Syntheses, structures, and physical properties of LnAsTe (Ln = La, Pr, Sm, Gd, Dy, Er)

Six rare-earth arsenic tellurides have been synthesized by the reactions of the rare-earth elements (Ln) with As and Te at 1123 K. LaAsTe (a = 7.8354(11) A, b = 4.1721(6) A, c = 10.2985(14) A, T = 153 K), PrAsTe (a = 7.728(2) A, b = 4.1200(11) A, c = 10.137(3) A, T = 153 K), SmAsTe (a = 7.6180(16) A, b = 4.0821(9) A, c = 9.991(2) A, T = 153 K), GdAsTe (a = 7.5611(15) A, b = 4.0510(8) A, c = 9.920(2) A, T = 153 K), DyAsTe (a = 7.4951(13) A, b = 4.0246(7) A, c = 9.8288(17) A, T = 153 K), and ErAsTe (a = 7.4478(1) A, b = 4.0078(1) A, c = 9.7552(2) A, T = 153 K) crystallize with four formula units in the orthorhombic space group D2h16-Pnma. These compounds are isostructural and belong to the beta-ZrSb2 structure type. In each compound, the Ln atoms are coordinated by a tricapped trigonal prism of four As atoms and five Te atoms. The entire three-dimensional structure is built up by the motif of the LnAs4Te5 tricapped trigonal prisms. Infinite nonalternating zigzag As chains are found along the b axis, with As-As distances in these compounds ranging from 2.5915(5) to 2.6350(9) A. Conductivity measurements in the direction of these As chains indicate that PrAsTe is metallic whereas SmAsTe and DyAsTe are weakly metallic. Antiferromagnetic transitions occur in SmAsTe and DyAsTe at 3 and 9 K, respectively. DyAsTe above 9 K follows the Curie-Weiss law.     

Medicinal foodstuffs. XIX. Absolute stereostructures of canavalioside, a new Ent-kaurane-type diterpene glycoside, and gladiatosides A1, A2, A3, B1, B2, B3, C1, and C2, new acylated flavonol glycosides, from sword bean, the seeds of Canavalia gladiata

A new ent-kaurane-type glycoside, canavalioside, and eight new acylated flavonol glycosides, gladiatosides A1, A2, A3, B1, B2, B3, C1, and C2, were isolated from the seed of Canavalia gladiata together with robinin, kaempferol 3-O-beta-D-galactopyranosyl-7-O-alpha-L-rhamnopyranoside, and kaikasaponin III. The absolute stereostructures of canavalioside and gladiatosides A1, A2, B1, B2, B3, C1, and C2 were elucidated on the basis of chemical and physicochemical evidence.     

KCl-NaCl(1:1mol)-RECl3熔体的电导率(RE=La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y、Ce族、Y族)

用交流电桥法测定了熔融KCl-NaCl(1:1摩尔)-RECl₃的电导。比电导的温度函数表达式如下: κ=A+B(t-700) κ:比电导(Ω^-1·cm^-1);t:温度(700—850℃); A、B:本文给出的常数。讨沦了实验值与计算值的偏差,当稀土氯化物在熔体中的浓度为10—50重量百分数时可能形成了络合物。     

The synthesis, structure, and properties of carbon-containing nanocomposites based on nickel, palladium, and iron

Nickel, iron, palladium, and bimetallic nickel-palladium nanoparticles encapsulated in carbon were synthesized by contactless levitation fusion of metals in a magnetic field in a flow of an inert gas containing a hydrocarbon. The products were characterized by X-ray diffraction, differential thermal analysis, thermogravimetry, high-resolution transmission electron microscopy, and adsorption. A layered carbon shell preventing agglomeration and oxidation formed on the surface of nickel- and iron-containing particles. The size of particles depended on preparation conditions and could be of 5–15 nm. Original Russian Text ? A.E. Ermakov, M.A. Uimin, E.S. Lokteva, A.A. Mysik, S.A. Kachevskii, A.O. Turakulova, V.S Gaviko, V.V. Lunin, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 7, pp. 1338–1345.     

