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Acta Crystallogr Sect E Struct Rep Online. 2010 September 1; 66(Pt 9): o2288.
Published online 2010 August 11. doi:  10.1107/S1600536810031570
PMCID: PMC3007872

10,12-Dimethyl­pteridino[6,7-f][1,10]phenanthroline-11,13(10H,12H)-dione–chloro­form (1/1)

Abstract

In the title co-crystal, C18H12N6O2·CHCl3, intra­molecular Cl3C—H(...)N hydrogen-bonding inter­actions occur between a single CHCl3 and both N atoms at the 1,10-positions on the phenanthroline portion of the mol­ecule. The inter­planar distance between inversion-related mol­ecules is 3.241 (2) Å.

Related literature

For the synthesis, see: Black et al. (1993 [triangle]). For the possible use of metal complexes of this ligand as DNA probes, see: Gao et al. (2007 [triangle]); Lawrence et al. (2006 [triangle]). For studies involving the non-methyl­ated analog of the title compound, see: Chen et al. (2010 [triangle]); Dalton et al. (2008 [triangle]); Ozawa et al. (2006 [triangle]). For a related stucture, see: Ton & Bolte (2005 [triangle]). For Cl3C—H(...)N hydrogen bonding, see: Fan et al. (2009 [triangle]); Li & Wang (2007 [triangle]).

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Object name is e-66-o2288-scheme1.jpg

Experimental

Crystal data

  • C18H12N6O2·CHCl3
  • M r = 463.70
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-o2288-efi1.jpg
  • a = 8.9043 (2) Å
  • b = 16.4009 (4) Å
  • c = 13.4872 (4) Å
  • β = 108.058 (1)°
  • V = 1872.63 (8) Å3
  • Z = 4
  • Cu Kα radiation
  • μ = 4.72 mm−1
  • T = 173 K
  • 0.45 × 0.22 × 0.17 mm

Data collection

  • Bruker APEXII CCD diffractometer
  • Absorption correction: numerical (SADABS; Bruker, 2008 [triangle]) T min = 0.224, T max = 0.508
  • 15543 measured reflections
  • 3370 independent reflections
  • 3115 reflections with I > 2σ(I)
  • R int = 0.033

Refinement

  • R[F 2 > 2σ(F 2)] = 0.032
  • wR(F 2) = 0.095
  • S = 1.08
  • 3370 reflections
  • 273 parameters
  • H-atom parameters constrained
  • Δρmax = 0.37 e Å−3
  • Δρmin = −0.26 e Å−3

Data collection: APEX2 (Bruker, 2008 [triangle]); cell refinement: APEX2 and SAINT (Bruker, 2008 [triangle]); data reduction: SAINT and XPREP (Bruker, 2008 [triangle]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: X-SEED (Barbour, 2001 [triangle]); software used to prepare material for publication: X-SEED.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, New_Global_Publ_Block. DOI: 10.1107/S1600536810031570/fl2311sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810031570/fl2311Isup2.hkl

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

Acknowledgments

We gratefully acknowledge the financial support of the National Science Foundation (CHE-0722547) to KAW.

supplementary crystallographic information

Comment

We first reported the synthesis of the title compound as part of our effort to study the pH-dependent electron transfer reactions of transition metal complexes of riboflavin mimics (Black et al., 1993). Since that time, others have investigated metal complexes of this ligand as possible DNA probes (see, for example, Gao et al., 2007; Lawrence et al., 2006). The title compound is only slightly soluble in many common solvents; it appears at least moderately soluble in CHCl3. We have grown crystals by vapor diffusion of hexane into a CHCl3/95% EtOH solution. As shown in Figure 1, the crystal structure revealed interesting H-bonding interactions involving the H-atom on CHCl3 and the N-atoms in the 1,10-phenanthroline portion of the ligand (C19—H···N1: 3.188 (2) Å, 136° and C19—H···N6: 3.181 (2) Å, 152°). This type of interaction has been reported previously (Ton & Bolte, 2005) for a co-crystal of CHCl3 and 1,10-phenanthroline(Cl3C—H···N: 3.175 (3) Å, 146° and 3.225 (3) Å, 141°). Ab initio calculations on the interaction between CHCl3 and pyridine (Li & Wang, 2007) predict a range of Cl3C—H···N distances (3.13–3.25 Å) and angles (156–167°), depending on the basis sets used. Fan et al. (2009) reported very weak Cl3C—H···N interaction in pyridine/chloroform solutions as measured by anti-Stokes Raman scattering. The interplanar distance between inversion-related molecules in I (viewed along the a-axis) is 3.241 (2) Å. The molecular planes in alternating stacks are oriented at 12.46 (2)° to each other; this could at least partially be due to packing constraints imposed by the slightly out-of-plane C18-methyl group (see packing diagram in Figure 2). Studies involving the non-methylated analog of the title compound have also been reported (Chen et al., 2010; Dalton et al., 2008; Gao et al., 2007; Ozawa et al., 2006) although, to our knowledge, no crystal structures of this analog have been reported.

