supplementary materials


jj2179 scheme

Acta Cryst. (2014). E70, o55-o56    [ doi:10.1107/S160053681303331X ]

2-(Naphthalen-1-yl)-1-phenyl-1H-benzimid­azole benzene hemisolvate

N. Srinivasan, A. Thiruvalluvar, S. Rosepriya, S. M. Prakash and R. J. Butcher

Abstract top

In the title compound, C23H16N2·0.5C6H6, the benzimidazole unit [maximum deviation = 0.0258 (6) Å] and the naphthalene ring system [maximum deviation = 0.0254 (6) Å] are both essentially planar and make a dihedral angle of 61.955 (17)°. The imidazole ring makes dihedral angle of 61.73 (4)° with the phenyl ring. An intra­molecular C-H...N hydrogen bond generates an S(6) ring motif. In the crystal, seven weak C-H...[pi] inter­actions involving the fused ring system, the benzene solvent mol­ecule, the imidazole phenyl rings are observed, leading to a three-dimensional architecture.

Comment top

Benzimidazole based chromophores have received increasing attention due to their distinctive linear, non-linear optical properties and also due to their excellent thermal stability in guest-host systems (Cross et al., 1995). They are a component of vitamin B12 (Brown, 2005) and are related to the DNA base purine and the stimulant caffeine. Substituted benzimidazole derivatives have found commercial applications in veterinarian medicine as anthelmintic agents and in diverse human therapeutic areas as an antiulcer and antihistaminic (Spasov et al., 1999). Therefore, the preparation of benzimidazoles has gained considerable attention in recent years. Jayamoorthy et al., (2012, 2013) and Rosepriya et al., (2011) have reported closely related structures of benzimidazole derivatives. We are interested to use 2-(naphthalen-1-yl)-1-phenyl-1H-benzimidazole as ligand to study its photophysical properties.

The assymmetric unit of the title compound, C23H16N2·0.5C6H6, (Fig. 1), contains a 2-(naphthalen-1-yl)-1-phenyl-1H-benzimidazole molecule and a hemibenzene solvent molecule. The benzimidazole unit is essentially planar [maximum deviation of -0.0258 (6) Å for C8]. The naphthalene unit is also essentially planar [maximum deviation of -0.0254 (6) Å for C23]. The benzimidazole unit makes dihedral angle of 61.955 (17)° with the naphthalene unit. The imidazole ring makes dihedral angle of 61.73 (4)° with the phenyl group attached to N1.

An intramolecular C28—H28···N3 hydrogen bond (Fig. 1) generates an S(6) ring motif (Bernstein et al., 1995). The packing of the title compound, viewed along the a axis is shown in Fig. 2. In the crystal, seven weak C7—H7···π interactions involving the fused benzene ring, C15—H15···π interactions involving the solvent benzene ring, C22—H22···π interaction involving the imidazole ring, C24—H24···π interaction involving the phenyl ring, C26—H26···π interaction involving the fused benzene ring, C27—H27···π interaction involving the imidazole ring, are observed, leading to a three dimensional architecture (Fig. 3, Table 1).

Related literature top

For linear and non-linear optical properties and the thermal stability of benzimidazole-based chromophores, see: Cross et al. (1995). For imidazole as a component of vitamin B12, purine and caffeine, see: Brown (2005). For commercial and therapeutic applications of substituted benzimidazole derivatives, see: Spasov et al. (1999). For related crystal structures, see: Jayamoorthy et al. (2012, 2013); Rosepriya et al. (2011). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

To the pure N-phenyl-o-phenylenediamine (17 mmol, 3.128 g) in ethanol (10 ml), napthaldehyde (17 mmol, 1.9 ml) and ammonium acetate (3 g) was added about 1 h by maintaining the temperature at 353 K. The reaction mixture was refluxed for 48 hrs and the completion of reaction was monitored by TLC, finally the reaction extracted by dichloromethane. The solid separated was purified by column chromatography using benzene as the eluent. Yield: 2.65 g (50%). The compound was dissolved in benzene and ethyl acetate (9:1) mixture and allowed to slow evaporation for two days, to obtain crystals suitable for X-ray diffraction studies.

