Issue contents
Download PDF of article
Download CIF
3D view
Navigation
Highlighting
Dictionary of Crystallography reference
IUPAC Gold Book reference
more ...
Download citation
FormatBIBTeX
EndNote
RefMan
Refer
Medline
CIF
SGML
Plain Text
share
Previous article
Next article
Previous article
Issue contents
Download PDF of article
Download CIF
3D view
Navigation
Highlighting
Dictionary of Crystallography reference
IUPAC Gold Book reference
more ...
Download citation
FormatBIBTeX
EndNote
RefMan
Refer
Medline
CIF
SGML
Plain Text
share
Next article

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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 65| Part 12| December 2009| Page m1562
doi:10.1107/S160053680904687X

Bis[2-(eth­oxy­carbonyl­amino)ethan­aminium] hexa­bromidostannate

R. Alan Howie,a Geraldo M. de Lima,b Edward R. T. Tiekink,c* James L. Wardellb‡ and Solange M. S. V. Wardelld

aDepartment of Chemistry, University of Aberdeen, Old Aberdeen AB15 5NY, Scotland, bDepartamento de Quimica, ICEx, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil, cDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, and dCHEMSOL, 1 Harcourt Road, Aberdeen AB15 5NY, Scotland
*Correspondence e-mail: edward.tiekink@gmail.com

(Received 5 November 2009; accepted 6 November 2009; online 11 November 2009)

In the title salt, (C5H13N2O2)2[SnBr6], the Sn atom (site symmetry [\overline{1}]) exists in a slightly distorted octa­hedral geometry. The cation is non-planar as the terminal CH2NH3+ residue lies below the plane defined by the remaining non-H atoms. In the crystal, cations associate via N—H⋯O hydrogen bonds involving the ammonium and carbonyl residues, forming a 14-membered {⋯HNC2NCO}2 synthon. The cations and anions are arranged in alternating layers arranged along the a-axis direction, the major association between them being N—H⋯Br contacts.

Related literature

For background to the synthesis of the title salt, see: Duschinsky (1950[Duschinsky, R. (1950). Chem. Abstr. 44, 56460.]); Kita et al. (1980[Kita, K., Haruta, J-I., Tagawa, H. & Tamura, Y. (1980). J. Org. Chem. 45, 4519-4522.]); Smith et al. (1998[Smith, G., Lynch, D. E. & Bott, R. C. (1998). Aust. J. Chem. 51?, 159-164.]); Tavridou et al. (1995[Tavridou, P., Russo, U., Marton, D., Valle, G. & Kovala-Demertzi, D. (1995). Inorg. Chim. Acta, 231, 139-145.]); Wilson & Nowick (1998[Wilson, M. E. & Nowick, J. S. (1998). Tetrahedron Lett. 39, 6613-6616.]).

[Scheme 1]

Experimental

Crystal data

  • (C5H13N2O2)2[SnBr6]

  • Mr = 864.48

  • Monoclinic, C 2/c

  • a = 21.8907 (5) Å

  • b = 7.4428 (2) Å

  • c = 15.5318 (4) Å

  • β = 105.934 (2)°

  • V = 2433.34 (11) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 10.92 mm−1

  • T = 120 K

  • 0.38 × 0.32 × 0.22 mm
Data collection

  • Bruker–Nonius 95mm CCD camera on κ-goniostat diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2003[Sheldrick, G. M. (2003). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.355, Tmax = 0.746

  • 15137 measured reflections

  • 2777 independent reflections

  • 2450 reflections with I > 2σ(I)

  • Rint = 0.051
Refinement

  • R[F2 > 2σ(F2)] = 0.034

  • wR(F2) = 0.070

  • S = 1.12

  • 2777 reflections

  • 120 parameters

  • 1 restraint

  • H-atom parameters constrained

  • Δρmax = 0.87 e Å−3

  • Δρmin = −1.35 e Å−3

Table 1
Selected bond lengths (Å)

Sn—Br2 2.5820 (4)
Sn—Br3 2.6053 (4)
Sn—Br1 2.6075 (4)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N1—H1n⋯Br3i 0.88 2.83 3.501 (3) 134
N2—H2n⋯Br1ii 0.91 2.64 3.495 (3) 157
N2—H3n⋯Br3iii 0.91 2.84 3.425 (3) 123
N2—H4n⋯O1iv 0.91 1.88 2.717 (5) 152
Symmetry codes: (i) [-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]; (ii) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (iii) [x, -y, z+{\script{1\over 2}}]; (iv) [-x, y, -z+{\script{3\over 2}}].