Crystal Structure of 3-methyl-1, 2, 3, 4, 4a, 4b, 9a, 15, 15a,15b-decahydro-(4,5);(4a,15)-dimethano-tricyclo(4, 3, 1, 0~(2,7)) deca 〔8, 9, 1, 10-a,b, c〕pyrido〔4,3-a〕-acridin-6-en-9-ol-8-one

1INTRODUCTIONIntheO-demethyIationof7a-o-amino-phenyl-6,14-endo-ethenotetrahydrothe-baine,catalyzedbyhydrobromicacid,ifinhightemperatureandprolongedtime,anewcomPoundwithyie1dof17.9%wasfound,whosestructurecannotbedeferredfromthepreviousacid-catalyzedrearrangementof6,14-endo-ethnotetrahydrothe-baines(1-33.ItwascrystallizedfromanhydrousethanolsolutionanditsstructurewasdeterminedbyX-raycrystallography.2EXPERmENTALAcrystalwithdimensionsofO.3mmXO.4mmXO.5mmwasmountedonanEnraf-NoniusCAD4d…     

Syntheses, thermal stability, and structure determination of the novel isostructural RBa3B9O18 (R = Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb)

A novel borate compound YBa(3)B(9)O(18) has crystallized in a melt of BaYB(9)O(16). Single-crystal X-ray diffraction measurements reveal that YBa(3)B(9)O(18) adopts a hexagonal space group P6(3)/m with cell parameters of a = 7.1761(6) A and c = 16.9657(6) A. The structure is made up of the planar B(3)O(6) groups parallel to each other along the (001) direction, regular YO(6) octahedra, and irregular BaO(6) and BaO(9) polyhedra to form an analogue structure of beta-BaB(2)O(4). A series of isostructural borate compounds RBa(3)B(9)O(18) (R = Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) were prepared by powder solid-state reactions. The DTA and TGA curves of YBaB(9)O(16) show an obvious weight loss at about 955 degrees C associated with a decomposition into YBO(3), B(2)O(3), and YBa(3)B(9)O(18) due to its incongruent melting behavior. The DTA and TGA curves of YBa(3)B(9)O(18) show that it is chemically stable and a congruent melting compound. A comparison of the structures of YBa(3)B(9)O(18) and beta-BaB(2)O(4) is presented.     

Stabilization of new forms of the intermetallic phases beta-RENiGe2 (RE = Dy, Ho, Er, Tm, Yb, Lu) in liquid indium

Flux conditions using liquid indium bypass the thermodynamically stable structure and yield new forms of the phases RENiGe2 (RE = Dy, Er, Yb, Lu). The compounds crystallize in the orthorhombic Immm space group and possess the YIrGe2 structure type. Lattice parameters for ErNiGe2, DyNiGe2, YbNiGe2, and LuNiGe2 are a = 4.114(1) A, b = 8.430(2) A, c = 15.741(5) A; a = 4.1784(9) A, b = 8.865(2) A, c = 15.745(3) A; a = 4.0935(6) A, b = 8.4277(13) A, c = 15.751(2) A, and a = 4.092(1) A, b = 8.418(3) A, c = 15.742(5) A, respectively. These phases represent a new structural arrangement (beta) of the compound type RENiGe2 as another set of compounds with identical stoichiometry are known to adopt the orthorhombic Cmcm CeNiSi2 type structure (alpha). In this paper we report the crystal and electronic band structure of four new members of the YIrGe2 structure type, as well as an investigation of the relative thermodynamic stabilities of the two forms.     

Synthesis of xyloketal A, B, C, D, and G analogues

A series of demethyl analogues of the natural products xyloketal A, B, C, D, and G have been prepared in a notably direct manner from 3-hydroxymethyl-2-methyl-4,5-dihydrofuran and a series of corresponding phenols. These syntheses featured a boron trifluoride diethyl etherate-promoted electrophilic aromatic substitution reaction as a key step. In the case of the synthesis of analogues of xyloketal A, the process was found to be highly efficient (up to 93% yield). The optimized isolated yield of these reaction products is remarkable in view of the fact that this transformation involves, minimally, six individual reactions. Moreover, these synthetic studies provide significant insight into the possible biogenic origin of the xyloketal natural products.     

STRUCTURE OF MOLECULAR COMPOUND CRYSTAL A_2B(A =1, 6, 7, 8,-TETRA-PHENYL (3, 4-BENZO)BICYCLO[4, 2, 0]OCTA-7-ENE, B=CIS, CIS-1,2,3,4,-TETRAPHENYLBUTADIENE)

<正> C100H78, (A: C36H28, B: C28H22) Mr = 1279. 74, monoclinic, P21/a, a=17. 282(3), b=10. 669(4), c= 19, 927(3) A , β =102. 99(1)°,V = 3580. 1(2) A3, Z=2, μ(MoKα) = 0. 623cm-1, F(000) = 1356, Dc=1. 187g/cm3, room temperature. The final R=0. 084, Rw = 0. 086 for 1255 independent observed reflections (I≥3σ(I)). Owing to the existence of 1,6,7, 8-Tetraphenyl (3,4-benzo)-bicyclo[4, 2, 0]octa-7-ene(A) , cis, cts-1, 2, 3, 4-Tetraphenylbutadiene (B) in A2B can take the different conformation from the one in the pure B crystal. The reason of the formation of this molecular compound crystal is put forward.     

