organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 67| Part 9| September 2011| Pages o2306-o2307

(E)-2-(4-Bromo­benzyl­­idene)indan-1-one

aInstitute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and bX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: hkfun@usm.my

(Received 29 July 2011; accepted 5 August 2011; online 11 August 2011)

In the title compound, C16H11BrO, the dihydro­indene ring system is approximately planar, with a maximum deviation of 0.008 (2) Å. The mean plane of this ring system forms a dihedral angle of 3.73 (11)°, with the bromo-substituted benzene ring. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into sheets parallel to the ab plane and further stabilization is provided by weak C—H⋯π inter­actions involving the bromo-substituted benzene rings.

Related literature

For background information on indanones, see: Schumann et al. (2001[Schumann, H., Stenzel, O. & Girgsdies, F. (2001). Organometallics, 20, 1743-1751.]); Herzog et al. (2002[Herzog, M. N., Chien, J. C. W. & Rausch, M. D. J. (2002). Organomet. Chem. 654, 29-35.]); Sato (1999[Sato, Y. (1999). Chem. Abstr. 130, 13852.]); Leoni et al. (2000[Leoni, L. M., Hamel, E., Genini, D., Shih, H., Carrera, C. J., Cottam, H. B. & Carson, D. A. (2000). J. Natl. Cancer Inst. 92, 217-224.]); Sugimoto (1999[Sugimoto, H. (1999). Pure Appl. Chem. 71, 2031-37.]); Beukes et al. (1998)[Beukes, D. R., Davies-Coleman, M. T., Kelly-Borges, M., Harper, M. K. & Faulkner, D. J. (1998). J. Nat. Prod. 61, 699-701.]. For closely related structures, see: Ali et al. (2010[Ali, M. A., Ismail, R., Choon, T. S., Rosli, M. M. & Fun, H.-K. (2010). Acta Cryst. E66, o2878.], 2011[Ali, M. A., Ismail, R., Choon, T. S., Loh, W.-S. & Fun, H.-K. (2011). Acta Cryst. E67, o1983-o1984.]).

[Scheme 1]

Experimental

Crystal data
  • C16H11BrO

  • Mr = 299.16

  • Monoclinic, P c

  • a = 6.1933 (7) Å

  • b = 4.7441 (5) Å

  • c = 21.8572 (19) Å

  • β = 99.108 (3)°

  • V = 634.10 (11) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 3.23 mm−1

  • T = 297 K

  • 0.35 × 0.16 × 0.06 mm

Data collection
  • Bruker SMART APEXII DUO CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.398, Tmax = 0.820

  • 6671 measured reflections

  • 2884 independent reflections

  • 2314 reflections with I > 2σ(I)

  • Rint = 0.023

Refinement
  • R[F2 > 2σ(F2)] = 0.027

  • wR(F2) = 0.057

  • S = 1.00

  • 2884 reflections

  • 164 parameters

  • 2 restraints

  • H-atom parameters constrained

  • Δρmax = 0.25 e Å−3

  • Δρmin = −0.15 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]) 1189 Friedel pairs

  • Flack parameter: 0.00 (6)

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the C10–C15 ring.

D—H⋯A D—H H⋯A DA D—H⋯A
C4—H4A⋯O1i 0.93 2.56 3.199 (3) 126
C9—H9B⋯O1ii 0.97 2.38 3.256 (3) 149
C9—H9ACg1iii 0.97 2.68 3.528 (3) 147
Symmetry codes: (i) x+1, y+1, z; (ii) x+1, y, z; (iii) x, y+1, z.

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

Indanones and related compounds are important bioactive molecules. These compounds have been studied for various biological activities including cancer and alzheimer's type of diseases. Indanones are also used as drug intermediates, ligands of olefinic polymerisation catalysts and discotic liquid crystals (Schumann et al., 2001; Herzog et al., 2002; Sato, 1999). Another indanone analogue donepezil hydrochloride has been approved by US-FDA for the treatment of mild to moderate alzheimer's disease. This drug acts as an AChE (Acetylcholinesterase) inhibitor and some other indanones have been isolated from natural products. Being such a useful moiety, several synthetic strategies have also been developed for their synthesis (Leoni et al., 2000; Sugimoto, 1999; Beukes et al., 1998). They are very useful intermediates for the synthesis of five and six membered heterocyclic compounds. Dihydroindene derivatives exhibit diverse pharmacological activities. Chemistry of dihydroindene has been recognized as a significant field of study.

