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1.
A. Rodríguez-Galn J. J. Bou S. Muoz-Guerra 《Journal of polymer science. Part A, Polymer chemistry》1992,30(5):713-721
Stereoregular polyamides containing two chiral backbone carbons in the repeating unit were prepared by polycondensation of bis(pentachlorophenyl) 2,3-O-methylene-L -tartrate with 1,9 and 1,12-alcanediamines activated as N,N′-bis(trimethylsilyl) derivatives. The polymers were characterized by elemental analysis, IR, and 1H-NMR spectroscopy, and differential scanning calorimetry. Both viscosimetry and GPC were used to estimate the molecular weights which ranged between 6000 and 44000. These polytartaramides were readily soluble in chloroform, displayed moderate optical activity in solution, and formed highly crystalline films. 相似文献
2.
M. Bueno J. A. Galbis M. G. García-Martín M. V. De Paz F. Zamora S. Muoz-Guerra 《Journal of polymer science. Part A, Polymer chemistry》1995,33(2):299-305
Two stereoregular polygluconamides, one ( 3 ) of polypeptide-type and the other ( 16 ) being a polycaproamide containing four stereocenters in the main chain of the repeating unit, have been prepared from D-glucosamine and D-glucose, respectively. The new polyamides were characterized by elemental analysis, and IR, 1H- and 13C-NMR spectroscopies. The molecular weights for 3 and 16 were estimated as 25,000 and 67,000, respectively, on the basis of viscosimetric measurements. Both polyamides display high optical activity; they are highly hydrophilic and readily soluble in water as well as in a variety of organic solvents including chloroform. Polyamide 16 is highly crystalline and yields resistant films with spherulitic texture. © 1995 John Wiley & Sons, Inc. 相似文献
3.
Manuel Bueno Francisca Zamora Inmaculada Molina Hernn A. Orgueira Oscar Varela Juan A. Galbis 《Journal of polymer science. Part A, Polymer chemistry》1997,35(17):3645-3653
The synthesis of three new stereoregular AB-type polyamides based on D -ribono-1,4-lactone, L -arabinose, and D -xylose has been carried out by the active ester polycondensation method. These polyamides were characterized by elemental analysis, IR and NMR spectroscopies, and powder X-ray diffraction. They displayed optical activity and had a pronounced affinity to water, although they were not soluble in this solvent. The polyamide obtained from D -ribono-1,4-lactone was highly crystalline and yielded films with spherulitic texture. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3645–3653, 1997 相似文献
4.
研究了反式DV菊酸对映体在含有手性选择体酒石酸酯的水-有机相双相体系中的萃取分配行为,考察了有机稀释剂种类、酒石酸酯的浓度、温度、水相的pH值、酒石酸酯烷基链长度对分配系数(D)和分配因子(α)的影响.研究表明:三氯甲烷作稀释剂时萃取分离效果较好;温度升高使分配系数增大,分离因子减小;分配系数随pH的升高而降低,随着酒石酸酯浓度的增大而增大,分离因子随pH的升高和酒石酸酯浓度的增大先增加后降低,pH和酒石酸酯浓度分别为4.50和0.40mol/L时取得较好的分离效果;取代烷基链长对分配系数(D)和分离因子(α)亦有较大影响. 相似文献
5.
Mei-rong Han Shao-dong Li Ling Ma Bang Yao Si-Si Feng Miao-li Zhu 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(9):1220-1227
A new mononuclear europium complex incorporating the (+)‐di‐p‐toluoyl‐d ‐tartaric acid (d ‐H2DTTA) ligand, namely, catena‐poly[tris{μ2‐3‐carboxy‐2,3‐bis[(4‐methylphenyl)carbonyloxy]propanoato}tris(methanol)europium(III)], [Eu(C20H17O8)3(CH3OH)3]n, (I), has been synthesized and characterized by IR spectroscopy, elemental analysis, powder X‐ray diffraction and single‐crystal X‐ray diffraction analysis. The structure analysis indicates that complex (I) crystallizes in the trigonal space group R3 and exhibits an infinite one‐dimensional chain structure, in which the Eu3+ ion is surrounded by six O atoms from six d ‐HDTTA? ligands and three O atoms from three coordinated methanol molecules, thus forming a tricapped trigonal prism geometry. The d ‐H2DTTA ligand is partially deprotonated and adopts a μ1,6‐coordination mode via two carboxylate groups to link adjacent Eu3+ ions, affording an infinite one‐dimensional propeller‐shaped coordination polymer chain along the c axis, with an Eu…Eu distance of 7.622 (1) Å. Moreover, C—H…π interactions lead to the formation of helical chains running along the c axis and the whole structure displays a snowflake pattern in the ab plane. The circular dichroism spectrum confirms the chirality of complex (I). The solid‐state photoluminescence properties were also investigated at room temperature and (I) exhibits characteristic red emission bands derived from the Eu3+ ion (CIE 0.63, 0.32), with a reasonably long lifetime of 0.394 ms, indicating effective energy transfer from the ligand to the metal centre. In addition, a magnetic investigation reveals single‐ion magnetic behaviour. The spin‐orbit coupling parameter (λ) between the ground and excited states is fitted to be 360 (2) cm?1 through Zeeman perturbation. Therefore, complex (I) may be regarded as a chiral optical‐magneto bifunctional material. 相似文献
6.
