2-(6-Methyl-2,3,4,9-tetra­hydro-1H-carbazol-1-yl­idene)propane­dinitrile

Sekar, M.; Velmurugan, R.; Chandramohan, A.; Ramesh, P.; Ponnuswamy, M.N.

doi:10.1107/S160053681104654X

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 12| December 2011| Page o3270

https://doi.org/10.1107/S160053681104654X

Open

access

2-(6-Methyl-2,3,4,9-tetrahydro-1H-carbazol-1-ylidene)propanedinitrile

M. Sekar,^a R. Velmurugan,^a A. Chandramohan,^a P. Ramesh ^b and M. N. Ponnuswamy ^b ^*

^aPost Graduate and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020, India, and ^bCentre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India
^*Correspondence e-mail: mnpsy2004@yahoo.com

(Received 19 October 2011; accepted 4 November 2011; online 12 November 2011)

In the title compound, C₁₆H₁₃N₃, the cyclohexene ring adopts a sofa conformation. An intramolecular N—H⋯N hydrogen bond generates an S(7) ring motif. In the crystal, the molecules are linked by pairs of N—H⋯N interactions, forming centrosymmetric dimers with an R₂²(14) motif.

Related literature

For the biological activity of carbazole derivatives, see: Magnus et al. (1992 ); Abraham (1975 ); Saxton (1983 ); Phillipson & Zenk (1980 ); Bergman & Pelcman (1990 ); Bonesi et al. (2004 ); Chakraborty et al. (1965 ); Kirtikar & Basu (1933 ); Chakraborty et al. (1973 ). For puckering parameters, see: Cremer & Pople (1975 ). For asymmetry parameters, see: Nardelli (1983 ). For hydrogen-bond motifs, see: Bernstein et al. (1995 ).

Experimental

Crystal data

C₁₆H₁₃N₃
M_r = 247.29
Triclinic, $[P \overline 1]$
a = 7.6396 (9) Å
b = 8.4381 (8) Å
c = 10.8967 (13) Å
α = 88.395 (6)°
β = 71.392 (7)°
γ = 71.217 (6)°
V = 628.08 (12) Å³
Z = 2
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 296 K
0.17 × 0.16 × 0.15 mm

Data collection

Bruker SMART APEX CCD detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1998 ) T_min = 0.986, T_max = 0.988
12507 measured reflections
3692 independent reflections
2815 reflections with I > 2σ(I)
R_int = 0.026

Refinement

R[F² > 2σ(F²)] = 0.050
wR(F²) = 0.154
S = 1.03
3692 reflections
177 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯N16	0.86 (2)	2.59 (2)	3.3099 (17)	141.4 (16)
N1—H1⋯N16ⁱ	0.86 (2)	2.49 (2)	3.2150 (17)	142.8 (16)
Symmetry code: (i) -x, -y+3, -z+1.

Data collection: SMART (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1998); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S160053681104654X/bt5683sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053681104654X/bt5683Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S160053681104654X/bt5683Isup3.cml

checkCIF report

Comment top

Carbazole alkaloids obtained from naturally occurring sources have been the subject of extensive research, mainly because of their widespread applications in traditional medicine (Bergman & Pelcman, 1990; Bonesi et al., 2004; Chakraborty et al., 1965; Kirtikar & Basu, 1933). Tetrahydrocarbazole systems are present in the framework of a number of indole-type alkaloids of biological interest (Magnus et al., 1992; Abraham, 1975; Saxton, 1983; Phillipson et al., 1980). These types of compounds possess significant antibiotic, anti-carcinogenic, antiviral and anti-inflammatory properties (Chakraborty et al., 1973). Against this background and to ascertain the molecular structure and conformation, the X-ray crystal structure determination of the title compound has been carried out.

