Tartaric Acid Molecules Research Articles

The influence of chirality on the structure of a tartaric acid-choline chloride deep eutectic solvent

The wide range of properties, relative ease and low cost of using Deep Eutectic Solvents garners them interest in an ever expanding range of applications. Among common DES components many are naturally occurring chiral molecules. Here we present the liquid structure of either single enantiomeric or racemic tartaric acid with choline chloride at a molar ratio of 2 choline chloride to 1 tartaric acid, as well as the influence of low amounts of added water (2:1:2) from neutron scattering data with H/D isotropic substitution, refined using empirical potential structure refinement. We show that the overall structure remains the same between the different enatiomeric compositions, with small differences in interactions only occurring between the tartaric acid molecules. The overall structure is also robust towards hydration, similar to what has been found in other DES. We also compare our structures to the structures of DES comprising of similar carboxylic acids (1:1 choline chloride - malic acid, 1:1 choline chloride - oxalic acid), finding overall similar dominant interactions, with differences that may be attributable to the number of available hydrogen bonding sites and steric effects.

Low-Cost and Sustainable Cross-Linked Polyvinyl Alcohol–Tartaric Acid Composite Binder for High-Performance Lithium–Sulfur Batteries

A high specific energy density in lithium–sulfur (Li-S) batteries can be achieved by constructing high-sulfur-loading electrodes. However, this electrode type leads to fast capacity decay owing to the formation of large cracks on its surface. Consequently, the optimization of polymeric binders is considered an effective strategy to decrease the volume expansion of sulfur electrodes during cycling. In this study, a three-dimensional (3D) cross-linked polymeric binder was prepared via the polymerization of polyvinyl alcohol (PVA) and tartaric acid (TA). Acetylene carbon black (C) and elemental sulfur (S) were mixed and melt-diffused to prepare a CS composite. The developed 3D cross-linked PVA-TA composite binder films exhibited improved breaking strengths and swelling degrees. Moreover, the inter/intramolecular reactions between the hydroxyl groups of the PVA and TA molecules effectively reduced expansion and suppressed lithium polysulfides (LiPSs) during cycling. The synthesized composite binder also improved the adhesion of the active material and mechanical properties, which decreased the self-discharge and overpotential polarization and increased the lithium-ion diffusion coefficient. The CS electrode (78% sulfur, 3.3–3.5 mg/cm2 sulfur loading) with PVA-TA composite binder exhibited a high initial discharge specific capacity of 537.7 mAh/g and maintained 463.99 mAh/g after 400 cycles at 1.0 C-rate with the decay rate of 0.14%. The outstanding electrochemical performance is due to the 3D cross-linked polymeric network and the excellent adsorption ability. To the best of our knowledge, a sulfur electrode with low-cost and sustainable 3D cross-linked PVA-TA composite binder with excellent electrochemical properties was used for the first time in Li-S batteries.

Enhancing acid-base-water ternary aerosol nucleation with organic acid: a case of tartaric acid.

The new particle formation (NPF) process has been observed globally in clean and polluted environments, where the fundamental mechanisms leading to multicomponent aerosol formation remain elusive. Dicarboxylic acids play an important role in atmospheric NPF. In this study, theoretical calculations are performed to assess the effect of tartaric acid (TA) on the formation of clusters consisting of sulfuric acid (SA), ammonia (AM) or amines (methylamine or dimethylamine, MA/DMA) in the presence of water. Both carboxyl groups and hydroxyl groups in the carbon chain of TA could be involved in hydrogen bonds. The presence of TA triggers proton transfer from SA to the base molecule to form new covalent bonds or strengthens the preexisting covalent bonds, hence, all the hydrated (SA)(TA)(base) cluster formations by adding one TA molecule to the (SA)(base) hydrates are energetically favorable. The dipole-dipole interaction is not only related to the Gibbs energy change for acid affinity reactions to (SA)(W)n and (SA)(base)(W)n (n = 0-4) clusters but also positively related to the reaction rate constant. These results combined with preliminary kinetic results indicate that TA is very likely to participate in clustering and promote subsequent growth involving hydrated SA and (SA)(base) clusters. In addition, our results further indicate that the NPF process can be promoted by multicomponent nucleation involving organic acids, SA, and base species, which will help in understanding NPF in polluted areas and improving global and regional models.

