The title compound, C10H6O8·2H2O, has been previously studied by single-crystal X-ray diffraction at room temperature [Takusagawa et al. (1971) Bull. Chem. Soc. Jpn, 44, 1274-1278]. We present here a redetermination of the structure at 160 K, resulting in a considerably improved precision. The organic molecule has crystallographic inversion symmetry.
Supporting information
CCDC reference: 221667
Key indicators
- Single-crystal X-ray study
- T = 160 K
- Mean (C-C) = 0.002 Å
- R factor = 0.034
- wR factor = 0.096
- Data-to-parameter ratio = 10.2
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Data collection: SMART (Siemens, 1994); cell refinement: SAINT (Siemens, 1994); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and local programs.
Crystal data top
C10H6O8·2H2O | Z = 1 |
Mr = 290.18 | F(000) = 150 |
Triclinic, P1 | Dx = 1.666 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 5.4651 (6) Å | Cell parameters from 1682 reflections |
b = 6.4044 (7) Å | θ = 3.5–28.4° |
c = 9.1145 (11) Å | µ = 0.15 mm−1 |
α = 71.941 (3)° | T = 160 K |
β = 88.612 (3)° | Plate, colourless |
γ = 72.933 (3)° | 0.48 × 0.42 × 0.09 mm |
V = 289.16 (6) Å3 | |
Data collection top
Bruker SMART 1K CCD diffractometer | 890 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.012 |
Graphite monochromator | θmax = 25.0°, θmin = 2.4° |
ω rotation with narrow frames scans | h = −6→6 |
1735 measured reflections | k = −7→6 |
1010 independent reflections | l = −10→9 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: All non-H atoms found by direct methods |
R[F2 > 2σ(F2)] = 0.035 | Hydrogen site location: Geom except H1W&H2W coords freely refined |
wR(F2) = 0.096 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0698P)2 + 0.025P] where P = (Fo2 + 2Fc2)/3 |
1010 reflections | (Δ/σ)max < 0.001 |
99 parameters | Δρmax = 0.21 e Å−3 |
0 restraints | Δρmin = −0.25 e Å−3 |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s.
planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor
wR and goodness of fit S are based on F2, conventional
R-factors R are based on F, with F set to zero for
negative F2. The threshold expression of F2 >
σ(F2) is used only for calculating R-factors(gt) etc.
and is not relevant to the choice of reflections for refinement.
R-factors based on F2 are statistically about twice as large
as those based on F, and R-factors based on ALL data will be
even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
C1 | 0.5163 (3) | 0.5658 (3) | 0.33991 (17) | 0.0186 (3) | |
C2 | 0.3875 (2) | 0.4051 (2) | 0.41155 (16) | 0.0186 (4) | |
C3 | 0.3710 (3) | 0.3411 (2) | 0.57104 (16) | 0.0190 (4) | |
H3 | 0.2824 | 0.2333 | 0.6193 | 0.023* | |
C4 | 0.5177 (3) | 0.6566 (2) | 0.16703 (16) | 0.0190 (3) | |
O1 | 0.3269 (2) | 0.7850 (2) | 0.08578 (12) | 0.0286 (3) | |
O2 | 0.7443 (2) | 0.5934 (2) | 0.11496 (12) | 0.0263 (3) | |
H2 | 0.7315 | 0.6432 | 0.0178 | 0.040* | |
