Colouring matters of the Aphidoidea. XLIII. Crystal structure of the aphid pigment 'Quinone A'

1977 ◽  
Vol 30 (12) ◽  
pp. 2705 ◽  
Author(s):  
DW Cameron ◽  
SR Hall ◽  
CL Raston ◽  
AH White

The crystal structure of the quinone A, C15H14O6, derived from protoaphin-fb, has been determined by single-crystal X-ray diffraction at 295 K and refined by least squares to a residual of 0.051 for 758 ?observed? reflections. Crystals are monoclinic, P21, a 5.239(4), b 16.551(9), c 7.920(8) Ǻ, β 108.92(6)�, Z 2. The structure determination confirms that proposed chemically, including the chirality of all asymmetric centres in the molecule.

1977 ◽  
Vol 30 (12) ◽  
pp. 2723 ◽  
Author(s):  
EN Maslen ◽  
CL Raston ◽  
AH White

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.


1978 ◽  
Vol 31 (2) ◽  
pp. 415 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
AC Willis

The crystal structure of the title compound, [Ni(en)3] (ClO4)2,H2O, has been determined from single-crystal X-ray diffraction data at 295(1) K and refined by least squares to a residual of 0.093 for 1400 'observed' reflections. Crystals are orthorhombic, P bca, a 17.043(7), b 15.922(6), c 13.496(5) Ǻ, Z 8. The precision of the structure determination is adversely affected by very high perchlorate thermal motion. <Ni-N> is 2.13 Ǻ.


1983 ◽  
Vol 36 (10) ◽  
pp. 2057 ◽  
Author(s):  
PC Healy ◽  
BW Skelton ◽  
AH White

The crystal structure of [Fe(bpy)3] [CI3FeOFeCI3] (1) has been determined by single-crystal X-ray diffraction at 295 K, and refined by least squares to a residual of 0.058 for 2002 'observed' reflections. Crystals are monoclinic, P21/c, a 9.616(3), b 26.264(6), c 13.821(7) Ǻ, β 99.68(2)°, Z4. In the cation, Fe-N distances range from 1.956(9) to 1 .989(10) Ǻ; in the anion, Fe-Cl distances range from 2.196(5) to 2.225(5) Ǻ. Fe-O distances are 1.763(11) and 1.740(11) Ǻ, and the Fe-O-Fe angle is 148.9(7)°. Recrystallization of 'compound A' from methanolic aqueous solution yields crystals with stoichiometry [{cis-Fe(phen)2Cl}2O]Cl2.nH2O( n ≈ 4.5) as established by structure determination (hampered by serious disorder); R is 0.09 for 749 'observed' reflections. Crystals are orthorhombic, Pcn2, a 18.05(1), b 13.83(1), c 10.481(6) Ǻ, Z 2. The Fe-N distances trans to each other are 2.12(3) and 2.13(3) Ǻ; Fe-N distances trans to Cl and O are 2.20(2) and 2.28(2) Ǻ, respectively. Fe-CI is 2.34(1) and Fe-O 1.787(6) A; Fe-O-Fe is 161(1)°. For crystals from aqueous solution, an isomorphous but larger unit cell is obtained [2754(7), cf. 2616(3) Ǻ3]; it is believed that this is a consequence of variable occupancy of the disordered solvent layers which lie parallel to bc between the ionic species.


1978 ◽  
Vol 31 (12) ◽  
pp. 2721 ◽  
Author(s):  
SR Hall ◽  
DG Hewitt ◽  
CL Raston ◽  
AH White

The crystal structure of the title compound, C32H49NO3, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.061 for 1721 'observed' reflections. Crystals are orthorhombic, Pcab, a 18.63(2), b 18.58(2), c 18.19(2) Ǻ, Z 8. The structure determination confirms that proposed on chemical grounds and shows an unusual t-butyl N.M.R. chemical shift to be a consequence of an unusual orientation.


1977 ◽  
Vol 30 (12) ◽  
pp. 2729 ◽  
Author(s):  
BL Johnson ◽  
JW Langley ◽  
CL Raston ◽  
AH White

The crystal structure of the title compound has been determined by single-crystal X-ray diffraction at 295 K and refined by least squares to a residual of 0.064 for 775 ?observed? reflections. The structure determination confirms the stereochemistry previously proposed for the molecule. Crystals are monoclinic, P21/n, a 11.131(7), b 18.908(3), c 7.121(5) Ǻ, β 104.56(5)�, Z 4.


1978 ◽  
Vol 31 (11) ◽  
pp. 2431 ◽  
Author(s):  
BN Figgis ◽  
CL Raston ◽  
RP Sharma ◽  
AH White

The crystal structure of the title compound has been determined at 295 K by single-crystal X-ray diffraction and refined by least squares to a residual of 0.062. Crystals are monoclinic, P2/c, a 19.102(8), b 8.117(4), c 16.610(8) Ǻ, β 111.90(3)°, Z. Unlike the tris(α-oxyimino ketonato)iron(II) complexes which are fac, the present derivative is based upon substitution of the two picoline moieties into a mer derivative, trans to the nitrogen atoms of the chelate ligands. <Fe- N(picoline)> is 2.020; <Fe-N, O(chelate)> 1.880, 1.952 Ǻ.


1977 ◽  
Vol 30 (9) ◽  
pp. 1979 ◽  
Author(s):  
SR Hall ◽  
CL Raston ◽  
AH White

The crystal structure of (E)-7-t-butyl-5-methoxy-3-[(E)-2?-methoxy- 5?,5?-dimethyl-4?-oxohex-2?enylidene]benzofuran-2(3H)-one, C22H28O5 (see preceding paper), has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.067 (3735 ?observed? reflections). Crystals are triclinic, Pī, a 14.955(7), b 13.142(5), c 10.910(3) Ǻ, α 85.76(3), β 85.67(3), γ 80.12(3)�, Z 4.


1979 ◽  
Vol 32 (10) ◽  
pp. 2187 ◽  
Author(s):  
RJ Fleming ◽  
MA Shaikh ◽  
BW Skelton ◽  
AH White

The crystal structure of the title compound, [EtPh3P]+ [(C12H4N4)2]-, has been established by single-crystal X-ray diffraction methods at 295(1) K and refined by least squares to a residual of 0�039 for 3047 'observed' reflections. Crystals are triclinic, Pī, a 8 �882(7), b 13�522(5), c 15�927(6) �, α 75�34(3), β 96�69(5), γ 100.56(3)�, Z 2. The structure closely resembles that of the methyl-triphenyl-phosphonium and -arsonium analogues, containing tetrads of α,α,α',α'- tetracyanoquino- dimethane* molecules, the molecular planes lying parallel to each other and approximately normal to b.


Author(s):  
A. E. Gunnæs ◽  
A. Olsen ◽  
P. T. Zagierski ◽  
B. Klewe ◽  
O. B. Karlsen ◽  
...  

AbstractThe crystal structure of


1978 ◽  
Vol 31 (3) ◽  
pp. 555 ◽  
Author(s):  
GI Feutrill ◽  
CL Raston ◽  
AH White

The crystal structure of the title compound has been determined at 295 K by single-crystal X-ray diffraction methods and refined by least- squares techniques to a residual of 0.049 for 1046 'observed' reflections. Crystals are monoclinic, P21/c, a 11.584(6), b 5.449(7), c 15.273(8) Ǻ, β 92.44(4)°, Z4. The pair of quinol hydrogen atoms are both located on the one benzene ring as the title indicates.


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