Synthesis and aldol cyclotrimerization of 4,7-di-tert-butylacenaphthenone

2006 ◽  
Vol 84 (10) ◽  
pp. 1268-1272 ◽  
Author(s):  
Aaron W Amick ◽  
Keith S Griswold ◽  
Lawrence T Scott
Keyword(s):  
Key Words ◽  
Crystal Structures ◽  
Silica Gel ◽  
Room Temperature ◽  
Titanium Tetrachloride ◽  
X Ray ◽  
Synthetic Intermediates

An efficient gram scale synthesis of the previously unknown 4,7-di-tert-butylacenaphthenone (3b) is reported. The facile isomerization of epoxide 9b to ketone 3b occurs simply on stirring a solution of 9b with silica gel at room temperature. Aldol cyclotrimerization of 3b with titanium tetrachloride gives 2,5,8,11,14,17-hexa-tert-butylde cacyclene (1b) in 58% isolated yield. X-ray crystal structures have been obtained for the synthetic intermediates 4,7-di-tert-butylacenaphthene (2b) and 4,7-di-tert-butylacenaphthylene (8b).Key words: aromatic, decacyclene, hydrocarbon, nonalternant, polycyclic.

Distorted chiolite crystal structures of α-Na5M3F14 (M=Cr,Fe,Ga) studied by X-ray powder diffraction

2003 ◽  
Vol 18 (2) ◽  
pp. 128-134 ◽  
Author(s):  
A. Le Bail ◽  
A.-M. Mercier
Keyword(s):  
Crystal Structures ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Rietveld Refinements ◽  
Space Group ◽  
X Ray ◽  
Precise Characterization

The crystal structures of the chiolite-related room temperature phases α-Na5M3F14 (MIII=Cr,Fe,Ga) are determined. For all of them, the space group is P21/n, Z=2; a=10.5096(3) Å, b=7.2253(2) Å, c=7.2713(2) Å, β=90.6753(7)° (M=Cr); a=10.4342(7) Å, b=7.3418(6) Å, c=7.4023(6) Å, β=90.799(5)° (M=Fe), and a=10.4052(1) Å, b=7.2251(1) Å, c=7.2689(1), β=90.6640(4)° (M=Ga). Rietveld refinements produce final RF factors 0.036, 0.033, and 0.035, and RWP factors, 0.125, 0.116, and 0.096, for MIII=Cr, Fe, and Ga, respectively. The MF6 polyhedra in the defective isolated perovskite-like layers deviate very few from perfect octahedra. Subtle octahedra tiltings lead to the symmetry decrease from the P4/mnc space group adopted by the Na5Al3F14 chiolite aristotype to the P21/n space group adopted by the title series. Facile twinning precluded till now the precise characterization of these compounds.

Crystal structures of highly stabilized ylides: methyl(3-methoxy,2-methoxycarbonylbenzoyl) triphenyl- phosphoranylideneacetate and methyl(2-methoxycarb-6-nitrobenzoyl)triphenyl phos phoranyl ideneacetate and the salt methyl(triphenylphosphoranylidene)acetate tetrafluoroborate

1998 ◽  
Vol 76 (12) ◽  
pp. 1844-1852
Author(s):  
Fernande D Rochon ◽  
Robert Melanson ◽  
Margaret M Kayser
Keyword(s):  
Key Words ◽  
Crystal Structures ◽  
Nitro Derivative ◽  
Transient Species ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ionic Salt ◽  
Higher Temperature ◽  
Cyclic Anhydrides ◽  
Wittig Reactions

At lower temperatures stabilized ylides react with unsymmetrically substituted phthalic anhydrides to give two acyclic adducts. When the reactions are allowed to proceed at higher temperature enol lactones are formed. Identification of the acyclic intermediates was necessary to understand the mechanism of these Wittig reactions. The transient species trapped in the reaction with trimethyloxonium tetrafluoroborate were unambiguously identified by crystallographic methods. The crystal structures of the tetrafluoroborate salt of methyl(triphenylphosphoranyl idene)- acetate (8), methyl(3-methoxy,2-methoxycarbonylbenzoyl)triphenylphosphoranylideneacetate (6β), and methyl(2-methoxycarbonyl,6-nitrobenzoyl)triphenylphosphoranylideneacetate (7α) were studied by X-ray diffraction. The ionic salt (8) is monoclinic, P21c,a= 12.640(5), b = 13.945(9), c = 14.825(6) Å, β = 125.32(3)°, Z = 4, and R = 0.065 (F >5.4 σ(F)). Crystal 6 β is monoclinic, P21c,a = 16.391(16), b = 9.029(6), c = 19.835(19) Å, β = 116.60(6)°, Z = 4, and R = 0.070 (F > 4.6 σ(F)), while crystal 7α is also monoclinic, P21c,a = 9.513(5), b = 9.361(3), c = 30.908(13) Å, β = 98.42(3)°, Z = 4, and R = 0.057 (F >5 σ(F)). In the BF 4- salt (12), the four P-C distances are equal (1.791(5)-1.801(7) Å) with identical tetrahedral angles. For the two triphenylphosphoranylideneacetate compounds, the fourth P-C(1) bond is shorter (1.762(6)-1.734(5) Å) than the three P-C(Ph) bonds (avg. 1.809(5) Å). The angles C(1)-P-C(Ph) are also larger (avg. 112.9(2)° for 6β and 111.9(2)° for 7α) than the C(Ph)-P-C(Ph) angles (avg. 105.8(2)° for 6 β and 106.9(2)° for 7α). These values suggest a multiple nature for the P-C(1) bond. In the nitro derivative, the nitro and the ester groups are disordered equally in positions 2 and 6. Key words: Wittig reactions, cyclic anhydrides, stabilized ylide, phosphoranylidenes, crystal structures.