Experimental

The title compound was prepared and purified using a previously published procedure (Black et al., 1993). A small amount of this compound was dissolved in ~1 ml of CHCl3 and one drop of 95% ethanol was added to the mixture. The vial containing this mixture was placed in a beaker with ~1 ml of hexane and the beaker was loosely sealed. In 14 days, yellow crystals, suitable for data collection, were observed on the sides of the vial.

Refinement

H atoms were positioned geometrically with C—H = 0.95, 0.96 and 1.00 Å, for aromatic, methyl and methine H atoms, respectively, and constrained to ride on their parent atoms, with Uiso(H) = 1.2Ueq(C)[Uiso(H) = 1.5Ueq(C) for methyl groups].

Figures

Fig. 1.
Perspective view of the title compound, with the atom numbering; displacement ellipsoids are at the 50% probability level.
Fig. 2.
Packing diagram for the title compound. The molecular planes of alternating stacks of molecules are oriented at 12.46 (2)° relative to one another. The CHCl3 molecules and H-atoms have been omitted for clarity.

Crystal data

C18H12N6O2·CHCl3F(000) = 944
Mr = 463.70Dx = 1.645 Mg m3
Monoclinic, P21/nCu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ynCell parameters from 8311 reflections
a = 8.9043 (2) Åθ = 4.3–71.9°
b = 16.4009 (4) ŵ = 4.72 mm1
c = 13.4872 (4) ÅT = 173 K
β = 108.058 (1)°Transparent prism, yellow
V = 1872.63 (8) Å30.45 × 0.22 × 0.17 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer3370 independent reflections
Radiation source: fine-focus sealed tube3115 reflections with I > 2σ(I)
graphiteRint = 0.033
phi and ω scansθmax = 68.2°, θmin = 4.4°
Absorption correction: numerical (SADABS; Bruker, 2008)h = −10→10
Tmin = 0.224, Tmax = 0.508k = −19→19
15543 measured reflectionsl = −16→15

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)] = 0.032Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.095H-atom parameters constrained
S = 1.08w = 1/[σ2(Fo2) + (0.061P)2 + 0.6946P] where P = (Fo2 + 2Fc2)/3
3370 reflections(Δ/σ)max = 0.001
273 parametersΔρmax = 0.37 e Å3
0 restraintsΔρmin = −0.26 e Å3

Special details

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)

