Preparation and Characterization of Composite Chiral Liquid Crystal Containing L-amino Acid Derivatives

A new composite chiral liquid crystal containing L-amino acid derivatives was prepared and their liquid crystal properties were investigated. Results show that they could exhibit liquid crystal through hydrogen bonding.

Synthesis,Crystal Structure,Theoretical Calculations,and Photoluminescent Property of a Mn(Ⅱ)Complex Assembled by 5-Aminoisophthalic Acid and Phen Ligands

A coordination polymer [Mn2（ctpt）2（aic）2]n （1, ctpt = 2-（4-chloro-phenyl）-1H- 1,3,7,8-tetraaza-cyclopenta[l]phenanthrene, H2aic = 5-amino-isophthalic acid） was hydrother- mally designed and synthesized. The complex was characterized by elemental analysis, IR spectro- scopy, single-crystal X-ray diffraction, and thermogravimetric analysis （TGA）. Each Mn（II） atom is linked by the aic ligands with neighbor Mn（II） atoms, forming an infinite one-dimensional （1D） double-chain structure. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 18.23（1）, b = 17.27（1）, c = 16.69（1） ？, V = 4814.0（7） ？3, C27H16ClMnN5O4, Mr = 564.84, Dc = 1.559 g/cm3, μ（MoKα） = 0.706 mm-1, F（000） = 2296, Z = 8, the final R = 0.0487 and wR = 0.1269 （I 〉 2σ（I））. The 1D chain structure of complex 1 is stable below 458 ℃. In addition, to elucidate the essential electronic characters of this complex, theoretical calculation analysis of 1 was performed by the PBE0/LANL2DZ method in Gaussian 03 Program.

Syntheses and Crystal Structures of Two Diethyltin Complexes of N-Salicylidene-α-amino Acid

Two novel diethyltin（IV） complexes of N-salicylidenevaline （H2L1） and N-Sali- cylidenetryptophan （H2L^2）, Et2SrtL^1 1 and Et2SnL^2 2, were synthesized and characterized by elemental analysis, IR, ^1H NMR and X-ray single-crystal diffraction analysis. Complex 1 belongs to the trigonal system, space group R-3 with a = b = 19.2730（5）, c = 23.6890（13）A^°, V= 7620.4（5） A^°^3, Z = 6, Dc= 1.553 g/cm^3,μ= 1.518 mm^-1, F（000） = 3600, R = 0.0238 and wR = 0.0636. Complex 2 is of monoelinie system, space group P21/c with a = 13.7550（8）, b = 11.5425（7）, c = 12.7876（7）A^°, β= 93.585（1）°, V = 2026.3（2） A^°^3, Z = 4, Dc= 1.548 g/cm^3,μ = 1.286 mm^-1, F（000） = 976, R = 0.0298 and wR = 0.0722. Complex 1 is a cyclic trimer with a macrocyclic 12-membered ring structure formed by the bidentate bridging coordination of carboxylate group to tin atoms. The tin atom is six-coordinated in a distorted octahedral geometry. In complex 2, the distorted trigonal bipyramidal Et2SnL2 units are linked into polymeric chains by the weak Sn…O interaction involving Sn and the earbonyl O of an adjacent ligand, and the chains are further connected by intermolecular N-H…O hydrogen bonds to form a two-dimensional supramolecular structure.

Syntheses and Crystal Structures of Three Novel Amino-acid-containing Polyoxomolybdosilicates

Three novel amino acid salts of 12-molybdosilicate formulated （Gly）6H4SiMo12O40·8H2O 1, K3（HGly）SiMol2O40·4H2O 2 and K2（HGly）2SiMo12O40·9H2O 3 （Gly = NH3CH2COO） were synthesized and characterized by elemental analysis, IR and single-crystal X-ray analysis. Compound 1 crystallizes in trigonal, space group R-3 with a = 17.0742（3）, b = 17.0742（3）, c = 16.792（4）A°, γ = 120°, F（000） = 3474, Mr = 2413.92, Z = 3, V = 4239.4（14）A°^3, Dc = 2.837 g/cm^3,μ（MoKα） = 2.728 mm^-1, the final R = 0.0622, wR = 0.1549 （I 〉 2σ（I）） and GOF = 1.143. In compound 1, each [SiMo12O40]^4- unit is surrounded by six Gly molecules through hydrogen bonding. Compounds 2 and 3 crystallize in monoclinic, space groups P21c and P21/c, respectively. The pH value of the reaction media plays a crucial role in the formations of the three compounds.

