Synthesis, Crystal Structure of catena-poly [[4,4′-bipyridine-N,N′-bis[(triphenylphosphine)-copper(I)]-pyridine-2-carbaldehyde azine-N,N′:N″,N′″] bis(tetrafluoroboride)]

Abstract  

The title complex [Cu₂(C₁₀H₈N₂)(C₁₂H₁₀N₄)(C₁₈H₁₅)₂(BF₄)₂] _n has been synthesized and characterized by single crystal X-ray analysis. The compound crystallizes in the monoclinic space group P2₁/c with a = 10.450(4) Å, b = 14.027(5) Å, c = 18.950(6) Å, β = 100.459(5)°, V = 2,731.7(16) ų. In the title complex, the cation forms a linear chain, which is bridged by 4,4′-bipyridine and pyridine-2-carbaldehyde azine. The crystallographic asymmetry unit could be expanded polymeric structure using symmetry code: x, 1 + y, z; 1 − x, −y, 1 − z. The Cu(I) atom is coordinated by one P atom of PPh₃ ligand, two N atoms of pyridine-2-carbaldehyde azine ligand and one N atom of 4,4′-bipyridine ligand. There is a crystallographic centre of symmetry at the mid-point of the C–C bond between two pyridine rings of 4,4′-bipyridine.     

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.     

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.     

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 the crystal and molecular structures of (H3L · Cl)[CoCl4] and H2L[CuBr4] (L is 2,4,6-Tri(N,N-dimethylamino)methylphenol)

The complex compounds (H₃ L · Cl)[CoCl₄] (I) and H₂ L[CuBr₄] (II), where L is 2,4,6-tri(N,N-dimethylamino)methylphenol, were isolated in the crystalline state and studied by X-ray diffraction. The organic cations were found to be outer-sphere ligands. All three nitrogen atoms of the tertiary amino groups are protonated. In compound I, the H₃ L ³⁺ cation exists as the cis tautomer. In compound II, the H₂ L ²⁺ dication exists as the trans isomer. In the crystal structure, the dications are arranged in layers via hydrogen bonds.     

Structure of Methyl N-(4-methoxyphenylmethyl)-N′-cyano-carbamimidothioate and Methyl N-[1-(phenylmethyl)-4-piperidinyl]-N′-cyanocarbamimidothioate

Abstract  

The title compounds, Methyl N-(4-methoxyphenylmethyl)-N′-cyanocarbamimidothioate, I, and Methyl N-[1-(phenylmethyl)-4-piperidinyl]-N′-cyanocarbamimidothioate, II, have been designed and synthesized for use as new potential organic molecular electronic materials. The crystal structure of I and II were determined with crystal data (I: Monoclinic, P2₁/c, a = 4.746(2) ?, b = 5.737(3) ?, c = 17.399(7) ?, β = 91.667(7)o, R _all = 0.0703; II: Orthorhombic, Pna2₁, a = 18.209(8) ?, b = 11.463(5) ?, c = 7.539(3) ?, β = 90.00 o, R _all = 0.0481). N–H···N hydrogen bonds were responsible for the formation of one-dimensional zigzag molecular chains of I, and trifurcated hydrogen-bonded molecular chains were indicated in structure of II. C–H···π and C–H···N hydrogen bonds were found in both structures. All these types of interaction together form an extended three-dimensional network and stabilize the title crystals.     

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.     

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 Characterization of a Novel Unsymmetrical Tetradentate Schiff Base Complex of Zinc(II) Derived from N,N′-bis (5-Bromosalicylidene) 2,3-Diaminopyridine (H2L): Crystal Structure of [Zn(II)L]Pyridine

Abstract  

Yellow crystals of [Zn(N,N′-bis (5-bromosalicylidene) 2,3-diaminopyridine)] Pyridine, [Zn(C₁₉H₁₁Br₂N₃O₂)]C₅H₅N, have been obtained and characterized by elemental analysis, FT-IR, UV–Vis, ¹H NMR spectroscopy and MALDI-TOF mass spectrometry. The structure has been determined by single crystal X-ray crystallography. The complex crystallizes in the triclinic space group P-1 with two molecules in the asymmetric unit and with unit cell dimensions a = 8.0103(3) ?, b = 12.8340(5) ?, c = 22.3682(11) ?, α = 91.715(2)°, β = 93.918(2)°, γ = 103.708(2)°. V = 2226.30(16) ?³, Z = 4, R ₁ = 0.0780 and wR ₂ = 0.1192. X-ray structure determination revealed that the complex consists of a [Zn(C₁₉H₁₁Br₂N₃O₂)] moiety with a coordinated pyridine molecule on the metallic centre. The zinc atom adopts a distorted square pyramidal geometry as it is shown in the crystal structure.     

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.     

