized by solution-state 1H, 11B, IR, and 13C NMR spectroscopy, mass spectrometry, and the structural archi...

Five new substituted benzamide derivatives as ionic solids are prepared and characterized by FT-IR, 1H, and 13C NMR spectroscopy. The crystal structure for compound 2 is determined by X-ray crystallography. The compounds are bio-assayed for their bactericidal, fungicidal, anti-oxidant, and urease inhibition activities. The molecular docking results accumulated for the compounds correlate with their biological activity and reveal high binding affinity towards jack bean urease.

While no alkylidene complexes of the f elements are known, the use of phosphorano-stabilized carbene complexes to produce short actinide–carbon bonds has been previously demonstrated. Complexes of the form, (C5Me5)2An(X)(CHPPh3), with short thorium(IV)– and uranium(IV)–carbon(carbene) bonds have been synthesized from the reaction of (C5Me5)2An(X)(CH3) (An = Th, U; X = Cl, Br, or I) with the ylide, CH2═PPh3. The resulting uranium complexes feature the shortest uranium(IV)–carbon bonds reported to date. The molecular and electronic structure of the thorium phosphorano-stabilized carbene complexes is detailed using X-ray crystallography, 13C NMR spectroscopy, and density functional theory calculations, and compared to thorium methandiide complexes.

WOS: 000428972900046 In this work 2-(bis(cyanomethyl)amino)-2-oxoethyl methacrylate monomer has been synthesized as newly, characterized both experimentally and theoretically. Experimentally, it has been characterized by FT-IR, FT-Raman, H-1 and C-13 NMR spectroscopy techniques. The theoretical calculations have been performed with Density Functional Theory (DFT) including B3LYP method. The scaled theoretical wave numbers have been assigned based on total energy distribution (TED). Electronic properties of monomer have been performed using time-dependent TD-DFT/B3LYP/B3LYP/6-311G++(d,p) method. The results of experimental have been compared with theoretical values. Both experimental and theoretical methods have shown that the monomer was suitable for the literature. (C) 2018 Elsevier B.V. All rights reserved. Ahi Evran University Scientific Project Unit (BAP)Ahi Evran University [PYO-FEN.4001.15.012] This work was supported by Ahi Evran University Scientific Project Unit (BAP) with, Project No: PYO-FEN.4001.15.012.

In this study, new quaternary bis(ammonium) salts with alkyl-1,X-bis(dimethyldecylammonium) cation and saccharinate, acesulfamate, lactate and pyroglutamate anions were synthesized and characterized by 1H and 13C NMR spectroscopy. Thermal gravimetric and differential scanning calorimetry analyses confirmed that all salts were thermally stable and the majority of them exhibited melting points below 100 °C. The physicochemical properties (viscosity, density, refractive index values, and solubility) of the obtained salts were determined for three compounds with lactate anions. All the tested salts have suitable properties which, in practical application, will reduce the losses caused by the most important storage insects. Most of the synthesized ionic liquids had comparable or better deterrent activity than azadirachtin—an alkaloid known as the most active antifeedant. Graphical abstract Electronic supplementary material The online version of this article (10.1007/s11696-018-0495-6) contains supplementary material, which is available to authorized users.

Preparative procedures for the synthesis of N1,N1,N3,N3-tetrasubstituted diethylenetriamines via aminoalkylation of N,N-disubstituted ethylenediamines with N,N-disubstituted 2-chloroethylamines were developed. Aminoalkylation of N,N-dimethylethylenediamine under heating gave simultaneously secondary N1,N1,N3,N3-tetrasubstituted diethylenetriamines and quaternary ammonium salts, N-(2-aminoethyl)-N-(2-dialkylaminoethyl)-N,N-dimethylammonium chlorides. Structures of the synthesized compounds were established by IR spectroscopy, 1H and 13C NMR spectroscopy, and electrospray ionization mass spectrometry.