Refinement top

The H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H = 0.95 Å. Uiso(H) = 1.2Ueq(C).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL2013 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as small spheres of arbitrary radius. The dashed line indicates the intramolecular C—H···N hydrogen bond. Symmetry code: (i) -x + 1, -y, -z + 1.
[Figure 2] Fig. 2. The packing of the title compound, viewed along the a axis.
[Figure 3] Fig. 3. Part of the crystal structure of compound, showing the formation of C—H···π interactions. Interactions involving benzene solvent Cg8 are not shown.
2-(Naphthalen-1-yl)-1-phenyl-1H-benzimidazole benzene hemisolvate top
Crystal data top
C23H16N2·0.5C6H6Z = 2
Mr = 359.43F(000) = 378
Triclinic, P1Dx = 1.288 Mg m3
Hall symbol: -P 1Melting point: 392 K
a = 8.5529 (3) ÅMo Kα radiation, λ = 0.71069 Å
b = 9.4517 (3) ÅCell parameters from 15125 reflections
c = 11.8936 (3) Åθ = 3.0–41.0°
α = 86.334 (2)°µ = 0.08 mm1
β = 89.838 (2)°T = 123 K
γ = 75.051 (3)°Prism, colourless
V = 926.94 (5) Å30.72 × 0.59 × 0.42 mm
Data collection top
Agilent Xcalibur Ruby Gemini
diffractometer
12045 independent reflections
Radiation source: Enhance (Mo) X-ray Source9086 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.063
Detector resolution: 10.5081 pixels mm-1θmax = 41.1°, θmin = 3.0°
ω scansh = 1515
Absorption correction: analytical
[CrysAlis PRO (Agilent, 2012), using a multifaceted crystal model (Clark & Reid, 1995)]
k = 1717
Tmin = 0.963, Tmax = 0.977l = 2121
57784 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)] = 0.057Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.160H-atom parameters constrained
S = 1.05 w = 1/[σ2(Fo2) + (0.076P)2 + 0.0921P]
where P = (Fo2 + 2Fc2)/3
12045 reflections(Δ/σ)max < 0.001
253 parametersΔρmax = 0.48 e Å3
0 restraintsΔρmin = 0.42 e Å3
Crystal data top
C23H16N2·0.5C6H6γ = 75.051 (3)°
Mr = 359.43V = 926.94 (5) Å3
Triclinic, P1Z = 2
a = 8.5529 (3) ÅMo Kα radiation
b = 9.4517 (3) ŵ = 0.08 mm1
c = 11.8936 (3) ÅT = 123 K
α = 86.334 (2)°0.72 × 0.59 × 0.42 mm
β = 89.838 (2)°
Data collection top
Agilent Xcalibur Ruby Gemini
diffractometer
12045 independent reflections
Absorption correction: analytical
[CrysAlis PRO (Agilent, 2012), using a multifaceted crystal model (Clark & Reid, 1995)]
9086 reflections with I > 2σ(I)
Tmin = 0.963, Tmax = 0.977Rint = 0.063
57784 measured reflectionsθmax = 41.1°
