3-Nitro­phenol–1,3,5-triazine-2,4,6-tri­amine (2/1)

The asymmetric unit of the title compound, C₃H₆N₆·2C₆H₅NO₃, contains one melamine and two 3-nitro­phenol mol­ecules. The mean planes of the 3-nitro­phenol mol­ecules are almost orthogonal to the plane of melamine, making dihedral angles of 82.77 (4) and 88.36 (5)°. In the crystal, mol­ecules are linked via O—H...N, N—H...N and N—H...O hydrogen bonds, forming a three-dimensional network. The crystal also features weak C—H...π and π–π inter­actions [centroid–centroid distance = 3.9823 (9) Å].

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.042
• wR factor = 0.119
• Data-to-parameter ratio = 15.1

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N1
PLAT420_ALERT_2_C D-H Without Acceptor       N6     -   H6A    ...          ?
PLAT420_ALERT_2_C D-H Without Acceptor       N6     -   H6B    ...          ?

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite         13
PLAT005_ALERT_5_G No _iucr_refine_instructions_details  in the CIF          ?
PLAT042_ALERT_1_G Calc. and Reported MoietyFormula Strings  Differ          ?
PLAT790_ALERT_4_G Centre of Gravity not Within Unit Cell: Resd.  #          2
              C6 H5 N O3
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          8
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600          2

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

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 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

Melamine (1,3,5-triazine-2,4,6-triamine) and its derivatives can develop well defined non-covalent supramolecular nanoarchitectures via multiple hydrogen bonds by self-assembly of components containing complementary arrays of hydrogen-bonding sites (Desiraju, 1990; Krische & Lehn, 2000). The geometric parameters of the title compound (Fig. 1) are comparable to those reported for similar structures (Kanagathara et al., 2012; Wang et al., 2007). The mean planes of the two nitrophenol molecules (C1···C6) and (C10···C15) are almost orthogonal to the melamine (N2/C7/N4/C9/N3/C8) molecule, with dihedral angles of 82.77 (4) and 88.36 (5)°, respectively.

The crystal packing of the title compound is influenced by intermolecular O—H···N, N—H···N and N—H···O hydrogen bonds, as well as weak C—H···π (Table 1 and Fig. 2) and π–π interactions: Cg1···Cg2 (x, 1/2-y, 3/2+z) distance of 3.9823 (9) Å; Cg2···Cg1 (-1/2+x, 1/2-y, 1-z) distance of 3.9823 (9) Å; Cg1···Cg2 (-x, 1-y, 1-z) distance of 4.2397 (9) Å; Cg3···Cg1 (1/2-x, 1/2+y, z) distance of 5.0406 (8) Å; where Cg1, Cg2 and Cg3 are the centroids of the rings C1···C6, C10···C15, and N2/C7/N4/C9/N3/C8, respectively.

Related literature

For general background to melamine derivatives, see: Desiraju et al. (1990); Krische & Lehn (2000). For related structures, see: Kanagathara et al. (2012); Wang et al. (2007).

S2. Experimental

Melamine (1.261 g, 10 mmol) was dissolved in 200 ml of hot distilled water. 3-Nitrophenol (1.391 g, 10 mmol) was dissolved in 100 ml of distilled water, separately. The 3-nitrophenol solution was added gently to the hot solution of melamine, and the mixture stirred well for nearly five hours to get an homogeneous solution. Water was then allowed to evaporate. Within few days, tiny transparent, yellowish crystals were formed.

S3. Refinement

H atoms of aromatic CH groups were positioned geometrically and refined using a riding model with C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C). The H atoms bound to O and N atoms were found in a difference map and refined isotropically, with distances restrained to N—H = 0.88 (1) Å and O—H = 0.82 (1) Å (Sheldrick, 2008).

Computing details

Data collection: APEX2 (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of the title compound, with 30% probability displacement ellipsoids for non-H atoms.
	Fig. 2. The packing of the title compound viewed down the a axis. Hydrogen bonds are shown as dashed lines.