THE CRYSTAL STRUCTURE OF RARE EARTH COMPLEX WITH AMINO ACIDS Ⅱ The Crystal Structure of Gtutamate Comptex of Erbium Perchtorate

The crystat structure of {[Er;（L—Glu）;（H;O）;]（ClO;）;·3H;O);has been studied by X-ray diffraction. The crystal is monoctinic with space group P2;and cell parameters a=19.987（3） , b=16.505（3） , c=11.040（2） , β=104.69（1）;, V=3538（1） , Z=2, Dc=2.29 g. cm;, μ=53.2 cm;, F（000）=2384. The asymmetric unit contains two complex motecules and four centre ions. Each erbium （Ⅲ） is coordinated by five oxygen donors from four different glutamates and four oxygen donors from the aqua ligand to form a nine coordination potyhedron. The mean distances of Er—0 （carboxylate） and Er—Ow are 2.439 and 2.41 respectivety. The finat R and Rw are 0.043 and 0. 058, respectivety.

Correlation of Combined Characters of Amino Acid and Whole Protein with Success Rate of Crystallization of <i>Lactobacillus</i>Proteins

Crystallization of proteins is a very delicate process, which is influenced by many known and unknown factors. Of tested factors, many factors are exclusively related to individual amino-acid characters such as molecular weight or protein characters such as protein length. It is considered necessary to test factors that combine both individual amino-acid characters and protein characters with respect to success rate of crystallization. In this study, two combined characters characterizing individual amino-acid character and protein character, amino acid distribution probability and future composition, were used to correlate the success rate of crystallization of proteins from Lactobacillus via modeling. The results obtained from logistic regression and neural network were compared against the results obtained from each of 533 individual amino-acid characters. This study demonstrated that the combined characters are involved in crystallization process and should be taken into account for predicting the success rate of crystallization process.

Synthesis and Structure Analysis of a Tripeptide Containing N-methyl Group Amino Acid

A convenient method of synthesizing a tripeptide-containing N-methyl group amino acid was developed using O-benzotriazole-N,N,N＇,N＇-tetramethyluronium-hexafluorophosphate as the condensing agent. The crystals of tripeptide had white needles belonging to the orthorhombic space group P2_12_12_1. The conformational preference for homochiral tripeptides with one N-methylated amide bond was also investigated. Crystal-structure analysis showed that homochiral tripeptides with an internal N-methylated amide bond preferred a trans-amide form, thereby giving the peptide β-fold characteristics. Intermolecular C-H···O and N-H···O hydrogen bonds linked the molecules into a one-dimensional chain and stabilized the structure.

Syntheses and Structural Characterization of Dimethyltin Complexs of N-(3-Methoxysalicylidene)-α-amino Acid

Three new dimethyltin complexes of N-（3-methoxysalicylidene）-α-amino acid,（CH3）2Sn（3-CH3O-2-OC6H3CH=NCHRCOO）（R = H,1;CH3,2;（CH3）2CH,3）,have been synthe-sized by treating dimethyltin dichloride with the potassium salt of the ligand and characterized by elemental analysis,IR and 1H NMR spectra.The crystal structure of [（CH3）2Sn（3-CH3O-2-OC6H3CH=NCH2COO）（CH3OH）]2 H2O（1a）,formed from methanol solution of 1,has been deter-mined.The crystal belongs to the monoclinic system,space group C/2c with a = 20.636（3）,b = 7.8854（9）,c = 20.668（2） ,β= 113.265（2）°,V = 3089.7（6） 3,Z = 4,Dc = 1.707 g/cm3,= 1.675 mm-1,F（000） = 1592,R = 0.0301 and wR = 0.0841.In complex 1a,the tin atom is six-coordinate and possesses a distorted [SnC2NO3] octahedral geometry with the two methyl groups occupying the trans positions.The weak Sn O interactions and intermolecular hydrogen bonds connected the molecules into an infinite chain.

Synthesis and Structural Characterization of Some Diorganotin Complexes of N-(3,5-Dibromosalicylidene)-α-amino Acid and their Diphenyltin Dichloride Adducts

The title complexes, R′2Sn(3,5-Br2-2-OC6H2CH=NCHRCOO), and their diphenyltindichloride adduct, R′2Sn(3,5-Br2-2-OC6H2CH=NCHRCOO)?SnPh2Cl2, were synthesized and char-acterized by elemental analysis, IR, H and C NMR and X-ray single crystal diffraction. The 1 13structural features of the compounds were described.