Data collection: COLLECT (Hooft, 1998[Hooft, R. W. W. (1998). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: DENZO (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]) and COLLECT; data reduction: DENZO and COLLECT; 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: DIAMOND (Brandenburg, 2006[Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680904687X/hb5214sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053680904687X/hb5214Isup2.hkl

checkCIF report


Comment top

Tin halides react with 2-imidazolidone, 1 (Scheme 2), in non-protic solvents such as dichloromethane, to form solid complexes [R2SnCl2(1-O)2] (R = Me, Bu or Ph), [MeSnCl3(1-O)2] and [SnX4(1-O)2] (X = Cl, Br or I) (Tavridou et al., 1995); 1-O is the O-bound form of 1. As reported herein, 2-imidazolidone reacts with SnBr4 in EtOH to form ethyl (2-ammonioethyl)carbamate hexabromostannate, (I), Fig. 4. The combination of SnBr4 and EtOH proved to have sufficient Brønsted acidity to open the 2-imidazidone ring. Ring opening reactions of 2-imidazolidone derivatives have been variously reported using bases, e.g. N-(2-nitrobenzenesulfonyl)-2-imidazolidon by a secondary amine, R R'NH (Wilson & Nowick, 1998) and acids, e.g., ring opening of 1-methyl-3–3-hydroxyphenyl-2-imidaxolidone by concentrated HCl to give MeNHCH2CH2NHC6H4OH-m (Duschinsky, 1950). With reduced acidity, co-crystallization can occur instead as shown by the isolation of a 1:1 adduct of 2-imidazolidone and 5-nitrosalicylic acid (Smith et al., 1998). The free base of 2 has been reported from the reaction of H2NCH2CH2NH2 with EtO2CO(MeO)CCH2 (Kita et al., 1980).

The structure of (I) comprises ethyl (2-ammonioethyl)carbamate cations and SnBr6 dianions in the ratio 2:1; the Sn atom is located on a crystallographic centre of inversion so that the asymmetric unit is defined by one cation and half an anion, Fig. 1. The cation is not planar. While the RMS deviation of the O1, O2, N1 and C1—C4 atoms is 0.019 Å, the C5 atom lies 1.410 (5) Å out of this plane; the C3/N1/C4/C5 torsion angle of 96.4 (4)°. In the anion, the Sn—Br2 bond distance of 2.5820 (4) Å is significantly shorter than the Sn–Br1 and Sn–Br3 bond distances of 2.6075 (4) and 2.6053 (4) Å, respectively, an observation rationalized in terms of the pattern of intermolecular interactions,see below. The carbonyl-O1 atom forms a hydrogen bond with an ammonium-H atom to form a dimeric aggregate, Table 1 and Fig. 2. The resulting 14-membered {···HNC2NCO}2 synthon has twofold symmetry. The remaining acidic H atoms form contacts to the Br1 and Br3 atoms, Table 1, explaining the variation of the Sn–Br bond distances, whereby the Br2 atom not engaged in a significant intermolecular contact forms the shorter of the Sn–Br bonds. Globally, the crystal packing comprises alternating layers of cations and anions stacking along the a direction.

Related literature top

For background to the synthesis of the title salt, see: Duschinsky (1950); Kita et al. (1980); Smith et al. (1998); Tavridou et al. (1995); Wilson & Nowick (1998).

Experimental top

A solution of 2-imidazolidone (0.86 g) and SnBr4 (2.20 g) in EtOH (10 ml) was heated to 323 K for 15 minutes, cooled and maintained at room temperature to slowly form crystals of (I); m. pt. 459–463 K. IR(KBr) = 1692 cm-1.

Refinement top

All H atoms were located from a difference map but, were geometrically placed (C–H = 0.98–0.99 Å, and N–H = 0.88–0.91 Å) and refined as riding with Uiso(H) = 1.2–1.5Ueq(C, N). The maximum and minimum residual electron density peaks of 0.85 and 1.26 e Å-3, respectively, were located 1.81 Å and 0.82 Å from the S1 and Sn atoms, respectively.