Single Crystal XRD Structure Determination and Analysis of Bis(2,9-Dimethyl-1,10-Phenanthroline-κ2N,N′)(Sulfato-κ2O,O′)Nickel(II), Hydrate (NiNeo2SO4·H2O; Neo: 2,9-Dimethyl-1,10-Phenanthroline)

Abstract  

The title compound is monomeric with a Ni(II) hexacoordinated center. The coordination sphere is formed with four nitrogens from two neocuproine molecules and two oxygens from a sulfate ion that acts as a bidentate ligand. A water molecule completes the formula with an important role in the stabilization of the structure through the formation of O_W–H···O_S bridges, in which it acts as a donor and interactions of the type C_ar–H···O_W and C_Met–H···O_W, where it is an acceptor group (W: water; S: sulfate; ar: arene; Met: methyl). The compound is monoclinic, space group P2₁ /c with a = 14.4829(4) ?, b = 14.4563(4) ?, c = 12.1559(3) ?, β = 94.407(1)°, V = 2,537.55(12) ?³ and Z = 4. The structure was solved by direct methods with a conventional R (on F) = 0.0359 for 4841 reflexions with Fo > 4σ(Fo). Three levels of super-structural hierarchy can be identified in the crystal construction: (1) the primary structure corresponding to the molecular skeletons of their building blocks, the isolated complex itself and the water molecule, (2) an 1D supramolecular array that form chains through a non-covalent polymerization via interactions O_W–H···O_S, C_ar–H···O_W, C_ar–H···O_S and C_Met–H···O_W and (3) finally the 3D macroscopic conglomerate formed through inter-chains interactions C_ar–H···O_W, C_ar–H···O_S, C_Met–H···ar and offset stacked arene–arene.     

Crystal Structures of Dipeptides Derived from the β-Amino Acids (1R,2S)-2-Aminocyclopentanecarboxylic Acid and (1S,2R,3S)-2-Amino-3-methylcyclopentanecarboxylic Acid

Abstract  

Crystals of the dimeric β-peptides 13 and 20, derived from (1R,2S)-2-aminocyclopentanecarboxylic acid and (1S,2R,3S)-2-amino-3-methylcyclopentanecarboxylic acid, respectively, were synthesised and studied by X-ray diffraction in order to establish their solid state secondary structural characteristics. Compound 13 crystallises in the monoclinic space group P 2 ₁ with cell parameters of a = 5.2682(1) ?, b = 9.1211(2) ?, c = 22.4467(6) ?, β = 91.3855(9)°, V = 1078.29(4) ?³ and Z = 2. Compound 20 crystallizes in the orthorhombic space group P 2 ₁ 2 ₁ 2 ₁ with cell parameters of a = 5.0968(1) ?, b = 11.5546(2) ?, c = 43.5414(8) ?, V = 2564.22(8) ?³ and Z = 4. In both cases adjacent molecules are linked by a series of N–H···O=C hydrogen bonds to form β-sheet like structures.     

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.     

The Synthesis and Crystal Structure of (4α,8β,13β,16β)-13-Methyl-16,18-diol-17-Norkaurane: A Simultaneous Reduction Product of Isosteviol

Abstract  

(4α,8β,13β,16β)-13-methyl-16,18-diol-17-norkaurane was synthesized by esterification and reduction of isosteviol, respectively. The structure of the title compound was established by spectral analysis and X-ray diffraction studies. The compound crystallizes in the orthorhombic space group P2₁2₁2₁ with unit cell parameters: a = 7.3705 (14) ?, b = 13.508 (3) ?, c = 20.139 (4) ?, V = 2005.1 (7) ?³, Z = 4. The conformation of rings A and B is chair, whereas the conformation of ring C is unsymmetrical distorted chair. The stereochemistry of the A/B and B/C ring junctions is trans, while the five-membered ring D adopts an envelope conformation.     

Supramolecular Aggregation Via Sb···S Interactions and O–H···O Hydrogen-bonding in Tris(N-methyl-N-2-hydroxyethyl)dithiocarbamato-S,S′)antimony(III) Methanol Solvate: Sb[S2CN(Me)(CH2CH2OH)]3?·?MeOH

Abstract The central antimony atom in Sb[S₂CN(Me)CH₂CH₂OH]₃ · MeOH is asymmetrically chelated by three dithiocarbamate ligands leading to a six-coordinate geometry that defines a distorted octahedron; the lone-pair of electrons projects out through the triangular face defined by the three sulphur atoms forming the longer Sb–S bonds. Centrosymmetrically related molecules associate via weak Sb···S interactions to form dimeric aggregates. The crystal packing is dominated by O–H···O interactions involving both the ethanol residues and solvent methanol molecules via a 16-membered [O–H···]₈ ring. These extend in two dimensions to form a layer architecture. The compound crystallizes in the triclinic space group P-1 with a = 9.1917(10) ?, b = 9.5326(10) ?, c = 15.5448(17) ?, α = 69.038(14)°, β = 70.506(15)°, γ = 70.447(16)°, and Z = 2. Index Abstract Supramolecular aggregation via Sb···S interactions and O–H···O hydrogen-bonding in tris ( N -methyl- N -2-hydroxyethyl)dithiocarbamato-S,S′)antimony(III) methanol solvate: Sb[S ₂ CN(Me)(CH ₂ CH ₂ OH)] ₃ · MeOH Edward R. T. Tiekink ⁽¹⁾ * and David J. Young ⁽²⁾ * Molecules associate into dinuclear aggregates via Sb···S interactions and these are connected into a two-dimensional architecture by O–H···O hydrogen-bonding interactions.      

Neutron diffraction investigation of the evolution of the crystal structure of oxygen-conducting solid solutions (Yb1 ? x Ca x )2Ti2O7 ( x = 0, 0.05, 0.10)

The crystal structure of pyrochlore-like solid solutions (Yb_{1 − x} Ca _x )₂Ti₂O₇ (x = 0, 0.05, 0.10) synthesized by high-temperature annealing of mechanically activated initial oxides at temperatures of 1300–1500°C is studied using neutron diffraction. It is found that the Ca²⁺ cations are located in the ytterbium sublattice, which apparently favors the splitting of one of the oxygen sublattices [O(2) (48f)] of the pyrochlore structure: the decrease in the occupancy of this sublattice is accompanied by the formation of a new sublattice O(3) (8b), whereas the other oxygen sublattice O(1) (8a) remains unchanged. This rearrangement of the anions in the oxygen subsystem due to the incorporation of an alkaline-earth cation explains the high ionic conductance (∼0.2 S/cm at 1000°C) for (Yb_0.9Ca_0.1)₂Ti₂O₇ ∼ 0.2, which is the maximum value observed to date for pyrochlores of the A ₂ B ₂O₇ type, where A = Ln and B is a Subgroup IVA element of the periodic system. The bulk and grain-boundary components of the conductivity of (Yb_0.95Ca_0.05)₂Ti₂O₇ synthesized at temperatures of 1300, 1400, and 1500°C are studied using impedance spectroscopy. It is found that the (Yb_0.95Ca_0.05)₂Ti₂O₇ sample synthesized at 1500°C has the highest total conductivity due to the increased grain-boundary component. The bulk component of the ionic conductivity of (Yb_0.95Ca_0.05)₂Ti₂O₇ is hardly affected by the synthesis temperature and depends mainly on the degree of heterovalent substitution. Original Russian Text ? A.V. Shlyakhtina, A.E. Sokolov, V.A. Ul’yanov, V.A. Trunov, M.V. Boguslavskiĭ, A.V. Levchenko, L.G. Shcherbakova, 2009, published in Kristallografiya, 2009, Vol. 54, No. 1, pp. 31–36.     

Structures and Characterization of [Zn(n-chlorosalicylato)2(N-methylnicotinamide)2(H2O)2] (n?=?4 or 5) Ligand Isomers

Abstract  

Two ligand isomers [Zn{4-ClC₆H₃-2-(OH)COO}₂(Menia)₂(H₂O)₂] (I) and [Zn{5-ClC₆H₃-2-(OH)COO}₂(Menia)₂(H₂O)₂] (II) (Menia = N-methylnicotinamide) were prepared and characterized by elemental analysis, IR spectroscopy and thermal analysis. The X-ray crystal structures of complexes (I) and (II) were determined. Compound (I) crystallizes in the triclinic space group P[`1] P\bar{1} with a = 8.105(1) ?, b = 10.036(2) ?, c = 10.545(2) ?, α = 109.088(9)°, β = 91.416(8)°, γ = 102.757(9)°, V = 786.2(2) ?<sup>3</sup>, Z = 1. Compound (II) crystallizes in the triclinic space group P[`1] P\bar{1} . Its cell parameters are: a = 8.133(1) ?, b = 10.119(2) ?, c = 10.428(1) ?, α = 66.44(1)°, β = 74.32(1)°, γ = 80.16(1)°, V = 755.5(2) ?³, Z = 1. The molecular structure of both isomers is monomeric. Each Zn(II) atom is hexacoordinated by three pairs of unidentate ligands in trans-positions (ZnO₄N₂). The 5-Clsal complex is somewhat less distorted than 4-Clsal complex (Cl-sal = chlorosalicylate). The structural data are compared with those found in similar [Zn(RCOO)₂(NL)₂(H₂O)₂].     

Synthesis and Structural Characterization of Bis(μ2-Iodo)-Bis(Diethyl Ether)-(N-N′-(Bis(2,6-Diisopropylphenyl)Pentane-2,4-Diketiminato)-Lithium-Chromium, a Cr(II) (β-Diketiminato) Complex with a Coordinated LiI Salt

Abstract  Addition of CrI₂ to the lithium salt of N-N′-bis(2,6-diisopropylphenyl)-2,4-diketiminate in diethylether yields a Cr(II) iodide complex with a coordinated, solvated LiI salt. This complex is the intermediate in the synthesis of a bridging iodide complex that is itself a precursor to a side-on bridging dinitrogen complex. This complex crystallizes in the P2₁/n space group with the crystal cell parameters a = 12.3160(19) ?, b = 21.067(3) ?, c = 15.837(3)?, β = 96.767°, V = 4080.6(11) ?³ and Z = 4. Graphical Abstract  Addition CrI2 to the lithium salt of N-N′-bis(2,6- diisopropylphenyl)-2,4-diketiminate in diethylether yields a Cr(II) iodide complex with a coordinated, solvated LiI salt. Herein we report the spectroscopic and structural characterization. An erratum to this article can be found at     

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.     

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.