Coordination of lanthanide triflates and perchlorates with N,N,N',N'-tetramethylsuccinamide

Compounds formed from the reaction of N,N,N',N'-tetramethylsuccinamide (TMSA) with trivalent lanthanide salts possessing the poorly coordinating counteranions triflate (CF3SO3-) and perchlorate (ClO4-) have been prepared and examined. Structural features of these Ln-TMSA compounds have been studied in the solid phase by thermogravimetric analysis, infrared spectroscopy, and, in selected cases, by single-crystal X-ray diffraction and in solution by infrared spectroscopy. Eight-coordinate compounds, [Ln(TMSA)4]3+, derived from coordination of four succinamide ligands to the metal ion could be formed with all lanthanides examined (Ln = La, Pr, Nd, Eu, Yb, Lu). Structural analyses by single-crystal X-ray diffraction were performed for the lanthanide triflate salts Ln(C8H16N2O2)4(CF3SO3)3: Ln = La, compound 1, monoclinic, P2(1)/n, a = 11.0952(2) A, b = 19.2672(2) A, c = 24.9759(3) A, beta = 90.637(1) degrees, Z = 4, Dcalcd = 1.586 g cm-3; Ln = Nd, compound 2, monoclinic, C2/c, a = 24.6586(10) A, b = 19.3078(7) A, c = 11.1429(4) A, beta = 90.450(1) degrees, Z = 4, Dcalcd = 1.603 g cm-3; Ln = Eu, compound 3, monoclinic, C2/c, a = 24.4934(2) A, b = 19.3702(1) A, c = 11.1542(1) A, beta = 90.229(1) degrees, Z = 4, Dcalcd = 1.617 g cm-3; Ln = Lu, compound 5, monoclinic, C2/c, a = 24.2435(4) A, b = 19.6141(2) A, c = 11.2635(1) A, beta = 90.049(1) degrees, Z = 4, Dcalcd = 1.626 g cm-3. X-ray analysis was also carried out for the perchlorate salt: Ln = Eu, compound 4, triclinic, P1, a = 10.9611(2) A, b = 14.6144(3) A, c = 15.7992(2) A, alpha = 106.594(1) degrees, beta = 91.538(1) degrees, gamma = 90.311(1) degrees, Z = 2, Dcalcd = 1.561 g cm-3. In the presence of significant amounts of water, 7-coordinate compounds with mixed aquo-TMSA cation structures [Ln(TMSA)3(H2O)]3+ (Ln = Yb) and [Ln(TMSA)2(H2O)3]3+ (Ln = La, Pr, Nd, Eu, Yb) have been isolated with structural determinations by single-crystal X-ray diffraction obtained for the following species: Yb(C8H16N2O2)3(H2O)(CF3SO3)3, compound 6, monoclinic, P2(1)/n, a = 8.9443(3) A, b = 11.1924(4) A, c = 44.2517(13) A, beta = 93.264(1) degrees, Z = 4, Dcalcd = 1.735 g cm-3; Yb(C8H16N2O2)3(H2O)(ClO4)3, compound 7, monoclinic, Cc, a = 19.2312(6) A, b = 11.1552(3) A, c = 19.8016(4) A, beta = 111.4260(1) degrees, Z = 4, Dcalcd = 1.690 g cm-3; Yb(C8H16N2O2)2(H2O)3(CF3SO3)3, compound 8, triclinic, P1, a = 8.6719(1) A, b = 12.2683(2) A, c = 19.8094(3) A, alpha = 75.815(1) degrees, beta = 86.805(1) degrees, gamma = 72.607(1) degrees, Z = 2, Dcalcd = 1.736 g cm-3. Unlike in the analogous nitrate salts, only bidentate binding of the succinamide ligand to the lanthanide metal is observed. IR spectroscopy studies in anhydrous acetonitrile suggest that the solid-state structures of these Ln-TMSA compounds are maintained in solution.     

Galloyl-oxypaeoniflorin, suffruticosides A, B, C, and D, five new antioxidative glycosides, and suffruticoside E, A paeonol glycoside, from Chinese moutan cortex.