本文综述了以天然酒石酸为光活性原料的手性含膦配体合成, 对三十三种手性含膦配体进行归类,同时也简要地介绍了部分配体的Rh(I)配合物催化剂对(Z)-α-乙酰氨基肉桂的催化氢反应结果。 相似文献
7.
Man Jiang Wei Chen Ping Fang Shangli Chen Junxiao Bai Yanfei Huang Miaowei Han Ping Lu Jian Dong 《Journal of polymer science. Part A, Polymer chemistry》2012,50(18):3819-3829
Copolymers of tributyl citrate (TBC) and hexamethylenediamine (HMDA) were synthesized with a solvent‐free condensation method with molar ratios of TBC to HMDA varying from 2:1 to 1:2. The reaction led to poly(succinimide‐co‐citramide) copolymers which were characterized by infrared and Raman spectroscopies, X‐ray diffraction, and thermal analyses. Hydrolysis of the copolymers resulted in water soluble polycitramides with number averaged molecular weights ranging from 1.16 × 104 to 5.00 × 103 as determined by gel permeation chromatography. 1H, 13C, and 13C‐1H‐heteronuclear single quantum coherence NMR spectroscopy has confirmed that the hydrolyzed polycitramides with COOH side chains and amide backbones are structurally similar to biodegradable poly(aspartic acid) (PASP). Interestingly, the polycitramides showed Ca2+ and Pb2+ ion chelating capabilities higher than PASP, citric acid–sorbitol copolymers, or conventional resins. Thus, the polycitramides offer promise as a totally new class of metal sequesters and renewable substitutes for PASP and poly(acrylic acid). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
8.
Hernan A. Orgueira Manuel Bueno Jose Luis Funes Juan A. Galbis Oscar Varela 《Journal of polymer science. Part A, Polymer chemistry》1998,36(15):2741-2748
Stereoregular, enantiomerically pure, chiral polyamides of the –AB– type, containing a natural (glycine) and a synthetic [(S)-5-amino-4-methoxypentanoic acid (AMP)] component have been prepared by the active ester polycondensation method. Thus, polyamide 7 was obtained by polycondensation of the conveniently activated H2NGly–AMPCO2R unit ( 6 ). In this reaction, 7 appeared accompanied by a considerable amount of cyclic (Gly–AMP)2 ( 8 ), which makes the isolation and purification of 7 difficult. The formation of cyclic byproducts could be avoided by preparing and polymerizing the oligoamide H2NGly–AMP–AMPCO2R ( 11 ), which has the terminal carboxyl group activated as the pentachlorophenyl ester. The resulting polyamide ( 12 ) was obtained in 85% yield and free of macrolactams, such as 8 . The new polyamides 7 and 12 were characterized by elemental analysis and infrared and 1H- and 13C-nuclear magnetic resonance spectroscopies. Thermal studies revealed that 12 is crystalline and yields films with spherulitic texture by slow evaporation of formic acid solutions. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2741–2748, 1998 相似文献
9.
M. Antonia Maj Abdelilah Alla Jordi J. Bou Concepcin Herranz Sebastin Muoz-Guerra 《European Polymer Journal》2004,40(12):2699-2708
Two sets of AA · BB-type polyamides (PLyTA) were synthesized from natural compounds L-lysine and D- or L-tartaric acid via the active ester polycondensation method. The carboxyl and hydroxyl side groups were orthogonally protected as methyl ester and methyl ether, respectively. Direct reaction of methyl L-lysinate dihydrochloride with bis(pentachlorophenyl) di-O-methyl tartaric acid led to the aregic polyamide ar-PLyTA, whereas isoregic (ir-PLyTA) and syndioregic (sr-PLyTA) polyamides were obtained by polycondensation of specifically designed amide–aminoacid and amide–diamine monomeric precursors, respectively. These polyamides have intrinsic viscosities in the 0.50–0.76 dl g−1 range, display optical activity, and are readily soluble in chloroform. They start to decompose well above 200 °C and display glass-transition temperatures at 100–105 °C. DSC and X-ray diffraction results indicated that these polyamides are not crystalline but they seem to adopt a partially ordered phase. No differences in properties other than optical rotation were observed between PLyTA made of D- and L-tartaric acid. 相似文献
10.
