Base-Catalyzed Self-Condensation of Arylacetaldehydes: Molecular Structures of (E)-2,4-Bis(9-Anthryl)but-2-enal and (E)-2,4-Diphenylbut-2-enal

1988 ◽  
Vol 41 (5) ◽  
pp. 727 ◽  
Author(s):  
O Axelsson ◽  
HD Becker ◽  
BW Skelton ◽  
H Sorenson ◽  
AH White
Keyword(s):  
Double Bond ◽  
Single Crystal ◽  
Structure Determination ◽  
Molecular Structures ◽  
Trans Conformation ◽  
X Ray ◽  
Olefinic Double Bond

Both 9-anthrylacetaldehyde and phenylacetaldehyde undergo stereoselective self-condensation in the presence of base to give (E)- 2,4-di(9-anthryl)but-2-enal (2a), and (E)-2,4-diphenylbut-2-enal (2b) respectively, as established by single-crystal X-ray structure determination. Crystals of (2a) are monoclinic, P21/n, Z 8, a 10.638(9), b 20.68(1), c 20.41(2)Ǻ, β 92.36(5)°; R was 0.061 for No 3476 'observed' reflections. Crystals of (2b) are monoclinic, P21/c, Z 4, a 5.781(2), b 23.163(8), c 9.297(5)Ǻ, β 91.54(4)°; R 0.037 for No 1174. In both compounds, the enal moiety assumes a virtually planar s-trans conformation, with the angles between the planes of the olefinic double bond and the adjacent aromatic π-system around 70°.

Crystal structure of (Z)-Cembr-4-ene-15,19,20-triol

1977 ◽  
Vol 30 (12) ◽  
pp. 2723 ◽  
Author(s):  
EN Maslen ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Single Crystal ◽  
Least Squares ◽  
Structure Determination ◽  
Title Compound ◽  
X Ray Diffraction ◽  
Relative Configuration ◽  
Macrocyclic Ring ◽  
X Ray

The crystal structure of the title compound, CZOH3803 [compound (1) in ref.'], has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.045 for 954 'observed' reflections. Crystals are monoclinic, P2', a 9.281(2), b 17.798(6), c 6.417(1) A, B 93.81(3)", Z 2. The structure determination establishes the relative configuration of the chiral centres within the 14-membered macrocyclic ring and shows the double bond to have the unusual (Z) configuration.

Diels-Alder dimerization of a hexenylidene-substituted Benzofuran-2(3H)-one

1983 ◽  
Vol 36 (2) ◽  
pp. 389 ◽  
Author(s):  
H Becker ◽  
SR Hall ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Double Bond ◽  
Single Crystal ◽  
Structure Determination ◽  
Diels Alder ◽  
Exocyclic Double Bond ◽  
X Ray ◽  
Aromatic Systems ◽  
Aromatic Hydrogen

(Z)-7-t-Butyl-5 methoxy-3-[(Z)-2?-methoxy-5,5'-dimethyl-4'-oxohex-2'-enylidene]benzofuran-2(3H)-one has been found to undergo Diels-Alder dimerization in which the exocyclic double bond adds to the s-cis diene moiety. The stereochemistry of the Diels-Alder dimer was established by a single-crystal X-ray structure determination. Crystals of the dimer, C44H56O10, are monoclinic, P21/n, a 12.23(1), b 19.43(2), c 18.71(2) �, β 107.76(7)�, Z 4; a residual of 0.046 was obtained for the 2519 'observed' reflections. In the dimer, two benzofuranone moieties are situated so as to be vicinal spiro substituents of the cyclohexene formed in the Diels-Alder addition. The bond between the two benzofuranone units is unusually long [1.597(6)�]. The shielding of one aromatic hydrogen in the n.m.r. spectrum of the dimer results from the disposition of the two aromatic systems.

Calcium Carbodiimide Compounds Revisited – Syntheses, Single Crystal Structure Determination and Vibrational Spectra of Ca11N6[CN2]2, Ca4N2[CN2] and Ca[CN2]

2008 ◽  
Vol 63 (5) ◽  
pp. 530-536 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Crystal Structure ◽  
Raman Spectrum ◽  
Single Crystal ◽  
Single Crystals ◽  
Vibrational Spectra ◽  
Structure Determination ◽  
X Ray ◽  
Characteristic Features ◽  
Reported Data ◽  
Correct Data

Single crystals of Ca11N6[CN2]2 (dark red needles, tetragonal, P42/mnm (no. 136), a = 1456.22(5), and c = 361.86(2) pm, Z = 2), Ca4N2[CN2] (transparent yellow needles, orthorhombic, Pnma (no. 62), a = 1146.51(11), b = 358.33(4), and c = 1385.77(13) pm, Z = 4) and Ca[CN2] (transparent, colorless, triangular plates, rhombohedral, R3̅m (no. 166), a = 369.00(3), and c = 1477.5(3) pm, Z = 3) were obtained by the reaction of Na2[CN2], CaCl2 and Ca3N2 (if demanded by stoichiometry) in arc-welded Ta ampoules at temperatures between 1200 - 1400 K. Their crystal structures were re-determined by means of single crystal X-ray structure analyses. Additionally, the Raman spectra were recorded on these same single crystals, whereas the IR spectra were obtained with the KBr pellet technique. The title compounds exhibit characteristic features for carbodiimide units with D∞h symmetry (d(C-N) = 121.7 - 123.8 pm and ∡ (N-C-N) = 180°). The vibrational frequencies of these units are in the expected range (Ca11N6[CN2]2: νs = 1230, νs = 2008; δ = 673/645/624 cm−1; Ca4N2[CN2]: νs = 1230, νs = 1986; δ = 672/647 cm−1; Ca[CN2]: νs = 1274, νs = 2031, δ = 668 cm−1). The structural results are more precise than the previously reported data, and with the newly attained Raman spectrum of Ca11N6[CN2]2 we correct data reported earlier.

Lewis-Base Adducts of Group 1B Metal(I) Compounds. XXI The Crystal and Molecular Structures of the Unsolvated Forms of Dibromotris(triphenylphosphine)dicopper(I) and 'step' Tetrabromotetrakis(triphenyl-phosphine)tetracopper(I)

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Lewis Base ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.

scholarly journals Syntheses, Characterization, Crystal Structures and Antimicrobial Activity of Schiff Base Copper(II) Complexes Derived from 2-Bromo-6-((2-(isopropylamino) ethylimino)methyl)phenol

2021 ◽  
Vol 68 (4) ◽  
pp. 1008-1015
Author(s):  
Yong Yuan ◽  
Xi-Kun Lu ◽  
Gao-Qi Zhou ◽  
Xiao-Yang Qiu
Keyword(s):  
Antimicrobial Activity ◽  
Schiff Base ◽  
Single Crystal ◽  
Elemental Analysis ◽  
Structure Determination ◽  
Antimicrobial Activities ◽  
X Ray ◽  
Zwitterionic Form ◽  
Square Planar ◽  
Vis Spectroscopy

Three new copper(II) complexes, [Cu(LH)2]Br2 (1), [Cu(LH)2]NCS2 (2), and [Cu(LH)2](NO3)2 (3), where LH is the zwitterionic form of 2-bromo-6-((2-(isopropylamino)ethylimino)methyl)phenol (HL), were synthesized and characterized by elemental analysis, IR and UV-vis spectroscopy. The structures of the complexes were further confirmed by single crystal X-ray structure determination. All compounds are mononuclear copper(II) complexes. The Cu atoms in the complexes are coordinated by two imino N and two phenolate O atoms from two LH ligands, forming square planar coordination. The compounds were assayed for their antimicrobial activities.

Studies of Australian soft corals. XXXII. The structure determination of degraded xenicin-type diterpenes from several Efflatounaria species

1983 ◽  
Vol 36 (11) ◽  
pp. 2279 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
VA Patrick ◽  
DM Tapiolas
Keyword(s):  
Single Crystal ◽  
Chemical Transformation ◽  
Structure Determination ◽  
High Field ◽  
Soft Corals ◽  
X Ray ◽  
The Third

Three new diterpenes have been isolated from soft corals of the genus Efflatounaria (Coelenterata, Octocorallia, Alcyonacea, Xeniidae). The structure of the first compound (4) was elucidated on the basis of high-field 1H n.m.r. spectroscopy while that of the second metabolite (5) was determined by single-crystal X-ray analysis. The third diterpene (6) was structurally related to (5), and its structure was confirmed by chemical transformation. All three diterpenes can be derived from xenicin-type precursors, by cleavage and recyclization.

Experimental and computational structural study of two hindered aminoanthraquinones in crystals and solutions

2000 ◽  
Vol 215 (9) ◽  
Author(s):  
A.V. Yatsenko ◽  
K.A. Paseshnichenko ◽  
S.I. Popov
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Electronic Spectra ◽  
Molecular Structures ◽  
Amino Group ◽  
Single Crystal Diffraction ◽  
Molecular Conformations ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Visible Spectra

The crystal and molecular structures of 2-methyl-1-methylamino-anthraquinone (I) and 1-methylphenylamino-anthraquinone (II) were studied by the X-ray single-crystal diffraction and the visible spectra of crystalline specimens and their solutions were recorded. The molecule I is closely planar, whereas in the molecule II the amino group is 58° rotated out of the plane of the anthraquinone skeleton. In both structures the molecules pack in stacks. The comparison of experimental and calculated (on the DFT and AM1 levels) molecular structures, together with the comparison of experimental and INDO/S-calculated electronic spectra, give the evidence that molecular conformations (especially for II) change upon transfer from the solid state to solutions, and the π-delocalisation throughout the whole molecule enhances in the solid state.

scholarly journals Über die Reaktion von Wolframhexachlorid mit Se4N2; Kristallstruktur von PPh4[WCl5(NSeCl)] / On the Reaction of Tungsten Hexachloride with Se4N2; Crystal Structure of PPh4[WCl5(NSeCl)]

1991 ◽  
Vol 46 (12) ◽  
pp. 1625-1628 ◽  
Author(s):  
Stefan Vogler ◽  
Werner Massa ◽  
Kurt Dehnicke
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Structure Determination ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Tetraphenylphosphonium Chloride ◽  
Tungsten Hexachloride

The reaction of tungsten hexachloride with Se4N2 leads to [WCl4(NSeCl)]2, which reacts with pyridine to form [WCl4(NSeCl)Py], and with tetraphenylphosphonium chloride to form PPh4[WCl5(NSeCl)], which was characterized by an X-ray structure determination. Space group P21, Z = 2, 1657 observed unique reflections, R = 0.074, wR = 0.061. Lattice dimensions at —80 C: a = 710.7(1), b = 2217.9(4), c = 953.6(2) pm; β = 111.93(3) . The [WCl5(NSeCl)]- ion possesses an almost linear WNSe group with bond lengths WN = 188 pm, corresponding to a double bond, and NSe = 200 pm.

scholarly journals 2-(3,5-Dimethyl-1H-pyrazol-1-yl)thiazolo[4,5-b]pyridine

Molbank ◽  
10.3390/m1077 ◽  
2019 ◽  
Vol 2019 (3) ◽  
pp. M1077
Author(s):  
Lan ◽  
Zheng ◽  
Wang
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
1H Nmr ◽  
Structure Determination ◽  
1H Nmr Spectroscopy ◽  
Pyrazole Ring ◽  
Hydrogen Atoms ◽  
X Ray ◽  
X Ray Crystallography

The compound 2-(3,5-dimethyl-1H-pyrazol-1-yl)thiazolo[4,5-b]pyridine (1) was synthesized with a yield of 71% by the reaction of 1-(thiazolo[4,5-b]pyridine-2-yl)hydrazine and acetylacetone. The structure was characterized by a single-crystal X-ray structure determination as well as 1H and 13C{1H} NMR spectroscopy. X-ray crystallography on 1 confirms the molecule consists of a pyridine–thiazole moiety and the pyrazole ring, and all non-hydrogen atoms are planar.

Sign in / Sign up

Export Citation Format

Share Document