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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 64| Part 2| February 2008| Page o478
doi:10.1107/S1600536807061259

1-Benzyl­imidazolium hexa­fluoro­phosphate–1-benzyl­imidazole (1/1)

Yan Zang,a Xiu-Mei Wu,a Zhan-Ying Zheng,b Hai-Bin Songb and Qing-Xiang Liua*

aKey Laboratory of Molecular Structure and Materials Performance, College of Chemistry and Life Science, Tianjin Normal University, Tianjin 300387, People's Republic of China, and bState Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, People's Republic of China
*Correspondence e-mail: tjnulqx@163.com

(Received 16 November 2007; accepted 20 November 2007; online 23 January 2008)

In the title compound, C10H11N2+·PF6−·C10H10N2, the H atom involved in protonation is disordered equally between the cation and the neutral mol­ecule. The dihedral angle between the phenyl and imidazole rings is 82.6 (2)°. In the crystal structure, there are head-to-tail π–π stacking inter­actions between imidazole rings; the inter­planar separation is 3.295 (1) Å and the centroid–centroid separation is 3.448 (3) Å. In the centrosymmetric anion, two F atoms are disordered over two positions; the refined site-occupancy factors are 0.855 (11) and 0.145 (11).

Related literature

For background to the chemistry of imidazolium compounds, see: Hunter & Sanders (1990[Hunter, C. A. & Sanders, J. K. M. (1990). J. Am. Chem. Soc. 112, 5525-5528.]); Sundberg & Martin (1974[Sundberg, R. J. & Martin, R. B. (1974). Chem. Rev. 74, 471-482.]); Kurdziel & Glowiak (2000[Kurdziel, K. & Glowiak, T. (2000). Polyhedron, 19, 2183-2188.]). For related literature, see: Liu et al. (2003[Liu, Q. X., Xu, F. B., Li, Q. S., Zeng, X. S., Leng, X. B., Chou, Y. L. & Zhang, Z. Z. (2003). Organometallics, 22, 309-314.]).

[Scheme 1]

Experimental

Crystal data

  • C10H11N2+·PF6−·C10H10N2

  • Mr = 462.38

  • Monoclinic, P 21 /n

  • a = 6.6459 (4) Å

  • b = 6.9825 (4) Å

  • c = 22.3558 (12) Å

  • β = 97.109 (1)°

  • V = 1029.45 (10) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.20 mm−1

  • T = 296 (2) K

  • 0.25 × 0.24 × 0.22 mm
Data collection

  • Bruker APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.951, Tmax = 0.957

  • 5057 measured reflections

  • 1820 independent reflections

  • 1585 reflections with I > 2σ(I)

  • Rint = 0.014
Refinement

  • R[F2 > 2σ(F2)] = 0.037

  • wR(F2) = 0.116

  • S = 1.05

  • 1820 reflections

  • 162 parameters

  • 2 restraints

  • H-atom parameters constrained

  • Δρmax = 0.23 e Å−3

  • Δρmin = −0.46 e Å−3

Data collection: APEX2 (Bruker, 2003[Bruker (2003). APEX2. Version 2.1-0. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1998[Bruker (1998). SAINT. Version 7.34A. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536807061259/wn2226sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536807061259/wn2226Isup2.hkl

checkCIF report


Comment top

Some weak interactions in crystal engineering, such as π-π stacking interactions (Hunter & Sanders, 1990), often affect the structure of complexes, and they can link discrete sub-units or low-dimensional entities into high-dimensional supramolecular networks. The imidazole ring is a structural component of many compounds occurring in living organisms (Sundberg & Martin, 1974). In the mechanisms of the majority of enzymatic reactions, an important role is played by the formation of coordination compounds with ions (Kurdziel & Glowiak, 2000.). We are interested in imidazole compounds with π-π stacking interactions and here report the synthesis and crystal structure of 1-benzylimidazolium hexafluoridophosphate.

In the title compound, C10H10N2.C10H11N2+.F6P-, atom H2 is disordered equally between the cation and neutral molecule. The dihedral angle between the phenyl and imidazole rings is 82.6 (2)° (Fig. 1). The N1A—C1A, N1A—C3A, N2A—C1A and N2A—C2A bond distances are 1.312 (2), 1.368 (3), 1.308 (3) and 1.355 (3) Å, respectively, and the N1A—C1A—N2A bond angle is 108.78 (18)°; these values are similar to those observed in 1-(9-anthracenylmethyl)-3-ethylimidazolium iodide (Liu et al., 2003).

