Absolute Configuration Determination of Two Optically Active Cyclopropyl-Ketoacids: (1′S, 3S) 3-(2′,2′-Dichloro-1′-methyl-cyclopropyl)-6-oxo-heptanoic acid and (1′S, 3S) 3-(2′,2′-Dibromo-1′-methyl-cyclopropyl)-6-oxo-heptanoic acid

Abstract  

The title compounds C₁₁H₁₆Cl₂O₃ (III) and C₁₁H₁₆Br₂O₃ (IV) have been prepared from (S)-Limonen. Their crystal structure and absolute configuration have been determined by X-ray analysis which confirmed the 1′S absolute configuration at the cyclopropyl moiety, in agreement with the known absolute configuration of the starting material. Both (III) and (IV) are orthorhombic, space group P2₁2₁2₁ with a = 7.2558(4) ? (for III) 7.4058(6) ? (for IV), b = 9.7885(5) ? (for III) 9.7459(7) ? (for IV), c = 17.7551(10) ? (for III) 18.0354(14) ? (for IV), α = 90°, β = 90°, γ = 90° and Z = 4.     

Stereospecific Ligands and Their Complexes. III. Oxalato and Malonato-(ethylenediamine- N , N ′-di- S , S -2-propionato)-Chromate(III) Complexes. Crystal Structure of the Δ-(–)589- s - cis -K[Cr( S , S -eddp)(ox)]?·?0.5H2O

Abstract  The s-cis-[Cr(S,S-eddp)L]⁻ complexes (S,S-eddp = S,S-ethylenediamine-N,N′-di-2-propionate ion; L = oxalate or malonate ions) were prepared. The complexes were purified by ion-exchange chromatography. The geometry of the complexes has been supposed on the basis of the electronic absorption spectra, and the absolute configurations of the isolated s-cis-[Cr(S,S-eddp)L]⁻ complexes have been predicted on the basis of their circular dichroism (CD) spectra and confirmed by X-ray analysis of the crystal structure of the Δ-(–)₅₈₉-s-cis-K[Cr(S,S-eddp)(ox)] 0.5H₂O complex. Index Abstract  The title compound, s-cis-potassium-(ethylenediamine-N,N’-di-S,S-2-propionato) (oxalato)chromate(III) semihydrate was synthesized by passing the corresponding sodium salt through cation exchange-resin Merck I in potassium form and its crystal structure determined. Single crystal X-ray diffraction analysis reveals s-cis geometry of the complex cation. For Part II see Glodjović VV, Trifunović SR (2008) J Serb Chem Soc 73:541.     

Synthesis and Structure of cis-Dioxo(3-Methoxysalicylaldehyde 4-Methylthiosemicarbazonato-N,O,S)(γ-Picoline-N)Molybdenum(VI)

Abstract  Red crystals of cis-dioxo(3-methoxysalicylaldehyde 4-methylthiosemicarbazonato-N,O,S)(γ-picoline-N)molybdenum(VI), [MoO₂L(γ-pic)], [L²⁻=CH₃OC₆H₄(O)CH=NN=C(S)NHCH₃, 3-methoxysalicylaldehyde 4-methylthiosemicarbazonato] were prepared by the reaction of [MoO₂L] _n with γ-picoline in dry methanol. The title compound crystallized in the monoclinic space group P2₁/n, a = 6.7984(7) ?, b = 15.9760(12) ?, c = 17.1466(14) ?, β = 93.613(8)°, V = 1858.6(3) ?³, Z = 4. The coordination geometry around the molybdenum center is distorted octahedral with the tridentate thiosemicarbazonato ligand (L²⁻) bonded meridionally to the [MoO₂]²⁺ core. The sixth coordination site is occupied by a weakly bound γ-picoline molecule. The adjacent molecules are joined by the N–H···O hydrogen bonds between their amino and methoxy groups thus forming infinite molecular chains. The three-dimensional solid-state structure is achieved by the additional C–H···O, C–H···π and van der Waals interactions. Graphical Abstract  In the title compound, [MoO₂L(γ-pic)], the tridentate thiosemicarbazonato ligand (L²⁻) is meridionally bound to the [MoO₂]²⁺ core, while a molecule of γ-picoline completes the distorted octahedral coordination around the metal atom.      

