scholarly journals Conformations of Bridged Diphenyls. II. Crystal Structure of 2-(2′,4′-Dinitrophenoxy)-1,3,5-tri-t-butylbenzene

1972 ◽  
Vol 50 (18) ◽  
pp. 2972-2978 ◽  
Author(s):  
E. A. H. Griffith ◽  
W. D. Chandler ◽  
B. E. Robertson

The structure of 2-(2′,4′-dinitrophenoxy)-1,3,5-tri-t-butylbenzene, C24H32N2O5, has been determined by X-ray diffraction. The crystals are triclinic, a = 12.160(30), b = 10.564(17), c = 10.684(16) Å, α = 119.23(10), β = 96.06(15), γ = 96.55(15)°, [Formula: see text] with Z = 2. The intensities of 5359 independent reflections were measured on a four circle diffractometer of which 2471 were used in the refinement to give a final least-squares weighted residue of 0.063. The presence of two electron withdrawing groups on one of the phenyl rings increases the conjugation between the ring and the ether oxygen atom to a greater degree than was found in the previous work. The tri-t-butyl-substituted ring is nearly orthogonal to the other ring. The bond angle at the ether oxygen atom is less than the value found earlier but ring distortions are similar.

1972 ◽  
Vol 50 (18) ◽  
pp. 2963-2971 ◽  
Author(s):  
E. A. H. Griffith ◽  
W. D. Chandler ◽  
B. E. Robertson

The structure of 2-(3′-methyl-4′-nitrophenoxy)-1,3-diisopropylbenzene, C19H23NO3, has been determined by X-ray diffraction. The crystals are triclinic, a = 12.422(24), b = 13.180(25), c = 11.241(30) Å, α = 89.99(20), β = 95.81(15), γ = 105.46(12)°, [Formula: see text] with Z = 4. The intensities of 8153 independent reflections were measured on a four circle diffractometer, of which 3701 were used in the refinement of the structure to give a final least-squares weighted residue of 0.053.The ether oxygen bond angle in each of the two independent molecules is 120°. The two phenyl rings are nearly orthogonal in each case, while the ring containing the electron withdrawing nitro group is conjugated with the ether oxygen atom. The rings show significant deviations from hexagonal symmetry and the nitro-substituted ring is bent away from the other ring.


1975 ◽  
Vol 53 (14) ◽  
pp. 2093-2101 ◽  
Author(s):  
Kapil Gurtu ◽  
W. David Chandler ◽  
Beverly E. Robertson

The crystal structure of 2-(2′,6′-dinitrophenoxy)-t-butylbenzene, C16HI5N2O5, has been determined by X-ray diffraction. The crystals are monoclinic, space group P21/c: a = 13.949(9), b = 9.652(6), c = 23.806(12) Å, β = 93.82(5), Z = 8. The integrated intensities of 6811 reflections were recorded with a four circle automated diffractometer at 20 °C; 3334 of these reflections were used in the refinement of the structure to a least-squares weighted residual of 0.057 and a traditional R factor of 0.057.The two crystallographically independent molecules both have the skew-t-butyl-distal conformation, suggesting that the steric effects of the two ortho-nitro groups play a greater role in determining the conformation than does conjugation with the bridging oxygen atom.


1975 ◽  
Vol 53 (14) ◽  
pp. 2102-2107 ◽  
Author(s):  
Simon P. N. Van Der Heijden ◽  
W. David Chandler ◽  
Beverly E. Robertson

The structure of 2-(4′-carbomethoxy-2′-nitrothiophenyl)-1,3,5-trimethylbenzene, C17H17-NO4S, has been determined by X-ray diffraction. The crystals are monoclinic, a = 18.616(15), b = 5.739(8), c = 15.712(14) Å, β = 101.97(3)°, P21/c with Z = 4. The intensities of 3820 independent reflections were measured on a four circle diffractometer; 2825 reflections were used in the refinement of the structure to give a final least-squares weighted residual of 0.059 and a traditional R factor of 0.054. The presence of electron-withdrawing groups on one of the phenyl rings increases the conjugation between the ring and the sulfur atom in a similar manner as that observed in diphenyl ethers. The mesityl ring is nearly orthogonal to the C—S—C plane.