Preparation of eco-friendly cryogel absorbent/paper mulch composite with cellulose/ZnCl2 gel as adhesive

Application of polyethylene (PE) mulch in agriculture and horticulture is challenging due to scarce fossil-oil resources and serious environmental pollution. Therefore, bio-based mulches represent a promising alternative for petroleum-derived ones. From the lignocellulose from the whole corn stalk, the eco-benign cryogel absorbent and paper mulch has been modified by tartaric acid (TA) esterification and polyvinyl alcohol (PVA)/cationic starch (CSt) coating, respectively. This work reports a hybrid mulch of these two products via cellulosic partial-dissolution and regeneration processes and its excellent performance of water preservation for cultivation soil. The modification of TA molecules onto cellulose chains were confirmed by FTIR and X-ray diffraction, which showed the formation of ester bonds and crystallinity transition from cellulose I to the coexistence of cellulose II. SEM analyses proved a successful composite of TA-esterified cellulose absorbent and PVA/CSt-coated paper by ZnCl2-dissolved cellulose gel. The abundant H-bonding between interfaces of the coated paper and cellulose-derivative cryogel contributed to the favorable connection and thus mechanical properties, which both dry tensile strength (41.5 MPa) and wet tensile strength (35.6 MPa). The composites showed the reduction of water vapor transmission rate (WVTR) and oxygen transmission rate (OTR), which were 755.43 g/m2 day and 10.6 mL/m2/day, respectively, and enhancement of water absorbency for 210.3 g/g as increasing the cryogel thickness. The green and biodegradable strategy proposed in this study will broaden the application range of composite mulches in agriculture and forestry.

Tailoring flexibility and dispersity of thermoplastic starch gel by controlling intermolecular structure for improving folding endurance of polylactide

• A biobased starch gel with high thermoplasticity was fabricated via reactive extrusion. • For the first time, we characterized and defined this thermoplastic starch as gel, instead of plastic. • A novel “Soft-Hard” structure provided by tartaric acid endowed TGTPS gel with better flexibility. • TGTPS-1 gel acted as micro/nano-meter toughener and motivated PLA to achieve outstanding folding endurance. Polysaccharide-based gels are green, non-toxic, and sustainable materials with a high absorption capability, which make them suitable for numerous applications. In this study, a novel starch-based thermoplastic gel (TGTPS gel) was facilely fabricated via reactive extrusion with glycerol, starch and tartaric acid. The TGTPS gels exhibited tremendous increase of flexibility and processability, which was attributed to the fact that TA molecules could facilitate hydrolysis of starch chains and enhance gel network slippage as evident from gel permeation chromatography and stress-relaxation measurement. Moreover, combining dynamic mechanical analysis and rheological behavior, we found that a special Soft-Hard Segments structure, varied with the fluctuation of tartaric acid (TA) concentration, was developed between TA molecules, glycerol and starch chains. Additionally, TGTPS gels with 1% TA content (TGTPS-1) could also serve as micro/nano-meter toughener, and motivate PLA to achieve outstanding folding endurance. The double folding resistance was performed on PLA/TGTPS-1 blend, and folding cycle time was improved from 1 time of PLA to over 2000 times of PLA/TGTPS-1 (80/20) blends. Overall, this novel TGTPS gels could be promising alternative to petroleum-based polymers and play a great potential in engineering applications.

Unveiling Five Naked Structures of Tartaric Acid.

