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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 67| Part 12| December 2011| Page o3467
https://doi.org/10.1107/S1600536811049683

N,N′,N′′-Tri­cyclo­hexyl­guanidinium iodide

Farouq F. Said,a* Basem F. Alia* and Darrin Richesonb

aDepartment of Chemistry, Al al-Bayt University, Mafraq 25113, Jordan, and bDepartment of Chemistry and Biochemistry, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
*Correspondence e-mail: fjuqqa@aabu.edu.jo, bfali@aabu.edu.jo

(Received 15 November 2011; accepted 21 November 2011; online 30 November 2011)

In the title compound, C19H36N3+·I−, the orientation of the cyclo­hexyl rings around the planar (sum of N—C—N angles = 360°) CN3+ unit produces steric hindrance around the N—H groups. As a consequence of this particular orientation of the tricyclo­hexyl­guanidinium cation (hereafter denoted CHGH+), hydrogen bonding is restricted to classical N—H⋯I and non-clasical (cyclo­hex­yl)C—H⋯I hydrogen bonds. The propeller CHGH+ cation and the oriented hydrogen-bonding interactions lead to a three-dimensional supra­molecular structure.

Related literature

For background to guanidines, see: Ishikawa & Isobe (2002[Ishikawa, T. & Isobe, T. (2002). Chem. Eur. J. 8, 552-557.]); Moroni et al. (2001[Moroni, M., Koksch, B., Osipov, S. N., Crucianelli, M., Frigerio, M., Bravo, P. & Burger, K. (2001). J. Org. Chem. 66, 130-133.]); Yoshiizumi et al. (1998[Yoshiizumi, K., Seko, N., Nishimura, N., Ikeda, S., Yoshino, K. & Kondo Kazutaka, H. (1998). Bioorg. Med. Chem. Lett. 8, 3397-3402.]). The title salt is isomorphous with the chloride anion-analogue (Cai & Hu, 2006[Cai, X.-Q. & Hu, M.-L. (2006). Acta Cryst. E62, o1260-o1261.]) and N,N′,N′′-triisopropyl­guanidinium chloride (Said et al., 2005[Said, F. F., Ong, T. G., Yap, G. P. A. & Richeson, D. (2005). Cryst. Growth Des., 5, 1881-1888.]). (Ishikawa & Isobe, 2002[Ishikawa, T. & Isobe, T. (2002). Chem. Eur. J. 8, 552-557.]). The structural features and hydrogen -bonding array provided by guanidinium cations suggest them to be good building blocks for the formation of supra­molecular entities, see: Said, Bazinet et al. (2006[Said, F. F., Bazinet, P., Ong, T. G., Yap, G. P. A. & Richeson, D. S. (2006). Cryst. Growth Des., 6, 258-266.]); Said, Ong et al. (2006[Said, F. F., Ong, T. G., Bazinet, P., Yap, G. P. A. & Richeson, D. S. (2006). Cryst. Growth Des., 6, 1848-1857.]). For bond-length data, see: Allen et al. (1987[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.]).

[Scheme 1]

Experimental

Crystal data

  • C19H36N3+·I−

  • Mr = 433.41

  • Cubic, P 21 3

  • a = 12.893 (4) Å

  • V = 2143 (2) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 1.50 mm−1

  • T = 188 K

  • 0.5 × 0.3 × 0.3 mm
Data collection

  • Bruker P4 diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker (2005). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.271, Tmax = 0.320

  • 2387 measured reflections

  • 802 independent reflections

  • 628 reflections with I > 2σ(I)

  • Rint = 0.055

  • 3 standard reflections every 97 reflections intensity decay: none
Refinement

  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.076

  • S = 1.04

  • 802 reflections

  • 70 parameters

  • H-atom parameters constrained

  • Δρmax = 0.33 e Å−3

  • Δρmin = −0.27 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 802 Friedel pairs

  • Flack parameter: 0.08 (8)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N1—H1A⋯I1i 0.86 2.86 3.693 (5) 165
C2—H2A⋯I1ii 0.98 3.03 3.950 (5) 158
Symmetry codes: (i) x, y-1, z; (ii) [-x+2, y-{\script{1\over 2}}, -z+{\script{3\over 2}}].