In the crystal structure of the title compound (Fig. 2), there are head-to-tail π-π stacking interactions between imidazole rings; the interplanar separation is 3.295 (1) Å and the centroid-to-centroid separation is 3.448 (3) Å.

Related literature top

For background to the chemistry of imidazolium compounds, see: Hunter & Sanders (1990); Sundberg & Martin (1974); Kurdziel & Glowiak (2000).

For related literature, see: Liu et al. (2003).

Experimental top

A 1,4-dioxane solution (20 ml) of imidazole (1.420 g, 20.8 mmol) was added to a suspension of oil-free sodium hydride (0.500 g, 20.8 mmol) in 1,4-dioxane (20 ml) and stirred for 1 h at 90°C. A 1,4-dioxane (20 ml) solution of benzyl bromide (3.240 g, 19 mmol) was then added dropwise to the above solution. The mixture was stirred for 22 h at 90°C, and a brown solution was obtained. The solvent was removed with a rotary evaporator and H2O (50 ml) was added to the residue. The solution was then extracted with CH2Cl2 (50 ml), and the solution was dried with anhydrous MgSO4. After removing CH2Cl2, 1-benzylimidazole, as a pale yellow liquid was obtained yield: 2.7 g (89.7%).

1-Benzylimidazole (2.000 g, 12.6 mmol) was reacted with hydrochloric acid (8 ml, 6 mol l-1) to afford 1-benzylimidazolium chloride as a pale yellow solid (2.618 g, 94%). NH4PF6 (5.050 g, 31 mmol) was added to a methanol solution (50 ml) of 1-benzylimidazolium chloride (2.000 g, 10.3 mmol). A pale yellow precipitate formed immediately, which was collected by filtration, washed with small portions of methanol, and dried in a vacuum to give 1-benzylimidazolium hexafluoridophosphate as a pale yellow powder (3.3 g, 95%). m.p. 202–204°C. Crystals suitable for X-ray diffraction were obtained by evaporating slowly a CH3OH solution at room temperature.

Refinement top

All H atoms were initially located in a difference Fourier map. They were then placed in geometrically idealized positions and constrained to ride on their parent atoms, with Csp3—H = 0.97 Å, Csp2—H = 0.93 Å and N—H = 0.86 Å and Uiso(H) = 1.2Ueq(C,N). In the centrosymmetric anion, atoms F2 and F3 are disordered over two positions; the refined site occupancy factors are 0.855 (11) and 0.145 (11). Atom H2 is disordered equally between the cation and the neutral molecule.