Refinement top
R[F2 > 2σ(F2)] = 0.057H-atom parameters constrained
wR(F2) = 0.160Δρmax = 0.48 e Å3
S = 1.05Δρmin = 0.42 e Å3
12045 reflectionsAbsolute structure: ?
253 parametersAbsolute structure parameter: ?
0 restraintsRogers parameter: ?
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N10.67234 (7)0.54147 (6)0.17737 (5)0.0196 (1)
N30.58580 (7)0.34162 (7)0.23145 (5)0.0218 (1)
C20.54214 (8)0.48307 (7)0.20135 (6)0.0197 (1)
C40.86569 (9)0.16857 (8)0.25577 (6)0.0230 (2)
C51.02936 (9)0.16196 (8)0.24850 (6)0.0241 (2)
C61.08319 (9)0.28681 (9)0.21552 (6)0.0237 (2)
C70.97488 (9)0.42165 (8)0.18733 (6)0.0222 (2)
C80.81081 (8)0.42675 (7)0.19437 (6)0.0194 (1)
C90.75441 (8)0.30379 (7)0.22843 (6)0.0200 (2)
C110.66581 (8)0.69261 (7)0.15057 (5)0.0190 (1)
C120.72504 (9)0.73392 (8)0.04813 (6)0.0217 (2)
C130.71614 (9)0.88153 (8)0.02178 (6)0.0247 (2)
C140.64697 (9)0.98608 (8)0.09676 (7)0.0253 (2)
C150.58828 (9)0.94403 (8)0.19913 (7)0.0259 (2)
C160.59863 (9)0.79665 (8)0.22698 (6)0.0233 (2)
C210.37491 (8)0.57825 (7)0.19356 (6)0.0194 (2)
C220.31678 (9)0.65122 (8)0.09166 (6)0.0230 (2)
C230.16256 (9)0.75196 (9)0.08347 (6)0.0252 (2)
C240.07012 (9)0.78075 (8)0.17773 (7)0.0243 (2)
C250.02654 (9)0.73198 (9)0.38062 (7)0.0270 (2)
C260.07884 (10)0.65771 (10)0.48214 (7)0.0291 (2)
C270.23194 (10)0.55553 (10)0.49096 (6)0.0271 (2)
C280.32981 (9)0.52890 (8)0.39875 (6)0.0225 (2)
C290.27828 (8)0.60281 (7)0.29210 (5)0.0187 (2)
C300.12426 (8)0.70669 (8)0.28362 (6)0.0210 (2)
C1A0.55334 (12)0.12597 (10)0.47928 (7)0.0319 (2)
C2A0.39180 (12)0.13022 (10)0.46027 (8)0.0329 (2)
C3A0.66115 (11)0.00416 (11)0.51904 (7)0.0315 (2)
H40.830100.084000.278600.0276*
H51.106680.071190.266160.0289*
H61.196120.278820.212450.0285*
H71.010840.505990.164430.0266*
H120.771090.662280.003340.0261*
H130.757460.910780.047630.0297*
H140.639781.086780.077950.0303*
H150.541071.015930.250130.0311*
H160.560280.767190.297410.0279*
H220.381290.633410.026350.0276*
H230.122950.799730.012630.0302*
H240.031680.851330.172080.0292*
H250.076250.801100.375230.0323*
H260.012100.675030.546420.0350*
H270.267700.504600.561470.0325*
H280.432880.460460.406320.0270*
H1A0.589970.212060.465070.0383*
H2A0.317900.219180.433200.0394*
H3A0.771440.006850.532110.0378*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0184 (2)0.0182 (2)0.0204 (2)0.0019 (2)0.0024 (2)0.0005 (2)
N30.0201 (2)0.0205 (2)0.0231 (3)0.0031 (2)0.0015 (2)0.0016 (2)
