Crystal structures of complexes of NAD+-dependent formate dehydrogenase from methylotrophic bacterium Pseudomonas sp. 101 with formate

Formate dehydrogenase (FDH) from the methylotrophic bacterium Pseudomonas sp. 101 catalyzes oxidation of formate to NI₂ with the coupled reduction of nicotinamide adenine dinucleotide (NAD⁺). The three-dimensional structures of the apo form (the free enzyme) and the holo form (the ternary FDH-NAD⁺-azide complex) of FDH have been established earlier. In the present study, the structures of FDH complexes with formate are solved at 2.19 and 2.28 Å resolution by the molecular replacement method and refined to the R factors of 22.3 and 20.5%, respectively. Both crystal structures contain four protein molecules per asymmetric unit. These molecules form two dimers identical to the dimer of the apo form of FDH. Two possible formatebinding sites are found in the active site of the FDH structure. In the complexes the sulfur atom of residue Cys354 exists in the oxidized state.     

Structure of (N-(2-hydroxyphenyl)-salicylaldiminopiperidino) Ni(II) complex

The crystal and molecular structure of the title complex, C₁₈H₁₉N₂O₂Ni, has been determined by direct methods. The compound crystallizes in the monoclinic crystal system witha=22.973(1),b=5.212(1),c=27.076(1)Å, β=106.46(1)°, space groupC2/c,V=3109.1(6)ų, Z=8, andD _x=1.51g cm^?3. The nickel atom is in a slightly distorted square-planar environment of two oxygens [Ni(1)?O(1) 1.824(3) and Ni(1)?O(2) 1.856(3)Å] and two nitrogens [Ni(1)?N(1) 1.849(3) and Ni(1)?N(2) 1.932(3)Å] with O?Ni?N angles between 85.7(1) and 97.1(1)°. The nickel atom is 0.006 Å out of the plane of its ligands.     

Structure of N-(2-thiophenyl)-salicylaldimino-diethylamino nickel(II) complex

N-(2-thiophenyl)-salicylaldimino-diethylamino nickel(II) complex crystallizes in the orthorhombic crystal system witha=19.089(4),b=14.268(7),c=12.091(4) Å, space group Pbca,Z=8, andD _x =1.449 g cm^–3. The central nickel atom is coordinated with S, O, and N atoms. The coordination plane is nearly planar and nearly perpendicular to the diethylamine plane which consist of N(2), C(14), C(15), C(16), and C(17).     

The crystal structure of a N-(2-thiophenyl)-salicylaldiminopiperidino nickel(II) complex

The crystal and molecular structure of the title complex, C₁₈H₁₉N₂OSNi, has been determined by direct methods. The compound crystallizes in monoclinic crystal system witha=11.968(1),b=12.182(1),c=12.399(1) Å, =115.23(1)°, space group P2₁/n. Nickel is in a slightly distorted square-planar environment of two nitrogens [1.881(2) and 1.952(2) Å] and one oxygen [1.856(3) Å] and one sulphur [2.138(2) Å] atom. Ni is 0.005 Å out of the plane of its ligands.     

Crystallization of fatty acid (C16H32O2) from short-chain hydrocarbon (C6H14)

A strong evidence for the occurrence of palmitic acid in highly fibrous form, when crystallized in presence of linear chain hydrocarbon, is obtained by crystallizing palmitic acid from n-hexane solutions, by the evaporation of solvent at high rate of evaporation.     

Crystal and molecular structure of N-(2-morpholinoethyl)-2-oximato-1-phenylpropan-1-iminechloropalladium(II)

The crystal structure ofN-(2-morpholinoethyl)-2-oximato-1-phenylpropan-1-iminechloropalladium(II), [Pd(L)Cl], has been determined from X-ray data collected by counter methods. The compound crystallizes in the orthorhombic space groupPna2₁ with four molecules per unit cell, the dimensions of which area=9.602(2),b=8.150(1),c=21.181(4) Å. Full matrix least-squares refinement gave a finalR value of 0.042 for the 3218 independent observed reflections. The oxime ligand is deprotonated and is acting as a tridentate ligand coordinating to the palladium through the oxime nitrogen, the imine nitrogen, and the tertiary amine nitrogen of the morpholine moiety. To complete four-coordination about the palladium atom, a chloride ion is also attached to the central metal atom. The donor atoms plus the palladium atom are planar.     

Synthesis and crystal structure of a cobalt(II) complex with tris(1-pyrazolylmethyl)amine

The synthesis of a cobalt(II) complex of tris(1-pyrazolylmethyl)amine (amtp) is reported. The complex [Co(amtp)Cl](BPh₄) crystallizes in the space group P-1, with a = 8.979(2), b = 19.329(3), c = 20.251(3) Å, = 93.321(2), = 93.685(3), = 98.930(2)°, and Z = 4. The Co(II) atom is nearly tetrahedrally coordinated by three pyrazole N-atoms and one Cl^–. The tertiary amine N-atom of amtp is only weakly coordinated to Co(II) atom at a Co—N(amine) distance of ca 2.40 Å.     