In the title compound (Fig. 1), the dihydroindene ring system (C8–C16) is approximately planar, with a maximum deviation of 0.008 (2) Å for atom C15. This ring system is almost coplanar with the benzene ring (C1–C6), with a dihedral angle of 3.73 (11)°. Bond lengths and angles are within the normal ranges and are comparable to those in the related crystal structures (Ali et al., 2010, 2011).

In the crystal (Fig. 2), intermolecular C4—H4A···O1i and C9—H9B···O1ii hydrogen bonds (Table 1) link the molecules into sheets parallel to the ab plane (Fig. 2) and further stabilization is provided by C—H···πiii interactions, involving the centroids of benzene rings (C10–C15; Cg1).

Related literature top

For background information on indanones, see: Schumann et al. (2001); Herzog et al. (2002); Sato (1999); Leoni et al. (2000); Sugimoto (1999); Beukes et al. (1998). For closely related structures, see: Ali et al. (2010, 2011).

Experimental top

A mixture of 2,3-dihydro-1H-indene-1-one (0.001 mmol) and 4-bromobenzaldehyde (0.001 mmol) was dissolved in methanol (10 mL) and to this mixture was added 30% sodium hydroxide solution (5ml). The mixture was stirred for 5 h. After completion of the reaction, as evident from TLC, the mixture was poured into crushed ice, then neutralized with concentrated HCl. The precipitated solid was filtered, washed with water and recrystallised from ethanol to yield the title compound as light yellow crystals.

