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We used 1H, 13C HRMAS and genomic analysis to investigate regionally the transition from oxidative to glycolytic phenotype and its relationship with altered gene expression in adjacent biopsies through the brain of rats bearing C6 gliomas. Tumor-bearing animals were anesthetized and infused with a solution of [1-13C]-glucose, and small adjacent biopsies were obtained spanning transversally from the contralateral hemisphere (regions I and II), the right and left peritumoral areas (regions III and V, respectively), and the tumor core (region IV). These biopsies were analyzed by 1H, 13C HRMAS and by quantitative gene expression techniques. Glycolytic metabolism, as reflected by the [3-13C]-lactate content, increased clearly from regions I to IV, recovering partially to physiological levels in region V. In contrast, oxidative metabolism, as reflected by the [4-13C]-glutamate labeling, decreased in regions I-IV, recovering partially in region V. This metabolic shift from normal to malignant metabolic phenotype paralleled changes in the expression of HIF1α, HIF2α, HIF3α genes, downstream transporters, and regulatory glycolytic, oxidative, and anaplerotic genes in the same regions. Together, our results indicate that genetic and metabolic alterations occurring in the brain of rats bearing C6 gliomas colocalize in situ and the profile of genetic alterations in every region can be inferred from the metabolomic profiles observed in situ by multinuclear HRMAS., The present work was supported by grants SAF2014-53739-R, SAF2017-83043-R, and B2017/BMD-3688 from the Ministry of Economy and Competitiveness and from the Community of Madrid to PL-L and SC, Acciones Integradas IH-HI2006-0101 from the Ministry of Science and Technology to L.S. and S.C. The authors are indebted to Mr. Javier Pérez CSIC for careful drafting of the illustrations and to Mrs. Teresa Navarro CSIC for granting access to the Biomedical NMR Services of the Institute of Biomedical Research “Alberto Sols” CSIC.

High Resolution Magic Angle Spinning (HR-MAS) is an NMR technique that can be applied to semi-solid samples. Flavedo, albedo, pulp, seeds, and oil gland content of lemon and citron were studied through HR-MAS NMR spectroscopy, which was used directly on intact tissue specimens without any physicochemical manipulation. HR-MAS NMR proved to be a very suitable technique for detecting terpenes, sugars, organic acids, aminoacids and osmolites. It is valuable in observing changes in sugars, principal organic acids (mainly citric and malic) and ethanol contents of pulp specimens and this strongly point to its use to follow fruit ripening, or commercial assessment of fruit maturity. HR-MAS NMR was also used to derive the molar percentage of fatty acid components of lipids in seeds, which can change depending on the Citrus species and varieties. Finally, this technique was employed to elucidate the metabolic profile of mold flavedo.

HR-MAS NMR spectroscopy was employed to monitor the metabolic profiles of Modena BioBank breast samples over 1 year of freezing at -80 A degrees C. The study includes 22 adult female patients living in Modena and its hinterland, who underwent total mastectomy or quadrantectomy in 2011-2012. Variations occur, especially affecting phosphocholine (PC) and choline. This is not a trivial finding, since many studies base the distinction between neoplastic and healthy tissues or the assessment of tumor grade on the analysis of choline metabolites. Despite the changes observed, we established that the diagnostic power of the HR-MAS NMR spectra of frozen samples is preserved, at least as far as the distinction between neoplastic and healthy samples is concerned. Lactate (Lac), PC, phosphoethanolamine (PE), taurine (Tau), myo-inositol (Myo) and glucose (Glc) are biomarkers that can be used to distinguish healthy from neoplastic tissues, whereas some metabolite ratios, such as Lac + PE + Tau/Glc + Myo, seem to have even higher discrimination potential.

A combination of van der Waals and electrostatic interactions was used to integrate SWNT and a suitably functionalized polythiophene into nanostructured ITO electrodes. In the resulting electron donor/acceptor nanocomposites, polythiophene represents the light-harvesting chromophore that readily donates an excited-state electron to the ground-state electron-accepting SWNT. Upon illumination, monochromatic incident photoconversion efficiencies between 1.2 and 9.3% were determined for single and eight-sandwiched layers, respectively.

This review reports the synthesis and the properties of chiral polythiophenes (PTs) and in particular it is focused on PTs bearing a sulfur atom directly bonded to the thiophene ring. These polymers show remarkable properties, related to their chirality and electrical conductivity and to the ability to interact with chiral molecules opening the possibility for using them in new potential applications, like chiral sensors, chiral resolution and electrodes.