The ORTEP plot of the molecule is shown in Fig. 1. The cyclohexane ring in the carbazole ring system adopts envelope conformation with the puckering parameters (Cremer & Pople, 1975) and the asymmetry parameters (Nardelli, 1983) are: q₂=0.330 (1) Å, q₃ = 0.262 (1) Å, φ₂ = 168.7 (2)° and Δ_s(C2 & C5)= 8.6 (2)°. The sum of the bond angles around N1 [359.8°] is in accordance with sp² hybridization. The bond lengths and bond angles of (C15—N16) 1.148 (2) Å, (C17—N18) 1.145 (2) Å, (C14—C15—N16) 178.8 (2)° and (C14—C17—N18) 178.6 (2)° show linear character of the cyano group, a feature observed in carbonitrile compounds.

The crystal packing reveals that symmetry-related molecules are linked by N—H···N interactions. The intramolecular N1—H1···N16 hydrogen bond generates a S(7) ring motif. The molecules at (x, y, z) and (2 - x, -1 - y, 1 - z) are linked by N1—H1···N16 hydrogen bonds into cyclic centrosymmetric R₂²(14) dimer.

Related literature top

For the biological activity of carbazole derivatives, see: Magnus et al. (1992); Abraham (1975); Saxton (1983); Phillipson & Zenk (1980); Bergman & Pelcman (1990); Bonesi et al. (2004); Chakraborty et al. (1965); Kirtikar & Basu (1933); Chakraborty et al. (1973). For puckering parameters, see: Cremer & Pople (1975). For asymmetry parameters, see: Nardelli (1983). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

A mixture of 6-methyl-1-oxo-1,2,3,4-tetrahydrocarbazole (7.5 mmol), and melanonitrile (7.5 mmol), ammonium acetate (0.57 g, 8.125 mmol) and acetic acid (1.5 ml, 24.75 mmol) in 12.5 ml of toluene was stirred at 105°C for 5 h. On cooling the precipitate that formed was filtered off, washed with hexane (20 ml) and dried at 100°C to give a crude product of 6-Methyl-2-(1,2,3,4- tetrahydro-9H-carbazol-1-ylidene)propanedinitrile.The crystals of the title compound suitable for single XRD analysis were obtained by the slow evaporation method by using dichloroethane as solvent at room temperature.

Structure description top

For the biological activity of carbazole derivatives, see: Magnus et al. (1992); Abraham (1975); Saxton (1983); Phillipson & Zenk (1980); Bergman & Pelcman (1990); Bonesi et al. (2004); Chakraborty et al. (1965); Kirtikar & Basu (1933); Chakraborty et al. (1973). For puckering parameters, see: Cremer & Pople (1975). For asymmetry parameters, see: Nardelli (1983). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1998); data reduction: SAINT-Plus (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The molecular structure of the title compound, showing the atomic numbering and displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. The crystal packing of the title compound. H atoms not involved in hydrogen bonding (dashed lines) have been omitted for clarity.

2-(6-Methyl-2,3,4,9-tetrahydro-1H-carbazol-1-ylidene)propanedinitrile top

Crystal data top

C₁₆H₁₃N₃	Z = 2
M_r = 247.29	F(000) = 260
Triclinic, P1	D_x = 1.308 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.6396 (9) Å	Cell parameters from 1675 reflections
b = 8.4381 (8) Å	θ = 2.0–30.6°
c = 10.8967 (13) Å	µ = 0.08 mm⁻¹
α = 88.395 (6)°	T = 296 K
β = 71.392 (7)°	Block, brown
γ = 71.217 (6)°	0.17 × 0.16 × 0.15 mm
V = 628.08 (12) Å³

Data collection top

Bruker SMART APEX CCD detector diffractometer	3692 independent reflections
Radiation source: fine-focus sealed tube	2815 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.026
ω scans	θ_max = 30.6°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 1998)	h = −10→10
T_min = 0.986, T_max = 0.988	k = −12→11
12507 measured reflections	l = −15→15

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.154	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ²(F_o²) + (0.0895P)² + 0.0632P] where P = (F_o² + 2F_c²)/3
3692 reflections	(Δ/σ)_max < 0.001
177 parameters	Δρ_max = 0.32 e Å⁻³
0 restraints	Δρ_min = −0.19 e Å⁻³