Data collection: XSCANS (Bruker, 1996[Bruker (1996). XSCANS . Bruker AXS Inc., Madison, Wisconsin, USA]); cell refinement: XSCANS; data reduction: XSCANS; 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 I, global. DOI: https://doi.org/10.1107/S1600536811049683/bq2321sup1.cif

Supporting information file. DOI: https://doi.org/10.1107/S1600536811049683/bq2321Isup2.mol

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536811049683/bq2321Isup3.hkl

Supporting information file. DOI: https://doi.org/10.1107/S1600536811049683/bq2321Isup4.cml

checkCIF report


Comment top

Guanidines are of special interest due to their possible application in medicine (Yoshiizumi et al., 1998; Moroni et al., 2001). They are considered super bases as they are easily protonated to generate guanidinium cations (Ishikawa & Isobe, 2002). The structural features and hydrogen bonding array provided by these cations suggest that they are good building blocks for the formation of supramolecular entities (Said, Bazinet et al., 2006, Said, Ong et al., 2006, Said et al., 2005).

The title compound (I), Fig. 1, is a typical N,N',N"-trisubstituted guanidinium halide salt with normal geometric parameters (Said et al., 2005). The central guanidinium fragment of the cation of the title salt is planar [sum of NCN angles is 360°] with bond lengths and angles as expected for a central Csp2 hybridization, accounting for charge delocalization between the three C—N bonds. The bond length C1—N1 [1.330 (5) Å] is comparable with literature averages for substituted and unsubstituted guanidinium cations (1.321 and 1.328 Å, respectively; (Allen et al., 1987)). The cyclohexyl ring has the normal chair conformation with conventional bond lengths and angles. A partial packing diagram is shown in Fig. 2. The CHGH+ ions occur in chains, with the I- anions arranged parallel to the cation chains. The cations and anions occur in a 3-fold array: three anions surround each cation [via its three N—H···I, 2.856 Å; (165°) and C—H···I (3.027 Å; 158°) interactions, Table 1, Fig. 3], and three cations surround each anion resulting in the formation of three-dimensional supramolecular structure.This type of supramolecular synthons has been observed frequently in other related compounds. The stability of this crystal lattice is evidenced by the crystallization of a whole series of isomorphous compounds of this type, such as N,N',N''-tricyclohexylguanidinium chloride (Cai & Hu, 2006), even with different substituents like N,N',N''-triisipropylguanidinium chloride (Said et al., 2005).

Related literature top

For background to guanidines, see: Ishikawa & Isobe (2002); Moroni et al. (2001); Yoshiizumi et al. (1998). For the title salt is isomorphous with the chloride anion-analogue (Cai & Hu, 2006) and N,N',N''-triisopropylguanidinium chloride (Said et al., 2005). (Ishikawa & Isobe, 2002). The structural features and hydrogen -bonding array provided by guanidinium cations suggest them to be good building blocks for the formation of supramolecular entities, see: Said, Bazinet et al. (2006); Said, Ong et al. (2006). For bond-length data, see: Allen et al. (1987);

Experimental top

General: N,N',N"-tricyclohexylguanidine was prepared according to literature methods. All other reagents were purchased from Aldrich Chemical Company and used without further purification. Elemental analyses were run on a Perkin Elmer PE CHN 4000 elemental analysis system.

Synthesis and crystallization of N,N',N"-tricyclohexylguanidinium iodide, {C(HNcyclohexyl)3}+I-

In a round bottom flask, a combination of 0.200 g (1.34 mmol) ammonium iodide and 0.41 g (1.34 mmol) N,N',N''-tricyclohexylguanidine were dissolved in 10 mL of distilled water. White precipitate of {C(HNcyclohexyl)3}+I- was deposited immediately of the solution (0.46 g, 92.0% yield). The product was crystallized from a mixture of methanol and distilled water to give white cubic crystals. In addition to confirming the molecular formula through elemental analysis, the solid obtained was examined by single-crystal X-ray analysis. Anal. Calcd for C19H36IN3 C, 52.65; H, 8.37; N, 9.70. Found C, 52.56; H, 8.63; N, 9.40.

Refinement top

Hydrogen atoms were included in calculated positions and refined as riding on their parent atoms with C—H = 0.97 Å and Uiso(H) = 1.2Ueq(C) and N—H = 0.86 Å and Uiso(H) = 1.2Ueq(N).