xyzUiso*/Ueq
Cl11.11933 (6)0.91490 (3)0.06882 (4)0.03314 (15)
Cl21.02227 (5)0.75947 (3)0.13113 (3)0.02516 (14)
Cl30.78834 (5)0.87388 (3)0.00893 (4)0.03132 (15)
O10.58359 (16)0.89641 (8)0.76117 (10)0.0252 (3)
O20.50035 (16)1.16797 (8)0.78817 (10)0.0253 (3)
N10.93260 (18)0.83887 (9)0.33300 (11)0.0211 (3)
N20.69578 (17)0.92402 (9)0.59325 (11)0.0185 (3)
N30.53018 (17)1.03163 (9)0.76877 (11)0.0199 (3)
N40.61174 (18)1.12873 (9)0.66532 (11)0.0193 (3)
N50.71061 (17)1.08699 (9)0.53254 (11)0.0185 (3)
N60.94027 (18)0.99643 (9)0.27110 (11)0.0206 (3)
C10.9330 (2)0.76237 (11)0.36516 (14)0.0228 (4)
H10.97440.72150.33100.027*
C20.8759 (2)0.73847 (11)0.44641 (15)0.0232 (4)
H20.87980.68290.46700.028*
C30.8141 (2)0.79660 (11)0.49591 (14)0.0207 (4)
H30.77390.78200.55100.025*
C40.8113 (2)0.87791 (10)0.46354 (13)0.0180 (3)
C50.7528 (2)0.94334 (10)0.51497 (13)0.0181 (3)
C60.6493 (2)0.98516 (11)0.64097 (13)0.0187 (4)
C70.5877 (2)0.96493 (10)0.72797 (13)0.0193 (4)
C80.5445 (2)1.11330 (11)0.74324 (13)0.0202 (4)
C90.6584 (2)1.06698 (10)0.61137 (13)0.0185 (4)
C100.7584 (2)1.02511 (10)0.48401 (13)0.0179 (3)
C110.8194 (2)1.04465 (11)0.39814 (13)0.0186 (3)
C120.8254 (2)1.12494 (11)0.36400 (14)0.0211 (4)
H120.78571.16860.39490.025*
C130.8895 (2)1.13969 (11)0.28512 (14)0.0221 (4)
H130.89581.19360.26090.027*
C140.9452 (2)1.07352 (11)0.24152 (14)0.0226 (4)
H140.98951.08430.18720.027*
C150.8776 (2)0.98147 (10)0.34867 (13)0.0185 (3)
C160.8732 (2)0.89648 (11)0.38207 (13)0.0181 (4)
C170.4656 (2)1.01675 (11)0.85485 (14)0.0241 (4)
H17A0.41590.96280.84650.036*
H17B0.38671.05860.85430.036*
H17C0.55111.01890.92130.036*
C180.6292 (2)1.21489 (11)0.64044 (14)0.0232 (4)
H18A0.70781.21950.60340.035*
H18B0.66411.24660.70510.035*
H18C0.52751.23590.59620.035*
C190.9722 (2)0.86285 (11)0.10784 (14)0.0226 (4)
H190.96450.88810.17360.027*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Cl10.0291 (3)0.0310 (3)0.0357 (3)−0.00401 (19)0.0049 (2)0.01122 (19)
Cl20.0350 (3)0.0176 (2)0.0227 (2)0.00243 (17)0.00862 (19)0.00046 (15)
Cl30.0251 (3)0.0264 (3)0.0357 (3)0.00431 (18)−0.0004 (2)−0.00619 (18)
O10.0364 (7)0.0162 (6)0.0245 (7)−0.0019 (5)0.0115 (6)−0.0004 (5)
O20.0348 (7)0.0187 (6)0.0233 (6)0.0043 (5)0.0104 (6)−0.0023 (5)
N10.0255 (8)0.0172 (7)0.0193 (7)−0.0007 (6)0.0048 (6)−0.0020 (6)
N20.0213 (7)0.0153 (7)0.0167 (7)−0.0020 (6)0.0023 (6)−0.0017 (5)
N30.0240 (7)0.0175 (7)0.0179 (7)−0.0003 (6)0.0059 (6)−0.0019 (5)
N40.0258 (8)0.0133 (7)0.0179 (7)0.0018 (6)0.0054 (6)−0.0010 (5)
N50.0213 (7)0.0146 (7)0.0170 (7)0.0009 (5)0.0023 (6)0.0001 (5)
N60.0255 (8)0.0180 (7)0.0168 (7)−0.0011 (6)0.0042 (6)0.0004 (6)
C10.0286 (9)0.0162 (9)0.0228 (9)0.0007 (7)0.0067 (8)−0.0030 (7)
C20.0296 (9)0.0141 (8)0.0244 (9)0.0000 (7)0.0065 (8)0.0000 (7)
C30.0239 (9)0.0179 (9)0.0189 (8)−0.0021 (7)0.0047 (7)−0.0011 (7)
C40.0194 (8)0.0150 (8)0.0165 (8)−0.0018 (6)0.0011 (7)−0.0015 (6)
C50.0194 (8)0.0161 (8)0.0159 (8)−0.0021 (7)0.0015 (7)−0.0014 (6)
C60.0201 (8)0.0168 (8)0.0167 (8)−0.0007 (7)0.0019 (7)−0.0014 (6)
C70.0227 (8)0.0164 (9)0.0164 (8)−0.0023 (7)0.0025 (7)−0.0026 (6)
C80.0221 (9)0.0183 (8)0.0172 (8)0.0007 (7)0.0018 (7)−0.0006 (7)
C90.0193 (8)0.0164 (8)0.0165 (8)−0.0002 (7)0.0006 (7)−0.0021 (6)
C100.0184 (8)0.0161 (8)0.0163 (8)−0.0001 (6)0.0011 (7)−0.0017 (6)
C110.0198 (8)0.0168 (8)0.0161 (8)−0.0002 (7)0.0012 (7)0.0006 (6)
C120.0228 (9)0.0172 (9)0.0198 (9)0.0009 (7)0.0015 (7)−0.0010 (7)
C130.0256 (9)0.0175 (8)0.0201 (9)−0.0015 (7)0.0024 (7)0.0033 (7)
C140.0266 (9)0.0209 (9)0.0187 (8)−0.0027 (7)0.0047 (7)0.0017 (7)
C150.0206 (8)0.0163 (9)0.0154 (8)−0.0007 (7)0.0008 (7)−0.0003 (6)
C160.0193 (8)0.0158 (8)0.0156 (8)−0.0006 (7)0.0000 (7)−0.0018 (6)
C170.0314 (10)0.0217 (9)0.0210 (9)−0.0015 (7)0.0105 (8)−0.0015 (7)
C180.0339 (10)0.0139 (8)0.0218 (9)0.0014 (7)0.0084 (8)−0.0002 (7)
C190.0264 (9)0.0191 (8)0.0197 (9)−0.0006 (7)0.0036 (7)−0.0005 (7)