Romina Marín Abdelilah Alla Sebastin Muoz‐Guerra 《Macromolecular rapid communications》2006,27(22):1955-1961
Summary: The formation of stereocomplexes from the pair of enantiomorphs of the chiral polyamide poly(hexamethylene di‐O‐methyl tartaramide) was investigated for a variety of experimental conditions. DSC and X‐ray diffraction data evidenced that efficiency in enantiomeric association is highly sensitive to the procedure used for preparing the complex. A comparative isothermal crystallization study revealed that the stereocomplex crystallized from the melt at a rate lower than the enantiomerically pure components. The radial growth of individual spherulites was also delayed in the crystallization of the complex. No evidence of stereocoupling was detected for other poly(alkylene di‐O‐methyl tartaramide)s with the alkylene unit length different from six. It was concluded that molecular interlocking of hydrogen bonds in the enantiomeric pair is highly selective in this family of polymers.
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12.
高效液相色谱法分离和测定酒石酸和马来酸 总被引:6,自引:0,他引:6
1引言 酒石酸(2,3一二羟基丁二酸)和马来酸(顺丁烯二酸)都是重要的有机化工原料,它们被广泛地应用于有机合成和其它化工生产领域[1]. 酒石酸的制备常用钨酸作为催化剂,由马来酸识水溶液与过氧化氢进行环氧化反应再经水解精制而成,其中常含有微量的没有反应的马来酸,因此,建立有效的分离和测定酒石酸和马来酸的方法,对于酒石酸生产条件的选择与控制,以及产品的质量检测等都有十分重要的意义. 目前尚未发现有关同时分离和测定酒石酸和马来酸的文献报道.我们首次采用反相高效液相色谱法,跟踪监测了酒石酸生产过程中的物… 相似文献
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14.
Romina Marín Antxon Martínez de Ilarduya Sebastián Muñoz‐Guerra 《Journal of polymer science. Part A, Polymer chemistry》2009,47(9):2391-2407
Naturally occurring tartaric acid was used as raw material for the synthesis of novel linear polyurethanes (PURs) bearing two carboxylate side‐groups in the repeating unit. Aliphatic and aromatic PURs were obtained by reaction in solution of alkyl and benzyl tartrates with hexamethylene diisocyanate and 4,4′‐methylene‐bis(phenyl isocyanate), respectively. All the novel PURs were thermally stable and optically active. The aliphatic carboxylate‐containing PURs had Mw in the 40–70 kDa range, with PD between 2.1 and 2.5; all were semicrystalline polymers with melting temperatures between 100 and 150 °C and Tg in the 50–80 °C range. The aromatic PURs were amorphous materials with molecular weights between 18 kDa and 25 kDa and Tg above 130 °C. Hydrogenolysis of the PUR made from hexamethylene diisocyanate and benzyl tartrate yielded PURs containing up to 40% of free carboxylic side‐groups. The tartrate‐derived PURs displayed enhanced sensitivity to hydrolysis compared with their unsubstituted 2,6‐PUR homologs. The PURs bearing free carboxylic groups were unique in being degraded by water upon incubation under physiological conditions. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2391–2407, 2009 相似文献
15.
Nan Lu Dezhan Chen Guiqiu Zhang Qingjian Liu 《International journal of quantum chemistry》2011,111(9):2031-2038
In this study, enantioselective Biginelli reaction of aldehyde, β‐ketoester, and urea catalyzed by natural (2R, 3R)‐tartaric acid has been investigated using density functional theory calculations. The results indicate that the most favorable pathway involves a protonated imine from aldehyde and urea in the first step. Tartaric acid forms H‐bonds network with substrates enhancing the electrophilicity of protonated imine and the nucleophilicity of β‐ketoester. (R)‐3,4‐Dihydropyrimidin‐2‐(1H)‐ones is preferable for the reaction. The solvent effect is discussed in the prediction of enantiomeric excess (ee) values in ethanol and water. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
16.
