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A second monoclinic polymorph of 2-(di­formyl­methyl­­idene)-3,3-di­methyl-2,3-di­hydro-1H-indole

aDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, and bDepartment of Molecular Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: hapipah@um.edu.my

(Received 10 September 2009; accepted 23 September 2009; online 30 September 2009)

The crystal structure of the title compound, C13H13NO2, is a polymorph of the structure first reported by Helliwell et al. [Acta Cryst. (2006), E62, o737-o738]. It is also monoclinic (space group P21/c), but with completely different cell constants. The mol­ecular conformations of these polymorphs differ by a 180° rotation of one formyl group. The present mol­ecule is planar [maximum deviation 0.089 (2) Å] with the exception of the two methyl groups which lie on either side of the plane. There are strong intra- and inter­molecular N—H⋯O hydrogen bonds. The latter link pairs of mol­ecules across crystallographic centers of symmetry. Two aldehyde O atoms are brought close together [2.896 (4) Å in this arrangement but are not hydrogen bonded. In the earlier polymorph, one formyl group is rotated by 180° to yield inter­molecular hydrogen bonding and an infinite polymeric chain. The other formyl group is involved in the same intra­molecular hydrogen bonding as has been found here.

Related literature

For the crystal structure of the other polymorph, see: Helliwell et al. (2006[Helliwell, M., Afgan, A., Baradarani, M. M. & Joule, J. A. (2006). Acta Cryst. E62, o737-o738.]). For a discussion of crystal growth conditions that can affect the occurrence of polymorphs, see: Hulliger et al. (1994[Hulliger, J. (1994). Angew. Chem. Int. Ed. Engl. 33, 143-162.]). For chemistry involving 2-(diformyl­methyl­idene)-3,3-dimethyl-2,3-dihydro-1H-indole, see: Baradarani et al. (2006[Baradarani, M. M., Afgan, A., Zebarjadi, F., Hasanzadeh, K. & Joule, J. A. (2006). J. Heterocycl. Chem. 43, 1591-1595.]).

[Scheme 1]

Experimental

Crystal data
  • C13H13NO2

  • Mr = 215.24

  • Monoclinic, P 21 /c

  • a = 6.9877 (10) Å

  • b = 18.688 (3) Å

  • c = 8.2154 (12) Å

  • β = 90.291 (3)°

  • V = 1072.8 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 103 K

  • 0.57 × 0.37 × 0.03 mm

Data collection
  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.950, Tmax = 0.997

  • 4763 measured reflections

  • 1865 independent reflections

  • 1123 reflections with I > 2σ(I)

  • Rint = 0.072

Refinement
  • R[F2 > 2σ(F2)] = 0.044

  • wR(F2) = 0.103

  • S = 0.92

  • 1865 reflections

  • 151 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.26 e Å−3

  • Δρmin = −0.22 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯O1 0.93 (3) 1.93 (3) 2.642 (3) 132 (2)
N1—H1⋯O1i 0.93 (3) 2.19 (3) 2.946 (2) 138 (2)
Symmetry code: (i) -x+1, -y+1, -z.

Data collection: APEX2 (Bruker, 2007[Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin,USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin,USA.]); data reduction: SAINT; 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: SHELXL97 and publCIF (Westrip, 2009[Westrip, S. P. (2009). publCIF. In preparation.]).

Supporting information


Related literature top

For the crystal structure of the other polymorph, see: Helliwell et al. (2006). For a discussion of crystal growth conditions that can affect the occurrence of polymorphs, see: Hulliger et al. (1994). For chemistry involving 2-(diformylmethylidene)-3,3-dimethyl-2,3-dihydro-1H-indole, see: Baradarani et al. (2006).