The O-polysaccharide was isolated from the lipopolysaccharide of a marine bacterium Pseudomonas glareae KMM 9500T and studied by chemical methods along with 1D and 2D 1H and 13C NMR spectroscopy including 1H,1H-TOCSY, 1H,1H-COSY, 1H,1H-ROESY, 1H,13C-HSQC and 1H,13C-HMBC experiments. The O-polysaccharide was found to consist of linear tetrasaccharide repeating units constituted by D-glucuronic acid (D-GlcA), L-rhamnose (L-Rha), D-glucose (D-Glc) and 5-acetamido-7,9-O-[(S)-1-carboxyethylidene]-3,5-dideoxy-L-glycero-L-manno-non-2-ulosonic acid (Sug7,9(S-Pyr)), partially O-acetylated at position 8 (∼70%): →4)-α-D-GlcpA-(1→3)-β-L-Rhap-(1→4)-β-D-Glcp-(1→4)-β-Sugp8Ac(∼70%)7,9(S-Pyr)-(2→.

The new flavanonol glycoside (2S,3S)-3,5-dihydroxy-2-(4′-hydroxyphenyl)-8-(3-methylbut-2-en-1-yl)-4-oxo-3,4-dihydro-2H-chromen-7-yl-β-D-glucopyranosyl-(3→1)-xylopyranoside (lavaloside) (1) and the known compound phellamurin (2) were isolated from leaves of Phellodendron lavallei. The structures of the flavanone glycosides were elucidated using chemical transformations and UV, PMR, and 13C NMR spectroscopy combined with HSQC, HMBC, COSY, and DEPT experiments and mass spectroscopy.

The structure of 5,5-bis(bromomethyl)-2-methyl-2-phenyl-1,3-dioxane 1 has been studied by means of 1H and 13C NMR spectroscopy as well as X-ray diffraction analysis. The molecules of compound 1 exist in the chair conformation with the axially oriented phenyl group. The computer simulation using DFT approximation at the PBE/3ξ level has revealed the route of interconversion of the ring and the optimal conformation of the phenyl group corresponding to the data of X-ray diffraction analysis.

Technological progress and high market demand contributed to a significant interest in the production of fertilizers based on humic acids. The aim of this study was to evaluate the possibilities of using humic acids obtained from lignite in the production of new commercial products. For this purpose, it is necessary to determine the quality standard requirements for such material. Properties of humic acids depend on source of origin as well as method of its extraction. The humic acids were extracted from polish deposit of lignite–Sieniawa Lubuska by alkaline extraction using for this purpose six kinds of extractants: 0.1 M NaOH and 0.25 M NaOH, 0.1 M KOH and 0.25 M KOH, and 0.1 M Na4P2O7 and 0.25 M Na4P2O7. The humic samples were used in solid powder form and characterized by UV-Vis spectroscopy, 13C NMR spectroscopy, fluorescence spectroscopy, and thermal analysis. The determining factor influencing a degree of humic acids extraction from lignite and their structure is type of extractant. The largest efficiency of extraction (about 50%) was obtained with the use of NaOH solutions. All examined humic acids were generally characterized by simple and heterogeneous molecularly structure with low molecular weight and low aromatic polycondensation. Therefore, it can be concluded that humic acids extracted with NaOH and KOH solutions are less condensed than those extracted with Na4P2O7 solutions. It can suggest that humic acids obtained from lignite using solutions of Na4P2O7 are characterized by a low transformation degree and greater amount of carboxyl groups. Low rank coal can be successfully used in agriculture as a rich source of humic acids. Reagent used in their extraction, apart from high efficiency should have a neutral impact on their structure. Studies on the physicochemical properties of humic acids can be helpful in predicting behaviors of such fertilizer components in the environment and in inventing new products taking the principles of sustainable development into consideration.