Synthesis and Structures of Two Functionalized Isobenzofurans: (3aR,7aR,4S,5S)-1,3,3a,4,5,7a-Hexahydro-5-methyl-3-oxoisobenzofuran-4-carboxylic acid and (3aα,4β,7β,7aα)-4-[(Acetyloxy)methyl]-3a,4,7,7a-tetrahydro-7-methyl-1,3-isobenzofurandione

Abstract  

The title compounds, C₁₀H₁₂O₄ and C₁₂H₁₄O₅, were prepared as part of an ongoing study to explore the practical aspects of solventless reaction methods. As confirmed by the crystal structures, treatment of maleic anhydride with (2E,4E)-hexa-2,4-dien-1-ol or its acetate counterpart resulted in cis bicyclo [4.3.0] molecular frameworks. The racemic product derived from the dienol synthon crystallized in chiral space group P2₁2₁2₁ via a pasteurian resolution process with molecules organized by carboxyl⋯carboxyl and C–H⋯O contacts. The acetate derivative crystallizes in space group Cc.     

Synthesis, Characterization and X-Ray Structure of Bis(O-propyldithiocarbonato-κ2S,S′)bis(4-cyanopyridine-κN)nickel(II)

Abstract  

The [Ni(S₂COCH₂CH₂CH₃)₂(C₆H₄N₂)₂] adduct of 4-cyanopyridine with [Ni(S₂COCH₂CH₂CH₃)₂] was synthesized and characterized by elemental analysis, magnetic susceptibility measurement, IR, electronic spectral data, Thermogravimetric analysis/DTA techniques and X-ray diffraction analysis. The Ni atom in the title complex is octahedrally coordinated within a trans-N₂S₄ donor set, with the Ni atom located on a centre of inversion. The title complex crystallizes in the monoclinic space group P2 ₁ /c with unit cell parameters a = 11.75(4), b = 11.62(3), c = 9.20(2) ?, β = 104.99(3)°. Crystal structure was solved by direct methods and refined by full matrix least squares procedures to a final R-value of 0.0294 for 1895 observed reflections. The packing of layers of molecules is stabilized by weak C–H···N and C–H···π interactions.     

Synthesis, Characterization, and Crystal Structures of 3-bromo-N′-(2-methoxybenzylidene)benzohydrazide and N′-(2-methoxybenzylidene)-3,4-methylenedioxybenzohydrazide

Abstract  

Two new hydrazone compounds, 3-bromo-N′-(2-methoxybenzylidene)benzohydrazide (1) and N′-(2-methoxybenzylidene)-3,4-methylenedioxybenzohydrazide (2), have been synthesized and characterized by elemental analysis, IR, and single crystal X-ray diffractions. Compound (1) crystallizes in the triclinic space group P1 with unit cell dimensions a = 8.4088(5) ?, b = 8.5398(5) ?, c = 10.6572(6) ?, α = 90.356(3)°, β = 102.868(3)°, γ = 97.987(3)°, V = 738.28(7) Ǻ³, Z = 2, R ₁ = 0.0406, and wR ₂ = 0.0804. Compound (2) crystallizes in the tetragonal space group P4₁ with unit cell dimensions a = b = 9.792(4) ?, c = 15.788(6) ?, V = 1513.8(10) Ǻ³, Z = 4, R ₁ = 0.0415, and wR ₂ = 0.0818. The molecules of both compounds display E configurations with respect to the C=N double bonds. In the crystal structure of (1), molecules are linked through N–H···O hydrogen bonds, forming chains running along the b axis. In the crystal structure of (2), molecules are linked through N–H···O hydrogen bonds, forming chains running along the c axis.     

