Colouring matters of Australian plants. XXII. Ventilagone: crystal structure and an approach to synthesis

1980 ◽  
Vol 33 (2) ◽  
pp. 303 ◽  
Author(s):  
RG Cooke ◽  
A Liu ◽  
CL Raston ◽  
AH White

The crystal structure of the title compound, a naturally occurring tricyclic quinone, C16H16O5, has been found to be (1R*,3S*)-7,10- dihydroxy-1,3,8-trimethyl-3,4,6,9-tetrahydro-1H-naphtho[2,3-c]-pyran- 6,9-dione by single-crystal X-ray diffraction methods at 295(1) K and refined by least squares to a residual of 0.033 for 1143 'observed' reflections. Crystals are monoclinic, P21, a 8.346(8), b 16.79(2), c 4.911(5)Ǻ, β 101.17(8)°, Z 2. The molecule is shown to have the cis configuration. As an approach to the synthesis of the pigment the model compound 5-chloro-8-methoxy-1,3-dimethylisochroman has been prepared and the two racemic forms have been separated and characterized.

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 (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.


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.


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.


1980 ◽  
Vol 33 (1) ◽  
pp. 69 ◽  
Author(s):  
GJ Honan ◽  
DL Kepert ◽  
SF Lincoln ◽  
JM Patrick ◽  
AH White

The crystal structure of the title compound, [UO2{OCHN(CH2)5}4(H2O)] (ClO4)2, has been determined by single-crystal X-ray diffraction at 295 K and refined by least squares to a residual of 0.051 for 3113 'observed' reflections. Crystals are monoclinic, C2/c, a 16.945(2), b 12.711(2), c 17.304(2)Ǻ, β 107.76(1)°, Z 4. The uranyl moiety [U=O, 1.76(2)Ǻ] is five-coordinated in the equatorial plane by the water molecule [U-O, 2.436(8)Ǻ] and four organic ligands [U-O, 2.379(8), 2.396(13)Ǻ]. The angles O-U-O in the equatorial plane range from 70.3(3) to 73.6(3)°; O=U-0 range between 86.7 and 95.3°. The angle O=U=O is 177.8(3)°. The stereochemistry of seven-coordinate uranyl compounds is examined by using repulsion theory.


1978 ◽  
Vol 31 (11) ◽  
pp. 2437 ◽  
Author(s):  
BN Figgis ◽  
CL Raston ◽  
RP Sharma ◽  
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 0.058 for 2363 'observed' reflections. Crystals are triclinic, Pī, Z 4, a 15.517(8), b 11.772(7), c 11.282(7) Ǻ, α 112.10(4), β 94.80(3), γ 90.60(4)°. <Co-N, O>| distances are 1.883, 1.925 Ǻ respectively, the disposition of the three bidentate ligands within each of the two independent molecules being fac.


1978 ◽  
Vol 31 (12) ◽  
pp. 2641 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
G Winter

The crystal structure of the title compound, [Sn(S2COEt)2(C9H6NO)2], has been determined by single-crystal X-ray diffraction at 298 K and refined by least squares to a residual of 0.049 for 1771 ?observed? reflections. Crystals are monoclinic, P21/n, a 12.21(1), b 24.33(1), c 9.159(7) Ǻ, β 102.12(6)°, Z 4. The environment of the tin atom is six- coordinate: the two coordinating sulfur atoms of the monodentate xanthate ligands lie cis in the coordination sphere [Sn-S, 2.484(4), 2.510(4) Ǻ], and one in turn trans to the two oxine nitrogen atoms [Sn- N, 2.260(8), 2.237(10) Ǻ]. The remaining positions, trans to each other, are occupied by the oxine oxygen atoms [Sn-O, 2.047(7), 2.065(8) Ǻ]. O-Sn-O is 157.0(3)°. The overall point symmetry of the molecule is a good approximation to 2.


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 (9) ◽  
pp. 1927 ◽  
Author(s):  
DL Kepert ◽  
CL Raston ◽  
NK Roberts ◽  
AH White

The crystal structure of the title compound, [Tl(S2CNEt2)3], has been determined by single-crystal X-ray diffraction methods at 295 K and refined by full-matrix least squares to a residual of 0.050 for 2517 'observed' reflections. Crystals are monoclinic, with space group A2/a, a 14.789(7), b 10.428(4), c 18.207(9) Ǻ, β 118.11(4)°, Z 4, and are isostructural with those of the previously determined gallium and indium analogues, the molecule having 2 symmetry with <Tl-S> 2.666 Ǻ. As in the dimethyl/thallium analogue, the departure of the TlS6 core symmetry from 3 is large and is examined in terms of electron-pair repulsion theory.


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