The crystal structures of solvent-free alkali-metal squarates from powder diffraction data

2005 ◽  
Vol 220 (11) ◽  
Author(s):  
Robert E. Dinnebier ◽  
Hanne Nuss ◽  
Martin Jansen
Keyword(s):  
High Resolution ◽  
Alkali Metal ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Room Temperature ◽  
Solvent Free ◽  
Crystallographic Data ◽  
Powder Diffraction Data ◽  
X Ray

AbstractThe crystal structures of solvent-free lithium, sodium, rubidium, and cesium squarates have been determined from high resolution synchrotron and X-ray laboratory powder patterns. Crystallographic data at room temperature of Li

Organolanthanoids. XXI Synthesis of Bis- and Tris-(diphenylphosphinocyclopenta- dienyl)lanthanoid Compounds and the X-Ray Crystal Structures of [Ln(C5H4PPh2)3(OPPh3)]·(thf)1

1997 ◽  
Vol 50 (10) ◽  
pp. 959 ◽  
Author(s):  
Glen B. Deacon ◽  
Craig M. Forsyth ◽  
Bryan M. Gatehouse ◽  
Anna Philosof ◽  
Brian W. Skelton ◽  
...  
Keyword(s):  
Oxygen Atom ◽  
Single Crystal ◽  
Crystal Structures ◽  
Room Temperature ◽  
Central Metal ◽  
Metal Oxidation ◽  
X Ray

Redox transmetallation ofTl(C5H4PPh2)with an excess of Sm in refluxing thf (thf = tetrahydrofuran) or Eu indme (dme = 1,2-dimethoxyethane) at room temperature gave thelanthanoid(II) compounds[Sm(C5H4PPh2)2](1) and[Eu(C5H4PPh2)2(dme)](2). Crystallization of (1) or[Yb(C5H4PPh2)2(dme)]with OPPh3 in dme yielded[Sm(C5H4PPh2)2(OPPh3)2](3) and[Yb(C5H4PPh2)2(OPPh3)2](4). Room-temperature transmetallation ofTl(C5H4PPh2)with Nd gave the lanthanoid(III) compound[Nd(C5H4PPh2)3(thf)](5), but analogous reactions with La, Pr, Er, Gd and Y in refluxing thfgenerally gave intractable oils, although in one instance impure[La(C5H4PPh2)3(thf)]·(thf)0 · 5,namely(6)·(thf)0 · 5, wasisolated. This complex was also obtained at room temperature by usingLaI3-activated La metal. Oxidation of (1) with 1 equiv.ofTl(C5H4PPh2)in toluene yielded solvent-freeSm(C5H4PPh2)3(7). Addition of OPPh3 to these systems allowed theisolation of[Ln(C5H4PPh2)3(OPPh3)]·(thf)x(x = 0-1 · 5; Ln = La (8), Pr (9),Nd (10), Sm (11), Er (12), Y (13)). Single-crystal X-ray structuredetermination of(10)·(thf)1 · 5,(11)·(thf)1 · 5 and(12)·(thf)1 · 5revealed formally 10-coordinate complexes with an O-bondedOPPh3, threeη5-C5H4PPh2ligands and lattice thf. The centroids of the C5 ringsand the oxygen atom surround the central metal in a distorted tetrahedralarray.

The reactions of [Pd2Cl2(μ-PP)2] (PP = dppm, dmpm) with Et2NC≡CNEt2 in methylene chloride solution: X-ray crystal structures of [Pd2Cl2(μ-CH2)(μ-dppm)2] and hexakis(diethylamino)benzene, C6(NEt2)6

1996 ◽  
Vol 74 (11) ◽  
pp. 2331-2339 ◽  
Author(s):  
Sean R. Klopfenstein ◽  
Constanze Kluwe ◽  
Kristin Kirschbaum ◽  
Julian A. Davies
Keyword(s):  
Key Words ◽  
Crystal Structures ◽  
Chloride Solution ◽  
Methylene Chloride ◽  
X Ray ◽  
Methylene Chloride Solution ◽  
Methylene Group

The binuciear palladium(I) complex, [Pd2Cl2(μ-dppm)2] (dppm = bis(diphenylphosphino)methane), has been shown to react with bis(diethylamino)acetylene, Et2NC≡CNEt2, in methylene chloride solution to yield two isolable products, the known methylene-bridged complex, [Pd2Cl2(μ-CH2)(μ-dppm)2], and hexakis(diethylamino)benzene, C6(NEt2)6, both of which have been characterized crystallographically. The source of the bridging methylene group in [Pd2Cl2(μ-CH2)(μ-dppm)2] has been shown to be the methylene chloride solvent. A mechanism that accounts for the formation of the two isolable products is proposed. The complex, [Pd2Cl2(μdmpm)2] (dmpm = bis(dimethylphosphino)methane), was similarly found to react with Et2NC≡NEt2 in methylene chloride solution to yield [Pd2Cl2(μ-CH2)(μ-dmpm)2], which was identified spectroscopically. Key words: acetylene, palladium, cyclooligomerization, aminoacetylene, hexakis(diethylamino)benzene.

