(1E,2E)-1,2-Bis[(1-benzyloxymethyl-1H-indol-3-yl)methylidene]hydrazine

The title compound, C₃₄H₃₀N₄O₂, lies on an inversion center and consists of two 3-substituted-1H-indole units linked by a 1,2-dimethyl­enehydrazine bridge. It is one of numerous examples in which two aromatic ring systems are joined by this 4-atom bridge. The geometry of the centrosymmetric bridge is: C(arom)-C = 1.444 (3), C=N = 1.284 (3), N-N = 1.414 (4) Å, C(arom)-C=N = 122.6 (2) and C=N-N = 111.9 (2)°. The nine non-H atoms of the indole unit lie in a plane ([delta]_r.m.s. = 0.0089 Å) which is twisted 6.0 (2)° with respect to the hydrazine bridge plane. The benzyl­oxymethyl substituents do not lie in the plane of the rest of the mol­ecule and are in a folded rather than an extended conformation. This is described by the three torsion angles in the middle of the C=N-C-O-C_Bz group, viz. 98.5 (3), -62.1 (3), and -66.3 (2)°.

Key indicators

• Single-crystal X-ray study
• T = 90 K, P = 0.0 kPa
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.056
• wR factor = 0.126
• Data-to-parameter ratio = 14.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT906_ALERT_3_C Large K value in the Analysis of Variance ......      6.562
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          2

Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT128_ALERT_4_G Alternate Setting of Space-group P21/c   .......      P21/n
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600          4

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   3 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Title compound I was synthesized as part of a project targeting the synthesis of tryptophan and other tyrosine derivatives (Shui, 1994). The molecule occupies a crystallographic inversion center and consists of two 3-substituted 1H-indole moieties linked by a (1E,2E)-1,2-dimethylenehydrazine bridge, one of numerous examples in which two aromatic ring systems are joined by this 4-atom bridge. The bridge geometry is consistent with that found, for example, in Ph—CH═N—N═CH—Ph [CAS:1048662–10-7, Mom & de With (1978); Burke-Laing & Laing (1976); CSD:BZAZIN02, BZAZIN11, respectively, Allen (2002)]. The geometry of the indole is also consistent with that found in other 1,3-disubstituted indoles [e.g., CSD:OBAVIW, CAS:256391–53-4, Biswas et al. (1999)].

Related literature

For the synthesis, see: Shui (1994). For related structures, see: Burke-Laing & Laing (1976); Mom & de With (1978); Biswas et al. (1999); Rizal et al. (2008). For a description of the Cambridge Structural Database, see: Allen (2002).

S2. Experimental

The synthesis of I is detailed by Shui (1994), who prepared a suitable single-crystal by recrystallization from dichloromethane.

S3. Refinement

All H atoms were placed in calculated positions, guided by difference maps, with C—H bond distances 0.95 (aromatic C) and 0.99 (alkyl C) Å, and U_iso=1.2U_eq, thereafter refined as riding.

Computing details

Data collection: COLLECT (Nonius, 2000); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997); data reduction: HKL DENZO and SCALEPACK (Otwinowski & Minor 1997); program(s) used to solve structure: SHELXS86 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999).

Figures

Fig. 1. View of (I) (50% probability displacement ellipsoids)

(1E,2E)-1,2-Bis[(1-benzyloxymethyl-1H-indol- 3-yl)methylidene]hydrazine

Crystal data

C34H30N4O2	F(000) = 556
Mr = 526.62	Dx = 1.285 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2472 reflections
a = 12.8518 (10) Å	θ = 2.6–26.0°
b = 7.9663 (9) Å	µ = 0.08 mm^−1
c = 13.6810 (12) Å	T = 90 K
β = 103.672 (5)°	Fragment, colorless
V = 1361.0 (2) Å^3	0.18 × 0.10 × 0.05 mm
Z = 2