Computing details top

Data collection: APEX2 (Bruker, 2003); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Perspective view of the title compound, with displacement ellipsoids drawn at the 30% probability level. The organic moiety with A atom labels is the cation; that with B atom labels is the centrosymmetrically related neutral molecule. In the centrosymmetric anion, only one disorder component is shown.
[Figure 2] Fig. 2. The π-π stacking interaction between imidazole rings in the title compound.
1-Benzylimidazolium hexafluorophosphate–1-benzylimidazole (1/1) top
Crystal data top
C10H11N2+·PF6−·C10H10N2F(000) = 476
Mr = 462.38Dx = 1.492 Mg m−3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 6.6459 (4) ÅCell parameters from 3167 reflections
b = 6.9825 (4) Åθ = 3.1–27.8°
c = 22.3558 (12) ŵ = 0.20 mm−1
β = 97.109 (1)°T = 296 K
V = 1029.45 (10) Å3Block, colorless
Z = 20.25 × 0.24 × 0.22 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer		1820 independent reflections
Radiation source: fine-focus sealed tube1585 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.014
ϕ and ω scansθmax = 25.0°, θmin = 1.8°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		h = −6→7
Tmin = 0.951, Tmax = 0.957k = −8→8
5057 measured reflectionsl = −26→21
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)] = 0.037H-atom parameters constrained
wR(F2) = 0.116 w = 1/[σ2(Fo2) + (0.0633P)2 + 0.4527P]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max < 0.001
1820 reflectionsΔρmax = 0.23 e Å−3
162 parametersΔρmin = −0.46 e Å−3
2 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.013 (3)
Crystal data top
C10H11N2+·PF6−·C10H10N2V = 1029.45 (10) Å3
Mr = 462.38Z = 2
Monoclinic, P21/nMo Kα radiation
a = 6.6459 (4) ŵ = 0.20 mm−1
b = 6.9825 (4) ÅT = 296 K
c = 22.3558 (12) Å0.25 × 0.24 × 0.22 mm
β = 97.109 (1)°
Data collection top
Bruker APEXII CCD area-detector
diffractometer		1820 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)		1585 reflections with I > 2σ(I)
Tmin = 0.951, Tmax = 0.957Rint = 0.014
5057 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0372 restraints
wR(F2) = 0.116H-atom parameters constrained
S = 1.05Δρmax = 0.23 e Å−3
1820 reflectionsΔρmin = −0.46 e Å−3
162 parameters
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
xyzUiso*/UeqOcc. (<1)
P10.50000.50000.00000.0381 (3)
F10.25151 (17)0.51481 (17)0.00618 (6)0.0514 (4)
F20.5364 (5)0.4064 (5)0.06870 (9)0.0695 (10)0.855 (11)
F30.5370 (4)0.7209 (3)0.02900 (16)0.0629 (9)0.855 (11)
F2'0.553 (3)0.310 (5)0.042 (2)0.152 (18)0.145 (11)
F3'0.542 (3)0.648 (6)0.0573 (15)0.160 (17)0.145 (11)
N10.0699 (2)0.1368 (2)0.09486 (6)0.0371 (4)
N20.1897 (3)−0.1141 (3)0.05810 (8)0.0527 (5)
H20.2730−0.19220.04440.063*0.50
C10.2320 (3)0.0610 (3)0.07629 (9)0.0445 (5)
H10.35640.12180.07610.053*
C2−0.0066 (4)−0.1526 (3)0.06429 (9)0.0550 (6)
H2A−0.0753−0.26640.05430.066*
C3−0.0827 (3)0.0043 (3)0.08755 (10)0.0479 (5)
H3−0.21410.02020.09690.058*
C40.0549 (4)0.3309 (3)0.11951 (9)0.0549 (6)
H4A−0.05770.39790.09690.066*
H4B0.17800.40140.11520.066*
C50.0237 (3)0.3236 (3)0.18532 (9)0.0456 (5)
C6−0.1565 (4)0.3843 (3)0.20279 (10)0.0594 (6)
H6−0.25840.43010.17410.071*
C7−0.1878 (4)0.3780 (4)0.26278 (11)0.0674 (7)
H7−0.30960.42140.27430.081*
C8−0.0405 (4)0.3081 (4)0.30527 (10)0.0619 (7)
H8−0.06320.30110.34540.074*
C90.1401 (4)0.2487 (3)0.28843 (10)0.0637 (7)
H90.24130.20300.31740.076*
C100.1734 (4)0.2560 (3)0.22857 (10)0.0566 (6)
H100.29670.21540.21740.068*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
P10.0353 (4)0.0392 (4)0.0410 (4)−0.0034 (3)0.0103 (3)−0.0044 (3)