Refinement top

All H atoms were positioned geometrically and refined using a riding model with Uiso(H) = 1.2 Ueq(C) [C–H = 0.93–0.97 Å]. The crystal is a twin with twin law, -1 0 0, 0 1 0, 0 0 -1 and BASF = 0.558 (7).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing 30% probability displacement ellipsoids.
[Figure 2] Fig. 2. The crystal packing of the title compound, viewed along the a axis. H atoms not involved in the intermolecular interactions (dashed lines) have been omitted for clarity.
(E)-2-(4-Bromobenzylidene)indan-1-one top
Crystal data top
C16H11BrOF(000) = 300
Mr = 299.16Dx = 1.567 Mg m3
Monoclinic, PcMo Kα radiation, λ = 0.71073 Å
Hall symbol: P -2ycCell parameters from 2130 reflections
a = 6.1933 (7) Åθ = 3.3–24.6°
b = 4.7441 (5) ŵ = 3.23 mm1
c = 21.8572 (19) ÅT = 297 K
β = 99.108 (3)°Plate, colourless
V = 634.10 (11) Å30.35 × 0.16 × 0.06 mm
Z = 2
Data collection top
Bruker SMART APEXII DUO CCD area-detector
diffractometer
2884 independent reflections
Radiation source: fine-focus sealed tube2314 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.023
ϕ and ω scansθmax = 29.0°, θmin = 1.9°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
h = 88
Tmin = 0.398, Tmax = 0.820k = 66
6671 measured reflectionsl = 2929
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.027H-atom parameters constrained
wR(F2) = 0.057 w = 1/[σ2(Fo2) + (0.0281P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.00(Δ/σ)max < 0.001
2884 reflectionsΔρmax = 0.25 e Å3
164 parametersΔρmin = 0.15 e Å3
2 restraintsAbsolute structure: Flack (1983) 1189 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.00 (6)
Crystal data top
C16H11BrOV = 634.10 (11) Å3
Mr = 299.16Z = 2
Monoclinic, PcMo Kα radiation
a = 6.1933 (7) ŵ = 3.23 mm1
b = 4.7441 (5) ÅT = 297 K
c = 21.8572 (19) Å0.35 × 0.16 × 0.06 mm
β = 99.108 (3)°
Data collection top
Bruker SMART APEXII DUO CCD area-detector
diffractometer
2884 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
2314 reflections with I > 2σ(I)
Tmin = 0.398, Tmax = 0.820Rint = 0.023
6671 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.027H-atom parameters constrained
wR(F2) = 0.057Δρmax = 0.25 e Å3
S = 1.00Δρmin = 0.15 e Å3
2884 reflectionsAbsolute structure: Flack (1983) 1189 Friedel pairs
164 parametersAbsolute structure parameter: 0.00 (6)
2 restraints
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
xyzUiso*/Ueq
Br11.082380 (15)1.59421 (5)0.528270 (11)0.06352 (10)
O10.1862 (3)0.3615 (4)0.29957 (9)0.0621 (5)
C10.5691 (4)1.0857 (5)0.45115 (11)0.0475 (6)
H1A0.43631.02740.46170.057*
C20.6967 (4)1.2730 (6)0.48919 (11)0.0508 (6)
H2A0.65051.34260.52470.061*
C30.8943 (4)1.3551 (5)0.47354 (11)0.0469 (5)
C40.9614 (4)1.2637 (6)0.41993 (11)0.0478 (6)
H4A1.09261.32750.40930.057*
C50.8327 (4)1.0764 (6)0.38194 (11)0.0466 (6)
H5A0.87841.01260.34580.056*
C60.6340 (4)0.9814 (6)0.39723 (11)0.0409 (5)
C70.4929 (3)0.7746 (6)0.36006 (10)0.0438 (5)
H7A0.36380.73330.37490.053*
C80.5191 (4)0.6371 (5)0.30879 (11)0.0399 (5)
C90.7021 (4)0.6449 (5)0.26989 (10)0.0414 (6)
H9A0.71750.83190.25320.050*
H9B0.84030.58850.29410.050*
C100.6285 (4)0.4365 (5)0.21908 (12)0.0415 (6)
C110.7351 (5)0.3606 (6)0.17000 (12)0.0541 (6)
H11A0.86820.44180.16540.065*
C120.6374 (5)0.1604 (6)0.12821 (13)0.0635 (7)
H12A0.70590.10780.09510.076*
C130.4405 (6)0.0381 (7)0.13496 (14)0.0609 (7)
H13A0.37910.09660.10650.073*
C140.3334 (4)0.1125 (6)0.18326 (12)0.0529 (6)
H14A0.20060.03050.18790.063*
C150.4308 (4)0.3145 (5)0.22484 (10)0.0445 (5)
C160.3531 (4)0.4282 (5)0.28031 (12)0.0450 (6)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.06614 (16)0.06279 (16)0.06060 (15)0.0043 (2)0.00682 (10)0.00762 (18)