Synthesis and Crystal Structure of a Cu(Ⅱ) Coordination Polymer: [Cu(L)(1,10-phen)]_n

A new complex [Cu（L）（1,10-phen）]n （1, L = N-3-pyridine sulfonyl amino acid） has been synthesized and characterized by IR, elemental analysis and X-ray diffraction analysis, and its crystal belongs to monoclinic, space group P2Jc with a = 11.481 （2）, b = 1 8.094（4）, c = 8.5198（17） ]°, β= 102.26（3）°, V = 1729.5（6） ,/k3, Z = 4, Dc = 1.759 g/cm3, F（000） = 932, p = 1.422 mm-1, R = 0.0368 and wR = 0.0893. In 1, the Cu（ll） ion adopts a slightly distorted five-coordinated square pyramidal geometry. The L2- ligand adopts O of the carboxyl bridging adjacent Cu（Ⅱ）units to form an infinite chain structure along the c axis. Also, π-π stacking interactions between the adjacent chains expanded the 1-D structures into a 3-D supramolecular structure.

Crystal and Molecular Structure of N-(1-Ethoxycarbonyl- ethyl)1-Ethoxycarbonylmethyl-3-ethyl-1,2,3,4- tetrahydro-4-oxo-1,3,2-benzodiazaphosphorin- 2-carboxamide 2-Oxide

The crystal structure of the title compound N-(1-ethoxycarbonyl-ethyl) 1-ethoxycarbonylmethy-3-ethyl-1,2,3,4-tetrahydro-4-oxo-1,3,2-benzodiazaphosphorin-2-carbox amide 2-oxide, (C19H_26N3O7P, Mr = 439.41), was determined by single crystal X-ray diffraction at 299(1) K. It crystallizes in the triclinic system, space group P (No.2) with a = 8.955(2), b = 11.863(2), c = 12.309(2) ?, ( = 62.67(3),β= 68.10(3), ( = 78.07(3)(, V = 1077(1) ?3, Z = 2, Dx =1.355 g·cm－3, ( = 0.71073 ?, ( = 0.1657 mm－1 and F(000) = 464. The structure was solved by direct methods. The final R factor is 0.071 and Rw is 0.076 for 2176 observed reflections with I ≥3((I). The results from X-ray crystallography analysis of the isomer with 31P NMR spectra exhibited as ( 4.09 show that the absolute configuration of the chiral phosphorus atom at P(1) was proved to be S-form, with reference to the known configuration of R-alanine moiety.

Synthesis,Crystal Structure and Luminescence Study of a New Two-dimensional Mn(Ⅱ)Coordination Polymer

The coordination polymer [Mn2（cipt）2（aic）2]n （cipt = 2-（3-chlorophenyl）-1H- imidazo[4,5-f][1,10]phenanthroline, aic = 5-amino-isophthalic acid） has been obtained from hydrothermal reaction and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The title compound crystallizes in the triclinic system, space group P , with a = 11.523（3）, b = 12.162（3）, c = 18.706（5） A^°, β = 81.789（5）°, V = 2455.2（1） A^°3, C54H32Cl2Mn2N10O8, Mr = 1129.68, Z = 2, Dc = 1.528 g/cm3, μ = 0.692 mm^-1, F（000） = 1148, R = 0.064 and wR = 0.145 for 9571 observed reflections （I 〉 2σ（I））. In this polymer, the Mn（II） atoms adopt different coordination modes. The Mn（1） atom is five-coordinated, forming a distorted tetragonal pyramidal geometry. Mn（2） atom is six-coordinated to get a distorted octahedral geometry, which is different from the Mn（1） atom. Each Mn（II） atom is linked by aic ligands with neighboring Mn（II） atoms, forming an infinite one-dimensional （1D） double-chain structure. The existence of N–H…O hydrogen bonding interactions leads the 1D chains to generate a 2D structure. Luminescent properties for the ligand cipt and compound 1 have also been discussed in detail.