C20.0188 (2)0.0205 (3)0.0184 (2)0.0031 (2)0.0016 (2)0.0005 (2)
C40.0238 (3)0.0194 (3)0.0233 (3)0.0013 (2)0.0001 (2)0.0004 (2)
C50.0226 (3)0.0222 (3)0.0236 (3)0.0011 (2)0.0003 (2)0.0009 (2)
C60.0192 (3)0.0260 (3)0.0234 (3)0.0009 (2)0.0011 (2)0.0025 (2)
C70.0197 (3)0.0226 (3)0.0230 (3)0.0034 (2)0.0023 (2)0.0016 (2)
C80.0183 (2)0.0191 (3)0.0186 (2)0.0013 (2)0.0016 (2)0.0009 (2)
C90.0199 (3)0.0192 (3)0.0190 (3)0.0021 (2)0.0011 (2)0.0003 (2)
C110.0184 (2)0.0184 (2)0.0186 (2)0.0021 (2)0.0010 (2)0.0001 (2)
C120.0222 (3)0.0213 (3)0.0198 (3)0.0026 (2)0.0024 (2)0.0003 (2)
C130.0248 (3)0.0240 (3)0.0238 (3)0.0050 (2)0.0014 (2)0.0050 (2)
C140.0230 (3)0.0195 (3)0.0315 (3)0.0032 (2)0.0053 (3)0.0023 (2)
C150.0245 (3)0.0214 (3)0.0303 (3)0.0021 (2)0.0003 (3)0.0062 (2)
C160.0242 (3)0.0235 (3)0.0215 (3)0.0045 (2)0.0034 (2)0.0040 (2)
C210.0175 (2)0.0196 (3)0.0198 (3)0.0028 (2)0.0003 (2)0.0004 (2)
C220.0221 (3)0.0252 (3)0.0199 (3)0.0036 (2)0.0003 (2)0.0019 (2)
C230.0241 (3)0.0251 (3)0.0238 (3)0.0032 (2)0.0043 (2)0.0041 (2)
C240.0201 (3)0.0219 (3)0.0282 (3)0.0008 (2)0.0039 (2)0.0000 (2)
C250.0202 (3)0.0296 (3)0.0287 (3)0.0011 (3)0.0032 (2)0.0065 (3)
C260.0264 (3)0.0355 (4)0.0246 (3)0.0055 (3)0.0067 (3)0.0059 (3)
C270.0273 (3)0.0326 (4)0.0199 (3)0.0054 (3)0.0027 (2)0.0001 (3)
C280.0211 (3)0.0245 (3)0.0201 (3)0.0030 (2)0.0004 (2)0.0004 (2)
C290.0167 (2)0.0191 (3)0.0194 (3)0.0033 (2)0.0001 (2)0.0008 (2)
C300.0179 (2)0.0206 (3)0.0233 (3)0.0023 (2)0.0004 (2)0.0027 (2)
C1A0.0385 (4)0.0284 (4)0.0274 (3)0.0071 (3)0.0019 (3)0.0013 (3)
C2A0.0360 (4)0.0282 (4)0.0290 (4)0.0004 (3)0.0000 (3)0.0030 (3)
C3A0.0301 (4)0.0350 (4)0.0271 (3)0.0047 (3)0.0005 (3)0.0001 (3)
Geometric parameters (Å, º) top
N1—C21.3861 (9)C27—C281.3741 (11)
N1—C81.3892 (9)C28—C291.4221 (9)
N1—C111.4304 (8)C29—C301.4249 (10)
N3—C21.3180 (9)C4—H40.9500
N3—C91.3943 (9)C5—H50.9500
C2—C211.4798 (10)C6—H60.9500
C4—C51.3878 (11)C7—H70.9500
C4—C91.4022 (10)C12—H120.9500
C5—C61.4066 (11)C13—H130.9500
C6—C71.3903 (11)C14—H140.9500
C7—C81.3941 (11)C15—H150.9500
C8—C91.4055 (9)C16—H160.9500
C11—C121.3897 (10)C22—H220.9500
C11—C161.3939 (10)C23—H230.9500
C12—C131.3928 (10)C24—H240.9500
C13—C141.3892 (11)C25—H250.9500
C14—C151.3892 (12)C26—H260.9500
C15—C161.3912 (10)C27—H270.9500
C21—C221.3825 (10)C28—H280.9500
C21—C291.4286 (9)C1A—C2A1.3906 (15)
C22—C231.4131 (11)C1A—C3A1.3891 (14)
C23—C241.3708 (11)C2A—C3Ai1.3876 (14)
C24—C301.4191 (11)C1A—H1A0.9500