Structure description top

Guanidines are of special interest due to their possible application in medicine (Yoshiizumi et al., 1998; Moroni et al., 2001). They are considered super bases as they are easily protonated to generate guanidinium cations (Ishikawa & Isobe, 2002). The structural features and hydrogen bonding array provided by these cations suggest that they are good building blocks for the formation of supramolecular entities (Said, Bazinet et al., 2006, Said, Ong et al., 2006, Said et al., 2005).

The title compound (I), Fig. 1, is a typical N,N',N"-trisubstituted guanidinium halide salt with normal geometric parameters (Said et al., 2005). The central guanidinium fragment of the cation of the title salt is planar [sum of NCN angles is 360°] with bond lengths and angles as expected for a central Csp2 hybridization, accounting for charge delocalization between the three C—N bonds. The bond length C1—N1 [1.330 (5) Å] is comparable with literature averages for substituted and unsubstituted guanidinium cations (1.321 and 1.328 Å, respectively; (Allen et al., 1987)). The cyclohexyl ring has the normal chair conformation with conventional bond lengths and angles. A partial packing diagram is shown in Fig. 2. The CHGH+ ions occur in chains, with the I- anions arranged parallel to the cation chains. The cations and anions occur in a 3-fold array: three anions surround each cation [via its three N—H···I, 2.856 Å; (165°) and C—H···I (3.027 Å; 158°) interactions, Table 1, Fig. 3], and three cations surround each anion resulting in the formation of three-dimensional supramolecular structure.This type of supramolecular synthons has been observed frequently in other related compounds. The stability of this crystal lattice is evidenced by the crystallization of a whole series of isomorphous compounds of this type, such as N,N',N''-tricyclohexylguanidinium chloride (Cai & Hu, 2006), even with different substituents like N,N',N''-triisipropylguanidinium chloride (Said et al., 2005).

For background to guanidines, see: Ishikawa & Isobe (2002); Moroni et al. (2001); Yoshiizumi et al. (1998). For the title salt is isomorphous with the chloride anion-analogue (Cai & Hu, 2006) and N,N',N''-triisopropylguanidinium chloride (Said et al., 2005). (Ishikawa & Isobe, 2002). The structural features and hydrogen -bonding array provided by guanidinium cations suggest them to be good building blocks for the formation of supramolecular entities, see: Said, Bazinet et al. (2006); Said, Ong et al. (2006). For bond-length data, see: Allen et al. (1987);