Geometric parameters (Å, °)

Cl1—C191.7747 (18)C3—C41.401 (2)
Cl2—C191.7564 (18)C3—H30.9500
Cl3—C191.7716 (19)C4—C161.407 (2)
O1—C71.214 (2)C4—C51.459 (2)
O2—C81.214 (2)C5—C101.410 (2)
N1—C11.327 (2)C6—C91.410 (2)
N1—C161.352 (2)C6—C71.479 (2)
N2—C61.325 (2)C10—C111.459 (2)
N2—C51.343 (2)C11—C121.401 (2)
N3—C71.392 (2)C11—C151.415 (2)
N3—C81.399 (2)C12—C131.376 (3)
N3—C171.467 (2)C12—H120.9500
N4—C91.384 (2)C13—C141.396 (3)
N4—C81.384 (2)C13—H130.9500
N4—C181.472 (2)C14—H140.9500
N5—C91.327 (2)C15—C161.469 (2)
N5—C101.346 (2)C17—H17A0.9800
N6—C141.331 (2)C17—H17B0.9800
N6—C151.352 (2)C17—H17C0.9800
C1—C21.399 (3)C18—H18A0.9800
C1—H10.9500C18—H18B0.9800
C2—C31.373 (3)C18—H18C0.9800
C2—H20.9500C19—H191.0000
C1—N1—C16117.55 (15)N5—C10—C11118.16 (15)
C6—N2—C5117.01 (15)C5—C10—C11120.02 (15)
C7—N3—C8125.62 (15)C12—C11—C15118.44 (16)
C7—N3—C17117.70 (15)C12—C11—C10121.93 (16)
C8—N3—C17116.25 (14)C15—C11—C10119.62 (15)
C9—N4—C8122.44 (15)C13—C12—C11119.12 (16)
C9—N4—C18120.82 (14)C13—C12—H12120.4
C8—N4—C18116.73 (14)C11—C12—H12120.4
C9—N5—C10116.45 (15)C12—C13—C14118.39 (16)
C14—N6—C15117.66 (15)C12—C13—H13120.8
N1—C1—C2123.77 (16)C14—C13—H13120.8
N1—C1—H1118.1N6—C14—C13124.28 (16)
C2—C1—H1118.1N6—C14—H14117.9
C3—C2—C1118.95 (17)C13—C14—H14117.9
C3—C2—H2120.5N6—C15—C11122.09 (16)
C1—C2—H2120.5N6—C15—C16117.76 (15)
C2—C3—C4118.70 (16)C11—C15—C16120.14 (15)
C2—C3—H3120.7N1—C16—C4122.58 (16)
C4—C3—H3120.7N1—C16—C15117.50 (15)
C3—C4—C16118.44 (16)C4—C16—C15119.91 (15)
C3—C4—C5121.75 (15)N3—C17—H17A109.5
C16—C4—C5119.76 (16)N3—C17—H17B109.5
N2—C5—C10120.93 (16)H17A—C17—H17B109.5
N2—C5—C4118.54 (15)N3—C17—H17C109.5
C10—C5—C4120.52 (15)H17A—C17—H17C109.5
N2—C6—C9121.92 (16)H17B—C17—H17C109.5
N2—C6—C7117.64 (16)N4—C18—H18A109.5
C9—C6—C7120.43 (16)N4—C18—H18B109.5
O1—C7—N3121.63 (16)H18A—C18—H18B109.5
O1—C7—C6124.15 (16)N4—C18—H18C109.5
N3—C7—C6114.20 (15)H18A—C18—H18C109.5
O2—C8—N4121.82 (16)H18B—C18—H18C109.5
O2—C8—N3121.06 (16)Cl2—C19—Cl3110.94 (10)
