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Acta Crystallogr Sect E Struct Rep Online. 2010 February 1; 66(Pt 2): m203.
Published online 2010 January 27. doi:  10.1107/S1600536810002710
PMCID: PMC2979783

Guanidinium chloro­chromate

Abstract

In the title compound, guanidinium chloridotrioxidochrom­ate(VI), (CH6N3)[CrClO3], both the cation and anion are generated by crystallographic mirror symmetry, with one O and one N atom and the Cr, Cl and C atoms lying on the mirror plane. The bond lengths in the guanidinium cation are inter­mediate between normal C—N and C=N bond lengths, indicating significant delocalization in this species. In the crystal structure, inter­molecular N—H(...)Cl inter­actions generate R 2 1(6) ring motifs. These ring motifs are further inter­connected by inter­molecular N—H(...)O hydrogen bonds into infinite chains along [010].

Related literature

For background to chlorido­chromates in organic synthesis, see: Ghammaamy & Maza­reey (2005 [triangle]). For bond-length data, see: Allen et al. (1987 [triangle]). For graph-set descriptions of hydrogen-bond motifs, see: Bernstein et al. (1995 [triangle]). For related structures, see: Al-Dajani et al. (2009 [triangle]); Lorenzo Luis et al. (1996 [triangle]). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 [triangle]).

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Object name is e-66-0m203-scheme1.jpg

Experimental

Crystal data

  • (CH6N3)[CrClO3]
  • M r = 195.54
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-66-0m203-efi2.jpg
  • a = 5.9708 (2) Å
  • b = 7.5302 (2) Å
  • c = 14.7085 (4) Å
  • V = 661.31 (3) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 2.07 mm−1
  • T = 100 K
  • 0.85 × 0.20 × 0.07 mm

Data collection

  • Bruker SMART APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2009 [triangle]) T min = 0.273, T max = 0.875
  • 11570 measured reflections
  • 1843 independent reflections
  • 1727 reflections with I > 2σ(I)
  • R int = 0.027

Refinement

  • R[F 2 > 2σ(F 2)] = 0.020
  • wR(F 2) = 0.054
  • S = 1.10
  • 1843 reflections
  • 61 parameters
  • All H-atom parameters refined
  • Δρmax = 0.55 e Å−3
  • Δρmin = −0.41 e Å−3

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

Table 1
Selected bond lengths (Å)
Table 2
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810002710/hb5314sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810002710/hb5314Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

HKF and JHG thank Universiti Sains Malaysia (USM) for the Research University Golden Goose grant (No. 1001/PFIZIK/811012). JHG also thanks USM for the award of a USM fellowship. SG thanks the CSIR, Government of India, for a research grant and AK is grateful to the CSIR for a fellowship.

supplementary crystallographic information

Comment

Many methods and oxidizing agents for organic synthesis are known but development and modification of known reagents have only been studied in recent years, e.g. tributylammonium chlorochromate (Ghammaamy & Mazareey, 2005).

The asymmetric unit of the title compound comprises of a guanidinium cation and a chlorochromate anion (Fig. 1). Both of the cation and anion lie on a crystallographic mirror plane and contain one-half molecule [symmetry code of atoms labelled with suffix A: x, -y+1/2, z]. The coordination geometry formed by three O atoms and a Cl atom around the Cr atom is distorted tetrahedral, as indicated by the O1—Cr1—Cl1 and O2—Cr1—O2A angles of 106.21 (3) and 112.06 (4)° respectively. The C1–N1 and C1–N2 bond lengths in the propeller-shaped guanidinium cation are almost equal [1.3310 (14) and 1.3289 (8) Å respectively], indicating that the usual model of electron dislocalization in this moiety (Allen et al., 1987). The bond lengths and angles are comparable to closely related guanidinium (Al-Dajani et al., 2009) and chlorochromate (Lorenzo Luis et al., 1996) structures.

In the crystal structure (Fig. 2), all guanidinium-H atoms participate in intermolecular hydrogen bonds. Intermolecular N2—H2N2···Cl1 interactions (Table 1) form bifurcated acceptor hydrogen bonds which generate R12(6) ring motifs (Bernstein et al., 1995). These ring motifs are further interconnected into one-dimensional infinite chain along the [010] direction by intermolecular N1—H1N1···O2 and N2—H1N2···O1 hydrogen bonds (Table 1).

Experimental

The new oxidizing reagent, guanidinium chlorochromate (GCC) was prepared by treatment of equivalent amounts of guanidinium hydrochloride and chromium trioxide in water at 273 K by stirring with a glass rod with instantaneous formation of yellow blocks of (I).

Refinement

All the H atoms were located from difference Fourier map and allowed to refine freely [Range of N—H = 0.805 (14) – 0.818 (14) Å].

Figures

Fig. 1.
The molecular structure of (I), showing 50% probability displacement ellipsoids for non-H atoms. The suffix A corresponds to the symmetry code [x, -y+1/2, z]. Intermolecular N—H···Cl hydrogen bonds are shown as dashed lines. ...
Fig. 2.
The crystal structure of (I), viewed along the a axis, showing R12(6) ring motifs being interconnected into one-dimensional chain along the b axis. Intermolecular hydrogen bonds are shown as dashed lines.