C25—C261.3724 (12)C2A—H2A0.9500
C25—C301.4189 (11)C3A—H3A0.9500
C26—C271.4120 (13)
C2—N1—C8106.49 (5)C5—C4—H4121.00
C2—N1—C11126.57 (6)C9—C4—H4121.00
C8—N1—C11126.72 (6)C4—C5—H5119.00
C2—N3—C9104.76 (6)C6—C5—H5119.00
N1—C2—N3113.12 (6)C5—C6—H6119.00
N1—C2—C21120.27 (6)C7—C6—H6119.00
N3—C2—C21126.61 (6)C6—C7—H7122.00
C5—C4—C9118.02 (7)C8—C7—H7122.00
C4—C5—C6121.39 (7)C11—C12—H12120.00
C5—C6—C7121.50 (7)C13—C12—H12120.00
C6—C7—C8116.58 (7)C12—C13—H13120.00
N1—C8—C7131.99 (6)C14—C13—H13120.00
N1—C8—C9105.10 (6)C13—C14—H14120.00
C7—C8—C9122.85 (6)C15—C14—H14120.00
N3—C9—C4129.80 (6)C14—C15—H15120.00
N3—C9—C8110.53 (6)C16—C15—H15120.00
C4—C9—C8119.65 (7)C11—C16—H16120.00
N1—C11—C12119.52 (6)C15—C16—H16120.00
N1—C11—C16119.59 (6)C21—C22—H22120.00
C12—C11—C16120.89 (6)C23—C22—H22120.00
C11—C12—C13119.26 (7)C22—C23—H23120.00
C12—C13—C14120.16 (7)C24—C23—H23120.00
C13—C14—C15120.30 (7)C23—C24—H24120.00
C14—C15—C16120.01 (7)C30—C24—H24120.00
C11—C16—C15119.37 (7)C26—C25—H25120.00
C2—C21—C22119.43 (6)C30—C25—H25120.00
C2—C21—C29120.29 (6)C25—C26—H26120.00
C22—C21—C29120.13 (6)C27—C26—H26120.00
C21—C22—C23120.80 (7)C26—C27—H27120.00
C22—C23—C24120.00 (7)C28—C27—H27120.00
C23—C24—C30120.97 (7)C27—C28—H28120.00
C26—C25—C30120.75 (7)C29—C28—H28120.00
C25—C26—C27119.94 (8)C2A—C1A—C3A120.00 (9)
C26—C27—C28120.78 (7)C1A—C2A—C3Ai119.81 (9)
C27—C28—C29120.63 (7)C1A—C3A—C2Ai120.19 (9)
C21—C29—C28122.80 (6)C2A—C1A—H1A120.00
C21—C29—C30118.72 (6)C3A—C1A—H1A120.00
C28—C29—C30118.48 (6)C1A—C2A—H2A120.00
C24—C30—C25121.24 (7)C3Ai—C2A—H2A120.00
C24—C30—C29119.33 (6)C1A—C3A—H3A120.00
C25—C30—C29119.42 (6)C2Ai—C3A—H3A120.00
C8—N1—C2—N30.31 (8)C16—C11—C12—C130.28 (11)
C8—N1—C2—C21178.80 (6)N1—C11—C16—C15178.15 (7)
C11—N1—C2—N3175.10 (6)C12—C11—C16—C151.18 (11)
C11—N1—C2—C214.01 (10)C11—C12—C13—C140.76 (11)
C2—N1—C8—C7177.27 (8)C12—C13—C14—C150.90 (12)
C2—N1—C8—C90.10 (7)C13—C14—C15—C160.00 (12)
C11—N1—C8—C72.50 (12)C14—C15—C16—C111.03 (12)
C11—N1—C8—C9174.68 (6)C2—C21—C22—C23174.88 (7)
C2—N1—C11—C12120.91 (8)C29—C21—C22—C230.72 (11)
C2—N1—C11—C1658.42 (10)C2—C21—C29—C285.79 (10)
C8—N1—C11—C1265.33 (9)C2—C21—C29—C30173.63 (6)
C8—N1—C11—C16115.34 (8)C22—C21—C29—C28178.65 (7)
C9—N3—C2—N10.57 (8)C22—C21—C29—C301.92 (10)
C9—N3—C2—C21178.47 (7)C21—C22—C23—C241.44 (12)
C2—N3—C9—C4177.86 (7)C22—C23—C24—C302.34 (12)
C2—N3—C9—C80.62 (8)C23—C24—C30—C25177.62 (8)
N1—C2—C21—C2260.23 (9)C23—C24—C30—C291.09 (11)