F10.0343 (7)0.0547 (7)0.0675 (8)−0.0048 (5)0.0155 (5)−0.0146 (6)
F20.0586 (14)0.100 (2)0.0487 (13)−0.0140 (13)0.0031 (8)0.0211 (12)
F30.0463 (10)0.0459 (13)0.101 (2)−0.0107 (7)0.0257 (14)−0.0320 (11)
F2'0.055 (8)0.13 (2)0.28 (4)0.032 (11)0.052 (16)0.16 (3)
F3'0.059 (8)0.31 (4)0.117 (19)−0.061 (17)0.031 (11)−0.17 (2)
N10.0446 (9)0.0352 (8)0.0325 (8)−0.0022 (7)0.0089 (6)−0.0015 (6)
N20.0710 (13)0.0487 (11)0.0388 (9)0.0183 (9)0.0087 (8)−0.0018 (8)
C10.0425 (11)0.0539 (12)0.0380 (10)0.0016 (9)0.0091 (8)0.0034 (9)
C20.0813 (17)0.0370 (11)0.0422 (11)−0.0110 (11)−0.0107 (10)0.0007 (9)
C30.0407 (11)0.0527 (13)0.0506 (12)−0.0064 (9)0.0067 (9)0.0048 (9)
C40.0907 (17)0.0326 (10)0.0429 (11)0.0006 (10)0.0152 (11)−0.0022 (9)
C50.0699 (14)0.0296 (9)0.0378 (10)0.0031 (9)0.0084 (9)−0.0033 (8)
C60.0710 (15)0.0586 (14)0.0474 (12)0.0162 (12)0.0026 (10)−0.0073 (10)
C70.0746 (17)0.0755 (17)0.0541 (14)0.0086 (13)0.0162 (12)−0.0162 (12)
C80.0926 (19)0.0541 (13)0.0402 (11)−0.0015 (12)0.0132 (11)−0.0085 (10)
C90.0926 (19)0.0507 (13)0.0441 (12)0.0114 (12)−0.0068 (12)−0.0023 (10)
C100.0686 (15)0.0487 (12)0.0522 (12)0.0126 (11)0.0068 (11)−0.0071 (10)
Geometric parameters (Å, º) top
P1—F2'i1.636 (8)C2—C31.338 (3)
P1—F2'1.636 (9)C2—H2A0.9300
P1—F3'1.641 (9)C3—H30.9300
P1—F3'i1.641 (9)C4—C51.512 (3)
P1—F2i1.659 (2)C4—H4A0.9700
P1—F21.659 (2)C4—H4B0.9700
P1—F11.6773 (11)C5—C61.372 (3)
P1—F1i1.6773 (11)C5—C101.382 (3)
P1—F31.679 (2)C6—C71.383 (3)
P1—F3i1.679 (2)C6—H60.9300
N1—C11.312 (2)C7—C81.367 (4)
N1—C31.368 (3)C7—H70.9300
N1—C41.471 (3)C8—C91.366 (4)
N2—C11.308 (3)C8—H80.9300
N2—C21.355 (3)C9—C101.384 (3)
N2—H20.8600C9—H90.9300
C1—H10.9300C10—H100.9300
F2'i—P1—F2'180.0 (16)F1—P1—F3i89.41 (10)
F2'i—P1—F3'86.7 (15)F1i—P1—F3i90.59 (10)
F2'—P1—F3'93.3 (15)F3—P1—F3i180.0 (2)
F2'i—P1—F3'i93.3 (15)C1—N1—C3108.37 (18)
F2'—P1—F3'i86.7 (15)C1—N1—C4125.90 (19)
F3'—P1—F3'i180.0 (11)C3—N1—C4125.74 (18)
F2'i—P1—F2i32 (2)C1—N2—C2109.05 (17)
F2'—P1—F2i148 (2)C1—N2—H2125.5
F3'—P1—F2i117.8 (19)C2—N2—H2125.5
F3'i—P1—F2i62.2 (19)N2—C1—N1108.78 (18)
F2'i—P1—F2148 (2)N2—C1—H1125.6
F2'—P1—F232 (2)N1—C1—H1125.6
F3'—P1—F262.2 (19)C3—C2—N2106.97 (19)
F3'i—P1—F2117.8 (19)C3—C2—H2A126.5
F2i—P1—F2180.0 (2)N2—C2—H2A126.5
F2'i—P1—F181.6 (6)C2—C3—N1106.84 (19)
F2'—P1—F198.4 (6)C2—C3—H3126.6
F3'—P1—F188.3 (7)N1—C3—H3126.6
F3'i—P1—F191.7 (7)N1—C4—C5110.92 (16)
F2i—P1—F191.13 (12)N1—C4—H4A109.5
F2—P1—F188.87 (12)C5—C4—H4A109.5
F2'i—P1—F1i98.4 (6)N1—C4—H4B109.5
F2'—P1—F1i81.6 (6)C5—C4—H4B109.5
F3'—P1—F1i91.7 (7)H4A—C4—H4B108.0
F3'i—P1—F1i88.3 (7)C6—C5—C10119.0 (2)
F2i—P1—F1i88.87 (12)C6—C5—C4119.8 (2)
F2—P1—F1i91.13 (12)C10—C5—C4121.3 (2)
F1—P1—F1i180.00 (9)C5—C6—C7120.5 (2)
F2'i—P1—F359 (2)C5—C6—H6119.8
F2'—P1—F3121 (2)C7—C6—H6119.8
F3'—P1—F328.2 (18)C8—C7—C6120.3 (2)
F3'i—P1—F3151.8 (18)C8—C7—H7119.8
F2i—P1—F389.61 (12)C6—C7—H7119.8
F2—P1—F390.39 (12)C9—C8—C7119.7 (2)
F1—P1—F390.59 (10)C9—C8—H8120.2
F1i—P1—F389.41 (10)C7—C8—H8120.2
F2'i—P1—F3i121 (2)C8—C9—C10120.4 (2)
F2'—P1—F3i59 (2)C8—C9—H9119.8
F3'—P1—F3i151.8 (18)C10—C9—H9119.8
F3'i—P1—F3i28.2 (18)C5—C10—C9120.1 (2)
F2i—P1—F3i90.39 (12)C5—C10—H10119.9
F2—P1—F3i89.61 (12)C9—C10—H10119.9
C2—N2—C1—N10.8 (2)N1—C4—C5—C1066.8 (3)
C3—N1—C1—N2−0.6 (2)C10—C5—C6—C70.0 (4)
C4—N1—C1—N2179.22 (17)C4—C5—C6—C7179.8 (2)
C1—N2—C2—C3−0.7 (2)C5—C6—C7—C8−1.0 (4)
N2—C2—C3—N10.3 (2)C6—C7—C8—C91.6 (4)
C1—N1—C3—C20.2 (2)C7—C8—C9—C10−1.0 (4)
C4—N1—C3—C2−179.65 (18)C6—C5—C10—C90.6 (3)
C1—N1—C4—C5−113.5 (2)C4—C5—C10—C9−179.3 (2)
C3—N1—C4—C566.3 (3)C8—C9—C10—C50.0 (4)
N1—C4—C5—C6−113.0 (2)
Symmetry code: (i) −x+1, −y+1, −z.

