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.

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.

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 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.

Synthesis,Characterization and Structure of Chiral Amino Acids and Their Corresponding Amino Alcohols with Camphoric Backbone

Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-（＋）-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among them, one intermediate （1S,3R）-3-amino-2,2,3- trimethyl cyclopentane-1-carboxylic acid hydrochloride 3 was structurally elucidated by X-ray diffraction techniques. Versatile intermolecular hydrogen bonding interactions observed in its packing structure result in a two-dimensional framework.

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.

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.

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.

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.

Synthesis,Structure Characterization and Biological Activity of Adenine Salt of 12-Phosphotungstic Acid

A novel adenine(Ade) salt of 12-phosphotungstic acid was synthesized and characterized by elemental analyses,IR, 1H NMR,CV and single crystal X-ray diffraction. The compound crystallized in a triclinic system with a space group P 1 and a =1.3108(3) nm, b =1.3515(3) nm,c =1.3870(3) nm, V =2.0217(7) nm 3,Z =1,R _1=0.0391,wR _2=0.0959. The structure unit of the complex was constructed from [HPW_ 12 ·O_ 40 ] -,(C_5H_6N_5) + and C_3H_7NO,which further extends to form a novel three-dimensional host-guest network via hydrogen-bonding interactions. The anti-tumor activity of the compound was examined in two human tumor cell lines in vitro .

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.

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.

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.

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.

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.

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.

Crystal Structure and Biological Activities of (R)-N′-[2-(4-Methoxy-6-chloro)-pyrimidinyl]-N-[3-methyl-2-(4-chlorophenyl)butyryl]-urea

The title compound （R）-N′-[2-（4-methoxy-6-chloro）-pyrimidyl]-N-[3-methyl-2-（4- chlorophenyl）butyryl]-urea has been synthesized, and its crystal structure and biological behaviors were studied. Crystallographic data： C17H18C12N4O3, Mr = 397.25, monoclinic, space group P21/c, a = 12.331（2）, b = 14.025（3）, c = 23.085（5） A, β = 99.607（4）°, Z = 8, V = 3936.2（13） A3, Dc = 1.341 g/cm^3, F（000） = 1648, R = 0.0718, wR = 0.1585 and/t（MoKα） = 0.353 mm^-1. The preliminary biological tests showed that the title compound has definite insecticidal and fungicidal activities.

苏氨酸醛缩酶的结构与功能及其在药物合成中的应用

β-羟基-α-氨基酸(β-hydroxy-α-amnio acids,HAAs)是一类广泛应用于制药工业的重要手性中间体。由于其含有双手性中心(C_(α)和C_(β)),探索其严格立体选择性的生物合成方法备受关注。苏氨酸醛缩酶(threonine aldolase,TA)可在温和条件下催化不同类型的醛与氨基酸缩合构筑丰富的HAAs产物库,显示了工业应用潜力。由于目前表征的TA普遍存在对Cβ立体选择性不严格、活性较低以及催化机制不清晰等问题,为其在HAAs合成中的应用带来了挑战。本文综述了TA在新酶挖掘、结构与催化机理解析、蛋白质工程以及合成应用等方面的研究进展,为推动酶催化绿色、高效合成手性药物提供参考。

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-.