Five new antioxidative glycosides named galloyl-oxypaeoniflorin, suffruticosides A, B, C, and D, and a new paeonol glycoside named suffruticoside E have been isolated from Chinese Moutan Cortex, the root cortex of Paeonia suffruticosa ANDREWS, together with antioxidative galloyl-paeoniflorin. Their structures were elucidated on the basis of chemical and physicochemical evidences. Galloyl-oxypaeoniflorin, galloyl-paeoniflorin, suffruticosides A, B, C, and D showed more potent radical scavenging and antioxidative effects than alpha-tocopherol.     

Crystal growth, structure, magnetic, and transport properties of TbRhIn5

Single crystals of TbRhIn5 were synthesized using the flux growth method. TbRhIn5 adopts the HoCoGa5 structure type and crystallizes in the space group P4/mmm, Z = 1. Lattice parameters are a = 4.6000(6) A, c = 7.4370(11) A, and V = 157.29(6) A3. Transport measurements show that TbRhIn5 is metallic (drho/dT > 0). A sharp antiferromagnetic transition is observed at T(N) = 48 K in the susceptibility data for TbRhIn5, which is highly anisotropic when the field is oriented along the c axis and a-b plane of the crystal and has an average effective moment of 9.72 muB/Tb3+.     

Nigellamines A3, A4, A5, and C, new dolabellane-type diterpene alkaloids, with lipid metabolism-promoting activities from the Egyptian medicinal food black cumin

New dolabellane-type diterpene alkaloids, nigellamines A(3), A(4), A(5), and C, were isolated from the methanolic extract of an Egyptian medicinal food, black cumin (the seeds of Nigella sativa). Their absolute configurations were determined on the basis of chemical and physicochemical evidence. Nigellamines were found to lower triglyceride levels in primary cultured mouse hepatocytes, and in particular, the activity of nigellamine A(5) was equivalent to that of the hypolipidemic agent, clofibrate.     

Chemical substance,material, product,goods, waste: a changing ontology

A chemical substance (CS) is instantiated in the material world by a number of quantities of such substance (QCSs), placed in different locations. A change of location implies a change in the net of relationships entertained by the QCS with the region wherein it is found. This fact entails changes of the ontological status of the CS, as this is not fully determined by the inherent features of the CS and includes a relevant relational contribution. In order to demonstrate this thesis, we have chosen to analyse the status of quantities of a same CS that are synchronically located in different spacetime regions: a synthetic lab, a lab where the QCS is turned into a material, an industrial plant, the market where the QCS gets a price and a dump waste where the QCS is discarded, respectively:

Chemical substance Open image in new window material Open image in new window (industrial) product Open image in new window goods Open image in new window waste

The use of first-order predicate logic, mereology and locative logic allows carrying out a regimentation process that highlights the ontological commitments implied by the formal expressions through which each element of the aforementioned series can be described. The presence of relational properties discloses the systemic nature of the CS instantiated within a spacetime region. The implications of such an aspect are discussed.

     

Aspergillus ochraceus: Metabolites,Bioactivities, Biosynthesis,and Biotechnological Potential

Fungus continues to attract great attention as a promising pool of biometabolites. Aspergillus ochraceus Wilh (Aspergillaceae) has established its capacity to biosynthesize a myriad of metabolites belonging to different chemical classes, such as isocoumarins, pyrazines, sterols, indole alkaloids, diketopiperazines, polyketides, peptides, quinones, polyketides, and sesquiterpenoids, revealing various bioactivities that are antimicrobial, cytotoxic, antiviral, anti-inflammatory, insecticidal, and neuroprotective. Additionally, A. ochraceus produces a variety of enzymes that could have variable industrial and biotechnological applications. From 1965 until June 2022, 165 metabolites were reported from A. ochraceus isolated from different sources. In this review, the formerly separated metabolites from A. ochraceus, including their bioactivities and biosynthesis, in addition, the industrial and biotechnological potential of A. ochraceus are highlighted.     

Die Chukrasine A,B, C,D und E,fünf neue Tetranortriterpene aus Chukrasia tabularisA. JUSS

The Chukrasines A, B, C, D and E, Five New Tetranortriterpenes From Chukrasia tabularis A . JUSS Five new tetranortriterpenes, chukrasins A, B, C, D and E, have been isolated from the wood of Chukrasia tabularis A . JUSS . On the basis of spectral and chemical evidence structures 1a - 1e were assigned to the new compounds.     