O10.0404 (9)0.0778 (14)0.0716 (12)0.0037 (9)0.0194 (8)0.0069 (10)
C10.0478 (12)0.0513 (15)0.0479 (12)0.0046 (13)0.0210 (10)0.0048 (12)
C20.0597 (15)0.0527 (16)0.0439 (12)0.0045 (13)0.0204 (11)0.0013 (11)
C30.0507 (12)0.0432 (14)0.0467 (12)0.0087 (11)0.0078 (10)0.0069 (10)
C40.0453 (12)0.0522 (16)0.0481 (12)0.0004 (12)0.0138 (9)0.0055 (12)
C50.0465 (12)0.0543 (17)0.0421 (12)0.0031 (13)0.0171 (9)0.0028 (11)
C60.0414 (11)0.0427 (12)0.0402 (12)0.0073 (11)0.0116 (10)0.0060 (11)
C70.0361 (10)0.0533 (15)0.0451 (12)0.0051 (11)0.0157 (9)0.0090 (11)
C80.0346 (10)0.0449 (14)0.0417 (12)0.0098 (10)0.0109 (10)0.0070 (10)
C90.0388 (12)0.0442 (15)0.0438 (12)0.0063 (11)0.0143 (10)0.0058 (10)
C100.0450 (12)0.0384 (14)0.0425 (13)0.0117 (11)0.0111 (10)0.0062 (10)
C110.0613 (14)0.0538 (16)0.0519 (13)0.0039 (13)0.0232 (12)0.0010 (12)
C120.083 (2)0.0614 (18)0.0494 (14)0.0138 (16)0.0208 (13)0.0018 (13)
C130.073 (2)0.0552 (17)0.0513 (16)0.0106 (17)0.0003 (13)0.0036 (13)
C140.0481 (13)0.0514 (16)0.0558 (14)0.0044 (13)0.0026 (11)0.0017 (12)
C150.0435 (11)0.0442 (13)0.0455 (12)0.0102 (11)0.0065 (9)0.0051 (10)
C160.0360 (12)0.0512 (16)0.0480 (13)0.0111 (11)0.0073 (10)0.0076 (11)
Geometric parameters (Å, º) top
Br1—C31.906 (3)C8—C91.521 (3)
O1—C161.219 (3)C9—C101.503 (4)
C1—C21.378 (4)C9—H9A0.9700
C1—C61.395 (3)C9—H9B0.9700
C1—H1A0.9300C10—C151.377 (4)
C2—C31.378 (4)C10—C111.393 (4)
C2—H2A0.9300C11—C121.388 (4)
C3—C41.374 (3)C11—H11A0.9300
C4—C51.380 (4)C12—C131.379 (5)
C4—H4A0.9300C12—H12A0.9300
C5—C61.400 (3)C13—C141.378 (4)
C5—H5A0.9300C13—H13A0.9300
C6—C71.470 (4)C14—C151.391 (4)
C7—C81.329 (3)C14—H14A0.9300
C7—H7A0.9300C15—C161.476 (3)
C8—C161.491 (4)
C2—C1—C6121.6 (2)C8—C9—H9A111.1
C2—C1—H1A119.2C10—C9—H9B111.1
C6—C1—H1A119.2C8—C9—H9B111.1
C1—C2—C3118.7 (2)H9A—C9—H9B109.1
C1—C2—H2A120.7C15—C10—C11119.9 (2)
C3—C2—H2A120.7C15—C10—C9112.3 (2)
C4—C3—C2121.5 (2)C11—C10—C9127.9 (2)
C4—C3—Br1119.07 (19)C12—C11—C10118.2 (3)
C2—C3—Br1119.40 (19)C12—C11—H11A120.9
C3—C4—C5119.5 (2)C10—C11—H11A120.9
C3—C4—H4A120.3C13—C12—C11121.2 (3)
C5—C4—H4A120.3C13—C12—H12A119.4
C4—C5—C6120.6 (2)C11—C12—H12A119.4
C4—C5—H5A119.7C14—C13—C12121.0 (3)
C6—C5—H5A119.7C14—C13—H13A119.5
C1—C6—C5118.0 (2)C12—C13—H13A119.5
C1—C6—C7118.6 (2)C13—C14—C15117.7 (3)
C5—C6—C7123.4 (2)C13—C14—H14A121.1
C8—C7—C6130.7 (2)C15—C14—H14A121.1
C8—C7—H7A114.6C10—C15—C14122.0 (2)
C6—C7—H7A114.6C10—C15—C16109.4 (2)
C7—C8—C16120.7 (2)C14—C15—C16128.7 (2)
C7—C8—C9131.4 (2)O1—C16—C15126.4 (2)
C16—C8—C9108.0 (2)O1—C16—C8126.5 (2)
C10—C9—C8103.4 (2)C15—C16—C8107.0 (2)
C10—C9—H9A111.1
C6—C1—C2—C30.8 (4)C9—C10—C11—C12179.6 (3)
C1—C2—C3—C42.7 (4)C10—C11—C12—C130.3 (4)
C1—C2—C3—Br1175.86 (18)C11—C12—C13—C140.5 (5)
C2—C3—C4—C52.6 (4)C12—C13—C14—C150.1 (4)
Br1—C3—C4—C5175.93 (18)C11—C10—C15—C140.8 (4)
C3—C4—C5—C60.7 (4)C9—C10—C15—C14179.1 (2)
C2—C1—C6—C51.1 (4)C11—C10—C15—C16179.7 (2)
C2—C1—C6—C7177.9 (2)C9—C10—C15—C160.3 (3)
C4—C5—C6—C11.2 (4)C13—C14—C15—C100.6 (4)
C4—C5—C6—C7177.8 (2)C13—C14—C15—C16179.2 (3)
C1—C6—C7—C8177.5 (3)C10—C15—C16—O1178.5 (3)
C5—C6—C7—C81.5 (4)C14—C15—C16—O10.3 (4)
C6—C7—C8—C16178.2 (2)C10—C15—C16—C80.7 (3)
C6—C7—C8—C90.6 (5)C14—C15—C16—C8179.5 (2)
C7—C8—C9—C10179.5 (3)C7—C8—C16—O10.7 (4)
C16—C8—C9—C100.7 (2)C9—C8—C16—O1178.3 (3)
C8—C9—C10—C150.2 (3)C7—C8—C16—C15179.8 (2)
C8—C9—C10—C11179.8 (3)C9—C8—C16—C150.9 (2)
C15—C10—C11—C120.4 (4)
Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the C10–C15 ring.
D—H···AD—HH···AD···AD—H···A
C4—H4A···O1i0.932.563.199 (3)126
C9—H9B···O1ii0.972.383.256 (3)149
C9—H9A···Cg1iii0.972.683.528 (3)147
Symmetry codes: (i) x+1, y+1, z; (ii) x+1, y, z; (iii) x, y+1, z.

