Molecular structure and conformations of a sterically hindered aryl derivative of 1,3,4-oxadiazole containing an o,o?-biphenyl ring system

1996 ◽  
Vol 32 (7) ◽  
pp. 844-850
Author(s):  
V. N. Baumer ◽  
A. O. Dorshenko ◽  
A. A. Verezubova ◽  
L. M. Ptyagina ◽  
A. V. Kirichenko ◽  
...  
2013 ◽  
Vol 69 (12) ◽  
pp. o1781-o1781 ◽  
Author(s):  
M. Umadevi ◽  
V. Saravanan ◽  
R. Yamuna ◽  
A. K. Mohanakrishnan ◽  
G. Chakkaravarthi

In the title compound, C18H16ClNO2S, the indole ring system forms a dihedral angle of 75.07 (8)° with the phenyl ring. The molecular structure is stabilized by a weak intramolecular C—H...O hydrogen bond. In the crystal, molecules are linked by weak C—H...O hydrogen bonds, forming a chain along [10-1]. C—H...π interactions are also observed, leading to a three-dimensional network.


1975 ◽  
Vol 28 (6) ◽  
pp. 1187 ◽  
Author(s):  
GR Clark ◽  
GJ Palenik

Crystals of 4-bromo-1,1,3,3,5,7,7,9,9- nonamethylbicyclo[4,4,0]pentaborophane, C9H35B5P5Br, are monoclinic, with a = 9.502(3), b = 20.185(15), c = 13.604(4) Ǻ, β = 116.49(2)�. The space group is P21/c, with four molecules in the cell. Intensity data were collected by means of an automated diffractometer. The atomic positions have been determined by least-squares refinement of 2859 observed reflections. The final residual, R, is 0.077. The molecule contains a framework of alternat- ing boron and phosphorus atoms constituting a decalin-like ring system. The two cis-fused cyclo- hexane type rings are both in the chair conformation. The bromine atom is equatorially bonded to the boron atom in the 4-position. The Br-B bond length is 2.039(10) Ǻ. The average P-B and P-C distances are 1.943 and 1.828 Ǻ respectively. Average internal ring angles are 112.2� for P-B-P, and 113.6� for B-P-B. This geometry indicates only very slight charge delocalization in the cyclic system.


1992 ◽  
Vol 47 (2) ◽  
pp. 171-174 ◽  
Author(s):  
H. W. Roesky ◽  
T. Raubold ◽  
M. Noltemeyer ◽  
M. Witt ◽  
R. Bohra

1The reaction of ClSO2N = PPh2Cl () with NH3 yields H2NSO2N = PPh2NH2 (2).This compound is converted to Me3Si(H)NSO2N = PPh2N(H)SiMe3 (3) by Me3SiNMe2. 3 reacts with WOCl4 under elimination of (Me3Si)2O and ClSO2NH2 to yield the eight-membered ring system (Cl3WNPPh2N)2 (4).The molecular structure of 4 was investigated by an X-ray structure analysis.


1988 ◽  
Vol 41 (3) ◽  
pp. 293 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
LM Engelhardt ◽  
IWK Gunawardana ◽  
AH White

Meisenheimer rearrangement of the N-oxides (4) derived from a series of 5-aryl-4-methyl-2,3,4,5-tetrahydro-1,4-benzoxazepines (3) gave rise to eight derivatives (5) of the new 2H,6H-1,5,4-benzodioxazocine ring system. Reaction of 9-methoxy-5-methyl-6-phenyl-3,4,5,6- tetrahydro-2H-1,5-benzoxazocine (6) with 3-chloroperoxybenzoic acid gave an unstable N-oxide (7). A Meisenheimer rearrangement product from (7), 10-methoxy-5-methyl-7-phenyl-2,3,4,5-tetrahydro-7 H-1,6,5- benzodioxazonine (8), the first example of this ring system, was isolated directly in moderate yield on oxidation of (6) with cooling. The crystal and molecular structure of (8) has been determined by X-ray crystallographic methods.