Computing details top

Data collection: COLLECT (Hooft, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); data reduction: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006; software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of (I) showing displacement ellipsoids at the 70% probability level. Unlabelled bromide ions are generated by the symmetry operation 1/2 - x, 1/2 - y, 1 - z.
[Figure 2] Fig. 2. Supramolecular dimer in (I) mediated by N–H···O hydrogen bonds (orange dashed lines).
[Figure 3] Fig. 3. Unit-cell contents for (I) viewed in projection down the c axis. The N–H···O hydrogen bonds (orange dashed lines) and N–H···Br contacts (blue dashed lines) indicate the mode of asscoiated between the components of the crystal structure.
[Figure 4] Fig. 4. The formation of the title compound.
Bis[2-(ethoxycarbonylamino)ethanaminium] hexabromidostannate top
Crystal data top
(C5H13N2O2)2[SnBr6]F(000) = 1624
Mr = 864.48Dx = 2.360 Mg m−3
Monoclinic, C2/cMo Kα radiation, λ = 0.71069 Å
Hall symbol: -C 2ycCell parameters from 11507 reflections
a = 21.8907 (5) Åθ = 2.9–27.5°
b = 7.4428 (2) ŵ = 10.92 mm−1
c = 15.5318 (4) ÅT = 120 K
β = 105.934 (2)°Block, light-yellow
V = 2433.34 (11) Å30.38 × 0.32 × 0.22 mm
Z = 4
Data collection top
Bruker–Nonius 95mm CCD camera on κ-goniostat
diffractometer		2777 independent reflections
Radiation source: Bruker-Nonius FR591 rotating anode2450 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.051
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 3.1°
ϕ and ω scansh = −28→28
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)		k = −9→9
Tmin = 0.355, Tmax = 0.746l = −20→20
15137 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.034Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.070H-atom parameters constrained
S = 1.12 w = 1/[σ2(Fo2) + (0.0263P)2 + 9.0406P]
where P = (Fo2 + 2Fc2)/3
2777 reflections(Δ/σ)max = 0.001
120 parametersΔρmax = 0.87 e Å−3
1 restraintΔρmin = −1.35 e Å−3
Crystal data top
(C5H13N2O2)2[SnBr6]V = 2433.34 (11) Å3
Mr = 864.48Z = 4
Monoclinic, C2/cMo Kα radiation
a = 21.8907 (5) ŵ = 10.92 mm−1
b = 7.4428 (2) ÅT = 120 K
c = 15.5318 (4) Å0.38 × 0.32 × 0.22 mm
β = 105.934 (2)°
Data collection top
Bruker–Nonius 95mm CCD camera on κ-goniostat
diffractometer		2777 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)		2450 reflections with I > 2σ(I)
Tmin = 0.355, Tmax = 0.746Rint = 0.051
15137 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0341 restraint
wR(F2) = 0.070H-atom parameters constrained
S = 1.12Δρmax = 0.87 e Å−3
2777 reflectionsΔρmin = −1.35 e Å−3
120 parameters
Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
Sn0.25000.25000.50000.01268 (10)
Br10.220893 (18)0.02595 (5)0.61162 (3)0.02190 (11)
Br20.135158 (17)0.22636 (5)0.39826 (3)0.02122 (11)
Br30.284421 (16)−0.01941 (5)0.41692 (3)0.01712 (11)
O1−0.02161 (12)0.3062 (4)0.6285 (2)0.0235 (6)
O20.01221 (13)0.2554 (4)0.5051 (2)0.0224 (6)
N10.08208 (14)0.3322 (5)0.6316 (2)0.0200 (7)
H1N0.10730.32590.59630.024*
N20.14598 (16)0.2592 (4)0.8785 (2)0.0183 (7)
H2N0.17490.35010.89050.027*
H3N0.16270.16060.91110.027*
H4N0.11030.29420.89310.027*
C1−0.0502 (2)0.1802 (6)0.3600 (3)0.0277 (10)