Coordination properties of sulfonyl-N-aminoacids: Crystal and molecular structure of the [Zn(II) (N-(p-toluenesulfonyl)-L-glutaminate)2(H2O)2] complex

The coordination behavior of N-tosyl-L-glutamine (hereafter abbreviated as tsglnH, tosyl =toluenesulfonyl group) toward the Zn(II) ion is investigated by means of structural and spectroscopic techniques. From aqueous solution, at acidic pH the Zn(II) ion separates a compound of empirical formula Zn(tsgln)₂·2H₂O whose crystal structure is determined. The crystal is monoclinic, space group C2, with cell dimensions:a=19.775(5),b=5.3146(3),c=16.543(8) Å, =119.93(3)°,Z=2. The Zn(II) is tetrahedrally coordinated by two symmetry-related tsgln monoanions acting as monodentate carboxylate ligands and two symmetry related water molecules. The Zn–O bond distances are similar while the angles at Zn(II) ion differ significantly from those of regular tetrahedron. The side chain amide group does not participate in metal coordination and forms intermolecular hydrogen bonds.     

Crystal structures of N-(2-aminoethyl)-1-naphthaleneneacetamide nitrate and hydrogen tartrate dihydrate

Nitrate (1): C₁₄H₁₇N₂O⁺·NO ₃ ^– , orthorhombic, Pbca,Z=8,a=9.6924(4),b=27.664(2) andc=10.8589(6)Å.Hydrogen tartrate dihydrate (2): C₁₄H₁₇N₂O⁺·C₄H₅O ₆ ^– ·2H₂O, orthorhombic, P2₁2₁2₁,Z=4,a=7.6703(5),b=7.9368(4) andc=31.953(2)Å. In the solid state, cation conformation differ due to molecular flexibility, very different anionic environments, and resultant hydrogen bonding patterns. Despite these differences, the two structures maintain the same separations (about 7.35 Å) of the two most distant potential pharmacophoric groups, i.e., the aromatic ring and the protonated amine group.     

Intramolecular hydrogen bonding and tautomerism in 1-[N-(4-bromophenyl)]aminomethylidene-2(1H) naphthalenone

1-[N-(4-bromophenyl)]aminomethylidene-2(1H)naphthalenone (C₁₇H₁₂NOBr) (1) was synthesized and its crystal structure was determined. Compound (1) is monoclinic, space group P2₁/n with a = 4.808(1) Å, b = 20.617(1) Å, c = 13.750(1) Å, = 93.004(1)°, V = 1361.11(3) ų, Z = 4, D_c = 1.592 g·cm^–3, (Mo K) = 3.014 mm^–1, R = 0.051 for 1013 reflections [I > 2(I)]. There is a strong intramolecular hydrogen bond of distance 2.544(2) Å between the hydroxyl oxygen atom and imine nitrogen atom, the hydrogen atom essentially being bonded to the nitrogen atom. The title molecule is not planar. X-ray crystal structure determination reveals the existence of the keto (or predominantly keto) tautomer in (1). Spectra of compound (1) were observed by IR and NMR, and UV–visible spectra of (1) were studied in different solvents and acidic media.     

The structure of N-(1H-benzo[d]imidazol-2-ylmethyl)-N-(2,6-dichlorophenyl)amine

The N-(1H-benzo[d]imidazol-2-ylmethyl)-N-(2,6-dichlorophenyl)amine, C₁₄H₁₁N₃Cl₂, M _r = 292.17, crystallizes in the orthorhombic space group Pbca with unit cell parameters a = 10.707(2), b = 9.615(2), c = 25.944(6) Å. The benzimidazole ring system is planar and makes a dihedral angle of 77.8(1)° with the phenyl ring. The structure is stabilized by an N–H···N hydrogen bond.     

Crystal Structure of N-(tert-Butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)cyclohexane Carboxamide

Abstract  The crystal structure of N-(tert-butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)-cyclohexane-carboxamide 1 has been determined. The title compound crystallized in the orthorhombic space group pbca with cell parameters, a = 10.6556(6) ?, b = 18.0132(11) ?, c = 19.5513(12) ?, v = 3752.7(4) ?³, Z = 8, D _cal = 1.269 Mg/m³ at T = 120 K. The structure refined by full-matrix least-squares procedures to find R ₁ = 0.0463 and wR ₂ = 0.0937 for 3059 reflections. The soxazole ring isn’t coplanar with the phenyl ring. Index Abstract  The crystal structure of N-(tert-butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)-cyclohexane-carboxamide 1 has been studied.      