2014 ◽  
Vol 70 (4) ◽  
pp. o424-o425 ◽  
Author(s):  
P. Narayanan ◽  
K. Sethusankar ◽  
Velu Saravanan ◽  
Arasambattu K. Mohanakrishnan

In the title compound, C28H22N2O8S, the carbazole ring system is roughly planar, with a maximum deviation of 0.084 (3) Å for the C atom connected to the 4,5-dimethoxy-2-nitrophenyl ring. The dihedral angle between the carbazole system and the dimethoxy-substituted nitrophenyl ring is 57.05 (10)°. The aldehyde C atom deviates by 0.164 (5) Å from its attached carbazole ring system. The molecular structure is stabilized by C—H...O interactions which generate twoS(6) and oneS(7) ring motif. In the crystal, molecules are linked by C—H...O hydrogen bonds, formingR33(15) ring motifs, which are further crosslinked byR32(19) ring motifs, resulting in (002) layers. The crystal packing also features C—H...π interactions.


1996 ◽  
Vol 51 (9) ◽  
pp. 1320-1324 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Heidi E. Maisei ◽  
Jürgen Süß ◽  
Wolfgang Milius

Tetra-1-alkynylsilanes, Si(C≡CR1)4 with R1 = tBu (1) and SiMe3 (2) react with triethylborane, Et3B. by intermolecular 1,1-ethyloboration followed by intramolecular 1,1-vinyloboration, to give the substituted siloles 3 and 5 with two R1C≡C groups linked to silicon. The formation of 5 (R1 = SiMe3) requires exactly one equivalent of Et3B, whereas 3 (R1 = tBu) is formed after ≈ 20 d in boiling toluene in the presence of a large excess of Et3B, and the remaining tBu -C ≡ C groups in 3 do not react with Et3B. The 1,1-organoboration of 2 using one equivalent of 9-ethyl-9-borabicyclo[3.3.1]nonane, Et-9-BBN, proceeds similar to the Et3B-reaction, to give mainly the silole derivative 6, in which the bicyclic ring system is enlarged by two carbon atoms. This product is the result of a kinetically controlled reaction. The single crystal X-ray analysis of 1 has been carried out (space group Pnma; a = 990.0(2), b = 1668.0(3), c = 1479.0(3) pm), and its crystal structure is com pared with that of the corresponding tin compound 1 (Sn).


2017 ◽  
Vol 73 (9) ◽  
pp. 1329-1332
Author(s):  
Md. Serajul Haque Faizi ◽  
Necmi Dege ◽  
Sergey Malinkin ◽  
Tetyana Yu. Sliva

The title compound, C25H20N2, (I), was synthesized from the condensation reaction of anthracene-9-carbaldehyde and tryptamine in dry ethanol. The indole ring system (r.m.s. deviation = 0.016 Å) makes a dihedral angle of 63.56 (8)° with the anthracene ring (r.m.s. deviation = 0.023 Å). There is a short intramolecular C—H...N interaction present, and a C—H...π interaction involving the two ring systems. In the crystal, the indole H atom forms an intermolecular N—H...π interaction, linking molecules to form chains along theb-axis direction. There are also C—H...π interactions present, involving the central and terminal rings of the anthracene unit, linking the chains to form an overall two-dimensional layered structure, with the layers parallel to thebcplane. The density functional theory (DFT) optimized structure, at the B3LYP/6-311 G(d,p) level, is compared with the experimentally determined molecular structure in the solid state.


1977 ◽  
Vol 32 (8) ◽  
pp. 899-902 ◽  
Author(s):  
G. Heppke ◽  
F. Oestreicher

Abstract A simple way of determining the helix screw sense of a cholesteric phase using the Grandjean-Cano method is described. The helix pitch as well as its sense is investigated for ten cholesteric phases, induced by mesogenic chiral com­pounds in the nematic isomere mixture of 4-methoxy-4′-n-butylazoxybenzene (Nematic Phase 4, Merck). For the chiral compounds with nematic-like molecular structure it is found that the screw sense alternates with the number of bonds between the chiral centre and the ring system.


ChemInform ◽  
2010 ◽  
Vol 25 (11) ◽  
pp. no-no
Author(s):  
H. SUZUKI ◽  
K. OKABE ◽  
R. KATO ◽  
N. SATO ◽  
Y. FUKUDA ◽  
...  

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