This study describes for the first time the use of high-resolution nuclear magnetic resonance (NMR) on Klamath (Aphanizomenon flos-aquae, AFA) blue-green algae directly on powder suspension. These algae are considered to be a “superfood”, due to their complete nutritional profile that has proved to have important therapeutic effects. The main advantage of NMR spectroscopy is that it permits the detection of a number of metabolites all at once. The Klamath alga metabolome was revealed to be quite complex, and the most peculiar phytochemicals that can be detected directly on algae by NMR are mycosporine-like amino acids (porphyra-334, P334; shinorine, Shi) and low molecular weight glycosides (glyceryl β-d-galactopyranoside, GalpG; glyceryl 6-amino-6-deoxy-α-d-glucopyranoside, ADG), all compounds with a high nutraceutical value. The presence of cis-3,4-DhLys was revealed for the first time. This molecule could be involved in the anticancer properties ascribed to AFA.

We present the synthesis and characterization of a novel copolymer from benzodithiophene and alkylsulfanyl-bithiophene units, poly[4,8-bis(2-ethylhexyloxy)benzo[1,2-b:4,5-b′]dithiophene-alt-4,4′-bis(octylsulfanyl)-2,2′-bithiophene] (PolyS). The structural, electrochemical and photophysical properties of PolyS were investigated by gel permeation chromatography (GPC), thermogravimetric analysis (TGA), NMR, UV–vis, photoluminescence (PL) spectroscopy and cyclic voltammetry (CV). PolyS was used to fabricate bulk-heterojunction polymer solar cells (PSCs) in combination with the [60]PCBM and [70]PCBM (electron acceptors). The device realized using [70]PCBM shows a better current output due to the increased absorption of the blend film compared to the PolyS:[60]PCBM one. The power conversion efficiency of the best PSC realized is 2.3% under 100 mW/cm2 AM 1.5 G illumination.

The water-soluble poly{trimethyl-[7-(3-thienylsulfanyl)heptyl]ammonium iodide-co-thiophene} (PTN+Me3) forms aggregates whose size span a large range of values, depending on solvent, concentration and film formation conditions. Larger aggregates were detected by atomic force microscopy and dynamic light scattering, smaller ones by DOSY NMR, UV–visible and fluorescence. All techniques indicate a reduced aggregation of PTN+Me3 in DMSO relative to water and a marked de-aggregation of PTN+Me3 in water following addition of bile-acid anions such as deoxycholate and ursodeoxycholate. The latter effect shows itself through a very large enhancement of the polymer photoluminescence likely caused by disruption of aggregated non-emissive exciton traps. A tailored combination of electrostatic and hydrophobic interactions between the polymer and the bile-acid anions seems to be necessary to achieve this effect. These observations suggest that this polythiophene might provide a basis for the development of fluorescent sensors suitable for the detection of medium-sized amphiphilic biomolecules.

The charge-transfer and spectral properties of two octithiophenes, namely 4',4''',3'(v),3(v)'-tetra(octylsulfanyl)-2,2':5',2'':5'',2''':5''',2'(v):5'(v),2(v):5(v),2(v)':5(v)',2(v)''-octithiophene and 4,3'',4(v),4(v)''-tetrabromo-4',4''',3'(v),3(v)'-tetra[(R)-2-methylbutylsulfanyl]-2,2':5',2'':5'',2''':5''',2'(v):5'(v),2(v):5(v),2(v)':5(v)',2(v)''-octithiophene, OT1 and OT2, respectively, are characterized by cyclic voltammetry and spectroelectrochemistry under ultradry conditions. The analysis of the voltammetric results shows the formation of up to the dication for both OT1 and OT2 and up to the tetraanion (OT1) and trianion (OT2) anions. The optical properties of the OT1 (2+, 1+, neutral, 1-, 2-) species were probed by in situ UV-vis-NIR spectroelectrochemistry. The calculated standard potentials at the B3LYP/cc-pVTZ level of the theory allowed the rationalization of the experimental electrochemical results. The UV-vis-NIR spectra were successfully compared with the theoretical electronic transitions and oscillator strength data obtained by time-dependent B3LYP/6-31G* calculations. Theoretical redox potentials and optical transitions properties are calculated including "the solvent effect" within the CPCM model. The consistency obtained between experimental and theoretical results indicates the existence of the hypothesized high-spin/high-charge p- and n-doped electronic states for the OT1 and OT2 octithiophenes here studied.