(Na1/2Bi1/2)TiO3-(Na1/2Bi1/2)(Zn1/3Nb2/3)O3无铅压电陶瓷的介电特性研究

采用固相合成法制备了(1-x)(Na1/2Bi1/2)TiO3-x(Na1/2Bi1/2)(Zn/23Nb2/3)O3(简写为(1-x)NBT-xNBZN)无铅压电陶瓷.研究了该体系陶瓷晶体结构、弥散相变特征与介电弛豫行为.X射线衍射分析表明,所研究的组成均能够形成纯钙钛矿(ABO3)型固溶体.当x≥0.5%摩尔分数时,该体系陶瓷具有三方、四方共存的晶体结构.材料的介电常数-温度曲线显示陶瓷具有两个介电反常峰Tf和Tm.修正的居里-外斯公式较好的描述了陶瓷弥散相变特征,弥散指数随x的增加而增加.x≤0.5%摩尔分数的陶瓷仅在低温介电反常峰Tf附近表现出明显的频率依赖性,随x的增加,陶瓷材料在室温和低温介电反常峰Tf之间都表现出明显的频率依赖性.根据有序-无序转变和宏畴.微畴转变理论探讨了该体系陶瓷介电弛豫特性的机理.     

N,N′-Dihydrogenpiperazonium dichloridobis(dimethylglyoximato-k2N,N′)cobaltate(III) Dihydrate

Abstract  

The title complex: C₄H₁₂N₂[Co(C₄H₇N₂O₂)₂Cl₂]₂·2H₂O, viz., PpH₂[Co(dmgH)₂Cl₂]₂·2H₂O, where, dmgH⁻ = dimethylglyoximate and Pp = piperazine was synthesized and analyzed by single crystal XRD studies. The complex was grown as brown crystals by the slow evaporation method in ethanol. The complex crystallizes as triclinic with the space group p[`1] p\overline{1} and unit cell parameters a = 8.4521 (10) Å, b = 10.0999 (11) Å, c = 10.8952(13) Å; α = 94.066(6)°, β = 106.047(6)° and γ = 100.901(6)°. There are two complex molecules present in the unit cell. The short intra molecular O–H···O hydrogen bonds link the glyoximate moieties in the crystal.     

X-ray diffraction study of R2[UO2(C3H2O4)2] ·H2O (R = K or Rb)

Compounds K₂[UO₂(C₃H₂O₄)₂] · H₂O (I) and Rb₂[UO₂(C₃H₂O₄)₂] · H₂O (II) are synthesized and their crystal structures are determined by X-ray diffraction. The compounds crystallize in the monoclinic crystal system; for I, a = 7.1700(2) ?, b =12.3061(3) ?, c = 14.3080(4) ?, β = 95.831(2)°, space group P2₁/n, Z = 4, and R = 0.0275; for II, a = 7.1197(2) ?, b = 12.6433(4) ?, c = 14.6729(6) ?, β = 96.353(2)°, space group P2₁/n, Z = 4, and R = 0.0328. It is found that I and II are isostructural. The main structural units of the crystals are the [UO₂(C₃H₂O₄)₂]²⁻ chains, which belong to the AT ¹¹ B ⁰¹ (A = UO₂²⁺, T ¹¹, and B ⁰¹ = C₃H₂O₄²⁻) crystal chemical group of uranyl complexes. The chains and alkali metal ions R (R = K or Rb) are connected by electrostatic interactions and hydrogen bonds. Some specific structural features of [UO₂(C₃H₂O4)₂]²⁻ complex groups are discussed.     