Crystal data

(CH6N3)[CrClO3]F(000) = 392
Mr = 195.54Dx = 1.964 Mg m3
Orthorhombic, PnmaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2nCell parameters from 7278 reflections
a = 5.9708 (2) Åθ = 2.8–40.1°
b = 7.5302 (2) ŵ = 2.07 mm1
c = 14.7085 (4) ÅT = 100 K
V = 661.31 (3) Å3Plate, yellow
Z = 40.85 × 0.20 × 0.07 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer1843 independent reflections
Radiation source: fine-focus sealed tube1727 reflections with I > 2σ(I)
graphiteRint = 0.027
[var phi] and ω scansθmax = 37.5°, θmin = 2.8°
Absorption correction: multi-scan (SADABS; Bruker, 2009)h = −8→10
Tmin = 0.273, Tmax = 0.875k = −12→12
11570 measured reflectionsl = −21→25

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.020Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.054All H-atom parameters refined
S = 1.10w = 1/[σ2(Fo2) + (0.0252P)2 + 0.1555P] where P = (Fo2 + 2Fc2)/3
1843 reflections(Δ/σ)max < 0.001
61 parametersΔρmax = 0.55 e Å3
0 restraintsΔρmin = −0.41 e Å3

Special details

Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1)K.
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)

xyzUiso*/Ueq
Cr10.38355 (3)0.25000.646530 (11)0.00989 (5)
Cl10.57743 (4)0.25000.518544 (17)0.01422 (6)
O10.12221 (13)0.25000.61735 (6)0.01476 (14)
O20.44850 (10)0.07267 (8)0.70172 (4)0.01594 (11)
N1−0.15734 (17)0.25000.31553 (7)0.01472 (16)
N20.11145 (12)0.09721 (9)0.39621 (5)0.01507 (12)
C10.02125 (18)0.25000.36969 (7)0.01107 (15)
H1N1−0.218 (2)0.1568 (19)0.3047 (8)0.024 (3)*
H1N20.060 (2)0.0026 (19)0.3789 (9)0.024 (3)*
H2N20.221 (2)0.0981 (19)0.4289 (9)0.027 (3)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Cr10.01033 (8)0.00893 (7)0.01042 (7)0.000−0.00080 (5)0.000
Cl10.01339 (11)0.01634 (11)0.01294 (10)0.0000.00166 (8)0.000
O10.0114 (3)0.0166 (3)0.0163 (3)0.000−0.0014 (3)0.000
O20.0184 (3)0.0132 (2)0.0162 (2)0.00135 (19)−0.0015 (2)0.00329 (18)
N10.0154 (4)0.0121 (3)0.0166 (4)0.000−0.0047 (3)0.000
N20.0169 (3)0.0099 (2)0.0184 (3)0.0013 (2)−0.0047 (2)0.0001 (2)
C10.0120 (4)0.0106 (3)0.0106 (4)0.0000.0014 (3)0.000

Geometric parameters (Å, °)

Cr1—O21.6101 (6)N1—H1N10.805 (14)
Cr1—O2i1.6102 (6)N2—C11.3289 (8)
Cr1—O11.6183 (8)N2—H1N20.818 (14)
Cr1—Cl12.2099 (3)N2—H2N20.811 (14)
N1—C11.3310 (14)C1—N2i1.3289 (8)
O2—Cr1—O2i112.06 (4)C1—N2—H1N2120.7 (9)
O2—Cr1—O1111.47 (3)C1—N2—H2N2119.5 (10)
O2i—Cr1—O1111.47 (3)H1N2—N2—H2N2119.8 (14)
O2—Cr1—Cl1107.66 (2)N2i—C1—N2119.94 (10)
O2i—Cr1—Cl1107.66 (2)N2i—C1—N1120.02 (5)
O1—Cr1—Cl1106.21 (3)N2—C1—N1120.02 (5)
C1—N1—H1N1118.5 (9)

Symmetry codes: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N1—H1N1···O2ii0.806 (14)2.211 (13)2.9984 (9)165.7 (12)
N2—H1N2···O1iii0.817 (14)2.192 (14)2.9702 (8)159.4 (13)
N2—H2N2···Cl10.812 (13)2.753 (13)3.5075 (8)155.5 (13)

Symmetry codes: (ii) −x, −y, −z+1; (iii) −x, y−1/2, −z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB5314).

References

  • Al-Dajani, M. T. M., Abdallah, H. H., Mohamed, N., Goh, J. H. & Fun, H.-K. (2009). Acta Cryst. E65, o2508–o2509. [PMC free article] [PubMed]
  • Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.
  • Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl.34, 1555–1573.
  • Bruker (2009). APEX2, SAINT and SADABS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst.19, 105–107.
  • Ghammaamy, S. & Mazareey, M. (2005). J. Serb. Chem. Soc.70, 687–693.
  • Lorenzo Luis, P. A., Martin-Zarza, P., Gili, P., Ruiz-Pérez, C., Hernández-Molina, M. & Solans, X. (1996). Acta Cryst. C52, 1441–1448.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2009). Acta Cryst. D65, 148–155. [PMC free article] [PubMed]

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