N1—C2—C21—C29115.36 (7)C30—C25—C26—C270.42 (13)
N3—C2—C21—C22120.80 (8)C26—C25—C30—C24178.77 (8)
N3—C2—C21—C2963.62 (10)C26—C25—C30—C290.05 (13)
C9—C4—C5—C60.43 (11)C25—C26—C27—C280.17 (13)
C5—C4—C9—N3178.03 (7)C26—C27—C28—C290.58 (13)
C5—C4—C9—C80.34 (10)C27—C28—C29—C21179.54 (7)
C4—C5—C6—C70.89 (11)C27—C28—C29—C301.04 (11)
C5—C6—C7—C80.51 (11)C21—C29—C30—C241.04 (10)
C6—C7—C8—N1177.03 (7)C21—C29—C30—C25179.78 (7)
C6—C7—C8—C90.28 (11)C28—C29—C30—C24179.51 (7)
N1—C8—C9—N30.45 (8)C28—C29—C30—C250.77 (10)
N1—C8—C9—C4178.22 (6)C3A—C1A—C2A—C3Ai0.10 (13)
C7—C8—C9—N3177.95 (7)C2A—C1A—C3A—C2Ai0.10 (14)
C7—C8—C9—C40.71 (11)C1A—C2A—C3Ai—C1Ai0.10 (13)
N1—C11—C12—C13179.04 (7)
Symmetry code: (i) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
Cg1, Cg2, Cg3, Cg4 and Cg8 are the centroids of the N1/C2/N3/C9/C8 imidazole ring, the C4–C9 fused benzene ring, the C11–C16 phenyl ring, the C21–C24,C30/C29 fused benzene ring and the C1A,C2A,C3A',C1A',C2A',C3A benzene ring, respectively.
D—H···AD—HH···AD···AD—H···A
C28—H28···N30.952.613.2113 (10)121
C7—H7···Cg4ii0.952.753.6019 (8)150
C15—H15···Cg8iii0.952.993.6981 (9)132
C15—H15···Cg8iv0.952.993.6981 (9)132
C22—H22···Cg1v0.952.913.6478 (8)136
C24—H24···Cg3vi0.952.763.4888 (9)134
C26—H26···Cg2iv0.952.873.5801 (9)133
C27—H27···Cg1iv0.952.973.7258 (8)137
Symmetry codes: (ii) x+1, y, z; (iii) x, y+1, z; (iv) x+1, y+1, z+1; (v) x+1, y+1, z; (vi) x1, y, z.
Hydrogen-bond geometry (Å, º) top
Cg1, Cg2, Cg3, Cg4 and Cg8 are the centroids of the N1/C2/N3/C9/C8 imidazole ring, the C4–C9 fused benzene ring, the C11–C16 phenyl ring, the C21–C24,C30/C29 fused benzene ring and the C1A,C2A,C3A',C1A',C2A',C3A benzene ring, respectively.
D—H···AD—HH···AD···AD—H···A
C28—H28···N30.952.613.2113 (10)121
C7—H7···Cg4i0.952.753.6019 (8)150
C15—H15···Cg8ii0.952.993.6981 (9)132
C15—H15···Cg8iii0.952.993.6981 (9)132
C22—H22···Cg1iv0.952.913.6478 (8)136
C24—H24···Cg3v0.952.763.4888 (9)134
C26—H26···Cg2iii0.952.873.5801 (9)133
C27—H27···Cg1iii0.952.973.7258 (8)137
Symmetry codes: (i) x+1, y, z; (ii) x, y+1, z; (iii) x+1, y+1, z+1; (iv) x+1, y+1, z; (v) x1, y, z.
Acknowledgements top

SMP thanks Annamaliar College of Engineering, Mudaiyur, for providing constant support for this research. RJB acknowledges the NSF–MRI program (grant No. CHE-0619278) for funds to purchase an X-ray diffractometer.

references
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