Temperature dependence of the AV3O7 (A = Ca, Sr) structure

2007 ◽  
Vol 63 (6) ◽  
pp. 836-842 ◽  
Author(s):  
Sebastian Prinz ◽  
Karine M. Sparta ◽  
Georg Roth
Keyword(s):  
Single Crystal ◽  
Temperature Dependence ◽  
Crystal Structures ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Space Groups ◽  
Temperature Ranges ◽  
First Time

The V4+ (spin ½) oxovanadates AV3O7 (A = Ca, Sr) were synthesized and studied by means of single-crystal X-ray diffraction. The room-temperature structures of both compounds are orthorhombic and their respective space groups are Pnma and Pmmn. The previously assumed structure of SrV3O7 has been revised and the temperature dependence of both crystal structures in the temperature ranges 297–100 K and 315–100 K, respectively, is discussed for the first time.

Crystal structures of the simple monoclinic and orthorhombic polytypes of tripotassium hexacyanoferrate(III)

1978 ◽  
Vol 31 (6) ◽  
pp. 1195 ◽  
Author(s):  
BN Figgis ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Room Temperature ◽  
Potassium Ferricyanide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Monoclinic Form

The room-temperature (295 K) crystal structures of potassium ferricyanide, K3[Fe(CN)6], have been determined for the simplest monoclinic (a reinvestigation) and orthorhombic polytypes by single- crystal X-ray diffraction. The monoclinic form is P21/c, a 7.047(3), b 10.400(3), c 8.384(3) Ǻ, β 107.29(3)°, Z 2. The iron atoms lie on special positions with symmetry 1. In the orthorhombic form, Pnca, a 13.422(6), b 10.396(4), 8.381(4) Ǻ, Z4, the iron atoms now lie on special positions with symmetry 2 (parallel to c). Residuals are 0.036 and 0.048 for 1232 and 855 'observed' reflections respectively.

Heterocyclic Tautomerism. II. 4-Acylpyrazolones. X-Ray Crystal Structures of 4-Benzoyl-5-methyl-2-phenylpyrazol-3(2H)-one and 4-Acetoacetyl-3-methyl-1-phenylpyrazol-5-ol

1985 ◽  
Vol 38 (3) ◽  
pp. 401 ◽  
Author(s):  
MJ O'Connell ◽  
CG Ramsay ◽  
PJ Steel
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Room Temperature ◽  
Crystalline Form ◽  
Intermolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
Intramolecular Hydrogen

The colourless crystalline form of the benzoylpyrazolone (2) has molecules with the NH structure (2c) stabilized by intermolecular hydrogen bonds. At room temperature crystals are monoclinic: P21/c, a 13.508(5), b 9.124(4), c 11.451(3)Ǻ, β 90.80(3)°, Z4; the structure was refined to R 0.059, Rw 0.048. The acetoacetylpyrazolone (3) has the OH structure (3c) with two intramolecular hydrogen bonds. At 193 K crystals are triclinic: Pī , a 7.142(2), b 13.704(8), c 14.699(7)Ǻ, α 117.36(3), β 96.87(3), γ 93.73(3)°, Z 4; the structure was refined to R 0.049, Rw 0.054.

Beiträge zum thermischen Verhalten von Sulfaten, IV* Neues zum Verhalten von PbSO4 bei höherer Temperatur / Contributions to the Thermal Behaviour of Sulfates, IV* New Facts About the Behaviour of PbSO4 at Higher Temperature

1979 ◽  
Vol 34 (3) ◽  
pp. 431-433 ◽  
Author(s):  
Manfred Spieß ◽  
Reginald Gruehn
Keyword(s):  
High Temperature ◽  
Crystal Structures ◽  
Thermal Behaviour ◽  
Room Temperature ◽  
X Ray ◽  
Temperature Form ◽  
Higher Temperature ◽  
Thermal Dilatation ◽  
High Temperature Form

Abstract Thermal Behaviour, Crystal Structures, Modifications Using the high temperature Guinier technique the transformation of the room temperature form N-PbSO4 to the cubic high-temperature form H-PbSO4 was observed. The nonquenchable H-PbSO4 modification crystallizes in the α-NaClO4-type with a(900°) = 7,23 Å, Z = 4 and dX-ray (900 °C) = 5,33 g/cm3 . The thermal dilatation of N-and H-PbSO4 was measured.

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