Syntheses, Structures, and Properties of Five Coordination Polymers Involving Phthalic Acid

Five new coordination polymers Cu（phen）（H2O）（phth）·CH3OH（1）, [Cu（2,2′-bipy）（H2O）]（phth）·3.5H2O（2）, Zn（phen）（phth）（H2O）·1.125H2O（3） and [M（4,4′-bipy）（H2O）2]（phth）·2H2O[M=Zn（4）, Mn（5）]（H2phth=phthalic acid, bipy=bipyridine, phen=1,10-phenanthroline） have been synthesized from the amino acid derivatives（phthalyl-l- valine, H2L） and structurally characterized. H2L was hydrolyzed into phth2- group during the reaction, but the strucure feature was different from that of the complex directly synthesized from H2phth in the reported literature, revealing that H2L played an important role in composing the novel compounds. Compounds 1, 2 and 3 are all 1D chains, but the differences are that compound 1 is further hydrogen-bonded into 2D networks, and compound 2 is further extended into 3D supramolecular network through π-π stacking and hydrogen-bonding interactions. However, compound 3 is a 1D helix chain structure and further links into 2D networks through π-π stacking. Compounds 4 and 5 are isostructural and exhibit the same 2D layers, which are further connected by hydrogen-bonding interactions to form 3D supramolecular network. Antiferromagnetic superexchange was observed for compounds 1, 2 and 5.

Synthesis，Crystal Structure and Infrared Spectrum of Lanthanum Dinuclear Coordination Compound with Alanine：〔La2（ala）4（H2O）8〕·（ClO4）6

Lanthanum coordination compound with l-alanine[La2（ala）4（H2O）8]·（ClO4）6（ala=l-alanine） was synthesized by reaction of lanthanum perchlorate with l-alanine in aqueous solution and obtained in the form of single crystals.The X-ray crystal structure has been determined and the IR spectrum has been studied.The title compound Cl6La2C12H44O40N4,Mr=1375.2,crystallizes in the triclinic,space group P1 , with parameters: a= 11.227（3）,b=11.445（2）,c=11.014（3）,α=114.46（2）,β=114.51（2）,γ=78.62（2）°,V=1171.73,Z=1,Dc=1.95 g/cm￣3,F（000）=680,μ=22.9 cm￣-1（MoKα）.The final R=0.050,Rω=0.051.In the crystal,two lanthanum ions are coordinated by four alanine molecules via four carboxylate bridges to form a dinuclear coordination compound.Four water molecules are coordinated to each lanthanum ion. There is a symmetric centre between the two lanthanum ions.The IR spectrum of the coordination compound and the relationship between the IR spectrum and the structure have been studied.The mechanism of the configuration inversion of alanine has been proposed.

Crystal Structure of Praseodymium Complex with L－proline，Pr_2（L－Pro）_6（H_2O）_4·6ClO_4

Pr2(L-Pro)6(H2O)4]·6ClO4(Pro= proline), Mr=1641.4, monoclinic, P21,α=9. 879(3),b=21. 883(4),c=13. 393(2) A, β=91. 23(2) A, V=2895(1) A3, Z=2,Dc=1. 88g/cm3,μ( MoKα)=20. 5cm￣(-1) . F(000)=1648, R =0. 035 for 5032 observed reflections. The coordination polyhedron of Pr( Ⅲ) ion comprises six oxygen atoms from the L-Pro molecules and two from the water molecules, Each L-Pro molecule coordinates to two Pr(Ⅲ) ions through the carboxyl oxygens in a bidentate bridging mode, thus creating one-dimensional chain structure.

Study of the Incorporation Behavior of L-Leu and D-Leu in L-Val Crystallization

Branched-Chain Amino Acids (BCAAs) are essential amino acids mainly produced through fermentation. With respect to BCAA crystallization, the incorporation behavior of L-form BCAAs as a guest amino acid in the crystallization of L-form BCAAs is well known. However, the incorporation behavior of D-form BCAAs as a guest amino acid in the crystallization of L-form BCAAs is not clear. In this study, we focused on the crystal conformation and incorporation behavior of D-Leucine (D-Leu) and L-leucine (L-Leu) in the crystallization of L-valine (L-Val). Moreover, the difference in the incorporation behavior was investigated on the basis of the distribution ratio of crystals to mother liquor, and the crystal structure and interaction energy were calculated using a molecular dynamics method. The crystal composed of L-Leu in L-Val formed as a solid solution and L-Leu was substituted into the crystal lattice of L-Val. In the case where D-Leu was added as a guest amino acid during L-Val crystallization, D-Leu was not incorporated into the L-Vallattice because the interaction energy between a D-Leu molecule and the L-Val crystal lattice was substantially greater than that between an L-Leu molecule and the L-Val crystal lattice.