Crystal data top

C₁₆H₁₃N₃	γ = 71.217 (6)°
M_r = 247.29	V = 628.08 (12) Å³
Triclinic, P1	Z = 2
a = 7.6396 (9) Å	Mo Kα radiation
b = 8.4381 (8) Å	µ = 0.08 mm⁻¹
c = 10.8967 (13) Å	T = 296 K
α = 88.395 (6)°	0.17 × 0.16 × 0.15 mm
β = 71.392 (7)°

Data collection top

Bruker SMART APEX CCD detector diffractometer	3692 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 1998)	2815 reflections with I > 2σ(I)
T_min = 0.986, T_max = 0.988	R_int = 0.026
12507 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.050	0 restraints
wR(F²) = 0.154	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	Δρ_max = 0.32 e Å⁻³
3692 reflections	Δρ_min = −0.19 e Å⁻³
177 parameters

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

	x	y	z	U_iso*/U_eq
N1	0.19262 (15)	1.14409 (12)	0.48492 (9)	0.0374 (2)
H1	0.140 (3)	1.251 (3)	0.4900 (18)	0.073 (5)*
C2	0.16168 (16)	1.03889 (13)	0.58442 (11)	0.0348 (2)
C3	0.02788 (16)	1.08208 (13)	0.71382 (10)	0.0352 (2)
C4	0.04245 (19)	0.94137 (16)	0.80188 (12)	0.0446 (3)
H4A	−0.0838	0.9623	0.8687	0.054*
H4B	0.1358	0.9420	0.8447	0.054*
C5	0.1046 (2)	0.76799 (16)	0.73322 (13)	0.0480 (3)
H5A	0.1234	0.6840	0.7947	0.058*
H5B	0.0007	0.7603	0.7033	0.058*
C6	0.29157 (19)	0.73000 (15)	0.61842 (13)	0.0452 (3)
H6A	0.4026	0.7046	0.6494	0.054*
H6B	0.3079	0.6323	0.5656	0.054*
C7	0.28556 (17)	0.87609 (14)	0.53817 (11)	0.0370 (2)
C8	0.39448 (16)	0.88053 (13)	0.40647 (11)	0.0363 (2)
C9	0.53599 (18)	0.75647 (15)	0.30953 (12)	0.0429 (3)
H9	0.5779	0.6452	0.3286	0.051*
C10	0.61190 (18)	0.80110 (15)	0.18626 (12)	0.0430 (3)
C11	0.54686 (18)	0.97060 (16)	0.15997 (12)	0.0427 (3)
H11	0.5987	0.9992	0.0763	0.051*
C12	0.41057 (17)	1.09577 (15)	0.25181 (11)	0.0400 (3)
H12	0.3713	1.2069	0.2319	0.048*
C13	0.33323 (16)	1.04906 (14)	0.37662 (11)	0.0350 (2)
C14	−0.10538 (18)	1.23850 (15)	0.76265 (11)	0.0402 (3)