Experimental details

Crystal data
Chemical formulaC10H11N2+·PF6−·C10H10N2
Mr462.38
Crystal system, space groupMonoclinic, P21/n
Temperature (K)296
a, b, c (Å)6.6459 (4), 6.9825 (4), 22.3558 (12)
β (°) 97.109 (1)
V (Å3)1029.45 (10)
Z2
Radiation typeMo Kα
µ (mm−1)0.20
Crystal size (mm)0.25 × 0.24 × 0.22
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.951, 0.957
No. of measured, independent and
observed [I > 2σ(I)] reflections		5057, 1820, 1585
Rint0.014
(sin θ/λ)max (Å−1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.116, 1.05
No. of reflections1820
No. of parameters162
No. of restraints2
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.23, −0.46

Computer programs: APEX2 (Bruker, 2003), SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

 

Acknowledgements

This project was supported by the National Science Found­ation of China (Project Grant No. 20672081) and the Natural Science Foundation of Tianjin (07JCYBJC00300).

References

First citationBruker (1998). SAINT. Version 7.34A. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationBruker (2003). APEX2. Version 2.1-0. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationHunter, C. A. & Sanders, J. K. M. (1990). J. Am. Chem. Soc. 112, 5525–5528.  CrossRef CAS Web of Science Google Scholar
 First citationKurdziel, K. & Glowiak, T. (2000). Polyhedron, 19, 2183–2188.  Web of Science CSD CrossRef CAS Google Scholar
 First citationLiu, Q. X., Xu, F. B., Li, Q. S., Zeng, X. S., Leng, X. B., Chou, Y. L. & Zhang, Z. Z. (2003). Organometallics, 22, 309–314.  Web of Science CSD CrossRef CAS Google Scholar
 First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationSundberg, R. J. & Martin, R. B. (1974). Chem. Rev. 74, 471–482.  CrossRef CAS Web of Science Google Scholar

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ISSN: 2056-9890
Volume 64| Part 2| February 2008| Page o478
doi:10.1107/S1600536807061259
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