N4—C8—N3117.12 (15)Cl2—C19—Cl1110.33 (10)
N5—C9—N4118.51 (16)Cl3—C19—Cl1108.81 (10)
N5—C9—C6121.85 (16)Cl2—C19—H19108.9
N4—C9—C6119.65 (16)Cl3—C19—H19108.9
N5—C10—C5121.81 (16)Cl1—C19—H19108.9
C16—N1—C1—C2−0.1 (3)N2—C6—C9—N51.6 (3)
N1—C1—C2—C30.7 (3)C7—C6—C9—N5−178.85 (16)
C1—C2—C3—C4−0.4 (3)N2—C6—C9—N4−178.51 (16)
C2—C3—C4—C16−0.5 (3)C7—C6—C9—N41.0 (3)
C2—C3—C4—C5−177.73 (17)C9—N5—C10—C50.3 (2)
C6—N2—C5—C10−1.6 (2)C9—N5—C10—C11−178.90 (15)
C6—N2—C5—C4177.43 (15)N2—C5—C10—N51.4 (3)
C3—C4—C5—N2−2.1 (3)C4—C5—C10—N5−177.55 (16)
C16—C4—C5—N2−179.32 (15)N2—C5—C10—C11−179.40 (15)
C3—C4—C5—C10176.93 (16)C4—C5—C10—C111.6 (3)
C16—C4—C5—C10−0.3 (3)N5—C10—C11—C12−1.6 (3)
C5—N2—C6—C90.1 (3)C5—C10—C11—C12179.22 (16)
C5—N2—C6—C7−179.42 (15)N5—C10—C11—C15177.03 (16)
C8—N3—C7—O1173.01 (17)C5—C10—C11—C15−2.2 (2)
C17—N3—C7—O10.8 (3)C15—C11—C12—C13−1.0 (3)
C8—N3—C7—C6−8.3 (2)C10—C11—C12—C13177.63 (16)
C17—N3—C7—C6179.50 (15)C11—C12—C13—C140.5 (3)
N2—C6—C7—O13.3 (3)C15—N6—C14—C13−0.2 (3)
C9—C6—C7—O1−176.22 (17)C12—C13—C14—N60.1 (3)
N2—C6—C7—N3−175.31 (15)C14—N6—C15—C11−0.3 (3)
C9—C6—C7—N35.1 (2)C14—N6—C15—C16−179.49 (15)
C9—N4—C8—O2−178.08 (16)C12—C11—C15—N61.0 (3)
C18—N4—C8—O20.8 (3)C10—C11—C15—N6−177.72 (16)
C9—N4—C8—N32.3 (3)C12—C11—C15—C16−179.93 (16)
C18—N4—C8—N3−178.82 (15)C10—C11—C15—C161.4 (2)
C7—N3—C8—O2−174.77 (17)C1—N1—C16—C4−0.8 (3)
C17—N3—C8—O2−2.5 (2)C1—N1—C16—C15178.08 (16)
C7—N3—C8—N44.9 (3)C3—C4—C16—N11.1 (3)
C17—N3—C8—N4177.20 (15)C5—C4—C16—N1178.42 (15)
C10—N5—C9—N4178.39 (15)C3—C4—C16—C15−177.78 (16)
C10—N5—C9—C6−1.7 (2)C5—C4—C16—C15−0.5 (3)
C8—N4—C9—N5174.92 (15)N6—C15—C16—N10.1 (2)
C18—N4—C9—N5−4.0 (2)C11—C15—C16—N1−179.05 (15)
C8—N4—C9—C6−5.0 (3)N6—C15—C16—C4179.05 (15)
C18—N4—C9—C6176.14 (16)C11—C15—C16—C4−0.1 (3)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C19—H19···N11.002.393.188 (2)136.
C19—H19···N61.002.263.181 (2)152.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FL2311).

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