1978 ◽  
Vol 31 (7) ◽  
pp. 1493 ◽  
Author(s):  
CL Raston ◽  
PR Tennant ◽  
AH White ◽  
G Winter

Tin(II) xanthates form adducts with donor molecules and react with excess xanthate to form the tris-xanthato ion, Sn(EtOCS2)3-. No such reactions are observed with tin(IV) xanthates. Reaction of quinolin-8- ol with tin(IV) ethylxanthate results in the replacement of two xanthate moieties by two oxinato ions. ��� The crystal structure of [Sn(EtOCS2)4] has been determined by single-crystal X-ray diffraction at 295 K and refined by least squares to a residual of 0.038 for 2378 'observed' reflections. The tin(IV) coordination environment resembles that observed in the N,N- diethyldithiocarbamate analogue, two of the xanthate ligands being monodentate and coordinating cis [Sn-S, 2.488(2), 2.499(2) Ǻ] in the six-coordinate coordination sphere while the other two ligands are bidentate, the Sn-S distances trans to the monodentate ligands being slightly longer [2.617(2), 2.627(2)Ǻ] than the other two [2.562(2), 2.539(2)Ǻ]. Crystals are monoclinic, P21/c, a 10.341(5), b 10.465(4), c 21.88(1) Ǻ, β 98.36(4)°, Z 4.


1978 ◽  
Vol 31 (1) ◽  
pp. 47 ◽  
Author(s):  
ES Kucharski ◽  
BW Skelton ◽  
AH White

The crystal structure of the title compound, [Co(terpy)(CO3)(OH)],4H2O, has been determined at 295 K by single-crystal X-ray diffraction and the use of diffractometer data, and refined by least squares to a residual of 0.075 for 1354 ?observed? reflections. Crystals are triclinic, Pī, a 11.407(6), b 10.566(6), c 8.445(4) Ǻ, α 100.21(5), β 107.35(5), γ 102.18(5)°, Z2. The structure of the molecule is unusual for a 1 : 1 transition metal/terpy complex in that the other ligating atoms are non-halide and the complex six-coordinate. The remaining three coordination positions about the metal are occupied by the bidentate carbonate (Co-O 1.918(9), 1.918(8) Ǻ) and the hydroxide ion (Co-O 1.894(10) Ǻ). The Co-N distances are appreciably shorter than those observed in other terpy systems (Co-N(central) 1.848(8); Co-N(outer) 1.946(9), 1.952(9) Ǻ).


1975 ◽  
Vol 53 (14) ◽  
pp. 2108-2114 ◽  
Author(s):  
Simon P. N. van der Heijden ◽  
W. David Chandler ◽  
Beverly E. Robertson

The crystal structure of 2′-(4′-carbomethoxy-2′-nitrophenylsulfinyl)-1,3,5-trimethylbenzene, C17H17NO5S, has been determined by X-ray diffraction. The crystals are triclinic, a = 9.848(11), b = 7.654(10), c = 12.513(15) Å, α = 107.33(8), β = 100.73(8), γ = 106.53(8)°, [Formula: see text] with Z = 2. The intensities of 3850 independent reflections were measured on a four circle diffractometer; 2985 reflections were used in the refinement to give a final least-squares residual of 0.053 and a traditional R factor of 0.052.Repulsion between the sulfoxide oxygen atom and the nitro oxygen atoms forces the molecule into the twist-nitro-proximal conformation as opposed to the nitro-distal conformation which has been observed for other bridged diphenyls in this series.


1985 ◽  
Vol 38 (5) ◽  
pp. 669 ◽  
Author(s):  
PC Healy ◽  
C Pakawatchai ◽  
AH White

The crystal structure of [C13H10N] [CuCl3(C13H9N)].H2O(C13H9N ≡ acridine ) has been determined by single-crystal X-ray diffraction methods at 295 K, being refined by least squares to a residual of 0.037 for 1942 independent 'observed' reflections. Crystals are triclinic, Pī , a 16.27(2), b 10.080(8), c 7.236(5) Ǻ, α 88.85(6), β 82.68(8), γ 81.12(9)°, Z 2. The metal atom stereochemistry is unusual, being of pseudo-m symmetry; one of the chlorine atoms is coplanar with the copper and the acridine [Cu- Cl 2.237(2) Ǻ, N-Cu- Cl 143.5(1)°], with the other two disposed to either side of that plane [Cu- Cl 2.252(3), 2.243(2) Ǻ; Cl-Cu-Cl 145.62(7)°]. Cu-N is 2.018(5) Ǻ.