Starting from 4-(octylsulfanyl)-2,2‘-bithiophene, 4-bromo-4‘-(octylsulfanyl)-2,2‘-bithiophene, 4-iodo-4‘-(octylsulfanyl)-2,2‘-bithiophene, 4-bromo-4‘-[(S)-2-methylbutylsulfanyl]-2,2‘-bithiophene, and 4-iodo-4‘-[(S)-2-methylbutylsulfanyl]-2,2‘-bithiophene, a new series of symmetrically β-substituted octithiophenes were synthesized by one-pot oxidative coupling with FeCl3. The octithiophenes obtained are soluble in common organic solvents and show different solvatochromic properties depending on the substitution type. In particular, the bromine atom exerts a positive influence on the supramolecular organization: the brominated octithiophenes display high filmability, solvatochromism, and CD induced by aggregation (when the chiral 2-methylbutylsulfanyl group is present), properties usually observed for polythiophenes. Density functional theory (DFT) calculations were carried out an a model bithiophene (4-substituted with a methylsulfanyl group) in order to understand the possible mechanism of the growth, th...

Different routes, based on the Stille coupling, to the obtainment of a polythiophene bearing a carboxyhexylsulfanyl chain every two thiophene rings (PTCOOH) are here reported and discussed. Two PTCOOHs with different chain lengths were obtained: the shorter by hydrolysis of a polymeric ester precursor and the longer by direct Stille coupling from suitable monomers. They possess similar electrochemical properties but behave differently when aggregation and fluorescence are concerned. The PTCOOH obtained by hydrolysis is found to be fluorescent in a good solvent such as THF, and its fluorescence quantum yield decreases as the extent of aggregation increases. The polymer obtained by direct Stille coupling is less fluorescent, consistently with its proneness to aggregate. The PTCOOH obtained by hydrolysis is therefore more promising in view of the build-up of solid-state devices with exploitable fluorescence properties.

Plant regeneration is a critical step in most in vitro breeding techniques. This paper studies the effects of a low-molecular-weight humic acid (HA) on morphogenesis from pear and quince leaf explants. Variable HA amounts [0 (control), 1, 5, 10, and 20 mg C L(-1)] were added to the regeneration media. A dose-response effect was observed in pear for root and shoot production; it was improved at HA 1 mg C L(-1) and considerably reduced at the highest amounts. HA was, instead, ineffective in quince. The (1)H HR-MAS NMR analyses of calli in the induction phase showed more evident metabolite (asparagine, alanine, and γ-aminobutyric acid) signals in quince than in pear. The assignment of overlapped signals in both genotypes was supported by the 2D NMR analyses. Spectroscopic characterization suggested also an enhancement of asparagine contents in morphogenic calli of pear with respect to the control and higher HA amount treatments.

The synthetic approach to methyl N-(tert-butoxycarbonyl)- S-(3-thienyl)-L-cysteinate (1) and methyl N-(tert-butoxycarbonyl)- S-[2-(3-thienyl)ethyl]-L-cysteinate (2) through tosylate intermediates is reported and discussed. These compounds, which combine the properties of the cysteine side-chain with those of the thiophene ring represent both potential bioactive molecules and interesting synthons for the development of new materials.

The reaction of 4-methyl-pyrrolidin-2-ones, chlorinated at the C(3) and C(6) positions, with n-propylamine constitutes a new method for the preparation of 5-propylimino-pyrrolidin-2-ones or 3-pyrrolin-2-ones in generally good yields. The transformation involves a series of eliminations, substitutions and double bond shifts. This constitutes a remarkable example of a functional rearrangement.

The dinuclear hydroxo complex cis-[L(2)Pt(mu-OH)](2)(NO(3))(2) (L = PMePh(2), 1), in CH(2)Cl(2), CH(3)CN, or DMF solution, deprotonates the NH(2) group of 9-methyladenine (9-MeAd) to give the complex cis-[L(2)Pt[9-MeAd(-H)]](3)(NO(3))(3), 2, which was isolated in good yield. The X-ray structure shows that the nucleobase binds symmetrically the metal centers through the N(1),N(6) atoms forming a cyclic trimer with Pt...Pt distances in the range 5.202(1)-5.382(1) A. Dissolution of 2 in DMSO or DMF determines the partial (or total) dissociation of the cyclic structure to form several fragments. A multinuclear NMR analysis of the resulting mixture supports the presence of the mononuclear species cis-[L(2)Pt[9-MeAd(-H)]](+), 3, in which the deprotonated nucleobase chelates the metal center with the N(6),N(7) atoms. Addition of a stoichiometric amount of the nitrato complex cis-[L(2)Pt(ONO(2))(2)] (L = PMePh(2), 4) to a DMSO or DMF solution of 2 affords quantitatively the diplatinated compound cis-[L(2)Pt(ONO(2))[9-MeAd(-H)]PtL(2)](NO(3))(2), 5. The single-crystal X-ray analysis shows that the adenine behaves as a tridentate ligand bridging two cis-L(2)Pt units at the N(1) and N(6),N(7) sites, respectively [Pt(1)-N(1) = 2.109(5) A, Pt(2)-N(6) = 2.095(7) A, Pt(2)-N(7) = 2.126(7) A]. The N(1)-bonded metal center completes the coordination sphere through an oxygen atom of a nitrate group, and its coordination plane is arranged orthogonally with respect the second one. The Pt-O distance [2.109(5) A] is similar to those found in the nitrato complex 4 [2.110 A, average]. The related complex cis-[[L(2)Pt(ONO(2))](2)(9-MeAd)](NO(3))(2), 6, containing the neutral adenine platinated at the N(1),N(7) atoms, was isolated and its stability in solution investigated by NMR spectroscopy. In DMSO, 6 undergoes decomposition forming a mixture of the species 4, 5, and the adenine mono- and bis-adducts cis-[L(2)Pt(9-MeAd)(DMSO)](2+), 7, and cis-[L(2)Pt(9-MeAd)(2)](2+), 8, respectively. This last complex, quantitatively formed upon addition of 9-MeAd (Pt/adenine = 1:2) to the mixture, was also isolated and characterized.