Data collection

Nonius KappaCCD diffractometer	2678 independent reflections
Radiation source: sealed tube	1481 reflections with I > 2σ(I)
Horizonally mounted graphite crystal monochromator	Rint = 0.067
Detector resolution: 9 pixels mm^-1	θmax = 26.0°, θmin = 3.0°
CCD rotation images, thick slices scans	h = −15→15
Absorption correction: multi-scan (HKL SCALEPACK; Otwinowski & Minor 1997)	k = −8→9
Tmin = 0.986, Tmax = 0.996	l = −16→16
4340 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.056	H-atom parameters constrained
wR(F^2) = 0.126	w = 1/[σ^2(Fo^2) + (0.0483P)^2 + 0.249P] where P = (Fo^2 + 2Fc^2)/3
S = 0.99	(Δ/σ)max = 0.001
2678 reflections	Δρmax = 0.25 e Å^−3
182 parameters	Δρmin = −0.25 e Å^−3
0 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 constraints	Extinction coefficient: 0.0062 (13)
Primary atom site location: structure-invariant direct methods

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	0.02086 (15)	0.0030 (3)	0.55263 (14)	0.0211 (5)
C1	0.11765 (18)	−0.0511 (3)	0.57786 (17)	0.0206 (6)
H1	0.15	−0.0917	0.5268	0.025*
C2	0.17927 (18)	−0.0526 (3)	0.68083 (16)	0.0191 (6)
C3	0.14858 (18)	−0.0067 (3)	0.77188 (17)	0.0180 (6)
C4	0.05355 (19)	0.0445 (3)	0.79619 (18)	0.0207 (6)
H4	−0.0108	0.0538	0.7452	0.025*
C5	0.05426 (19)	0.0813 (3)	0.89494 (18)	0.0236 (6)
H5	−0.0098	0.1178	0.9115	0.028*
C6	0.14857 (19)	0.0654 (3)	0.97152 (19)	0.0258 (7)
H6	0.147	0.0915	1.0389	0.031*
C7	0.24299 (19)	0.0127 (3)	0.95068 (17)	0.0226 (6)
H7	0.3066	0.0011	1.0023	0.027*
C8	0.24147 (18)	−0.0229 (3)	0.85072 (17)	0.0182 (6)
N2	0.32454 (15)	−0.0785 (3)	0.81007 (14)	0.0190 (5)
C9	0.28592 (19)	−0.0961 (3)	0.70805 (17)	0.0205 (6)
H9	0.3269	−0.133	0.6628	0.025*
C10	0.43362 (18)	−0.1094 (3)	0.86494 (18)	0.0218 (6)
H10A	0.4327	−0.1657	0.9293	0.026*
H10B	0.468	−0.1866	0.8254	0.026*
O1	0.49589 (12)	0.0398 (2)	0.88566 (11)	0.0225 (4)
C11	0.50844 (19)	0.1279 (3)	0.79804 (18)	0.0241 (6)
H11A	0.5435	0.237	0.8194	0.029*
H11B	0.4365	0.152	0.7552	0.029*
C12	0.57299 (18)	0.0365 (3)	0.73523 (18)	0.0219 (6)
C13	0.5658 (2)	0.0890 (3)	0.63721 (18)	0.0276 (7)
H13	0.5168	0.1754	0.6092	0.033*
C14	0.6293 (2)	0.0168 (4)	0.57959 (19)	0.0329 (7)
H14	0.6248	0.0562	0.5132	0.039*
C15	0.6992 (2)	−0.1122 (4)	0.6180 (2)	0.0352 (7)
H15	0.7423	−0.1619	0.5782	0.042*
C16	0.7056 (2)	−0.1679 (4)	0.71520 (19)	0.0328 (7)
H16	0.7525	−0.2576	0.7419	0.039*
C17	0.64369 (19)	−0.0929 (3)	0.77379 (19)	0.0263 (7)
H17	0.6497	−0.1304	0.8408	0.032*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0247 (12)	0.0193 (12)	0.0164 (10)	0.0004 (11)	−0.0011 (9)	−0.0027 (10)
C1	0.0221 (14)	0.0174 (15)	0.0212 (13)	−0.0012 (12)	0.0030 (11)	−0.0005 (11)
C2	0.0203 (12)	0.0162 (14)	0.0186 (13)	0.0005 (11)	0.0004 (10)	−0.0009 (11)
C3	0.0209 (12)	0.0141 (14)	0.0185 (13)	−0.0019 (12)	0.0038 (10)	0.0015 (11)
C4	0.0190 (12)	0.0189 (14)	0.0225 (14)	−0.0022 (12)	0.0017 (10)	0.0011 (12)
C5	0.0235 (13)	0.0229 (16)	0.0272 (14)	−0.0017 (12)	0.0116 (11)	0.0002 (12)
C6	0.0292 (15)	0.0261 (17)	0.0228 (14)	−0.0024 (13)	0.0074 (12)	−0.0007 (12)
C7	0.0253 (13)	0.0217 (15)	0.0189 (13)	0.0000 (13)	0.0016 (11)	−0.0007 (12)
C8	0.0196 (12)	0.0136 (14)	0.0218 (13)	−0.0007 (12)	0.0059 (10)	0.0000 (11)
N2	0.0198 (11)	0.0198 (13)	0.0161 (11)	0.0003 (9)	0.0013 (8)	−0.0012 (9)
C9	0.0237 (13)	0.0197 (15)	0.0172 (13)	0.0002 (12)	0.0031 (10)	−0.0017 (11)
C10	0.0214 (13)	0.0179 (15)	0.0242 (14)	0.0003 (12)	0.0016 (11)	0.0000 (12)
O1	0.0240 (9)	0.0201 (10)	0.0220 (9)	−0.0030 (8)	0.0025 (7)	−0.0021 (8)
C11	0.0241 (13)	0.0227 (15)	0.0252 (14)	−0.0006 (12)	0.0052 (11)	0.0048 (12)
C12	0.0209 (13)	0.0204 (14)	0.0224 (13)	−0.0035 (12)	0.0016 (11)	−0.0009 (12)
C13	0.0292 (14)	0.0246 (16)	0.0274 (15)	−0.0002 (13)	0.0031 (12)	0.0045 (13)
C14	0.0357 (15)	0.0386 (19)	0.0251 (15)	−0.0055 (15)	0.0088 (12)	−0.0007 (14)
C15	0.0326 (16)	0.0410 (19)	0.0348 (17)	0.0004 (15)	0.0136 (13)	−0.0079 (15)
C16	0.0295 (15)	0.0346 (18)	0.0324 (16)	0.0066 (14)	0.0036 (12)	−0.0025 (14)
C17	0.0229 (14)	0.0330 (17)	0.0218 (14)	0.0017 (13)	0.0030 (11)	−0.0008 (13)

Geometric parameters (Å, º)

N1—C1	1.284 (3)	C9—H9	0.95
N1—N1^i	1.414 (4)	C10—O1	1.424 (3)
C1—C2	1.444 (3)	C10—H10A	0.99
C1—H1	0.95	C10—H10B	0.99
C2—C9	1.377 (3)	O1—C11	1.431 (3)
C2—C3	1.440 (3)	C11—C12	1.514 (3)
C3—C4	1.400 (3)	C11—H11A	0.99
C3—C8	1.413 (3)	C11—H11B	0.99
C4—C5	1.380 (3)	C12—C13	1.387 (3)
C4—H4	0.95	C12—C17	1.393 (4)
C5—C6	1.408 (3)	C13—C14	1.386 (3)
C5—H5	0.95	C13—H13	0.95
C6—C7	1.376 (3)	C14—C15	1.384 (4)
C6—H6	0.95	C14—H14	0.95
C7—C8	1.392 (3)	C15—C16	1.385 (4)
C7—H7	0.95	C15—H15	0.95
C8—N2	1.388 (3)	C16—C17	1.391 (3)
N2—C9	1.373 (3)	C16—H16	0.95
N2—C10	1.446 (3)	C17—H17	0.95
C1—N1—N1^i	111.9 (2)	O1—C10—N2	113.05 (19)
N1—C1—C2	122.6 (2)	O1—C10—H10A	109
N1—C1—H1	118.7	N2—C10—H10A	109
C2—C1—H1	118.7	O1—C10—H10B	109
C9—C2—C3	106.77 (19)	N2—C10—H10B	109
C9—C2—C1	123.2 (2)	H10A—C10—H10B	107.8
C3—C2—C1	130.0 (2)	C10—O1—C11	114.34 (17)
C4—C3—C8	118.2 (2)	O1—C11—C12	115.2 (2)
C4—C3—C2	135.4 (2)	O1—C11—H11A	108.5
C8—C3—C2	106.41 (19)	C12—C11—H11A	108.5
C5—C4—C3	119.3 (2)	O1—C11—H11B	108.5
C5—C4—H4	120.3	C12—C11—H11B	108.5
C3—C4—H4	120.3	H11A—C11—H11B	107.5
C4—C5—C6	121.0 (2)	C13—C12—C17	118.5 (2)
C4—C5—H5	119.5	C13—C12—C11	118.9 (2)
C6—C5—H5	119.5	C17—C12—C11	122.5 (2)
C7—C6—C5	121.3 (2)	C12—C13—C14	120.8 (2)
C7—C6—H6	119.4	C12—C13—H13	119.6
C5—C6—H6	119.4	C14—C13—H13	119.6
C6—C7—C8	117.2 (2)	C15—C14—C13	120.5 (2)
C6—C7—H7	121.4	C15—C14—H14	119.7
C8—C7—H7	121.4	C13—C14—H14	119.7
N2—C8—C7	128.7 (2)	C16—C15—C14	119.3 (3)
N2—C8—C3	108.3 (2)	C16—C15—H15	120.4
C7—C8—C3	123.0 (2)	C14—C15—H15	120.4
C9—N2—C8	108.20 (19)	C15—C16—C17	120.2 (3)
C9—N2—C10	125.7 (2)	C15—C16—H16	119.9
C8—N2—C10	126.11 (19)	C17—C16—H16	119.9
N2—C9—C2	110.3 (2)	C16—C17—C12	120.7 (2)
N2—C9—H9	124.9	C16—C17—H17	119.6
C2—C9—H9	124.9	C12—C17—H17	119.6
C1^i—N1^i—N1—C1	180	C7—C8—N2—C10	−1.0 (4)
N1^i—N1—C1—C2	177.9 (2)	C3—C8—N2—C10	179.2 (2)
N1—C1—C2—C9	−174.1 (2)	C8—N2—C9—C2	0.2 (3)
N1—C1—C2—C3	3.4 (4)	C10—N2—C9—C2	−178.6 (2)
C9—C2—C3—C4	−178.3 (3)	C3—C2—C9—N2	−0.8 (3)
C1—C2—C3—C4	4.0 (5)	C1—C2—C9—N2	177.2 (2)
C9—C2—C3—C8	1.0 (3)	C9—N2—C10—O1	98.5 (3)
C1—C2—C3—C8	−176.8 (2)	C8—N2—C10—O1	−80.1 (3)
C8—C3—C4—C5	1.6 (4)	N2—C10—O1—C11	−62.1 (3)
C2—C3—C4—C5	−179.2 (3)	C10—O1—C11—C12	−66.3 (2)
C3—C4—C5—C6	−1.0 (4)	O1—C11—C12—C13	163.0 (2)
C4—C5—C6—C7	0.0 (4)	O1—C11—C12—C17	−20.4 (3)
C5—C6—C7—C8	0.5 (4)	C17—C12—C13—C14	−1.4 (4)
C6—C7—C8—N2	−179.5 (2)	C11—C12—C13—C14	175.3 (2)
C6—C7—C8—C3	0.2 (4)	C12—C13—C14—C15	1.7 (4)
C4—C3—C8—N2	178.5 (2)	C13—C14—C15—C16	−0.4 (4)
C2—C3—C8—N2	−0.9 (3)	C14—C15—C16—C17	−1.0 (4)
C4—C3—C8—C7	−1.2 (4)	C15—C16—C17—C12	1.3 (4)
C2—C3—C8—C7	179.4 (2)	C13—C12—C17—C16	0.0 (4)
C7—C8—N2—C9	−179.8 (3)	C11—C12—C17—C16	−176.7 (2)
C3—C8—N2—C9	0.4 (3)

Symmetry code: (i) −x, −y, −z+1.