1980 ◽  
Vol 58 (7) ◽  
pp. 658-663 ◽  
Author(s):  
Ramanathan Gopal ◽  
W. David Chandler ◽  
Beverly E. Robertson

The structure of (4′-carbomethoxy-2′-nitrophenoxy)benzene, C14H11NO5, has been determined by X-ray diffraction. The crystals are monoclinic, a = 8.880(7), b = 9.792(4), c = 14.820(5), β = 90.07(5), P21/c with Z = 4. The integrated intensities of 2966 independent reflections were measured on a four-circle diffractometer, 2072 of which were used in the refinement to give a final least-squares weighted residual of 0.062 and a conventional R factor of 0.086. The absence of ortho substituents on one ring of the molecule allows it to adopt the twist-nitro-distal conformation. The lengths of the bonds from the unsubstituted ring and the substituted ring to the bridging oxygen atom are 1.409(3) and 1.353(3) Å respectively. The torsional angles about those bonds are 54.6° and 16.5°. The angle subtended at the bridging oxygen atom is 120.0(3)°.The unusual thermal ellipsoids associated with one of the nitro oxygen atoms of this structure and with a nitro oxygen atom of three related structures occur when the nitro substituent is nearly coplanar with the phenyl ring on which it is substituted and also has a neighbouring substituent or bridging group. The unusual thermal ellipsoids then result from repulsive exchange forces.


1979 ◽  
Vol 57 (20) ◽  
pp. 2767-2774 ◽  
Author(s):  
Ramanathan Gopal ◽  
W. David Chandler ◽  
Beverly E. Robertson

The structure of 2-(4′-carbomethoxy-2′-aminophenoxy)-1,3,5-trimethylbenzene, C17H19NO3, has been determined by X-ray diffraction. The crystals are monoclinic, a = 23.895(9), b = 7.821(4), c = 16.641(8) Å, β = 99.26(3), C2/c, Z = 8. The integrated intensities of 3540 independent reflections were measured on a four-circle diffractometer. A total of 2403 of these reflections was used in the refinement to give a final least-squares weighted residual of 0.069 and a conventional R factor of 0.096. The molecule adopts the skew-amino-distal conformation as does the analogous ortho-nitro-substituted compound. The lengths of the bonds from the amino substituted ring and the mesityl ring are 1.404(3) and 1.376(4) Å respectively and the torsional angles about those bonds are ±5.8 and [Formula: see text]. The angle subtended at the bridging oxygen atom is 120.1°. Variations in the endocyclic angles subtended at substituted ring carbon atoms in this and other bridged diphenyls may be understood in terms of a combination of hybridization effects, and the spatial requirements of the bonds to substituents.


1980 ◽  
Vol 33 (2) ◽  
pp. 431 ◽  
Author(s):  
A Farrand ◽  
AK Gregson ◽  
BW Skelton ◽  
AH White

The crystal structure of the title compound, K2Cu(CO3)2, has been determined by single-crystal X-ray diffraction at 295(1) K, and refined by least squares to a residual of 0.027 for 1441 'observed' reflections. Crystals are orthorhombic, space group Fdd2, a 11.425(3), b 17.658(4), c 6.154(2) A, Z 8. The structure comprises potassium cations embedded in an infinite three-dimensional polymeric anionic array of square-planar coordinated copper atoms with bridging carbonate groups [Cu-O 1.934(2), 1.936(2) Ǻ]. Within the latter, the non- coordinating oxygen-carbon bond is shorter [1.259(3) Ǻ] than the other two [1.303(3), 1.307(2) Ǻ] and the O-C-O angle opposite it is correspondingly reduced to 117.1(2)°. The CO3 plane lies at 83.9° to the CuO4 'plane'.


Sign in / Sign up

Export Citation Format

Share Document