A sonogel–carbon–polythiophene microstructured electrode has been synthesised via sonocatalytic procedure. The composite material was characterised by cyclic voltammetry, atomic force microscopy and optical microscopy. A comparison with a similar polythiophene directly cast on a platinum electrode has been made. In contrast with the degrading behaviour (overoxidation) observed at sufficiently positive potentials for alkylsulphanyl substituted polythiophenes cast on the electrode surface, the entrapment of the polymer inside a composite material drastically enhances the stability of the redox-active phase towards irreversible oxidation. In addition, the sonogel–carbon–polythiophene composite represents a good approach to test and, possibly, exploit the electrochemical properties of the polymer which, due to its complete insolubility in the common organic solvents, cannot be adequately cast on an electrode surface or electrosynthesised.

A new copolymer bearing a cysteine Moiety, designed for molecular interaction, metal-ion detection, and chiral recognition, was synthesised starting from the dibromo derivative of methyl N-(tert-butoxycarbonyl)-S-thien-3-ylcysteinate and distannylthiophene through a Stille coupling reation. UV-vis spectroscopy, circular dichroism, NMR spectroscopy, and gel permeation chromatography analyses evidenced that this polymer is able to form self-assembling structures, through the formation of a hydrogen-bond network, not only in the solid state but also in solution.

Treatment of 9-methyladenine (9-MeAd) with cis-[PtL2(NO3)2] (1) (L = PMe2Ph) in a 2:1 molar ratio generated the bis(adduct) cis-[PtL2(9-MeAd)2](NO3)2 (2), which was isolated and fully characterized by multinuclear (1H, 31P, 13C, 195Pt and 15N) NMR analysis, which showed that the two nucleobases are selectively coordinated through the N1 atom. Small amounts of a mono(adduct) cis-[PtL2(S)(9-MeAd)]2+ (3) (S = solvent) and of a diplatinated species cis-[L2Pt(S){9-MeAd(−H)}PtL2]3+ (4) are formed in DMSO solution when 9-MeAd is present in smaller quantities than 1. Complex 3 is platinated at N1, with a solvent molecule representing the fourth ligand around the metal center. Complex 4 contains an adenine molecule deprotonated and platinated at N1,N6,N7, with two cis-L2Pt units bonded to nitrogen atom N1 and to nitrogen atoms N6 and N7, respectively. With increasing relative concentration of the nucleobase, both complexes 3 and 4 progressively convert into the bis(adduct) 2, the only species detectable in solution when the Ad/Pt molar ratio is 2:1. The trinuclear compound cis-[L2Pt{9-MeAd(−H)}]3(NO3)3 (5) (L = PMe2Ph), containing an NH2-deprotonated nucleobase bridging the metal centers through the N1 and N6 atoms, is quantitatively formed when the dinuclear hydroxo complex cis-[Pt(μ-OH)L2]2(NO3)2 (6) reacts with 9-MeAd in CH3CN solution. The isolated complex was fully characterized by multinuclear NMR spectroscopy and mass spectrometry. It appears to be stable in solution in CH3CN and chlorinated solvents, whereas in DMSO it partially converts into a new species, probably the dinuclear analog cis-[PtL2{9-MeAd(−H)}]2(NO3)2, in which the adenine maintains its coordination mode. At equilibrium the trinuclear/dinuclear species molar ratio is 20:1. Through the addition of a stoichiometric amount of nitrate 1 to a DMSO solution of 5 we were able to generate the diplatinated compound 4 in high yield. Complex 4 displays a new coordination mode for the adeninate ion, with N1 bonded to one platinum atom whereas N6 and N7 are chelated to a second one. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Magnetic Resonance Spectroscopy visible mobile lipids are considered important markers in the diagnosis of human cancer and are thought to be closely involved in various aspects of tumour transformation, such as cell proliferation, necrosis, apoptosis, hypoxia and drug resistance. A method allowing the straightforward identification of the lipid classes contributing to the mobile lipids in human malignant tissues is highly advisable. Ex vivo High Resolution Magic Angle Spinning Magnetic Resonance Spectroscopy was done directly on human cerebral, renal and colorectal malignant tissue specimens. A diffusion edited sequence, based on stimulated echo and bipolar gradient pulses, was used to characterize molecules with low diffusion rates, arising from mobile lipid components. Cholesterol, triglycerides and phosphatidylcholine are simultaneously detected and all contribute to the mobile lipid resonances present in malignant glioma and clear cell renal carcinoma tissue specimens spectra. On the contrary, papillary cell renal carcinoma spectrum is predominated by phosphatidylcholine resonances and that of colorectal adenocarcinoma is characterized by signals arising from triglycerides. Ex vivo diffusion edited High Resolution Magic Angle Spinning Magnetic Resonance Spectroscopy, done on intact tissue, is a powerful analytical tool to obtain a simple and immediate identification of mobile lipid components. This can offer a significant contribution to better understanding their involvement in cancer tissues. Furthermore, ex vivo high resolution spectroscopic measurements allow to improve the interpretation of in vivo Magnetic Resonance spectra, increasing its clinical potentiality.