H1A−0.03230.28570.33790.042*
H1B−0.09330.15840.32190.042*
H1C−0.02350.07510.35840.042*
C2−0.05232 (18)0.2130 (6)0.4539 (3)0.0212 (9)
H2A−0.08120.31430.45610.025*
H2B−0.06770.10470.47850.025*
C30.02071 (18)0.2985 (5)0.5912 (3)0.0163 (8)
C40.10453 (17)0.3786 (5)0.7254 (3)0.0187 (8)
H4A0.06930.43150.74550.022*
H4B0.13870.46950.73390.022*
C50.1296 (2)0.2146 (6)0.7810 (3)0.0227 (9)
H5A0.09710.11850.76740.027*
H5B0.16790.16950.76570.027*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Sn0.01042 (17)0.01213 (17)0.0158 (2)0.00012 (12)0.00415 (14)−0.00043 (13)
Br10.0233 (2)0.01857 (19)0.0286 (2)0.00387 (15)0.01518 (17)0.00774 (16)
Br20.01230 (18)0.0248 (2)0.0236 (2)0.00109 (15)−0.00008 (16)−0.00413 (16)
Br30.01406 (18)0.01542 (18)0.0230 (2)−0.00038 (14)0.00701 (15)−0.00511 (15)
O10.0150 (13)0.0372 (16)0.0200 (16)−0.0028 (12)0.0075 (11)−0.0051 (13)
O20.0141 (13)0.0355 (17)0.0170 (15)0.0003 (11)0.0034 (12)−0.0037 (12)
N10.0116 (14)0.0328 (19)0.0161 (18)−0.0009 (14)0.0046 (13)0.0002 (15)
N20.0125 (14)0.0211 (16)0.0195 (18)0.0017 (12)0.0016 (13)−0.0030 (13)
C10.031 (2)0.026 (2)0.023 (2)0.0041 (19)0.0008 (18)−0.0024 (18)
C20.0159 (18)0.026 (2)0.017 (2)0.0009 (16)−0.0038 (16)−0.0016 (17)
C30.0164 (18)0.0160 (17)0.016 (2)0.0001 (15)0.0044 (15)−0.0005 (15)
C40.0158 (17)0.0199 (18)0.019 (2)−0.0042 (15)0.0034 (15)−0.0015 (16)
C50.0205 (19)0.028 (2)0.017 (2)0.0045 (17)−0.0002 (16)−0.0079 (17)
Geometric parameters (Å, º) top
Sn—Br2i2.5820 (4)N2—H3N0.9100
Sn—Br22.5820 (4)N2—H4N0.9100
Sn—Br32.6053 (4)C1—C21.493 (6)
Sn—Br3i2.6053 (4)C1—H1A0.9800
Sn—Br1i2.6075 (4)C1—H1B0.9800
Sn—Br12.6075 (4)C1—H1C0.9800
O1—C31.222 (5)C2—H2A0.9900
O2—C31.339 (5)C2—H2B0.9900
O2—C21.453 (5)C4—C51.509 (6)
N1—C31.341 (5)C4—H4A0.9900
N1—C41.445 (5)C4—H4B0.9900
N1—H1N0.8800C5—H5A0.9900
N2—C51.494 (5)C5—H5B0.9900
N2—H2N0.9100
Br2i—Sn—Br2180.000 (10)C2—C1—H1B109.5
Br2i—Sn—Br389.437 (12)H1A—C1—H1B109.5
Br2—Sn—Br390.563 (12)C2—C1—H1C109.5
Br2i—Sn—Br3i90.563 (12)H1A—C1—H1C109.5
Br2—Sn—Br3i89.437 (12)H1B—C1—H1C109.5
Br3—Sn—Br3i180.0O2—C2—C1106.4 (3)
Br2i—Sn—Br1i89.357 (13)O2—C2—H2A110.4
Br2—Sn—Br1i90.643 (13)C1—C2—H2A110.4
Br3—Sn—Br1i90.355 (12)O2—C2—H2B110.4
Br3i—Sn—Br1i89.645 (12)C1—C2—H2B110.4
Br2i—Sn—Br190.643 (13)H2A—C2—H2B108.6
Br2—Sn—Br189.357 (13)O1—C3—O2124.8 (3)
Br3—Sn—Br189.646 (12)O1—C3—N1124.2 (4)
Br3i—Sn—Br190.354 (12)O2—C3—N1111.0 (3)
Br1i—Sn—Br1180.000 (16)N1—C4—C5110.7 (3)
C3—O2—C2116.5 (3)N1—C4—H4A109.5
C3—N1—C4122.4 (3)C5—C4—H4A109.5
C3—N1—H1N114.7N1—C4—H4B109.5
C4—N1—H1N122.9C5—C4—H4B109.5
C5—N2—H2N109.5H4A—C4—H4B108.1
C5—N2—H3N109.5N2—C5—C4110.4 (3)
H2N—N2—H3N109.5N2—C5—H5A109.6
C5—N2—H4N109.5C4—C5—H5A109.6
H2N—N2—H4N109.5N2—C5—H5B109.6
H3N—N2—H4N109.5C4—C5—H5B109.6
C2—C1—H1A109.5H5A—C5—H5B108.1
C3—O2—C2—C1176.8 (3)C4—N1—C3—O2−178.8 (3)
C2—O2—C3—O1−0.8 (6)C3—N1—C4—C596.4 (4)
C2—O2—C3—N1179.1 (3)N1—C4—C5—N2−173.7 (3)
C4—N1—C3—O11.1 (6)
Symmetry code: (i) −x+1/2, −y+1/2, −z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1n···Br3i0.882.833.501 (3)134
N2—H2n···Br1ii0.912.643.495 (3)157
N2—H3n···Br3iii0.912.843.425 (3)123
N2—H4n···O1iv0.911.882.717 (5)152
Symmetry codes: (i) −x+1/2, −y+1/2, −z+1; (ii) −x+1/2, y+1/2, −z+3/2; (iii) x, −y, z+1/2; (iv) −x, y, −z+3/2.

