Molecular geometry of (E)- and (Z)-9-(β-Styryl)anthracenes

1984 ◽  
Vol 37 (11) ◽  
pp. 2215 ◽  
Author(s):  
H Becker ◽  
VA Patrick ◽  
AH White

The molecular structures of (Z)-9-(8-styryl)anthracene, C22H16,(I),(E)-9-(P-styryl)anthracene, (2), and the photo-Diels-Alder dimer of 9-phenylethynylanthracene, C44H28, (3), containing a (Z)-9- (β-styryl) anthracene moiety of limited mobility have been determined by X-ray diffraction. Crystals of (1) are monoclinic, P21/c, a 5.507(4), b 13.050(7), c 21.425(10)�, β 95.73(5)�, Z 4; R was 0.047 for No 1604 independent 'observed' reflections. Crystals of (2) are monoclinic, P21/n, a 11.77(1), b 24.35(2), c 5.503(5) �, β 107.38(7)�, Z 4; R 0.050 for No 1100. Crystals of (3) are monoclinic, P21/c, a 10.719(7), b 18.627(8), c 15.509(8) �, β 101.10(5)�, Z 4; R 0.070 for No 1055. Increase in angle between the plane of the anthracene and the plane of the ethylenic double bond (78.4, 65.5, 81.9� respectively) is reflected in the electronic absorption spectra by an enhancement of the fine structure typical of the anthracene chromophore.

1985 ◽  
Vol 38 (1) ◽  
pp. 97
Author(s):  
H Becker ◽  
CL Raston ◽  
BW Skelton ◽  
AH White

The crystal and molecular structures of [1]benzopyrano[4,3- c][1]benzopyran-5,11-done (dibenzo-naphthyrone) and three of its symmetrically tetrasubstituted derivatives have been determined by single-crystal X-ray diffraction methods. Only the tetra-t-butyl-substituted dibenzonaphthyrone was found to deviate significantly from planarity by having the two carbonyl groups folded and 'syn'-oriented relative to the plane of the connecting ethylene double bond. The dihedral angle between the two aromatic rings was found to be 25. The molecular geometry of all the other dibenzo-naphthyrones in their crystalline states is characterized by planarity, and their structures are centrosymmetric.


1993 ◽  
Vol 48 (4) ◽  
pp. 409-417 ◽  
Author(s):  
Rostislav D. Lampeka ◽  
Zamira D. Uzakbergenova ◽  
Victor V. Skopenko

Mixed complexes of Co(III) with 2-oximinopropionic (H2A) or 2-oximino-3-phenylpropionic (H2B) acid and different amine (imidazole, benzimidazole, pyridine, β-picoline, γ-picoline) are reported. Characterization of the complexes was based upon elemental analysis, conductivity and JR, 1H NMR, and electronic absorption spectra, and X-ray diffraction analysis. The organic ligands behave as O,N donors via the carboxyl oxygen and the oxime nitrogen atoms. A trans-octahedral structure has been assigned to the bis(2-oximinocarboxylato)bis(amine)cobalt(III) on the basis of 1H NMR data.The crystal and molecular structures of the complexes trans-[bis(2-oximinopropionato)bis-(imidazole)]- (I) and trans-[bis(2-oximinopropionato)bis(pyridine)]cobalt(III) (II) were determined. I crystallizes in space group P2/n with a = 14.1 67(2), b = 8.774(1), c = 14.785(2) Å,β = 113.37(1)°, Z = 4, Dcalc = 1.568 g · cm-3. II crystallizes in space group P1̄ with a = 9.122(2), b = 10.038(2), c = 11.759(2) Å, α = 69.95(1)°, β = 67.47(2)°, γ = 69.49(2)°, Ζ = 2, Dcalc = 1.547 g cm-3. The structures were refined to unweighted R factors of 0.036 and 0.028, respectively. The coordination sphere around Co is pseudo-octahedral with the 2-oximinopropionato ligands occupying four equatorial positions, and the amines in axial positions.


1983 ◽  
Vol 36 (7) ◽  
pp. 1361 ◽  
Author(s):  
H Becker ◽  
BW Skelton ◽  
AH White

The Diels-Alder addition of dimethyl acetylenedicarboxylate to sterically hindered 2,4-cyclohexadienones (spiro-quinol ethers) gives rise to stereoisomeric bicyclo[2.2.2]octadienones. The structures of three of these have been elucidated by single-crystal X-ray diffraction methods and their 1H n.m.r. and electronic absorption spectral properties are reported.


1989 ◽  
Vol 42 (11) ◽  
pp. 1869 ◽  
Author(s):  
HD Becker ◽  
BW Skelton ◽  
AH White

The molecular structures of ethyl di-9-anthrylglycolate (1) and methyl di-9-anthrylglycolate (2), as well as those of three isomerization products of (2), have been established by single-crystal X-ray diffraction studies. In both (1) and (2), the anthracenemoieties are characterized by marked deviations from planarity. The stereospecific course of the thermal and photochemical isomerization of (2) by Diels -Alder reaction is suggested to be governed by the spatial demand of the alkoxycarbonyl group. Base-catalysed isomerization of (2) by migration of 9-anthryl from carbon to oxygen is associated with steric relief.