Experimental top

A solution of trimethylindolenine, (5.57 g, 35 mmol), in anhydrous dimethylformamide (15 ml) was cooled in an ice bath. A solution of phosphoryl chloride (10 ml) in dimethylformamide (15 ml) was added dropwise with stirring over a period of 1 h at below 283 K. The cooling bath was removed and the reaction mixture was stirred at 363 K for 2 h. The resulting solution was poured onto ice water (400 ml), the pH was adjusted to 9.0 by the addition of aqueous NaOH (35%) whereupon the solid product was precipitated. It was filtered, washed with hot water, dried and recrystallized from n-hexane/ethyl acetate to give a yellow solid in 4.35 g, 58% yield. Further recrystallization, from ethanol/water (3:1 v/v), led to a mixture of lath and prismatic habits. The prism cell dimensions confirmed the form reported earlier but the laths appeared new.

Refinement top

C-bound hydrogen atoms were placed at calculated positions (C–H = 0.95–0.98 Å) and refined as riding with U(H) = 1.2–1.5 times Ueq(C). The N-bound hydrogen atom was located from a difference map, and freely refined to give a bond length of 0.93 (3) Å.

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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: SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2009).

Figures top
[Figure 1] Fig. 1. A perspective drawing of two molecules of the title compound showing dimerization through intermolecular H-bonds. Displacement ellipsoids are drawn at the 30% probability level. Symmetry code: A = 1-x, 1-y, -z
2-(diformylmethylidene)-3,3-dimethyl-2,3-dihydro-1H-indole top
Crystal data top
C13H13NO2F(000) = 456
Mr = 215.24Dx = 1.333 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 864 reflections
a = 6.9877 (10) Åθ = 2.2–24.7°
b = 18.688 (3) ŵ = 0.09 mm1
c = 8.2154 (12) ÅT = 103 K
β = 90.291 (3)°Lath, yellow
V = 1072.8 (3) Å30.57 × 0.37 × 0.03 mm
Z = 4
Data collection top
Bruker APEXII CCD
diffractometer
1865 independent reflections
Radiation source: fine-focus sealed tube1123 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.072
ω scansθmax = 25.1°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 58
Tmin = 0.950, Tmax = 0.997k = 2122
4763 measured reflectionsl = 99
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)] = 0.044Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.103H atoms treated by a mixture of independent and constrained refinement
S = 0.92 w = 1/[σ2(Fo2) + (0.0424P)2]
where P = (Fo2 + 2Fc2)/3
1865 reflections(Δ/σ)max < 0.001
151 parametersΔρmax = 0.26 e Å3
0 restraintsΔρmin = 0.22 e Å3
Crystal data top
C13H13NO2V = 1072.8 (3) Å3
Mr = 215.24Z = 4
Monoclinic, P21/cMo Kα radiation
a = 6.9877 (10) ŵ = 0.09 mm1
b = 18.688 (3) ÅT = 103 K
c = 8.2154 (12) Å0.57 × 0.37 × 0.03 mm
β = 90.291 (3)°
Data collection top
Bruker APEXII CCD
diffractometer
1865 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1123 reflections with I > 2σ(I)
Tmin = 0.950, Tmax = 0.997Rint = 0.072
4763 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0440 restraints
wR(F2) = 0.103H atoms treated by a mixture of independent and constrained refinement
S = 0.92Δρmax = 0.26 e Å3
1865 reflectionsΔρmin = 0.22 e Å3
151 parameters
Special details top