Computing details top

Data collection: XSCANS (Bruker, 1996); cell refinement: XSCANS (Bruker, 1996); data reduction: XSCANS (Bruker, 1996); 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. The structure of (I) with the guanidinium cation symmetry unique atoms are labeled. The other atoms are related by threefold rotation (3/2 – z, 1 – x, 1/2 + y and 1 – y, – 1/2 + y, 3/2 – x).
[Figure 2] Fig. 2. A partial packing diagram of (I), showing the CHGH+ cations and anions occur in a 3-fold array: three anions surround each cation and three cations surround each anion. Different colors and molecular rendering is used to clarify the arrangement.
[Figure 3] Fig. 3. The diagram showing one guanidium cation and three anions in order to emphasize the orientation of the supramolecular synthon that results from hydrogen bonding array of three N—H···I and three C—H···I interactions.
N,N',N''-Tricyclohexylguanidinium iodide top
Crystal data top
C19H36N3+·I−Dx = 1.343 Mg m−3
Mr = 433.41Mo Kα radiation, λ = 0.71073 Å
Cubic, P213Cell parameters from 30 reflections
Hall symbol: P 2ac 2ab 3θ = 3.9–6.9°
a = 12.893 (4) ŵ = 1.50 mm−1
V = 2143 (2) Å3T = 188 K
Z = 4Block, colorless
F(000) = 8960.5 × 0.3 × 0.3 mm
Data collection top
Bruker P4
diffractometer		628 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.055
Graphite monochromatorθmax = 25.9°, θmin = 2.2°
ω scansh = 0→15
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		k = 0→15
Tmin = 0.271, Tmax = 0.320l = 0→15
2387 measured reflections3 standard reflections every 97 reflections
802 independent reflections intensity decay: none
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)] = 0.038H-atom parameters constrained
wR(F2) = 0.076 w = 1/[σ2(Fo2) + (0.0269P)2 + 0.7683P]
where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max < 0.001
802 reflectionsΔρmax = 0.33 e Å−3
70 parametersΔρmin = −0.27 e Å−3
0 restraintsAbsolute structure: Flack (1983), 802 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.08 (8)
Crystal data top
C19H36N3+·I−Z = 4
Mr = 433.41Mo Kα radiation
Cubic, P213µ = 1.50 mm−1
a = 12.893 (4) ÅT = 188 K
V = 2143 (2) Å30.5 × 0.3 × 0.3 mm
Data collection top
Bruker P4
diffractometer		628 reflections with I > 2σ(I)
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		Rint = 0.055
Tmin = 0.271, Tmax = 0.3203 standard reflections every 97 reflections
2387 measured reflections intensity decay: none
802 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.038H-atom parameters constrained
wR(F2) = 0.076Δρmax = 0.33 e Å−3
S = 1.04Δρmin = −0.27 e Å−3
802 reflectionsAbsolute structure: Flack (1983), 802 Friedel pairs
70 parametersAbsolute structure parameter: 0.08 (8)
0 restraints
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*/Ueq
I10.89107 (4)0.89107 (4)0.89107 (4)0.0589 (2)
N10.8894 (5)0.1398 (4)0.7489 (4)0.0715 (16)
H1A0.88030.07810.77280.086*
C10.8343 (6)0.1657 (6)0.6657 (6)0.064 (3)
C20.9631 (6)0.2045 (6)0.8033 (6)0.071 (2)
H2A0.98120.26360.75910.086*
C30.9164 (6)0.2440 (8)0.9017 (8)0.114 (4)
H3A0.89510.18610.94480.137*
H3B0.85560.28550.88620.137*
C40.9957 (9)0.3091 (9)0.9588 (11)0.149 (5)
H4A1.01150.37010.91770.179*
H4B0.96600.33231.02390.179*
C51.0919 (7)0.2525 (9)0.9799 (7)0.100 (3)
H5A1.07800.19671.02850.120*
H5B1.14190.29901.01160.120*
C61.1359 (5)0.2091 (7)0.8838 (7)0.084 (2)
H6A1.19570.16680.90090.101*
H6C1.15930.26540.83970.101*
C71.0581 (6)0.1441 (7)0.8255 (7)0.086 (3)
H7C1.08850.12060.76080.103*
H7A1.04040.08350.86630.103*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.0589 (2)0.0589 (2)0.0589 (2)−0.0007 (3)−0.0007 (3)−0.0007 (3)
N10.084 (4)0.060 (3)0.070 (4)−0.014 (4)−0.026 (4)0.014 (3)
C10.064 (3)0.064 (3)0.064 (3)−0.012 (4)−0.012 (4)0.012 (4)
C20.082 (6)0.071 (5)0.061 (5)−0.020 (5)−0.024 (4)0.010 (4)
C30.082 (7)0.132 (8)0.129 (9)0.040 (6)−0.022 (7)−0.045 (8)
C40.129 (9)0.147 (10)0.172 (12)0.014 (9)−0.035 (9)−0.102 (10)
C50.097 (7)0.138 (8)0.065 (5)−0.021 (8)−0.028 (6)0.008 (6)
C60.064 (5)0.090 (6)0.098 (6)−0.014 (4)−0.005 (5)0.007 (6)
C70.049 (4)0.104 (7)0.105 (6)−0.010 (4)−0.001 (5)−0.026 (6)
Geometric parameters (Å, º) top
N1—C11.330 (5)C4—C51.465 (13)
N1—C21.446 (9)C4—H4A0.9700
N1—H1A0.8600C4—H4B0.9700
C1—N1i1.330 (5)C5—C61.473 (13)
C1—N1ii1.330 (5)C5—H5A0.9700
C2—C71.479 (10)C5—H5B0.9700
C2—C31.493 (11)C6—C71.508 (10)
C2—H2A0.9800C6—H6A0.9700
C3—C41.514 (13)C6—H6C0.9700
C3—H3A0.9700C7—H7C0.9700
C3—H3B0.9700C7—H7A0.9700
C1—N1—C2126.7 (5)C5—C4—H4B109.1
C1—N1—H1A116.7C3—C4—H4B109.1
C2—N1—H1A116.7H4A—C4—H4B107.8
N1i—C1—N1119.99 (3)C4—C5—C6111.1 (8)
N1i—C1—N1ii119.99 (3)C4—C5—H5A109.4
N1—C1—N1ii119.99 (3)C6—C5—H5A109.4
N1—C2—C7109.5 (6)C4—C5—H5B109.4
N1—C2—C3110.1 (7)C6—C5—H5B109.4
C7—C2—C3110.4 (7)H5A—C5—H5B108.0
N1—C2—H2A108.9C5—C6—C7112.0 (7)
C7—C2—H2A108.9C5—C6—H6A109.2
C3—C2—H2A108.9C7—C6—H6A109.2
C2—C3—C4109.3 (8)C5—C6—H6C109.2
C2—C3—H3A109.8C7—C6—H6C109.2
C4—C3—H3A109.8H6A—C6—H6C107.9
C2—C3—H3B109.8C2—C7—C6110.8 (7)
C4—C3—H3B109.8C2—C7—H7C109.5
H3A—C3—H3B108.3C6—C7—H7C109.5
C5—C4—C3112.7 (8)C2—C7—H7A109.5
C5—C4—H4A109.1C6—C7—H7A109.5
C3—C4—H4A109.1H7C—C7—H7A108.1
Symmetry codes: (i) −z+3/2, −x+1, y+1/2; (ii) −y+1, z−1/2, −x+3/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···I1iii0.862.863.693 (5)165
C2—H2A···I1iv0.983.033.950 (5)158
Symmetry codes: (iii) x, y−1, z; (iv) −x+2, y−1/2, −z+3/2.