Inmaculada Molina Pinilla Manuel Bueno Martínez Juan A. Galbis 《Journal of polymer science. Part A, Polymer chemistry》2010,48(21):4711-4720
Stereoregular poly(ester amide)s (PEAs) were prepared by the polycondensation method using naturally occurring D ‐xylose and aromatic diacids as the starting materials. The polymers were characterized by elemental analysis, GPC, IR, and 1H‐ and 13C NMR spectroscopies. Thermal and X‐ray diffraction studies revealed them to be mainly amorphous. The polymers are hydrophilic and their degradation studies were carried out at 37 and 80 °C in buffered salt solution at pH 8. The degradation study was monitored by mass loss, GPC, IR, and NMR spectroscopies. The hydrolytic degradation of these PEAs occurred rapidly by hydrolysis of the ester functions to a final compound, which maintained the amide functions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
17.
In order to develop a practical method for the construction of chiral molecules, we have designed a novel chiral reaction system possessing multi‐metal centers utilizing tartaric acid ester as a chiral auxiliary. Based on this concept, we have developed an asymmetric 1,3‐dipolar cycloaddition reaction of azomethine imines, an asymmetric hetero Diels‐Alder reaction of nitroso compounds, an asymmetric Diels‐Alder reaction of o‐quinodimethanes. Furthermore, an asymmetric nucleophilic addition of alkynylzinc reagents, prepared in situ from dialkylzinc and 1‐alkynes, to nitrones was achieved with high level of stereocontrol. In the last case, the addition of methylzinc salt of a product‐like racemic hydroxylamine was found to be effective for unprecedented enhancement of enantioselectivity. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 10: 173–187; 2010: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.201000002 相似文献
18.
Xiaowen Cui 《European Polymer Journal》2004,40(6):1111-1118
A series of novel even-odd nylons were synthesized through step-heating melting-polycondensation of undecanedioic acid with various diamines. The synthesized polyamides were characterized comprehensively by means of elements analysis, intrinsic viscosity, Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), Raman spectra, thermogravimetry analysis (TGA) and differential scanning analysis (DSC). The obtained products except nylons 4 11 and 2 11 have intrinsic average molecular weights ranging from 1.3 × 104 to 2.5 × 104. Nylons 4 11 and 2 11 have intrinsic average molecular weights of 8400 and 7200, respectively. The melting temperatures of this series of even-odd nylons decrease with declining the concentration of hydrogen bonds. Furthermore, the dynamic mechanical analysis (DMA) was performed for nylons 12 11, 10 11, 8 11 and 6 11. The glass transition temperatures of nylons 12 11, 10 11, 8 11 and 6 11 are in the range of 40.1-45.7 °C. 相似文献
19.
Partial molar volumes of citric acid and tartaric acid have been determined in water and binary aqueous mixtures of ethanol
(5, 10, 15, 20 and 25% by weight of ethanol) at different temperatures and acid concentrations from the solution density measurements.
The data have been evaluated by using Masson equation and the obtained parameters have been interpreted in terms of solute-solvent
interactions. The partial molar volumes vary with temperature as a power series of temperature. Structure making/breaking
capacities of the organic acids have been inferred from the sign of
i.e. second derivative of partial molar volume with respect to temperature at constant pressure. Both the organic acids behave
as structure breakers in water and water + ethanol. 相似文献
20.
Preparation of Stereoregular Isotactic Poly(mandelic acid) through Organocatalytic Ring‐Opening Polymerization of a Cyclic O‐Carboxyanhydride 下载免费PDF全文
Dr. Antoine Buchard Dr. David R. Carbery Prof. Matthew G. Davidson Dr. Petya K. Ivanova Dr. Ben J. Jeffery Dr. Gabriele I. Kociok‐Köhn Dr. John P. Lowe 《Angewandte Chemie (International ed. in English)》2014,53(50):13858-13861
Poly(mandelic acid) (PMA) is an aryl analogue of poly(lactic acid) (PLA) and a biodegradable analogue of polystyrene. The preparation of stereoregular PMA was realized using a pyridine/mandelic acid adduct (Py?MA) as an organocatalyst for the ring‐opening polymerization (ROP) of the cyclic O‐carboxyanhydride (manOCA). Polymers with a narrow polydispersity index and excellent molecular‐weight control were prepared at ambient temperature. These highly isotactic chiral polymers exhibit an enhancement of the glass‐transition temperature (Tg) of 15 °C compared to the racemic polymer, suggesting potential future application as high‐performance commodity and biomedical materials. 相似文献