Cu(II) Complex of L-Leucine Favor a Different Type of Crystal Structure from Cu(II)-L-Val and Cu(II)-L-Ile

Crystallization behavior of Cu(II) complexes of branched chain amino acids (BCAAs) has been studied. Mixing of Cu(II) and L-leucine in solution caused immediate precipitation of Cu(II)-L-Leu complex, while no precipitants were obtained when L-Val or L-Ile were used as ligands. These results are discussed based on structure differences among the precipitants.

Crystal Structure of Praseodymium Complex with L－proline，Pr2（L－Pro）6（H2O）4·6ClO4

Pr2(L-Pro)6(H2O)4]·6ClO4(Pro= proline), Mr=1641.4, monoclinic, P21,α=9. 879(3),b=21. 883(4),c=13. 393(2) A, β=91. 23(2) A, V=2895(1) A3, Z=2,Dc=1. 88g/cm3,μ( MoKα)=20. 5cm￣(-1) . F(000)=1648, R =0. 035 for 5032 observed reflections. The coordination polyhedron of Pr( Ⅲ) ion comprises six oxygen atoms from the L-Pro molecules and two from the water molecules, Each L-Pro molecule coordinates to two Pr(Ⅲ) ions through the carboxyl oxygens in a bidentate bridging mode, thus creating one-dimensional chain structure.

Studies on the Halogen Substituted β-Amino Acids and Their Cu（II） Coordination Complexes in Crystallography

Halogen substituted β-amino acids, D,L-3-amino-3-（4-fluoro）phenylpropionic acid（D,L-HL1, 1） and D,L-3-amino-3-（4-bromo）phenylpropionic acid（D,L-HL2, 2）, as well as their Cu（II） coordination complexes [Cu（L1）2（CH3OH）2].2CH3OH（3） and [Cu（L2）2（CH3OH）2]-2CHaOH（4） were investigated and their single crystal structures were discussed in details. Supramolecular helical chains were found in β-amino acids 1 and 2 while there was no helix in their coordination complexes 3 and 4. The formation of supramolecular helixes could be due to the hydrogen bonds between terminal -NH3＋ and adjacent -COO- in β-amino acids 1 and 2. While, this kind of hydrogen bonds could not be observed in their Cu（II） coordination complexes 3 and 4, in which central-symmetrical dimers could be formed via coplanar coordinated bonds（N-Cu-O） between -NH2 and -COO-.

脱酚棉籽粉替代部分鱼粉对西伯利亚鲟幼鱼生长、体成分及血清生化指标的影响

本文旨在研究用脱酚棉籽粉(solvent-extracted cottonseed meal,SECM)替代部分鱼粉对西伯利亚鲟幼鱼生长性能、体成分和血清生化指标的影响。试验日粮用脱酚棉籽粉等蛋白质替代基础日粮中0、25%和40%的鱼粉,25%和40%替代水平分别设2个氨基酸平衡组:血粉氨基酸平衡组(B)和晶体氨基酸平衡组(C)。5种日粮分别命名为SECM0、SECM25B、SECM25C、SECM40B和SECM40C。选用初重为(57.36±0.17)g的西伯利亚鲟幼鱼400尾,随机分为5组(每组设4个重复,每个重复20尾),分别饲喂1种试验日粮,试验期8周。结果显示,SECM25C组的增重率、特定生长率和蛋白质效率显著高于SECM25B组(P<0.05)。SECM25C组的饲料系数与对照组差异不显著(P>0.05),其他试验组显著高于对照组(P<0.05)。随着SECM替代量的增加,摄食率也不断上升,其中SECM25C组、SECM40C组和SECM40B组显著高于对照组(P<0.05)。SECM25B组和SECM40B组的蛋白质效率显著低于其他各组(P<0.05),且蛋白质储积率显著低于对照组和SECM25C组(P<0.05)。与血粉相比,晶体氨基酸可显著降低西伯利亚鲟内脏比和肝指数(P<0.05)。SECM25C组和SECM40C组的丙氨酸氨基转移酶显著高于SECM25B组(P<0.05),与其他组差异不显著(P>0.05)。由此得出,在理想蛋白质模式下,在西伯利亚鲟幼鱼日粮中添加脱酚棉籽粉可等蛋白质替代40%的鱼粉;此外,与血粉相比,西伯利亚鲟可以更有效的利用晶体氨基酸。