C15	−0.1323 (2)	1.38051 (16)	0.68896 (13)	0.0507 (3)
N16	−0.1573 (2)	1.49658 (16)	0.63094 (14)	0.0757 (4)
C17	−0.2293 (2)	1.26880 (16)	0.89586 (12)	0.0459 (3)
N18	−0.3258 (2)	1.29469 (17)	1.00271 (12)	0.0639 (4)
C19	0.7624 (2)	0.67329 (19)	0.07853 (15)	0.0603 (4)
H19A	0.8867	0.6900	0.0587	0.090*
H19B	0.7228	0.6862	0.0026	0.090*
H19C	0.7735	0.5623	0.1057	0.090*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0432 (5)	0.0282 (5)	0.0350 (5)	−0.0081 (4)	−0.0091 (4)	0.0063 (4)
C2	0.0378 (5)	0.0310 (5)	0.0351 (5)	−0.0105 (4)	−0.0126 (4)	0.0079 (4)
C3	0.0371 (6)	0.0354 (5)	0.0354 (6)	−0.0134 (4)	−0.0140 (4)	0.0074 (4)
C4	0.0483 (7)	0.0428 (6)	0.0390 (6)	−0.0122 (5)	−0.0131 (5)	0.0138 (5)
C5	0.0533 (7)	0.0390 (6)	0.0503 (7)	−0.0155 (5)	−0.0161 (6)	0.0180 (5)
C6	0.0508 (7)	0.0323 (5)	0.0477 (7)	−0.0084 (5)	−0.0161 (5)	0.0126 (5)
C7	0.0387 (6)	0.0325 (5)	0.0394 (6)	−0.0109 (4)	−0.0134 (4)	0.0084 (4)
C8	0.0372 (6)	0.0308 (5)	0.0394 (6)	−0.0102 (4)	−0.0119 (4)	0.0059 (4)
C9	0.0421 (6)	0.0322 (5)	0.0473 (7)	−0.0083 (5)	−0.0095 (5)	0.0034 (5)
C10	0.0411 (6)	0.0385 (6)	0.0435 (6)	−0.0111 (5)	−0.0075 (5)	−0.0010 (5)
C11	0.0436 (6)	0.0428 (6)	0.0383 (6)	−0.0153 (5)	−0.0081 (5)	0.0044 (5)
C12	0.0436 (6)	0.0345 (5)	0.0384 (6)	−0.0118 (5)	−0.0104 (5)	0.0087 (4)
C13	0.0364 (5)	0.0314 (5)	0.0355 (5)	−0.0104 (4)	−0.0110 (4)	0.0051 (4)
C14	0.0452 (6)	0.0370 (6)	0.0361 (6)	−0.0138 (5)	−0.0100 (5)	0.0040 (4)
C15	0.0575 (8)	0.0348 (6)	0.0448 (7)	−0.0081 (5)	−0.0038 (6)	0.0020 (5)
N16	0.0935 (10)	0.0380 (6)	0.0602 (8)	−0.0035 (6)	0.0026 (7)	0.0117 (5)
C17	0.0528 (7)	0.0391 (6)	0.0413 (6)	−0.0140 (5)	−0.0107 (5)	0.0027 (5)
N18	0.0785 (9)	0.0543 (7)	0.0450 (7)	−0.0193 (6)	−0.0046 (6)	0.0014 (5)
C19	0.0588 (9)	0.0472 (8)	0.0544 (8)	−0.0072 (6)	−0.0008 (7)	−0.0068 (6)