C5 | 0.2794 (3) | 0.2929 (2) | 0.31782 (16) | 0.0186 (3) | |
O3 | 0.3523 (2) | 0.29257 (19) | 0.19038 (12) | 0.0260 (3) | |
O4 | 0.1121 (2) | 0.19434 (19) | 0.38730 (12) | 0.0256 (3) | |
H4 | 0.0548 | 0.1390 | 0.3282 | 0.038* | |
O1W | −0.0787 (2) | 1.0165 (2) | 0.21940 (13) | 0.0229 (3) | |
H1W | 0.035 (4) | 0.942 (4) | 0.173 (2) | 0.034* | |
H2W | −0.184 (4) | 1.101 (4) | 0.148 (2) | 0.034* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0189 (7) | 0.0209 (7) | 0.0152 (7) | −0.0042 (6) | 0.0023 (5) | −0.0065 (6) |
C2 | 0.0176 (7) | 0.0223 (8) | 0.0157 (8) | −0.0045 (6) | 0.0019 (6) | −0.0074 (6) |
C3 | 0.0200 (7) | 0.0206 (7) | 0.0160 (8) | −0.0064 (6) | 0.0027 (6) | −0.0051 (6) |
C4 | 0.0231 (7) | 0.0205 (7) | 0.0165 (8) | −0.0085 (6) | 0.0018 (6) | −0.0084 (6) |
O1 | 0.0272 (6) | 0.0363 (6) | 0.0159 (6) | −0.0017 (5) | 0.0014 (4) | −0.0070 (5) |
O2 | 0.0242 (6) | 0.0401 (7) | 0.0128 (6) | −0.0080 (5) | 0.0045 (4) | −0.0075 (5) |
C5 | 0.0185 (7) | 0.0208 (7) | 0.0153 (7) | −0.0036 (6) | 0.0006 (6) | −0.0064 (6) |
O3 | 0.0297 (6) | 0.0380 (7) | 0.0173 (6) | −0.0143 (5) | 0.0054 (5) | −0.0147 (5) |
O4 | 0.0319 (6) | 0.0352 (7) | 0.0193 (6) | −0.0195 (5) | 0.0054 (5) | −0.0134 (5) |
O1W | 0.0252 (6) | 0.0263 (6) | 0.0182 (6) | −0.0081 (5) | 0.0002 (5) | −0.0079 (5) |
Geometric parameters (Å, º) top
C1—C3i | 1.391 (2) | C4—O2 | 1.3113 (18) |
C1—C2 | 1.402 (2) | O2—H2 | 0.8400 |
C1—C4 | 1.502 (2) | C5—O3 | 1.2191 (18) |
C2—C3 | 1.391 (2) | C5—O4 | 1.3033 (19) |
C2—C5 | 1.500 (2) | O4—H4 | 0.8400 |
C3—H3 | 0.9500 | O1W—H1W | 0.85 (2) |
C4—O1 | 1.2120 (18) | O1W—H2W | 0.81 (2) |
| | | |
C3i—C1—C2 | 119.78 (14) | O1—C4—O2 | 124.00 (13) |
C3i—C1—C4 | 118.28 (13) | O1—C4—C1 | 122.03 (13) |
C2—C1—C4 | 121.73 (13) | O2—C4—C1 | 113.89 (12) |
C3—C2—C1 | 119.94 (13) | C4—O2—H2 | 109.5 |
C3—C2—C5 | 119.82 (13) | O3—C5—O4 | 125.09 (13) |
C1—C2—C5 | 120.16 (13) | O3—C5—C2 | 121.02 (13) |
C1i—C3—C2 | 120.27 (14) | O4—C5—C2 | 113.87 (12) |
C1i—C3—H3 | 119.9 | C5—O4—H4 | 109.5 |
C2—C3—H3 | 119.9 | H1W—O1W—H2W | 101.7 (19) |
| | | |
C3i—C1—C2—C3 | 0.6 (2) | C2—C1—C4—O1 | 69.8 (2) |
C4—C1—C2—C3 | −174.16 (12) | C3i—C1—C4—O2 | 71.86 (17) |
C3i—C1—C2—C5 | −176.23 (12) | C2—C1—C4—O2 | −113.34 (15) |
C4—C1—C2—C5 | 9.0 (2) | C3—C2—C5—O3 | −158.54 (13) |
C1—C2—C3—C1i | −0.6 (2) | C1—C2—C5—O3 | 18.3 (2) |
C5—C2—C3—C1i | 176.24 (12) | C3—C2—C5—O4 | 19.59 (18) |
C3i—C1—C4—O1 | −104.97 (17) | C1—C2—C5—O4 | −163.60 (13) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H1W···O1 | 0.85 (2) | 1.92 (2) | 2.7664 (16) | 171.6 (18) |
O2—H2···O3ii | 0.84 | 1.85 | 2.6724 (14) | 165 |
O4—H4···O1Wiii | 0.84 | 1.73 | 2.5656 (14) | 175 |
O1W—H2W···O1iv | 0.81 (2) | 2.11 (2) | 2.8586 (16) | 152.0 (19) |
O1W—H2W···O3v | 0.81 (2) | 2.55 (2) | 3.0642 (16) | 122.4 (17) |
Symmetry codes: (ii) −x+1, −y+1, −z; (iii) x, y−1, z; (iv) −x, −y+2, −z; (v) x−1, y+1, z. |