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 > 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
O10.4035 (3)0.49657 (9)0.1554 (2)0.0308 (5)
O20.4628 (3)0.65460 (9)0.6032 (2)0.0346 (5)
N10.7133 (3)0.57750 (10)0.1457 (2)0.0192 (5)
H10.637 (4)0.5445 (14)0.092 (3)0.054 (9)*
C10.6569 (3)0.60337 (11)0.2893 (3)0.0195 (5)
C20.8061 (3)0.65754 (12)0.3488 (3)0.0199 (6)
C30.9518 (3)0.65385 (12)0.2146 (3)0.0197 (6)
C41.1227 (3)0.68961 (12)0.1934 (3)0.0225 (6)
H41.16730.72280.27250.027*
C51.2281 (4)0.67584 (12)0.0535 (3)0.0253 (6)
H51.34590.70020.03730.030*
C61.1650 (4)0.62761 (12)0.0621 (3)0.0259 (6)
H61.24050.61900.15600.031*
C70.9931 (3)0.59154 (12)0.0434 (3)0.0221 (6)
H70.94790.55850.12260.027*
C80.8906 (3)0.60609 (11)0.0965 (3)0.0196 (5)
C90.4879 (3)0.57998 (12)0.3639 (3)0.0192 (6)
C100.3723 (4)0.52662 (12)0.2862 (3)0.0258 (6)
H100.25910.51280.34150.031*
C110.4105 (4)0.60552 (13)0.5160 (3)0.0257 (6)
H110.30180.58010.55390.031*
C120.7221 (4)0.73372 (12)0.3575 (3)0.0262 (6)
H12A0.82480.76790.38120.039*
H12B0.62610.73590.44380.039*
H12C0.66210.74580.25300.039*
C130.8926 (3)0.63454 (12)0.5131 (3)0.0241 (6)
H13A0.94360.58590.50390.036*
H13B0.79320.63570.59680.036*
H13C0.99610.66740.54330.036*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0343 (11)0.0320 (10)0.0261 (10)0.0086 (9)0.0002 (8)0.0040 (8)
O20.0367 (12)0.0377 (11)0.0295 (10)0.0023 (9)0.0058 (9)0.0071 (9)
N10.0143 (12)0.0217 (11)0.0215 (11)0.0051 (9)0.0010 (9)0.0019 (9)
C10.0213 (15)0.0178 (12)0.0192 (12)0.0006 (11)0.0039 (11)0.0024 (10)
C20.0234 (15)0.0187 (12)0.0176 (12)0.0011 (11)0.0010 (11)0.0001 (10)
C30.0223 (15)0.0183 (12)0.0185 (12)0.0021 (11)0.0003 (11)0.0028 (10)
C40.0205 (15)0.0230 (13)0.0239 (13)0.0023 (11)0.0024 (11)0.0018 (10)
C50.0198 (15)0.0262 (14)0.0299 (14)0.0006 (11)0.0033 (12)0.0067 (11)
C60.0292 (17)0.0253 (13)0.0233 (13)0.0041 (12)0.0055 (12)0.0039 (11)
C70.0227 (15)0.0237 (13)0.0201 (12)0.0017 (11)0.0009 (11)0.0000 (10)
C80.0208 (14)0.0157 (12)0.0223 (12)0.0028 (11)0.0000 (11)0.0031 (10)
C90.0154 (14)0.0216 (13)0.0204 (12)0.0019 (11)0.0005 (11)0.0033 (10)
C100.0235 (16)0.0267 (14)0.0271 (14)0.0004 (12)0.0010 (12)0.0077 (11)
C110.0207 (15)0.0278 (14)0.0286 (14)0.0045 (12)0.0003 (12)0.0040 (12)
C120.0313 (16)0.0215 (13)0.0259 (13)0.0023 (12)0.0020 (12)0.0006 (10)
C130.0214 (15)0.0301 (14)0.0207 (13)0.0033 (11)0.0011 (11)0.0016 (10)
Geometric parameters (Å, º) top
O1—C101.233 (3)C5—H50.9500
O2—C111.219 (3)C6—C71.387 (3)
N1—C11.336 (3)C6—H60.9500
N1—C81.410 (3)C7—C81.384 (3)
N1—H10.93 (3)C7—H70.9500
C1—C91.403 (3)C9—C101.431 (3)
C1—C21.531 (3)C9—C111.445 (3)
C2—C31.506 (3)C10—H100.9500
C2—C131.538 (3)C11—H110.9500
C2—C121.542 (3)C12—H12A0.9800
C3—C41.380 (3)C12—H12B0.9800
C3—C81.384 (3)C12—H12C0.9800
C4—C51.392 (3)C13—H13A0.9800
C4—H40.9500C13—H13B0.9800
C5—C61.380 (3)C13—H13C0.9800
C1—N1—C8112.3 (2)C6—C7—H7121.7
C1—N1—H1119.3 (17)C3—C8—C7123.3 (2)
C8—N1—H1128.4 (17)C3—C8—N1108.2 (2)
N1—C1—C9121.7 (2)C7—C8—N1128.5 (2)
N1—C1—C2108.5 (2)C1—C9—C10119.8 (2)
C9—C1—C2129.8 (2)C1—C9—C11126.5 (2)
C3—C2—C1101.40 (18)C10—C9—C11113.8 (2)
C3—C2—C13111.46 (19)O1—C10—C9127.1 (2)
C1—C2—C13111.06 (18)O1—C10—H10116.4
C3—C2—C12109.57 (18)C9—C10—H10116.4
C1—C2—C12111.51 (19)O2—C11—C9130.1 (2)
C13—C2—C12111.43 (18)O2—C11—H11114.9
C4—C3—C8119.2 (2)C9—C11—H11114.9
C4—C3—C2131.2 (2)C2—C12—H12A109.5
C8—C3—C2109.6 (2)C2—C12—H12B109.5
C3—C4—C5118.4 (2)H12A—C12—H12B109.5
C3—C4—H4120.8C2—C12—H12C109.5
C5—C4—H4120.8H12A—C12—H12C109.5
C6—C5—C4121.4 (2)H12B—C12—H12C109.5
C6—C5—H5119.3C2—C13—H13A109.5
C4—C5—H5119.3C2—C13—H13B109.5
C5—C6—C7121.0 (2)H13A—C13—H13B109.5
C5—C6—H6119.5C2—C13—H13C109.5
C7—C6—H6119.5H13A—C13—H13C109.5
C8—C7—C6116.7 (2)H13B—C13—H13C109.5
C8—C7—H7121.7
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O10.93 (3)1.93 (3)2.642 (3)132 (2)
N1—H1···O1i0.93 (3)2.19 (3)2.946 (2)138 (2)
Symmetry code: (i) x+1, y+1, z.