Synthesis,structure, electrical properties,and band structure calculations of TiAsTe

The new compound TiAsTe has been synthesized by the reaction of the elements in a LiCl/KCl flux at 923 K. The compound crystallizes with four formula units in space group Immm of the orthorhombic system in a cell at 153 K of a = 3.5730(8) A, b = 5.249(1) A, c = 12.794(3) A, V = 240.0(1) A(3). The structure, which is of the NbPS structure type, is a three-dimensional extended framework built from bicapped TiAs(4)Te(4) trigonal prisms. It may be considered to comprise infinity (2) [TiTe] slabs perpendicular to [001] that are interspersed with linear infinity (1)[As] chains running along [010]. The As-As distances alternate at 2.554(2) and 2.695(2) A. Electrical and thermopower measurements indicate that TiAsTe is an n-type metallic compound. Density functional theory calculations help rationalize the chemical bonding and physical properties.     

Synthesis, morphology, structure, and magnetic characterization of layered cobalt hydroxyisocyanates

New layered pink cobalt hydroxyisocyanates have been prepared by controlled hydrolysis of aqueous solutions of CoCl2.6H2O. Co(OH)(1.4)(NCO) 0.6.0.6H 2O ( 1) is formed when urea is used as the hydrolysis agent and mannitol as the stabilizer, while Co(OH)(1.25)(NCO)(0.75).0.2H2O ( 2) is formed when the hydrolysis agent is changed to hexamethylenetetramine and NaOCN is added to the solution. IR spectroscopy of 1 and 2 indicates that the OCN (-) is N-bonded to Co (2+). The X-ray powder data for 1 could be indexed using an intergrowth model consisting of both rhombohedral ( R3 m (166); a = 3.2031(1) A, c = 23.6876(11) A, hydrotalcite-like, 3 R 1) and hexagonal ( P 63/ mmc (194); a = 3.2005(2) A, c = 15.8303(5) A, Manasseite-like, 2H1) polytypes. Rietveld refinement of the X-ray powder data was performed using a two polytype model and 30% random substitution of the OH (-) ions by OCN (-). Although it is less crystalline, the XRD data for 2 can be indexed using a rhombohedral-symmetry cell with unit cell parameters, a = 3.158 A and c = 21.57 A. Both 1 and 2 exhibit magnetically ordered ground states with a saturation magnetization of ca. 2.0 mu B. The magnetization data is consistent with 3D ferromagnetic ordering of edge-share octahedral-Co (2+) layers with effective spin S' = 1/2.     

Triterpene glycosides from the sea cucumber Eupentacta fraudatrix. Structure and biological action of cucumariosides A1, A3, A4, A5, A6, A12 and A15, seven new minor non-sulfated tetraosides and unprecedented 25-keto, 27-norholostane aglycone

Seven new minor triterpene glycosides, cucumariosides A1 (1), A3 (2), A4 (3), A5 (4), A6 (5), A12 (6) and A15 (7) have been isolated from the Far Eastern sea cucumber Eupentacta fraudatrix. Structures of the glycosides were elucidated by 2D NMR spectroscopy and MS. Glycosides 1-7 belong to the group of cucumariosides A, having linear tetrasaccharide carbohydrate moieties without any sulfate group and possessing 3-O-methyl-D-xylose as a terminal monosaccharide unit. The latter peculiarity is rare in sea cucumber glycosides, but typical for the glycosides from E. fraudatrix. Glycosides 1-7 differ from each other by side chain structures in the aglycone moieties; three of them have unique structural features. The first is the presence of a 25-butoxy-group in the side chain of cucumarioside A3 (2), the second is a 23E,25-diene system in cucumarioside A6 (5) and the third is a 25-keto-27-nor-holostane aglycone in cucumarioside A12 (6); these were never previously found in sea cucumber glycosides. Cytotoxic activity of glycosides 1-7 against mouse spleen lymphocytes and the cells of the ascite form of mouse Ehrlich carcinoma, along with hemolytic activity against mouse erythrocytes and antifungal activity were studied. Glycosides 1 and 5 were the most active in all the tests.     

Improved synthesis of isogranulatimide, a G2 checkpoint inhibitor. Syntheses Of didemnimide C, isodidemnimide A, neodidemnimide A, 17-methylgranulatimide, and isogranulatimides A-C

A concise, improved synthesis of isogranulatimide (6), a naturally occurring substance with G2 checkpoint inhibition activity, is described. Also reported are the syntheses of didemnimide C (18), isodidemnimide A (24), neodidemnimide A (36), 17-methylgranulatimide (9), and isogranulatimides A (10), B (11), and C (12). Compounds 9-12, congeners of isogranulatimide (6), are now available for biological evaluation.