Geometric parameters (Å, º) top

N1—C13	1.3708 (15)	C8—C9	1.4088 (16)
N1—C2	1.3918 (14)	C8—C13	1.4106 (15)
N1—H1	0.86 (2)	C9—C10	1.3775 (18)
C2—C7	1.3906 (16)	C9—H9	0.9300
C2—C3	1.4265 (16)	C10—C11	1.4088 (17)
C3—C14	1.3747 (16)	C10—C19	1.5081 (18)
C3—C4	1.5040 (15)	C11—C12	1.3738 (17)
C4—C5	1.5209 (18)	C11—H11	0.9300
C4—H4A	0.9700	C12—C13	1.4004 (16)
C4—H4B	0.9700	C12—H12	0.9300
C5—C6	1.5150 (19)	C14—C15	1.4198 (17)
C5—H5A	0.9700	C14—C17	1.4340 (17)
C5—H5B	0.9700	C15—N16	1.1478 (18)
C6—C7	1.4884 (15)	C17—N18	1.1445 (17)
C6—H6A	0.9700	C19—H19A	0.9600
C6—H6B	0.9700	C19—H19B	0.9600
C7—C8	1.4172 (16)	C19—H19C	0.9600

C13—N1—C2	108.39 (9)	C9—C8—C13	119.72 (10)
C13—N1—H1	124.4 (13)	C9—C8—C7	133.50 (11)
C2—N1—H1	127.0 (13)	C13—C8—C7	106.76 (10)
C7—C2—N1	108.68 (10)	C10—C9—C8	119.53 (11)
C7—C2—C3	123.14 (10)	C10—C9—H9	120.2
N1—C2—C3	128.18 (10)	C8—C9—H9	120.2
C14—C3—C2	125.69 (10)	C9—C10—C11	119.15 (11)
C14—C3—C4	119.19 (10)	C9—C10—C19	121.77 (12)
C2—C3—C4	115.11 (10)	C11—C10—C19	119.08 (12)
C3—C4—C5	114.33 (10)	C12—C11—C10	123.24 (11)
C3—C4—H4A	108.7	C12—C11—H11	118.4
C5—C4—H4A	108.7	C10—C11—H11	118.4
C3—C4—H4B	108.7	C11—C12—C13	117.21 (11)
C5—C4—H4B	108.7	C11—C12—H12	121.4
H4A—C4—H4B	107.6	C13—C12—H12	121.4
C6—C5—C4	112.68 (11)	N1—C13—C12	130.09 (10)
C6—C5—H5A	109.1	N1—C13—C8	108.75 (10)
C4—C5—H5A	109.1	C12—C13—C8	121.14 (10)
C6—C5—H5B	109.1	C3—C14—C15	124.22 (11)
C4—C5—H5B	109.1	C3—C14—C17	120.91 (11)
H5A—C5—H5B	107.8	C15—C14—C17	114.87 (11)
C7—C6—C5	110.49 (10)	N16—C15—C14	178.80 (16)
C7—C6—H6A	109.6	N18—C17—C14	178.61 (15)
C5—C6—H6A	109.6	C10—C19—H19A	109.5
C7—C6—H6B	109.6	C10—C19—H19B	109.5
C5—C6—H6B	109.6	H19A—C19—H19B	109.5
H6A—C6—H6B	108.1	C10—C19—H19C	109.5
C2—C7—C8	107.42 (10)	H19A—C19—H19C	109.5
C2—C7—C6	123.45 (11)	H19B—C19—H19C	109.5
C8—C7—C6	129.13 (11)

C13—N1—C2—C7	0.46 (13)	C8—C9—C10—C11	0.34 (19)
C13—N1—C2—C3	−179.37 (11)	C8—C9—C10—C19	−179.48 (12)
C7—C2—C3—C14	−176.13 (11)	C9—C10—C11—C12	0.3 (2)
N1—C2—C3—C14	3.69 (19)	C19—C10—C11—C12	−179.91 (13)
C7—C2—C3—C4	5.41 (16)	C10—C11—C12—C13	−0.68 (19)
N1—C2—C3—C4	−174.77 (10)	C2—N1—C13—C12	178.08 (11)
C14—C3—C4—C5	149.75 (12)	C2—N1—C13—C8	−0.20 (13)
C2—C3—C4—C5	−31.69 (15)	C11—C12—C13—N1	−177.58 (11)
C3—C4—C5—C6	52.95 (15)	C11—C12—C13—C8	0.51 (18)
C4—C5—C6—C7	−45.23 (15)	C9—C8—C13—N1	178.52 (10)
N1—C2—C7—C8	−0.54 (13)	C7—C8—C13—N1	−0.13 (13)
C3—C2—C7—C8	179.31 (10)	C9—C8—C13—C12	0.06 (17)
N1—C2—C7—C6	−179.76 (10)	C7—C8—C13—C12	−178.59 (10)
C3—C2—C7—C6	0.08 (18)	C2—C3—C14—C15	1.6 (2)
C5—C6—C7—C2	20.28 (17)	C4—C3—C14—C15	−179.95 (12)
C5—C6—C7—C8	−158.76 (12)	C2—C3—C14—C17	−178.17 (11)
C2—C7—C8—C9	−177.97 (13)	C4—C3—C14—C17	0.23 (17)
C6—C7—C8—C9	1.2 (2)	C3—C14—C15—N16	159 (8)
C2—C7—C8—C13	0.41 (13)	C17—C14—C15—N16	−22 (9)
C6—C7—C8—C13	179.58 (11)	C3—C14—C17—N18	105 (7)
C13—C8—C9—C10	−0.50 (18)	C15—C14—C17—N18	−74 (7)
C7—C8—C9—C10	177.73 (12)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N16	0.86 (2)	2.59 (2)	3.3099 (17)	141.4 (16)
N1—H1···N16ⁱ	0.86 (2)	2.49 (2)	3.2150 (17)	142.8 (16)