2013 ◽  
Vol 17 (08n09) ◽  
pp. 673-681 ◽  
Author(s):  
Chunhua Huang ◽  
Yi Zhang ◽  
Junshan Sun ◽  
Yongzhong Bian ◽  
Dennis P. Arnold

Bis/tris(phthalocyaninato) europium double- and triple-decker complexes Eu [ Pc (β- SC 6 H 13)8]2 (1) and Eu 2[ Pc (β- SC 6 H 13)8]3 (2) [ Pc (β- SC 6 H 13)8 = 2, 3, 9, 10, 16, 17, 23, 24-octakis(hexylthio)phthalocyaninate] have been synthesized and characterized by a series of spectroscopic methods including mass, NMR, electronic absorption and IR spectroscopy in addition to elemental analysis. Their molecular structures have been determined by single crystal X-ray diffraction analysis and electrochemical properties studied by cyclic voltammetry.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
R. A. Farfán ◽  
J. A. Espíndola ◽  
M. I. Gomez ◽  
M. C. L. de Jiménez ◽  
M. A. Martínez ◽  
...  

The molecular structures of two isostructural complexes of lapacholate (Lap) anion and dimethylformamide (DMF), M(Lap)2(DMF)2 with M: Co Cu, were determined by X-ray diffraction methods. The substances crystallize in the triclinic space group P1¯ with one molecule per unit cell and cell constants a=7.7591(3), b=10.3560(3), c=11.2224(4) Å, α=95.110(2), β=94.310(2), and γ=107.704(2)° for the Co complex and a=7.9308(2), b=10.0033(4), c=10.7508(4), α=97.387(2), β=93.621(2), and γ=103.980(2)° for the Cu complex. The structures were solved from 2933 (Co) and 2888 (Cu) reflections with I>2σ (I) and refined by full matrix least squares to agreement R1-factors of 0.041 (Co) and 0.033 (Cu). The metal M(II) ion is sited on a crystallographic inversion center in a MO6 distorted octahedral environment. This ion is coordinated equatorially to two lapacholate anions through their adjacent carbonyl and phenol oxygen atoms [M–O bond distances of 2.134(1) and 2.008(1) Å (Co) and 2.301(1) and 1.914(1) Å (Cu)] and axially to two DMF molecules through oxygen atoms [M–O bond lengths of 2.143(1) Å (Co) and 2.069(1) Å (Cu)]. The solid state IR transmittance and solution electronic absorption spectra of both Co and Cu compounds are also reported and compared to each other and to the corresponding spectra of other members of the lapacholate metal family of complexes.


1971 ◽  
Vol 24 (3) ◽  
pp. 501 ◽  
Author(s):  
AT Phillip ◽  
W Mazurek ◽  
AT Casey

The quinquedentate ligand, N,N,N?-tris[2-(2?- pyridyl)ethyl]ethylenediamine (tpen), has been synthesized from ethylenediamine and 2-vinylpyridine. The free amine tpen is thermally unstable, but readily forms chemically stable metal complexes of the composition [M(tpen)](ClO4)2 (M = Cu, Ni, Zn) and [Co(tpen)O2Co(tpen)]- (ClO4)4. In each of these compounds, the amine tpen is bonded to the metal ion through all five of its nitrogen atoms, as indicated by infrared and electronic absorption spectra and magnetic susceptibility measurements. The compound [Ni(tpen)](ClO4)2 shows four d-d transitions whose energies correspond closely to the values predicted from a ligand field calculation for a square pyramidal NiN5 chromophore. This structure has been confirmed by X-ray diffraction analysis. These complexes of tpen are the first reported quinquedentate pentaamine chelate structures of copper(II), nickel(II), and zinc(II).


2018 ◽  
Vol 73 (5) ◽  
pp. 305-309
Author(s):  
Bartłomiej Bereska ◽  
Krystyna Czaja ◽  
Błażej Dziuk ◽  
Bartosz Zarychta ◽  
Krzysztof Ejsmont ◽  
...  

AbstractThe crystal and molecular structures of two polymorphs of N,N,N′,N′-tetrakis(2-cyanoethyl)-1,2-ethylenediamine have been characterized by X-ray diffraction along with density functional theory (DFT) studies. The molecules differ from each other by conformation. N,N,N′,N′-tetrakis(2-cyanoethyl)-1,2-ethylenediamine has been synthesized by cyanoethylation of ethylenediamine. Cyanoethylation of vicinal diamines is important for the synthesis of hyperbranched polymeric materials applied as catalysts, surfactants and encapsulating agents in drug delivery systems. The molecular geometry of N,N,N′,N′-tetracyanoethyl-1,2-ethylenediamine is similar to that of homologous compounds. DFT calculations were performed to analyze the differences in the molecular geometry of the studied compounds in a crystalline state and for an isolated molecule.


1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.


1992 ◽  
Vol 47 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Anja Edelmann ◽  
Sally Brooker ◽  
Norbert Bertel ◽  
Mathias Noltemeyer ◽  
Herbert W. Roesky ◽  
...  

Abstract The Molecular Structures of [2,4,6-(CF3)3C6H2S]2 (1) [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2 (3) have been determined by X-ray diffraction. Crystal data: 1: orthorhombic, space group P212121, Z = 4, a = 822.3(2), b = 1029.2(2), c = 2526.6(5) pm (2343 observed independent reflexions, R = 0.042); 2: orthorhombic, space group Iba 2, Z = 8, a = 1546.5(2), b = 1578.4(2), c = 1483.9(1) pm (2051 observed independent reflexions, R = 0.030); 3: monoclinic, space group P 21/c, Z = 4, a = 1118.7(1), b = 1536.5(2), c = 1492.6(2) pm, β = 98.97(1)° (3033 observed independent reflexions, R = 0.025).


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