Experimental details

Crystal data
Chemical formulaC13H13NO2
Mr215.24
Crystal system, space groupMonoclinic, P21/c
Temperature (K)103
a, b, c (Å)6.9877 (10), 18.688 (3), 8.2154 (12)
β (°) 90.291 (3)
V3)1072.8 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.57 × 0.37 × 0.03
Data collection
DiffractometerBruker APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.950, 0.997
No. of measured, independent and
observed [I > 2σ(I)] reflections
4763, 1865, 1123
Rint0.072
(sin θ/λ)max1)0.596
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.103, 0.92
No. of reflections1865
No. of parameters151
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.26, 0.22

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O10.93 (3)1.93 (3)2.642 (3)132 (2)
N1—H1···O1i0.93 (3)2.19 (3)2.946 (2)138 (2)
Symmetry code: (i) x+1, y+1, z.
 

Acknowledgements

The authors thank the University of Malaya for funding this study (UMRG grant No. RG136/09HTM).

References

First citationBaradarani, M. M., Afgan, A., Zebarjadi, F., Hasanzadeh, K. & Joule, J. A. (2006). J. Heterocycl. Chem. 43, 1591–1595.  CrossRef CAS Google Scholar
First citationBruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin,USA.  Google Scholar
First citationHelliwell, M., Afgan, A., Baradarani, M. M. & Joule, J. A. (2006). Acta Cryst. E62, o737–o738.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationHulliger, J. (1994). Angew. Chem. Int. Ed. Engl. 33, 143–162.  CrossRef Web of Science Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWestrip, S. P. (2009). publCIF. In preparation.  Google Scholar

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