The aim of the study is to evaluate the interaction of amphoteric polymer resins with cellulose fibers at the molecular level.The interaction of amphoteric polymer resins with cellulose fragments was determined by standard 1H NMR and 13C spectroscopy techniques.To study the interaction of amphoteric polymeric resins with cellulose at the molecular level, imitation modeling has been carried out in the work. The essence of the simulation is the replacement of cellulose fibers with substances that are close to the functional purpose of cellulose. Such substances include glucose, sucrose, starch and ethylene glycol, which dissolve in water. It is established that in the presence of a large amount of water in the APS – waste paper system, intermolecular and interfluid hydrogen bonds are formed, and upon reaching a critical amount of water in the system, new covalent ether-type bonds are formed between the functional groups of the components as model systems and amphoteric polymeric systems resin - cellulose and this indicates the possibility of increasing the physical and mechanical properties of paper and paperboard from secondary raw materials.The results show that simulation simulation of structural and functional transformations in complex systems, including the cellulose-APS system, confirms the presence in them of processes that occur during the interaction of amphoteric polymeric resins with hydroxyl groups of cellulose fibers, Цель исследования заключается в оценке процесса взаимодействия амфотерных полимерных смол (АПС) с волокнами целлюлозы на молекулярном уровне.По стандартным методикам ЯМР 1Н и 13С-спектроскопии определено взаимодействие АПС с фрагментами целлюлозы.С целью изучения взаимодействия амфотерной полимерной смолы (АПС) с целлюлозой на молекулярном уровне в работе проведено их имитационное моделирование. Суть имитационного моделирования заключается в замене целлюлозных волокон на вещества, близкие по функциональному назначению к целлюлозе. К таким веществам относятся глюкоза, сахароза, крахмал и этиленгликоль, которые растворяются в воде. Установлено, что при наличии большого количества воды в системе АПС – волокна макулатуры образуются межмолекулярные и межфрагментные водородные связи, а при достижении в системе критического количества воды происходит образование новых ковалентных связей эфирного типа между функциональными группами компонентов модельных систем и системы АПС – целлюлоза, что свидетельствует о возможности повышения физико-механических показателей бумаги и картона из вторичного сырья.Полученные результаты показывают, что имитационное моделирование структурно-функциональных преобразований в сложных по природе системах, к которым относится система целлюлоза – АПС, подтверждает наличие в них процессов, которые происходят при взаимодействии АПС с гидроксильными группами целлюлозных волокон.

International audience; Four terpyridine ligands containing different aryl substituents 4'-(4-quinolinyl)-3,2':6′,3″-terpyridine (3-qtpy), 4'-(4-quinolinyl)-2,2':6′,2″-terpyridine (2-qtpy), 4'-(3-methyl-2-thienyl)-4,2':6′,4″-terpyridine (4-stpy) and 4'-(3-methyl-2-thienyl)-2,2':6′,2″-terpyridine (2-stpy) were synthesized in a one-pot procedure and characterized by elemental analysis, FT-IR and 1H- and 13C NMR spectroscopy. Additionally, the 2-stpy structure was confirmed by single crystal X-ray diffraction analysis. The influence of the N-position in the tpy and aryl substituents on the photophysical properties was systematically investigated by spectroscopic methods and simulated by density functional theory (DFT and TD-DFT) calculations. Thermal stability was observed until about 280 °C, making these kind of ligands interesting candidates for their use as complex ligands, which are obtained by solvothermal synthesis under temperatures of about 180 °C. The electrochemical behavior was also investigated. All molecules show irreversible anodic and cathodic voltammetric peaks in organic medium.

We investigated the influence of functionalization strategy (post- or pre-) on the structure of amino-modified porous aromatic frameworks (PAF-NH2). Different techniques, such as low-temperature N2 adsorption-desorption, IR spectroscopy and solid-state CP-MAS 13C NMR spectroscopy, were used to characterize the synthesized materials. Palladium catalysts were prepared based on obtained PAF-NH2 supports, characterized by TEM, XPS and elemental analysis and studied in the semihydrogenation of C8-acetylenes and dienes. The results show that the modification approach influences structure of PAF and, therefore, the morphology and distribution of palladium nanoparticles. Post-modified catalysts proved to be more active, while pre-modified ones exhibited enhanced selectivity towards desired olefins and improved stability.