N-(4-吡啶甲基)-L-丝氨酸铜配合物的合成、晶体结构和磁性

氨基酸还原希夫碱HL (N-(4-吡啶甲基)-L-丝氨酸)与CuCl2·2H2O在室温条件通过扩散法合成了配位聚合物{[Cu2(L)2(Cl)2]·H2O}n(I).采用元素分析、红外光谱、X-射线单晶衍射、粉末衍射和热重分析进行了表征.两个结晶学独立Cu(II) 包含于其晶体结构中,Cu1为变形八面体CuO2N2Cl2几何构型;Cu2则呈现略有变形的四方锥结构.Cu1和Cu2通过配体L-的吡啶氮原子以及氯离子的桥连作用连接为2D网状结构.变温磁化率实验表明在温度为2~300 K,配合物I表现为铁磁性耦合.     

Phase Characterization,Enthalpies and Entropies of Transition,of Five Substituted N-(1-Biphenylethylidene) Benzylamines

Five N-(1-biphenylethylidene) benzylamines expressed by the general formula C₆H₅C₆H₄C(CH₃) = N-CH₂-C₆4HX (X = H, m-F, m-Cl, M-Br and p-OCH₃) were synthesized and their thermal behavior studied within the temperature range of -75 to 250°C.

The solid-liquid, liquid-solid transition temperatures were recorded with a DSC analyzer and the thermodynamic parameters ΔH_m and ΔS_m were estimated. A relationship between these parameters and the molecular weigth was found. The compound m-fluoro N- (1-biphenylethylidene) benzylamine showed an l_i → l_n transition at 341.5°K, which was better observed by cooling the sample at 10°C/min. The liquid crystal behavior was confirmed by cross polarized microscopy.     

Crystal Structure of N-Propargylcarbazole and N-(3-lodopropargyl)carbazole

An X-ray study of N-propargylcarbazole (I) and N-(3-iodopropargyl)carbazole (II) has been carried out. In the crystal II acetylenic groups form zigzag ladder-like infinite motives extended along the b axis. The motives are characterized by alternation of more close (and capable, in principle, of topochemical dimerization in crystal) and more distant pairs of acetylenic groups. A hypothetical possibility of topochemical polymerization in crystal II under uniaxial compression with formation of the ordered trans-polyacetylene is considered.     

Crystal structure and conformation of N-(t-butoxycarbonyl)-L-isoleucyl-L-alanine benzylester

C₂₂N₂O₅H₃₂,M _r =404.5, monoclinic,C2,a=21.781(5),b=5.065(1),c=22.333(4)Å,=112.81(2)°,V=2271.1(9)ų,D _calc=1.148 g cm³, (CuK )=1.5418 Å,=5.89 cm^–1,F(000)=848, room temperature,R=0.058 for 2178 unique reflections [I2.5(I)]. The peptide linkage is in thetrans conformation. The molecule adopts the-sheet structure. The crystal structure is stabilized by a three-dimensional network of N-HO and C-HO hydrogen bonds.DCB Contribution No. 813.     

Sr1+xSm1-xAl1-xTixO4微波陶瓷介电性能研究

以SrCO3,Sm12 O3,Al2O3,TiO2为原料,采用固相反应法制备了Sr1+xSm1-xAl1-xTixO4(x=0,0.1,0.2,0.3)陶瓷,研究了SrTiO3掺人量对其显微结构和微波介电性能的影响.结果表明:SrSmAlO4晶相中固溶SrTiO3,晶胞出现了明显的膨胀;SrSmAlO4陶瓷中固溶SrTiO3相,可降低其烧结温度和陶瓷烧结体的密度;SrSmAlO4陶瓷中固溶SrTiO3相后,可提高其介电常数和品质因素,但对其温频系数影响较小.在1420C/2 h烧结条件下,Sr1.2Sm0.8Al08Ti0 2 O4陶瓷微波介电性能达到:εr=28,Q×f=52600 GHz,τf=4 ppm/℃.     

The crystal and molecular structure of N-(methylsulfonyl)-N-(2,6)-(dimethylphenyl)methanesulfonamide

The title compound, crystallizes in the triclinic space group witha=8.232(4),b=9.159(2),c=10.230(3)Å. =74.07(3)°, =72.50(4)°, =63.65(3)° andZ=2. The structure was solved by direct methods and refined by full matrix least squares methods toR=0.054 for 1817 observed reflections. The plane containing the nitrogen and sulfur atoms is perpendicular to the aromatic plane. One of the S–O bonds in each methanesulfonyl group is in nearly eclipsed conformation with the N–C bond.