Experimental details

Crystal data
Chemical formula(C5H13N2O2)2[SnBr6]
Mr864.48
Crystal system, space groupMonoclinic, C2/c
Temperature (K)120
a, b, c (Å)21.8907 (5), 7.4428 (2), 15.5318 (4)
β (°) 105.934 (2)
V (Å3)2433.34 (11)
Z4
Radiation typeMo Kα
µ (mm−1)10.92
Crystal size (mm)0.38 × 0.32 × 0.22
Data collection
DiffractometerBruker–Nonius 95mm CCD camera on κ-goniostat
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2003)
Tmin, Tmax0.355, 0.746
No. of measured, independent and
observed [I > 2σ(I)] reflections		15137, 2777, 2450
Rint0.051
(sin θ/λ)max (Å−1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.070, 1.12
No. of reflections2777
No. of parameters120
No. of restraints1
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.87, −1.35

Computer programs: , DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2006.

Selected bond lengths (Å) top
Sn—Br22.5820 (4)Sn—Br12.6075 (4)
Sn—Br32.6053 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1n···Br3i0.882.833.501 (3)134
N2—H2n···Br1ii0.912.643.495 (3)157
N2—H3n···Br3iii0.912.843.425 (3)123
N2—H4n···O1iv0.911.882.717 (5)152
Symmetry codes: (i) −x+1/2, −y+1/2, −z+1; (ii) −x+1/2, y+1/2, −z+3/2; (iii) x, −y, z+1/2; (iv) −x, y, −z+3/2.
 

Footnotes

‡Additional correspondence author, e-mail: j.wardell@abdn.ac.uk.

Acknowledgements

The use of the EPSRC X-ray crystallographic service at the University of Southampton, England and the valuable assistance of the staff there is gratefully acknowledged. JLW acknowledges support from FAPEMIG (Brazil).

References

First citationBrandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
 First citationDuschinsky, R. (1950). Chem. Abstr. 44, 56460.  Google Scholar
 First citationHooft, R. W. W. (1998). COLLECT. Nonius BV, Delft, The Netherlands.  Google Scholar
 First citationKita, K., Haruta, J-I., Tagawa, H. & Tamura, Y. (1980). J. Org. Chem. 45, 4519–4522.  CrossRef CAS Web of Science Google Scholar
 First citationOtwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press.  Google Scholar
 First citationSheldrick, G. M. (2003). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationSmith, G., Lynch, D. E. & Bott, R. C. (1998). Aust. J. Chem. 51?, 159–164.  Google Scholar
 First citationTavridou, P., Russo, U., Marton, D., Valle, G. & Kovala-Demertzi, D. (1995). Inorg. Chim. Acta, 231, 139–145.  CSD CrossRef CAS Web of Science Google Scholar
 First citationWilson, M. E. & Nowick, J. S. (1998). Tetrahedron Lett. 39, 6613–6616.  Web of Science CrossRef CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 65| Part 12| December 2009| Page m1562
doi:10.1107/S160053680904687X
Follow Acta Cryst. E
Sign up for e-alerts
E-alerts
Follow Acta Cryst. on Twitter
Twitter
Follow us on facebook
Facebook
Sign up for RSS feeds
RSS