A regioregular head-to-head/ tail-to-tail poly(beta,beta'-disubstituted bithiophene) P1 was synthesised by chemical and electrochemical polymerisation of 2,2'-bithiophene that bears (S)-2-methylbutylsulfanyl chains in the beta and beta'-positions. The polymer was characterised by GPC, NMR and UV/Vis spectroscopy, CD, AFM and by electrochemical and conductivity measurements. The CD spectra of P1 in solutions in which poor solvents are present show interesting features and allow the presence of different optically active species to be distinguished. Upon varying the casting conditions of P1, different relative amounts of grainy and homogeneous aggregated phases were observed in AFM micrographies of films and corresponding negative or positive first Cotton effects were found in the CD spectra. AFM, CD and UV/Vis characterisations were also performed on an electrogenerated optically active polymer PE1, in order to make a comparison with the chemically synthesised one. The interesting, small band gap of P1 allows for easy p- and n-electrochemical doping.

Three natural chondroitin sulfates (CSs), from porcine and bovine trachea, and from shark cartilage, were studied using a variety of NMR techniques (DQS, TOCSY, NOESY, HMQC). A good 1H and 13C characterization of the major components, chondroitin 4-sulfate (CS4) and chondroitin 6-sulfate (CS6), was obtained and a number of signals coming from chondroitin 2,6-disulfate (CS2,6) (present only in shark CS) was identified. The study of a chemically desulfated CS was necessary in order to understand the difficulties encountered in detecting signals from the chondroitin non-sulfate (CS0) component of porcine and bovine CSs. The singular pattern of UC-4 and NC-1 signals was recognized and explained in terms of a diad model. The “excess of multiplicity” affecting mainly these two signals was attributed to the differences in the conformation of the N 1:4 U glycosidic bond. Further support to this hypothesis comes from the comparison of the NOESY spectra of the three CSs.

An alternating methoxyhexylthiophene–thiophene copolymer was synthesized from 3-(6-methoxyhexyl)-2,2′-bithiophene and studied chiefly by means of optical absorption and nuclear magnetic resonance spectroscopy. The results were compared with those of the previously obtained poly[3-(6-methoxyhexyl)-2,5-thienylene]. The differences in the UV-Vis spectra of the two polymers in pure solvents, solvent/non-solvent mixtures and in films are discussed on the basis of the microstructure and the steric hindrance along the backbone. NMR spectroscopy revealed copolymer configuration to be regiorandom with a slight prevalence of head-to-head and tail-to-tail junctions.

The stability of chondroitin sulfate (CS) was studied under acidic, neutral and basic conditions at 30 and 60 degrees C. CS is remarkably stable under neutral conditions at low temperature, while it degrades at 60 degrees C producing low-molecular-mass fragments and desulfated products. This decomposition process begins at ca. 500-600 h and is consistent with an acid-catalyzed hydrolysis of glycosidic linkages caused by a drop in pH resulting from acidic products. Under basic conditions, a breakdown of glycosidic linkages causes a decrease in molecular mass due to the beta-elimination reaction, confirmed by a strong increase of absorbance at 232 nm and 1H NMR. Virtually no loss of O-sulfate groups can be detected in the base-treated CS. Under acidic conditions, the molecular mass decreases probably through hydrolysis of polysaccharidic linkages resulting in an increased number of reducing end groups. Little or no beta-elimination occurs. A loss of O-sulfate groups was detected, producing desulfated derivatives.

Azobenzene-substituted polythiophenes were prepared by copolymerization of 3-alkylthiophenes functionalized with an azo-chromophore and 3-alkylthiophenes as plastifying comonomers to improve solubility. Monomers with different oligomethylenic spacer and alkylic chain lengths were synthesized and copolymerized via FeCl3 oxidative polymerization. Polymer soluble fractions were characterized by 1H and 13C NMR, FTIR, UV–Vis spectroscopy, and GPC, DSC and TGA. Second-order non-linear optical properties were measured by the second harmonic generation technique.

The X-ray structures of 4,4′-dibromo-2,2′-bithiophene 1, 3,3′-dibromo-2,2′-bithiophene 2 and 3,3′,5,5′-tetrabromo-2,2′-bi-thiophene 3 are rweported. The tail-to-tail dimer 1 is found in an anti planar conformation whereas a large distortion is present in the two head-to-head bithiophenes 2 and 3. These bromo derivatives are model compounds for structural studies on poly(3-bromothiophene).

In this paper we present the synthesis and characterization of two novel copolymers obtained from a bithiophene unit carrying octylsulfanyl side chains and thienothiophene units substituted with keto (PK) or ester (PE) groups. Their structural, electrochemical and photophysical properties were investigated by gel permeation chromatography (GPC), thermogravimetric analysis (TGA), NMR, UV-visible-NIR spectroscopy, cyclic voltammetry (CV) and atomic force microscopy (AFM). They possess good solubility in common organic solvents, filmability, proneness to form π-stacks, moderate solvatochromism, good thermal stability and low band gap energy. They were tested as donor materials in combination with [70]PCBM (electron acceptor) in bulk-heterojunction polymer solar cells. The geometry of the devices is: glass/ITO/PEDOT:PSS/copolymer:[70]PCBM/Ca/Al. The external quantum efficiency curve of the best device, realized using a blend of PK : [70]PCBM, 1 : 2 weight ratio, shows a broad response from 350 to 1000 nm. The power conversion efficiency under 100 mW cm-2 AM 1.5G illumination is greater than 1%. © 2014 The Royal Society of Chemistry.

We investigated the effect of an electric field on the alignment and structural properties of thin films of a chiral polybithiophene-based conductive polymer, functionalized with a protected l-cysteine amino acid. Thin films were obtained by exploiting both drop-casting and spin-coating procedures. The electric properties, the polarized Raman spectrum, the UV–vis spectrum, and the CD spectra were measured as a function of the electric field intensity applied during film formation. It was found that beyond the enhancement of the conductivity observed when the electric field aligns the polymer, the electric field significantly affects the chiral properties and the effect depends on the method of deposition.

A dramatic variation of the magnetic coupling in large polyiron clusters can be induced by exploiting host−guest interactions. Subtle structural changes and much weaker antiferromagnetic interactions are the result of the substitution of Na+ with Li+ in the hollow core of the cyclic complex [Fe6(OCH3)12(dbm)6] (Hdbm = dibenzoylmethane).

3,4′-Dibromo-2,2′-bithiophene was converted, in high yield, into the corresponding dibutoxy derivative. The 1H 13C and nmr data are discussed in comparison with those of 3,3′- and 4,4′-dibutoxy-2,2′-bithiophene in relation to regiochemistry.

The poly(3-hexanoyloxyethyl-2,5-thienylene) was studied by means of mono-and bidimensional nuclear magnetic resonance spectroscopy. The regiochemistry of the polymer is assigned on the basis of the 13C chemical shifts, which are easily obtained through inverse detection experiments, utilizing a triad-based model. © 1997 Elsevier Science Ltd. All rights reserved.

A series of 1,3-dioxolane-based ligands, bearing hydroxymethyl or ester functionalities, was synthesized and tested as potential muscarinic antagonists. The compounds display moderate to low affinity for the three receptor subtypes M1-M3, with some of them showing a significant selectivity for the M3 subtype. The configurational and conformational properties were studied using NOE experiments and vicinal coupling constants. The 1H and 13C NMR chemical shifts show stereochemically dependent trends. Quantitative analysis of conformer populations showed that the exocyclic CH2N+(CH3)3 group is prevalently in a pseudo-axial orientation in the cis isomers and in a pseudo-equatorial orientation in the trans isomers.

The reaction of ferric chloride and β-diketones (HL) in alkaline methanol solution represents a good synthetic route to hexairon(III) clusters [MFe6-(OCH3)12(L)6]+ (M = Na, Li), which exhibit an unusual sixfold molecular symmetry. Single-crystal X-ray diffraction showed that the six octahedrally coordinated iron(III) ions define a ring and are linked by twelve bridging methoxide ligands. The resulting [Fe6(OCH3)12] skeleton has the remarkable property of acting as a host for an alkali-metal ion both in the solid state and in organic solution, as demonstrated by 23Na and 7Li NMR experiments. The magnetic behavior of these systems is consistent with the presence of a nonmagnetic S = 0 ground state and of antiferromagnetic exchange interactions between the high-spin ferric ions. The energy of the excited states was studied in detail by high-field DC and pulsed-field differential magnetization experiments at 0.7 and 1.5 K. Single-crystal susceptibility measurements at variable temperature revealed a sizeable magnetic anisotropy, which has been successfully analyzed in terms of single-ion and dipolar contributions. The results are relevant to research into the origin of superparamagnetic-type behavior in transition-metal clusters.

The interaction of two biliar acids (chenodeoxycholic acid and cholic acid) with 2-hydroxypropyl-β-cyclodextrin (HPβCD) in solution and in the solid state was studied using different techniques. The formation of an inclusion complex with a 1:1 stoichiometry was suggested by the phase solubility studies. Both differential scanning calorimetry and X-ray diffractometry exhibited the amorphous state of the complex. The inclusion of both biliar acids into the HPβCD cavity was confirmed by the13C-NMR studies. Cholic acid showed a weaker affinity with respect to chenodeoxycholic acid probably owing to the presence of a hydroxyl group onC(12) (12α) close to the complexation site.

A confrgurational and conformational study of NH, N-acetyl- and N-sulfonylaziridine carboxylates is performed by1H ,13C,17O, and15N NMR spectroscopy. The presence of acetyl and su fonyl groups on the ring nitrogen atom seems to reduce greatly the configurational stability at nitrogen.

The 1H and 13C signals of the hexyl chains of the title compounds were fully assigned. The regiochemical features of the aliphatic region of proton and carbon spectra were analysed in dimers and trimers. Dimers and trimers proved to be reliable model compounds in the regiochemical assignment of poly(3-hexylthiophene) even when the aliphatic region of proton and carbon spectra was involved. The chemical shifts of the protons of CH2(α)s and of the hexyl chain as a whole and those of the first three aliphatic carbons appear to be the most significant.

NMR inverse detection was applied to the study of regiochemistry of a highly head to tail (HT)-regioregular poly(3-hexylthiophene) (PHT). It proved to be a valuable tool in the characterization of polymerization defects not directly revealable or assignable by inspection of the one-dimensional 13 C spectrum. Almost all the 13 C chemical shifts of the four configurational triads of PHT were derived by utilizing the aromatic protons, whereas through the α-protons of the aliphatic chain only carbons belonging to HT-HT connections were detected, owing to the high regiospecificity of the PHT under study and to the high multiplicity of aliphatic proton signals. The correctness of the model of the interpretation of PHT structure based on the four trimers of 3-hexylthiophene was confirmed.

The configurational and conformational properties of six 4-trimethylammoniummethyl 2,2-disubstituted 1,3-dioxolanes were studied using NOE experiments and vicinal coupling constants. Selective 1D NOE experiments proved to be effective tools in the configurational assignment of C-2 relative to C-4. The preferred conformation of the dioxolane ring and the exocyclic group at C-4 was obtained by employing vicinal coupling constants and NOE results. The 1H and 13C NMR chemical shifts show stereochemically dependent trends. Quantitative analysis of conformer populations was performed using Haasnoot et al's equation. The N+(CH3)3 group was found to be synclinal with respect to the heterocyclic O-3 atom and points outside the ring. When a phenyl group is present at C-2, the 4-CH2N+— group in a trans relationship to the 2-phenyl ring was found to occur prevalently in a pseudo-axial orientation, whereas it was established to be prevalently pseudo-equatorial when cis with respect to the phenyl ring.

The conformational properties of the title compounds, which are the basic head-to-head, head-to-tail and tail-to-tail repeat units of regioregular poly(3-methylthiophenes) and poly[3-(methylsulfanyl)thiophenes], are discussed. The paper reports the X-ray structures of the two 4,4′-derivatives, 1H NMR NOE data on the 3,4′ and 4,4′-derivatives and force field MM2 calculations of the conformation of the three bis(methylsulfanyl) derivatives.

GC/OligoThiophene/Ag(NP) hybrid interfaces are synthesized and characterized: GC is the glassy carbon surface; OligoThiophene stands for both an ultrathin bithiophene grafted film and a 4-Br-Bithiophene grafted polymer; Ag(NP) stands for silver nanoparticles. The hybrid interface preparation involves different steps: first, the electrode surface is functionalized through a combination of electrochemically assisted grafting (under reduction regime) and polymerization (under oxidation regime); then, silver nanoparticles are chemisorbed by dipping. In particular, an ultrathin film of grafted bithiophene can be obtained by applying one cyclic voltammetry reduction cycle (GC/BT surface), while subsequent cyclic voltammetry cycling under oxidation regime yields an immobilized 4Br-Bithiophene polymer (GC/4BrBT surface). AFM and TEM images were recorded to investigate the morphology and chemical composition of the Ag(NP). Fe(II)/Fe(III) cyclic voltammetry, Zn underpotential deposition (UPD), XPS, LA-ICP-MS, and Raman techniques were exploited to characterize both the GC/OligoThiophene and GC/OligoThiophene/Ag(NP) interfaces. Theoretical calculation, at the B3LYP/6-311G** level of the theory, enabled rationalization of the electroreduction mechanism and the Raman results.

Intracranial hemangiopericytomas (HPCs) are rare tumors and their radiological appearance resembles that of meningiomas, especially meningothelial meningiomas. To increase the knowledge on the biochemical composition of this type of tumor for better diagnosis and prognosis, we performed a molecular study using ex vivo high resolution magic angle spinning (HR-MAS) magnetic resonance spectroscopy (MRS) perfomed on HPC and peritumoral edematous tissues. Moreover, to help in the discrimination between HPC and meningothelial meningioma we compared the ex vivo HR-MAS spectra of samples from one patient with HPC and 5 patients affected by meningothelial meningioma. Magnetic resonance imaging (MRI), in vivo localized single voxel 1H-MRS was also performed on the same patients prior to surgery and the in vivo and ex vivo MRS spectra were compared. We observed the presence of OH-butyrate, together with glucose in HPC and a low amount of N-acetylaspartate in the edema, that may reflect neuronal alteration responsible for associated epilepsy. Many differences between HPC and meningothelial meningioma were identified. The relative ratios of myo-inositol, glucose and gluthatione with respect to glutamate are higher in HPC compared to meningioma; whereas the relative ratios of creatine, glutamine, alanine, glycine and choline-containing compounds with respect to glutamate are lower in HPC compared to meningioma. These data will be useful to improve the interpretation of in vivo MRS spectra resulting in a more accurate diagnosis of these rare tumors.

We describe the synthesis of alternating bithiophene–fluorene copolymers (P1–P3) with different regiochemistry of the bithienyl unit and different alkylsulfanyl chain lengths. The structural, electrochemical and photophysical properties of these polymers were investigated by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), NMR, UV/Vis and photoluminescence (PL) spectroscopy and cyclic voltammetry (CV), and the polymers were used to assemble organic solar cells (OSCs), in combi-nation with the fullerene derivative methyl [6,6]-phenyl-C61- butyrate (PCBM). P3, with a head-to-head bithienyl unit, shows a broader absorption and a lower band gap with respect to P1 and P2, which have tail-to-tail bithienyl units. The PL intensity of P1–P3 is dramatically quenched in the presence of PCBM, demonstrating that an efficient charge transfer between donor and acceptor occurs. The best OSC device was obtained with P3

It is well recognized that a high dietary intake of long-chain polyunsaturated fatty acids (LC-PUFA) has profound benefits on health and prevention of chronic diseases. In particular, in recent years there has been a dramatic surge of interest in the health effects of n-3 LC-PUFA derived from fish, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Notwithstanding, the metabolic fate and the effects of these fatty acids once inside the cell has seldom been comprehensively investigated. Using cultured neonatal rat cardiomyocytes as model system we have investigated for the first time, by means of high-resolution magic-angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy in combination with gas chromatography (GC), the modification occurring in the cell lipid environment after EPA and DHA supplementation. The most important difference between control and n-3 LC-PUFA-supplemented cardiomyocytes highlighted by HR-MAS NMR spectroscopy is the increase of signals from mobile lipids, identified as triacylglycerols (TAG). The observed increase of mobile TAG is a metabolic response to n-3 LC-PUFA supplementation, which leads to an increased lipid storage. The sequestration of mobile lipids in lipid bodies provides a deposit of stored energy that can be accessed in a regulated fashion according to metabolic need. Interestingly, while n-3 LC-PUFA supplementation to neonatal rat cardiomyocytes causes a huge variation in the cell lipid environment, it does not induce detectable modifications in water-soluble metabolites, suggesting negligible interference with normal metabolic processes.

The X-ray crystal structure analysis for racemic N-chloro-2,2-bis(methoxycarbonyl)aziridine is reported. The complete assignments of the 1H, 13C and 17O chemical shifts are performed using 2D NMR techniques (C–H COSY, COLOC) to establish unequivocally the relative configuration of the aziridine.

A systematic multinuclear (1H, 13C, 15N, 17O) magnetic resonance study provides an easy method of determining relative configurations of N-chloroaziridinecarboxylates.