Experimental details

Crystal data
Chemical formulaC19H36N3+·I−
Mr433.41
Crystal system, space groupCubic, P213
Temperature (K)188
a (Å)12.893 (4)
V (Å3)2143 (2)
Z4
Radiation typeMo Kα
µ (mm−1)1.50
Crystal size (mm)0.5 × 0.3 × 0.3
Data collection
DiffractometerBruker P4
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.271, 0.320
No. of measured, independent and
observed [I > 2σ(I)] reflections		2387, 802, 628
Rint0.055
(sin θ/λ)max (Å−1)0.614
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.076, 1.04
No. of reflections802
No. of parameters70
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.33, −0.27
Absolute structureFlack (1983), 802 Friedel pairs
Absolute structure parameter0.08 (8)

Computer programs: XSCANS (Bruker, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···I1i0.862.863.693 (5)165
C2—H2A···I1ii0.983.033.950 (5)158
Symmetry codes: (i) x, y−1, z; (ii) −x+2, y−1/2, −z+3/2.
 

Acknowledgements

We would like to thank Dr Thomas Haas for his help in the analysis of the structure.

References

First citationAllen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.  CSD CrossRef Web of Science Google Scholar
 First citationBruker (1996). XSCANS . Bruker AXS Inc., Madison, Wisconsin, USA  Google Scholar
 First citationBruker (2005). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationCai, X.-Q. & Hu, M.-L. (2006). Acta Cryst. E62, o1260–o1261.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationFlack, H. D. (1983). Acta Cryst. A39, 876–881.  CrossRef CAS Web of Science IUCr Journals Google Scholar
 First citationIshikawa, T. & Isobe, T. (2002). Chem. Eur. J. 8, 552–557.  CrossRef PubMed CAS Google Scholar
 First citationMoroni, M., Koksch, B., Osipov, S. N., Crucianelli, M., Frigerio, M., Bravo, P. & Burger, K. (2001). J. Org. Chem. 66, 130–133.  Web of Science CrossRef PubMed CAS Google Scholar
 First citationSaid, F. F., Bazinet, P., Ong, T. G., Yap, G. P. A. & Richeson, D. S. (2006). Cryst. Growth Des., 6, 258–266.  Web of Science CSD CrossRef CAS Google Scholar
 First citationSaid, F. F., Ong, T. G., Bazinet, P., Yap, G. P. A. & Richeson, D. S. (2006). Cryst. Growth Des., 6, 1848–1857.  Web of Science CSD CrossRef CAS Google Scholar
 First citationSaid, F. F., Ong, T. G., Yap, G. P. A. & Richeson, D. (2005). Cryst. Growth Des., 5, 1881–1888.  Web of Science CSD CrossRef CAS Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationYoshiizumi, K., Seko, N., Nishimura, N., Ikeda, S., Yoshino, K. & Kondo Kazutaka, H. (1998). Bioorg. Med. Chem. Lett. 8, 3397–3402.  Web of Science CrossRef CAS PubMed Google Scholar

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Journal logoCRYSTALLOGRAPHIC
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ISSN: 2056-9890
Volume 67| Part 12| December 2011| Page o3467
https://doi.org/10.1107/S1600536811049683
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