Experimental details

Crystal data
Chemical formulaC16H11BrO
Mr299.16
Crystal system, space groupMonoclinic, Pc
Temperature (K)297
a, b, c (Å)6.1933 (7), 4.7441 (5), 21.8572 (19)
β (°) 99.108 (3)
V3)634.10 (11)
Z2
Radiation typeMo Kα
µ (mm1)3.23
Crystal size (mm)0.35 × 0.16 × 0.06
Data collection
DiffractometerBruker SMART APEXII DUO CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.398, 0.820
No. of measured, independent and
observed [I > 2σ(I)] reflections
6671, 2884, 2314
Rint0.023
(sin θ/λ)max1)0.682
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.027, 0.057, 1.00
No. of reflections2884
No. of parameters164
No. of restraints2
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.25, 0.15
Absolute structureFlack (1983) 1189 Friedel pairs
Absolute structure parameter0.00 (6)

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the C10–C15 ring.
D—H···AD—HH···AD···AD—H···A
C4—H4A···O1i0.932.563.199 (3)126
C9—H9B···O1ii0.972.383.256 (3)149
C9—H9A···Cg1iii0.97002.683.528 (3)147
Symmetry codes: (i) x+1, y+1, z; (ii) x+1, y, z; (iii) x, y+1, z.
 

Footnotes

Thomson Reuters ResearcherID: C-7581-2009.

§Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

The authors wish to express their thanks to Universiti Sains Malaysia (USM), Penang, Malaysia, for providing research facilities. HKF and WSL thank USM for the Research University Grant (1001/PFIZIK/811160). WSL also thanks the Malaysian Government and USM for the award of a research fellowship.

References

First citationAli, M. A., Ismail, R., Choon, T. S., Loh, W.-S. & Fun, H.-K. (2011). Acta Cryst. E67, o1983–o1984.  CrossRef IUCr Journals Google Scholar
First citationAli, M. A., Ismail, R., Choon, T. S., Rosli, M. M. & Fun, H.-K. (2010). Acta Cryst. E66, o2878.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationBeukes, D. R., Davies-Coleman, M. T., Kelly-Borges, M., Harper, M. K. & Faulkner, D. J. (1998). J. Nat. Prod. 61, 699–701.  CrossRef CAS Google Scholar
First citationBruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFlack, H. D. (1983). Acta Cryst. A39, 876–881.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationHerzog, M. N., Chien, J. C. W. & Rausch, M. D. J. (2002). Organomet. Chem. 654, 29–35.  CAS Google Scholar
First citationLeoni, L. M., Hamel, E., Genini, D., Shih, H., Carrera, C. J., Cottam, H. B. & Carson, D. A. (2000). J. Natl. Cancer Inst. 92, 217–224.  CrossRef CAS Google Scholar
First citationSato, Y. (1999). Chem. Abstr. 130, 13852.  Google Scholar
First citationSchumann, H., Stenzel, O. & Girgsdies, F. (2001). Organometallics, 20, 1743–1751.  Web of Science CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSugimoto, H. (1999). Pure Appl. Chem. 71, 2031–37.  CrossRef CAS Google Scholar

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ISSN: 2056-9890
Volume 67| Part 9| September 2011| Pages o2306-o2307
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