Symmetry code: (i) −x, −y+3, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₆H₁₃N₃
M_r	247.29
Crystal system, space group	Triclinic, P1
Temperature (K)	296
a, b, c (Å)	7.6396 (9), 8.4381 (8), 10.8967 (13)
α, β, γ (°)	88.395 (6), 71.392 (7), 71.217 (6)
V (Å³)	628.08 (12)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.17 × 0.16 × 0.15

Data collection
Diffractometer	Bruker SMART APEX CCD detector
Absorption correction	Multi-scan (SADABS; Bruker, 1998)
T_min, T_max	0.986, 0.988
No. of measured, independent and observed [I > 2σ(I)] reflections	12507, 3692, 2815
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.717

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.154, 1.03
No. of reflections	3692
No. of parameters	177
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.32, −0.19

Computer programs: SMART (Bruker, 1998), SAINT-Plus (Bruker, 1998), SHELXS97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N16	0.86 (2)	2.59 (2)	3.3099 (17)	141.4 (16)
N1—H1···N16ⁱ	0.86 (2)	2.49 (2)	3.2150 (17)	142.8 (16)

Symmetry code: (i) −x, −y+3, −z+1.

Acknowledgements

The authors thank Solid State Unit, Indian Institute of Science, Bangalore, India, for the data collection.

References

Abraham, D. J. (1975). The Catharanthus Alkaloids, edited by W. I. Taylor & N. R. Farnsworth, chs. 7 and 8. New York: Marcel Decker. Google Scholar
Bergman, J. & Pelcman, B. (1990). Pure Appl. Chem. 62, 1967–1976. CrossRef CAS Web of Science Google Scholar
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bonesi, S. M., Crevatin, L. K. & Erra-Balsells, R. (2004). Photochem. Photobiol. Sci. 3, 381–388. Web of Science CrossRef PubMed CAS Google Scholar
Bruker (1998). SMART, SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconcin, USA. Google Scholar
Chakraborty, D. P., Barman, B. K. & Bose, P. K. (1965). Tetrahedron, 21, 681–685. CrossRef CAS Web of Science Google Scholar
Chakraborty, D. P., Das, K. C., Das, B. P. & Chowdhury, B. K. (1973). Trans. Bose Res. Inst. 38, 1–10. Google Scholar
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358. CrossRef CAS Web of Science Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Kirtikar, K. R. & Basu, B. D. (1933). Indian Medicinal Plants, edited by L. M. Basu, 2nd ed., pp. 2131–2133. Allahabad: Central Council for Research in Ayurveda & Siddha (Deptt. of AYUSH, Min. of Health & Family Welfare), Govt. of India. Google Scholar
Magnus, P., Sear, N. L., Kim, C. S. & Vicker, N. (1992). J. Org. Chem. 57, 70–78. CSD CrossRef CAS Web of Science Google Scholar
Nardelli, M. (1983). Acta Cryst. C39, 1141–1142. CrossRef CAS Web of Science IUCr Journals Google Scholar
Phillipson, J. D. & Zenk, M. H. (1980). Indole and Biogenetically Related Alkaloids, ch 3. New York: Academic Press. Google Scholar
Saxton, J. E. (1983). Editor. Heterocyclic Compounds, Vol. 25, The Monoterpenoid Indole Alkaloids, chs. 8 and 11. New York: Wiley. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar