N-Nitrosomelatonin

The title compound, N-[2-(5-methoxy-1-nitro­so-1H-indol-3-yl)­ethyl]­acet­amide, C₁₃H₁₅N₃O₃, an N-nitroso derivative of melatonin, crystallizes in the monoclinic C2/c space group. The mol­ecules are arranged in such a way that the aromatic rings are in a planar conformation, with the alkyl­amide side chains in a different plane, at a dihedral angle of 108.60 (6)°. The alkyl­amide chains are interconnected by hydrogen bonds, constituting an infinite array.

Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: SDP (Frenz, 1983); program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL93 (Sheldrick, 1993); molecular graphics: ORTEP (Johnson, 1965); software used to prepare material for publication: SHELXL93.

N-nitrosomelatonin

Crystal data

C13H15N3O3	F(000) = 1104
Mr = 261.28	Dx = 1.349 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 13.580 (5) Å	Cell parameters from 23 reflections
b = 9.488 (2) Å	θ = 9.8–15.7°
c = 20.266 (7) Å	µ = 0.10 mm^−1
β = 99.73 (3)°	T = 293 K
V = 2574 (1) Å^3	Triangular prism, yellow
Z = 8	0.44 × 0.44 × 0.28 mm

Data collection

Enraf-Nonius CAD4 diffractometer	Rint = 0.011
Radiation source: fine-focus sealed tube	θmax = 28.0°, θmin = 2.0°
Graphite monochromator	h = −17→17
ω/2θ scan	k = 0→12
3178 measured reflections	l = 0→26
3094 independent reflections	1 standard reflections every 30 min
2015 reflections with I > 2σ(I)	intensity decay: 1.1%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.109	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0594P)^2 + 1.79P] where P = (Fo^2 + 2Fc^2)/3
3085 reflections	(Δ/σ)max < 0.001
177 parameters	Δρmax = 0.15 e Å^−3
0 restraints	Δρmin = −0.21 e Å^−3

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 on F² for ALL reflections except for 0 with very negative F² or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The observed criterion of F² > 2σ(F²) is used only for calculating R factor obs 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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.87455 (14)	0.2415 (2)	0.59395 (9)	0.0417 (4)
C2	0.88099 (13)	0.2435 (2)	0.52626 (9)	0.0391 (4)
H2	0.88781 (13)	0.3277 (2)	0.50398 (9)	0.051 (3)*
C3	0.87684 (13)	0.1146 (2)	0.49309 (8)	0.0361 (4)
C4	0.86632 (13)	−0.0097 (2)	0.52732 (9)	0.0382 (4)
C5	0.85724 (14)	−0.0128 (2)	0.59424 (9)	0.0445 (4)
H5	0.84818 (14)	−0.0968 (2)	0.61607 (9)	0.051 (3)*
C6	0.8623 (2)	0.1148 (2)	0.62691 (9)	0.0465 (5)
H6	0.8574 (2)	0.1169 (2)	0.67213 (9)	0.051 (3)*
O1	0.87852 (12)	0.35842 (15)	0.63327 (7)	0.0552 (4)
C7	0.8877 (2)	0.4916 (2)	0.60300 (11)	0.0563 (5)
H7A	0.8868 (14)	0.5647 (2)	0.6356 (3)	0.093 (4)*
H7B	0.8330 (7)	0.5048 (8)	0.5668 (6)	0.093 (4)*
H7C	0.9496 (6)	0.4953 (7)	0.5861 (8)	0.093 (4)*
C8	0.88287 (13)	0.0770 (2)	0.42409 (8)	0.0380 (4)
C9	0.87660 (14)	−0.0640 (2)	0.41879 (9)	0.0413 (4)
H9	0.87845 (14)	−0.1156 (2)	0.38001 (9)	0.051 (3)*
N1	0.86679 (12)	−0.1208 (2)	0.48136 (8)	0.0413 (4)
C10	0.8950 (2)	0.1828 (2)	0.37167 (9)	0.0433 (4)
H10A	0.9575 (2)	0.2324 (2)	0.38548 (9)	0.050 (3)*
H10B	0.8415 (2)	0.2514 (2)	0.36917 (9)	0.050 (3)*
C11	0.8943 (2)	0.1224 (2)	0.30197 (9)	0.0454 (5)
H11A	0.9152 (2)	0.1952 (2)	0.27370 (9)	0.050 (3)*
H11B	0.9427 (2)	0.0465 (2)	0.30501 (9)	0.050 (3)*
N2	0.79779 (13)	0.0692 (2)	0.27069 (7)	0.0421 (4)
H2A	0.78426 (13)	−0.0183 (2)	0.27553 (7)	0.051 (3)*
C12	0.7294 (2)	0.1507 (2)	0.23482 (9)	0.0456 (5)
C13	0.6325 (2)	0.0817 (3)	0.20683 (11)	0.0620 (6)
H13A	0.6306 (6)	−0.0110 (8)	0.2255 (7)	0.093 (4)*
H13B	0.6264 (6)	0.0750 (17)	0.15904 (14)	0.093 (4)*
H13C	0.5783 (2)	0.1368 (10)	0.2180 (8)	0.093 (4)*
O2	0.74487 (14)	0.2758 (2)	0.22447 (9)	0.0688 (5)
N3	0.86643 (14)	−0.2560 (2)	0.50033 (9)	0.0500 (4)
O3	0.87183 (13)	−0.3404 (2)	0.45566 (8)	0.0644 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0428 (10)	0.0445 (10)	0.0380 (9)	0.0015 (8)	0.0071 (8)	0.0021 (8)
C2	0.0399 (9)	0.0409 (9)	0.0359 (9)	−0.0030 (8)	0.0049 (7)	0.0055 (7)
C3	0.0336 (8)	0.0426 (9)	0.0312 (8)	−0.0015 (7)	0.0027 (6)	0.0051 (7)
C4	0.0346 (9)	0.0424 (10)	0.0371 (9)	−0.0025 (7)	0.0042 (7)	0.0045 (8)
C5	0.0502 (11)	0.0457 (11)	0.0387 (10)	−0.0001 (9)	0.0108 (8)	0.0116 (8)
C6	0.0536 (11)	0.0539 (12)	0.0339 (9)	0.0007 (9)	0.0129 (8)	0.0066 (8)
O1	0.0809 (11)	0.0457 (8)	0.0406 (7)	−0.0011 (7)	0.0151 (7)	−0.0015 (6)
C7	0.0720 (14)	0.0437 (11)	0.0531 (12)	−0.0030 (10)	0.0102 (10)	−0.0004 (9)
C8	0.0371 (9)	0.0434 (10)	0.0323 (8)	−0.0026 (7)	0.0024 (7)	0.0019 (7)
C9	0.0457 (10)	0.0441 (10)	0.0335 (9)	−0.0029 (8)	0.0045 (7)	0.0020 (8)
N1	0.0439 (9)	0.0407 (8)	0.0385 (8)	−0.0033 (7)	0.0050 (6)	0.0056 (6)
C10	0.0515 (11)	0.0436 (10)	0.0341 (9)	−0.0066 (8)	0.0050 (8)	0.0045 (8)
C11	0.0538 (11)	0.0478 (11)	0.0366 (9)	0.0025 (9)	0.0136 (8)	0.0071 (8)
N2	0.0594 (10)	0.0324 (8)	0.0341 (7)	0.0027 (7)	0.0067 (7)	0.0014 (6)
C12	0.0663 (13)	0.0378 (10)	0.0316 (9)	0.0057 (9)	0.0050 (8)	−0.0021 (7)
C13	0.0700 (15)	0.0652 (14)	0.0456 (12)	0.0000 (12)	−0.0055 (10)	0.0015 (11)
O2	0.0976 (13)	0.0358 (8)	0.0649 (10)	0.0057 (8)	−0.0095 (9)	0.0075 (7)
N3	0.0577 (10)	0.0395 (9)	0.0526 (10)	−0.0032 (8)	0.0091 (8)	0.0049 (8)
O3	0.0900 (12)	0.0437 (8)	0.0608 (10)	−0.0044 (8)	0.0163 (9)	−0.0018 (7)

Geometric parameters (Å, º)

C1—O1	1.362 (2)	C8—C9	1.344 (3)
C1—C2	1.389 (3)	C8—C10	1.491 (2)
C1—C6	1.398 (3)	C9—N1	1.404 (2)
C2—C3	1.392 (3)	N1—N3	1.339 (2)
C3—C4	1.388 (2)	C10—C11	1.523 (3)
C3—C8	1.459 (2)	C11—N2	1.447 (3)
C4—C5	1.383 (3)	N2—C12	1.327 (2)
C4—N1	1.407 (2)	C12—O2	1.229 (2)
C5—C6	1.376 (3)	C12—C13	1.493 (3)
O1—C7	1.419 (2)	N3—O3	1.221 (2)
O1—C1—C2	124.3 (2)	C9—C8—C10	128.8 (2)
O1—C1—C6	114.6 (2)	C3—C8—C10	123.3 (2)
C2—C1—C6	121.1 (2)	C8—C9—N1	108.9 (2)
C1—C2—C3	117.4 (2)	N3—N1—C9	129.2 (2)
C4—C3—C2	120.3 (2)	N3—N1—C4	121.8 (2)
C4—C3—C8	107.3 (2)	C9—N1—C4	108.80 (15)
C2—C3—C8	132.3 (2)	C8—C10—C11	115.0 (2)
C5—C4—C3	122.8 (2)	N2—C11—C10	113.6 (2)
C5—C4—N1	130.1 (2)	C12—N2—C11	122.4 (2)
C3—C4—N1	107.1 (2)	O2—C12—N2	122.1 (2)
C4—C5—C6	116.6 (2)	O2—C12—C13	121.6 (2)
C5—C6—C1	121.8 (2)	N2—C12—C13	116.3 (2)
C1—O1—C7	118.0 (2)	O3—N3—N1	114.4 (2)
C9—C8—C3	107.9 (2)