The unbiased, naked structures of tartaric acid, one of the most important organic compounds existing in nature and a candidate to be present in the interstellar medium, has been revealed in this work for the first time. Solid samples of its naturally occurring (R,R) enantiomer have been vaporized by laser ablation, expanded in a supersonic jet, and characterized by Fourier transform microwave spectroscopy. In the isolation conditions of the jet, we have discovered up to five different structures stabilized by intramolecular hydrogen‐bond networks dominated by O−H⋅⋅⋅O=C and O−H⋅⋅⋅O motifs extended along the entire molecule. These five forms, two with an extended (trans) disposition of the carbon chain and three with a bent (gauche) disposition, can serve as a basis to represent the shape of tartaric acid. This work also reports the first set of spectroscopy data that can be used to detect tartaric acid in the interstellar medium.

Chiral Nitrogen-Doped Graphene Quantum Dot Electrochemical Sensor for Recognition of Tartaric Acid Isomers

Chirality is a basic attribute of object in three-dimensional space, and the phenomenon of chirality exists widely in nature. By covalently grafting L/D-cysteine to nitrogen-doped graphene quantum dots (NGQDs) through amide reaction, a new type of chiral NGQDs was obtained. Its morphology was characterized by transmission electron microscope, and its structure and composition were determined by X-ray powder diffraction, infrared spectroscopy, raman spectroscopy, ultraviolet spectroscopy and X-ray photoelectron spectroscopy. In the linear cyclic voltammetry test, it is found that chiral NGQDs have different peak current values in different configurations of tartaric acid, and the changes in the peak current intensity can specifically identify L/D-tartaric acid isomers. There are two identical asymmetric carbon atoms in the tartaric acid molecule, which is a by-product of the wine industry. Due to its low price, it is often used to resolve other racemates, such as epinephrine and chloramphenicol. Through the method of molecular simulation and docking calculation, the combination of chiral graphene quantum dots and tartaric acid was studied, and the mechanism of chiral recognition was discussed. This work broadens the application range of graphene quantum dots and provides new ideas for the preparation of chiral inorganic nanomaterials.

Synthesis, characterization and water-absorption behavior of tartaric acid-modified cellulose gel fromcorn stalk pith

The eco-benign water-absorbent gel was obtained by modification of tartaric acid (TA) onto parenchyma cellulose from corn stalk pith (CSP) in N, N-dimethylacetamide (DMAc)/LiCl system. The water affinity of the gel was aided with TA as both grafting agent and cross-linker via esterification. The degree of swelling was strongly influenced by TA amount, reaction temperature and duration, and the absorbency of TA-esterified product reached up to about 417 g H2O/g dry gel. The three-dimensional macro-porous structures of the bio-absorbent led to fast penetration and diffusion of water into gel. Studies of absorption behavior in deionized water showed that the initial water uptake followed the non-Fickian mechanism, the Schott second-order equation governed the swelling kinetics, and the later part of swelling was relaxation of polymer chains. FTIR and X-ray diffraction analyses confirmed successful modification of TA molecules onto cellulose chains through the formation of ester bonds and transition of crystalline forms from cellulose Ⅰ to cellulose Ⅱ. Moreover, thermogravimetric outcomes illustrated the thermal resistance of the TA-esterified gel with a loose structure was lower than SCP cellulose. This work designed a green water-absorbent that could be potentially utilized as favorable water retention material in agriculture and horticulture.

Adsorption of a chiral modifier on an oxide surface: Chemical nature of tartaric acid on rutile TiO2 (110)

Tartaric acid (TA) is one of the most known chiral modifier used in heterogeneous enantioselective catalysis and understanding how it interacts with oxide supports is of significant importance for the design of efficient supported metal catalysts. This work presents a detailed surface science characterisation of (R,R)-TA adsorption on a rutile TiO2(110) surface from a chemical and structural point of view. X-ray Photoelectron Spectroscopy (XPS), High Resolution Electron Energy Loss Spectroscopy (HREELS), Low Energy Electron Diffraction (LEED) and Scanning Tunnelling Microscopy (STM) were used to decipher the adsorption mode and geometrical arrangement of TA on TiO2(110). For XPS analysis, spectra were compared to references recorded on model metal surfaces, namely Au(111) and Cu(110), on which a better understanding of the TA chemical nature is available. On TiO2, both XPS and HREELS converged to show the monotartrate chemical nature (only one acidic group is deprotonated) of the adsorbed TA molecules, while STM and LEED evidenced a (2 × 1) 2D network arrangement. TA molecules are anchored via both oxygen atoms of one carboxylate group binding directly to two adjacent Ti5c of the underlying oxide surface. No chiral ordered domains were observed whatever the coverage, suggesting that surface chirality is induced at the molecular level.

Spontaneous and directed symmetry breaking in the formation of chiral nanocrystals

Symmetry plays a crucial part in our understanding of the natural world. Mirror symmetry breaking is of special interest as it is related to life as we know it. Studying systems which display chiral amplification, therefore, could further our understanding of symmetry breaking in chemical systems, in general, and thus also of the asymmetry in Nature. Here, we report on strong chiral amplification in the colloidal synthesis of intrinsically chiral lanthanide phosphate nanocrystals, measured via circularly polarized luminescence. The amplification involves spontaneous symmetry breaking into either left- or right-handed nanocrystals below a critical temperature. Furthermore, chiral tartaric acid molecules in the solution direct the amplified nanocrystal handedness through a discontinuous transition between left- and right-handed excess. We analyze the observations based on the statistical thermodynamics of critical phenomena. Our results demonstrate how chiral minerals with high enantiopurity can form in a racemic aqueous environment.

Ti-O膜表面固定不同手性酒石酸及其血液相容性评价

手性是生命体系的基本特征，生命体系具有高度的手性选择性，表面手性可能显著影响生物材料的生物学功能。本文将不同手性酒石酸分子固定在Ti-O膜表面，获得了不同手性表面。XPS检测结果显示，沉积了多巴胺的样品表面出现了新的N1s峰，接枝了己二胺的样品表面N:C值升高，随后又因为接枝了手性酒石酸，其表面的O:C值升高，XPS结果表明各层次表面均已制备成功。水接触角检测结果显示，L-酒石酸表面和D-酒石酸表面的水接触角几乎没有差异，说明表面手性不会影响材料表面的亲疏水性。通过纤维蛋白原变性实验和体外血小板粘附与激活实验来评价手性对于材料表面血液相容性的影响。相对于L-酒石酸表面，D-酒石酸表面显示出较低的纤维蛋白原变性程度，并且血小板的粘附量更少，血小板被激活的程度更低。这些结果表明手性对于生物材料的抗凝血性能有着不容忽视的影响，为开发性能优异的抗凝血材料提供了新的思路。 Chirality is one of the basic characteristics of life system, which has a high degree of chiral selectivity, surface chirality may significantly affect the biological function of biomaterials. In this paper, different chiral tartaric acid molecules were immobilized on the surface of Ti-O films. XPS test results showed the peak of nitrogen appeared on the samples which had deposited dopamine, the ratio of nitrogen to carbon was increased when hexamethylendiamine was introduced. When chiral tartaric acid was grafted, the ratio of oxygen to carbon was increased. XPS results showed that all surfaces had been successfully prepared. The water contact angle test results showed that no difference was present on the L-surface and D-surface, indicating that surface chirality had little effect on surface hydrophobicity. The effects of chirality on the blood compatibility of materials were evaluated by fibrinogen denaturation test and platelet adhesion and activation assay in vitro. Compared with L-tartaric acid surface, D-tartaric acid surface showed a lower degree of denatura-tion of fibrinogen, less platelet adhesion and a lower degree of platelet activation. These results indicate that chirality cannot be ignored in the anticoagulant properties of biomaterials, which provides a new idea for the development of anticoagulant materials with excellent properties.

Structural and functional characterization of aspartate racemase from the acidothermophilic archaeon Picrophilus torridus.

Functional and structural characterizations of pyridoxal 5'-phosphate-independent aspartate racemase of the acidothermophilic archaeon Picrophilus torridus were performed. Picrophilus aspartate racemase exhibited high substrate specificity to aspartic acid. The optimal reaction temperature was 60°C, which is almost the same as the optimal growth temperature. Reflecting the low pH in the cytosol, the optimal reaction pH of Picrophilus aspartate racemase was approximately 5.5. However, the activity at the putative cytosolic pH of 4.6 was approximately 6 times lower than that at the optimal pH of 5.5. The crystal structure of Picrophilus aspartate racemase was almost the same as that of other pyridoxal 5'-phosphate -independent aspartate racemases. In two molecules of the dimer, one molecule contained a tartaric acid molecule in the catalytic site; the structure of the other molecule was relatively flexible. Finally, we examined the intracellular existence of D-amino acids. Unexpectedly, the proportion of D-aspartate to total aspartate was not very high. In contrast, both D-proline and D-alanine were observed. Because Picrophilus aspartate racemase is highly specific to aspartate, other amino acid racemases might exist in Picrophilus torridus.

Influence of etidronic acid and tartaric acid on the growth of different calcite morphologies

AbstractThe influence of organic additives on the crystal growth of different calcite morphologies in two crystallization processes operating under steady state and batch mode is described. The crystal growth kinetics and overgrown morphological observations of rhombohedral, scalenohedral and prismatic calcite seed crystals in the systems containing etidronic acid (HEDP) and tartaric acid (TA) were investigated. The crystallization systems were of low supersaturations (SI<1.1) and of moderate pH (8.0). Kinetic parameters of the crystal growth in the presence of selected additives, such as reduction of the growth rates, rate constant and reduced critical supersaturation were calculated and correlated with additive concentration and different calcite seeds. The results indicate strong interactions of HEDP molecules and weak but specific interactions of TA for calcite surfaces. Interactions occur at the step edges which finally results in the expression of near-{hk0} faces and highly polar faces, consisting of solely Ca layer on the surface, stabilised by TA and HEDP molecules, respectively. The affinity of both additives is significantly higher for scalenohedral and prismatic calcite in contrast to rhombohedral calcite seeds. The effect of calcite seed morphology was attributed to different surface energetics of the predominant crystal faces of the studied calcite seeds.

Glycine–D-tartaric acid (1/1)

In the title co-crystal, C2H5NO2·C4H6O6, the gylcine mol­ecule is present in the zwitterion form. In the tartaric acid mol­ecule there is a short intra­molecular O—H⋯O contact. In the crystal, the tartaric acid mol­ecules are linked via pairs of O—H⋯O hydrogen bonds, forming inversion dimers. These dimers are linked via a number of O—H⋯O and N—H⋯O hydrogen bonds involving the two components, forming a three-dimensional network.

Asymmetric Noncovalent Synthesis of Self-Assembled One-Dimensional Stacks by a Chiral Supramolecular Auxiliary Approach

Stereoselective noncovalent synthesis of one-dimensional helical self-assembled stacks of achiral oligo(p-phenylenevinylene) ureidotriazine (AOPV3) monomers is obtained by a chiral supramolecular auxiliary approach. The racemic mixture of helical stacks of achiral AOPV3 molecules is converted into homochiral helical stacks, as shown by both spectroscopic measurements and molecular modeling simulations. The conversion is promoted by an orthogonal two-point ion-pair interaction with the chiral auxiliary dibenzoyl tartaric acid (D- or L-TA) molecules, which biases the angle population distribution and thereby the stack helicity. The induced preferred helicity is maintained by the OPV stacks even after the removal of the chiral auxiliary by extraction with ethylenediamine (EDA), due to the kinetic stability of the OPV stacks at room temperature. Spectroscopic probing of the helical self-assembly and the racemization process of these π-conjugated OPV chromophores shed further light into the mechanistic pathways of this chiral asymmetric noncovalent synthesis and the kinetic stability of the stacks produced. The racemization of the stacks follows first-order kinetics and no switch in mechanism is observed as a result of a temperature change; therefore, a racemization via disassembly assembly is proposed. Remarkably, the preferred helicity of the stacks of achiral AOPV3 can be retained almost completely after a heating-cooling cycle where the stacks first partially depolymerize and then polymerize again with the still existing stacks being the seeds for self-assembly of achiral AOPV3. Only after a fully dissociated state is obtained at high temperatures, the optical activity of the supramolecular stack self-assembled at room temperature is lost.

Pasteur — The harbinger of stereochemistry

Twenty five years before the tetrahedral structure for carbon was proposed in 1874 to explain the optical activity and other properties of organic compounds, Louis Pasteur discovered the existence of enantiomerism in tartaric acid. He separated the oppositely shaped crystals of tartaric acid by handpicking, found their optical rotation to be in opposite directions, and concluded that this optical property was attributable to the existence of two oppositely shaped tartaric acid molecules. Thus the new subject of stereochemistry was heralded.

Proton-transfer and non-transfer in compounds of quinoline and quinaldic acid withL-tartaric acid

The structures of two compounds of L-tartaric acid with quinoline, viz. the proton-transfer compound quinolinium hydrogen (2R,3R)-tartrate monohydrate, C9H8N+.C4H5O6-.H2O, (I), and the anhydrous non-proton-transfer adduct with quinaldic acid, bis(quinolinium-2-carboxylate) (2R,3R)-tartaric acid, 2C10H7NO2.C4H6O6, (II), have been determined at 130 K. Compound (I) has a three-dimensional honeycomb substructure formed from head-to-tail hydrogen-bonded hydrogen tartrate anions and water molecules. The stacks of pi-bonded quinolinium cations are accommodated within the channels and are hydrogen bonded to it peripherally. Compound (II) has a two-dimensional network structure based on pseudo-centrosymmetric head-to-tail hydrogen-bonded cyclic dimers comprising zwitterionic quinaldic acid species which are interlinked by tartaric acid molecules.

(R)-1-Hydroxybutan-2-ammonium (2R,3R)-tartrate monohydrate

In the formation of the title compound, C4H12NO+·C4H5O6 −·H2O, the (R)-2-amino-1-butanol molecule is converted to a cationic form containing a positively charged amino group, and the tartaric acid molecule to a mono- or half-ionized tartrate anion. The structure is stabilized by a three-dimensional network of hydrogen bonds.

Chiral metal surfaces from the adsorption of chiral and achiral molecules

Chiral surfaces, capable of existing in two distinguishable mirror forms that cannot be superimposed, are attracting worldwide attention. The adsorption of complex organic molecules provides a means of introducing the ultimate discrimination function of chirality to a metal surface. Here, a comparison of the chiral tartaric acid (HOOC–CHOH–CHOH–COOH) molecule and the achiral succinic acid (HOOC–CH 2–CH 2–COOH) molecule on a Cu(110) surface is presented. For both molecules, two-dimensional assembly is found to depend strongly on molecule–metal bonding interactions, whereas the presence/absence of the OH groups causes subtler, second-order effects on the self-assembled structure. The driving force for creating chiral organisations is shown to arise from adsorption-induced asymmetrisation, via molecular distortion and/or metal reconstruction of the local adsorption unit. The macroscopic chirality of the surface is then determined by whether nucleation points of both chirality can be equally created, or whether non-degeneracy can be introduced to favour one chirality.

Induction of Homochirality in Achiral Enantiomorphous Monolayers

We report the induction of homochirality in enantiomorphous layers of achiral succinic acid on a Cu(110) surface after doping with tartaric acid (TA) enantiomers. Succinic acid becomes chiral upon adsorption due to symmetry-breaking interactions with the Cu(110) surface. The doubly deprotonated bisuccinate forms mirror domains on the surface, which leads to a superposition of (11,-90) and (90,-11) patterns observed by low-energy electron diffraction (LEED). On average, however, the surface layer is racemic. An amount of 2 mol % of (R,R)- or (S,S)-tartaric acid in the monolayer, corresponding to an absolute coverage of 0.001 tartaric acid molecule per surface copper atom, is sufficient to make the LEED spots of one enantiomorphous lattice disappear. After thermally induced desorption of TA, the succinic acid lattice turns racemic again. In analogy to the "sergeants-and-soldiers" principle described for helical polymers, this effect is explained by a lateral cooperative interaction within the two-dimensional lattice.