Synthesis and the crystal and molecular structures of 4-(piperidyl-1)-2-phenylpyrido[2,3- a ]anthraquinone-7,12 Mono- and dibromohydrates (H L )Br · 3H2O and (H2 L )Br2 · 3H2O

4-(Piperidyl-1)-2-phenylpyrido[2,3-a]anthraquinone-7,12 monobromohydrate (HL)Br · 3H₂O (I) and 4-(piperidyl-1)-2-phenylpyrido[2,3-a]anthraquinone-7,12 dibromohydrate (H₂ L)Br₂ · 3H₂O (II) are isolated in the crystalline state. The crystal structures of compounds I and II are determined using X-ray diffraction. It is established that the protonation of 4-(piperidyl-1)-2-phenylpyrido[2,3-a]anthraquinone-7,12 proceeds primarily through the pyridine atom at pH 2–3. The attachment of the second proton occurs through the piperidine nitrogen atom at pH ∼ 1. Original Russian Text ? O.V. Kovalchukova, A.I. Stash, V.K. Belsky, S.B. Strashnova, B.E. Zaĭtsev, M.A. Ryabov, 2009, published in Kristallografiya, 2009, Vol. 54, No. 1, pp. 72–76.     

Crystal Structure of (E)-2,3-Dihydro-2-(R-Phenylacylidene)-1,3,3-Trimethyl-1H-Indole (R?=?4-CN, 4-Cl)

Abstract  

Two new 1,3,3-trimethyl-2-methylene-2,3-dyhidro-1H-indole derivatives, (E)-2,3-dihydro-2-(4-cyanophenylacylidene)-1,3,3-trimethyl-1H-indole, (I), and (E)-2,3-dihydro-2-(4-chlorophenylacylidene)-1,3,3-trimethyl-1H-indole, (II), have been synthesized and their crystal structure determined by single crystal X-ray diffraction. (I), C₂₀H₁₈N₂O, crystallizes in a monoclinic space group, P2₁/c, with unit cell parameters a = 9.882 (3), b = 15.614(4), c = 11.181(3) ?, β = 106.691(4)°, Z = 4. (II), C₁₉H₁₈Cl N O, crystallizes in a monoclinic space group, P2₁/n, with unit cell parameters a = 14.6722(19), b = 7.2597(9), c = 16.304(2) ?, β = 111.249 (2)°, Z = 4. The molecules consist of a enaminoketone group formed by a Fischer base 1,3,3-trimethyl-2-methylene-2,3-dihydro-1H-indole bonded, at the exocyclic electron-rich β-carbon atom of the indole moiety, with the benzoyl chloride derivatives substituted at para-positions with cyano and chloro groups. The molecules adopt a s-cis conformation with respect to the C=O bond towards the C=C bond, and a E configuration about the latter indole exocyclic alkene C–C bond. Intermolecular arrangement of the crystals show, for (I) an antiparallel stacking mode favored by the formation of weak C–H···π interactions involving the phenyl ring attached to the carbonyl group and the phenyl of the indole fragment in a head-to-tail mode, whereas, (II) present an weak C–H···Hal interaction.     

Synthesis and crystal structures of cis- and trans-1-(3′-N, N-dimethylthiocarbamoyl-4′-methoxy)-2-(3″, 4″, 5″trimethoxyphenyl) ethene

The combretastatin A-4 analogue cis-1-(3-N,N-dimethylthiocarbamoyl-4-methoxy)-2-(3,4, 5-trimethoxyphenyl) ethene (1) and its trans stereoisomer (2) were synthesized. The molecular structures of these compounds were obtained by single-crystal X-ray diffraction. Crystallization of 1 occurs in the centrosymmetric monoclinic space group C2/c (No. 15) with a = 21.468(5), b = 7.932(1), c = 23.949(3); and = 100.75(1) and Z = 8. Crystallization of 2 occurs in the centrosymmetric monoclinic space group P2₁/n (No. 14) with a = 11.7825(7), b = 11.562(1), c = 14.911(1) and = 93.294(6); and Z = 4. Details of the synthesis and the structural characterization of the title compounds are presented and discussed.     

Complementary Supramolecular Aggregation via O–H···O Hydrogen-bonding and Hg···S Interactions in Bis[N,N′-di(2-hydroxyethyl)-dithiocarbamato-S,S′]mercury(II): Hg[S2CN(CH2CH2OH)2]2

Abstract  The central mercury atom in Hg[S₂CN(CH₂CH₂OH)₂]₂ is asymmetrically chelated by two dithiocarbamate ligands leading to a distorted square planar geometry. Molecules aggregate into supramolecular chains via Hg···S interactions that are connected into a three dimensional array by extensive hydrogen bonding interactions. The compound crystallizes in the orthorhombic space group Pna2₁ with a = 13.8173(7) ?, b = 4.5307(1) ?, c = 26.0261(12) ?, and Z = 4. Index Abstract  Molecules associate into supramolecular chains via Hg···S interactions and these are connected into a three dimensional architecture by O–H···O hydrogen-bonding interactions.      

Pb(Sc1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3-PbZrO3弛豫铁电晶体的生长及表征

采用高温溶液法生长了准同型相界(MPB)四元弛豫铁电单晶Pb(Sc1/2Nb1/2) O3-Pb(Mg1/3 Nb2/3)O3-PbTiO3-PbZrO3,得到较大尺寸且具有规则外形的立方单晶.研究结果表明所生长的晶体为钙钛矿结构,立方晶粒平整的暴露面均为(001)面;晶体以层状方式生长,生长机制为搭桥生长;所生长晶体的矫顽场Ec～3.52kV/cm,三方四方相变温度Tr-t～104℃,居里温度Tc～149.5℃,压电常数d33～1089 pC/N,剩余极化强度Pr～25.4 μC/cm2;随着频率增加,晶体的相变弥散度减小.     

三元铁电单晶Pb(Yb1/2Nb1/2)O3-Pb(Zn1/3Nb2/3)O3-PbTiO3生长及性能表征

采用高温助熔剂法首次成功生长出了Pb(Yb1/2Nb1/2) O3-Pb(Zn1/3Nb2/3) O3-PbTiO3 (PYZNT)三元铁电单晶,并对晶体组分、介电、铁电和压电性能进行了研究.结果表明,晶体为纯三方钙钛矿相,实际组分为0.68PYN-0.22PZN-0.1PT.分别对晶体的介电,铁电和压电性能进行研究.介电常数ε'和介电损耗tanδ对温度和频率表现出典型的弛豫行为.晶体的居里温度TC为80℃.由于反铁电体PYN含量较高,晶体具有非常大的矫顽场,在100kV/cm的外电场条件下极化还不能反转,因而无法得到饱和的电滞回线.在未极化条件下,测得晶体的压电常数d33为78 pC/N.     

Synthesis and Crystal Structures of N′-3,5-Dibromo-2-Hydroxybenzylidene)-2-Hydroxy-3-Methylbenzohydrazide and its Oxovanadium(V) Complex [N′-(3,5-Dibromo-2-Oxidobenzylidene-κO)-2-Hydroxy-3-Methylbenzohydrazidato-κ2N′,O](Methanol-κO)(Methanolato-κO)Oxidovanadium(V)

Abstract  

A new hydrazine ligand N′-3,5-dibromo-2-hydroxybenzylidene)-2-hydroxy-3-methylbenzohydrazide (1) and its oxovanadium(V) complex [N′-(3,5-dibromo-2-oxidobenzylidene-κO)-2-hydroxy-3-methylbenzohydrazidato-κ ² N′,O](methanol-κO)(methanolato-κO)oxidovanadium(V) (2), were prepared and were structurally characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic space group P−1, with unit cell dimensions a = 7.813(2) ?, b = 8.748(2), c = 26.071(6) ?, α = 85.763(2)°, β = 81.521(2)°, γ = 89.358(3)°, V = 1757.6(7) ?³, Z = 4, R ₁ = 0.0587, and wR ₂ = 0.1054. Compound 2 crystallizes in the triclinic space group P-1, with unit cell dimensions a = 7.777(3) ?, b = 11.594(3), c = 12.363(3) ?, α = 107.965(3)°, β = 103.190(2)°, γ = 96.656(2)°, V = 1011.3(5) ?³, Z = 2, R ₁ = 0.0634, and wR ₂ = 0.1480. The hydrazine ligand coordinates to the V atom through the phenolic O, imino N, and ethanolic O atoms. The V atom in the complex is in an octahedral coordination, with the three donor atoms of the hydrazine ligand and one methanolato O atom defining the equatorial plane, and with one methanol O and one oxo O atoms occupying the axial positions. The displacement of the V atom from the equatorial plane towards the axial oxo O atom is 0.305(2) ?.     

Synthesis and Structural Characterization of Dibromidobis(N,N′-dimethylthiourea-κS)cadmium(II) and Diiodidobis(N,N′-dimethylthiourea-κS)cadmium(II)

Abstract  

Cadmium(II) complexes, dibromidobis(N,N′-dimethylthiourea-S)cadmium(II), [Cd(Dmtu)₂Br₂] (1) and diiodidobis(N,N′-dimethylthiourea-S)cadmium(II), [Cd(Dmtu)₂I₂] (2), have been prepared and their structures have been determined by X-ray crystal structure analysis. Compound 1 crystallized in the monoclinic space group C2/c, and the metal ion is situated on a twofold rotation axis. Compound 2 also crystallized in a monoclinic space group, P2₁/c, but here the molecules have no crystallographic symmetry. In both compounds the cadmium atom is bonded to two halide ions and to two dimethylthiourea molecules through the sulfur atoms in a tetrahedral environment. The molecules are linked via N–H⋯Halide hydrogen bonds to form infinite one-dimensional chains in 1 and infinite two dimensional networks in 2. The complexes were also characterized by IR and NMR spectroscopy and the data are consistent with the structures of the compounds.     

The X-Ray Structure and Spectroscopic Characterization of [Zn(H2O)6][{Zn(H2O)}2(ttha)]·4H2O (ttha?=?Triethylenetetraamine-N,N,N′,N″,N?,N?-hexaacetate)

Abstract  

[Zn(H₂O)₆][{Zn(H₂O)}₂(ttha)]·4H₂O (ttha = triethylenetetraamine-N,N,N′,N″,N‴,N‴-hexaacetate) has been structurally characterized (triclinic, P-1, a = 7.4014(4) ?, b = 8.5521(4) ?, c = 15.0309(7) ?, α = 73.582(1)°, β = 85.173(1)°, γ = 69.935(1)°; V = 857.15(7) ?³; Z = 1). The two Zn²⁺ ions bound by the [ttha]⁻⁶ ligand are in distorted octahedral environments. While there exists a center of symmetry in the [{Zn(H₂O)}₂(ttha)]²⁻ anion in the crystalline state, ¹³C{¹H} NMR spectroscopy demonstrates the absence of a center of symmetry in aqueous solution. Furthermore, electronic absorption spectroscopy reveals that [Zn(H₂O)₆][{Zn(H₂O)}₂(ttha)]·4H₂O reacts with vanadyl(IV) acetate in aqueous solution at room temperature to yield [(VO)₂(ttha)]²⁻. This reaction implies that Zn²⁺ can dissociate from [{Zn(H₂O)}₂(ttha)]²⁻ in aqueous solution.     

Pb(In1/2Nb1/2)O3-Pb(Ni1/3Nb2/3)O3-PbTiO3压电陶瓷的介电、铁电和压电性能

采用两步法制备了0.30Pb(In1/2 Nb1/2)O3-(0.70-x)Pb(Ni1/3Nb2/3)O3-xPbTiO3(PIN-PNN-PT,x=0.33,0.35,0.37,0.39)压电陶瓷.研究了PIN-PNN-PT压电陶瓷的相结构、介电、铁电和压电性能.研究表明位于准同型相界(MPB)的组分0.30PIN-0.33PNN-0.37PT具有最佳电学性能,其居里温度TC、压电系数d33、平面机电耦合系数kp、自由介电常数ε二介电损耗tanδ、剩余极化Pr、矫顽场EC分别为200℃、386 pC/N、50;、2692、0.045、34 μC/cm2、18 kV/cm.结果 显示PIN-PNN-PT三元系相比于PNN-PT有更高的居里温度,同时保持了优异的压电性能.