3-Nitrophenol–1,3,5-triazine-2,4,6-triamine (2/1)

Crystal data

C3H6N6·2C6H5NO3	F(000) = 1680
Mr = 404.36	Dx = 1.503 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 4327 reflections
a = 15.5150 (6) Å	θ = 2.3–28.3°
b = 12.9137 (6) Å	µ = 0.12 mm^−1
c = 17.8323 (6) Å	T = 295 K
V = 3572.8 (2) Å^3	Block, yellow
Z = 8	0.28 × 0.24 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer	4447 independent reflections
Radiation source: fine-focus sealed tube	3352 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
ω and ϕ scans	θmax = 28.3°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −20→13
Tmin = 0.967, Tmax = 0.977	k = −17→7
19568 measured reflections	l = −23→23

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)] = 0.042	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.119	w = 1/[σ^2(Fo^2) + (0.0577P)^2 + 0.7906P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max < 0.001
4447 reflections	Δρmax = 0.24 e Å^−3
295 parameters	Δρmin = −0.20 e Å^−3
8 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 constraints	Extinction coefficient: 0.0028 (5)
Primary atom site location: structure-invariant direct methods

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

	x	y	z	Uiso*/Ueq
C1	0.20295 (11)	0.13223 (11)	0.30457 (8)	0.0472 (4)
C2	0.18602 (9)	0.11918 (10)	0.22906 (8)	0.0406 (3)
H2	0.1305	0.1048	0.2123	0.049*
C3	0.25379 (9)	0.12802 (10)	0.17907 (8)	0.0365 (3)
C4	0.33676 (9)	0.14713 (12)	0.20566 (9)	0.0475 (4)
H4	0.3826	0.1521	0.1723	0.057*
C5	0.35064 (12)	0.15871 (14)	0.28162 (10)	0.0597 (5)
H5	0.4062	0.1712	0.2989	0.072*
C6	0.28408 (13)	0.15216 (13)	0.33219 (9)	0.0586 (5)
H6	0.2935	0.1609	0.3833	0.070*
C7	0.01234 (8)	0.66741 (10)	0.47227 (7)	0.0337 (3)
C8	0.08123 (8)	0.82016 (10)	0.49038 (7)	0.0337 (3)
C9	0.14073 (8)	0.67001 (10)	0.53192 (7)	0.0322 (3)
C10	−0.15540 (9)	0.60489 (10)	0.68536 (8)	0.0383 (3)
C11	−0.07322 (10)	0.59736 (15)	0.65597 (9)	0.0546 (4)
H11	−0.0643	0.5851	0.6052	0.066*
C12	−0.00506 (10)	0.60861 (16)	0.70459 (10)	0.0595 (5)
H12	0.0510	0.6040	0.6864	0.071*
C13	−0.01848 (9)	0.62665 (13)	0.78025 (9)	0.0464 (4)
H13	0.0283	0.6340	0.8124	0.056*
C14	−0.10170 (8)	0.63378 (10)	0.80810 (8)	0.0365 (3)
C15	−0.17126 (8)	0.62232 (10)	0.76020 (8)	0.0369 (3)
H15	−0.2274	0.6263	0.7782	0.044*
N1	0.13017 (13)	0.12490 (12)	0.35762 (9)	0.0659 (4)
N2	0.01376 (7)	0.77043 (9)	0.46051 (6)	0.0361 (3)
N3	0.14703 (7)	0.77395 (8)	0.52606 (6)	0.0354 (2)
N4	0.07430 (6)	0.61329 (8)	0.50739 (6)	0.0345 (3)
N5	−0.05479 (8)	0.61359 (11)	0.44621 (8)	0.0461 (3)
N6	0.08276 (9)	0.92415 (10)	0.48582 (8)	0.0457 (3)
N7	0.20470 (8)	0.61983 (10)	0.56654 (8)	0.0445 (3)
N8	−0.22955 (8)	0.59341 (10)	0.63461 (7)	0.0459 (3)
O1	0.23651 (6)	0.11610 (8)	0.10455 (6)	0.0433 (3)
O2	0.14494 (13)	0.13811 (14)	0.42402 (8)	0.1006 (6)
O3	0.05950 (11)	0.10386 (16)	0.33363 (10)	0.0968 (5)
O4	−0.11865 (7)	0.65065 (10)	0.88192 (6)	0.0537 (3)
O5	−0.30194 (7)	0.60094 (10)	0.66114 (7)	0.0583 (3)
O6	−0.21580 (9)	0.57499 (12)	0.56836 (6)	0.0716 (4)
H1	0.2744 (10)	0.1481 (14)	0.0807 (10)	0.068 (6)*
H4A	−0.0754 (9)	0.6682 (15)	0.9062 (9)	0.064 (6)*
H6A	0.0446 (9)	0.9511 (14)	0.4564 (9)	0.065 (5)*
H6B	0.1328 (8)	0.9538 (13)	0.4931 (10)	0.061 (5)*
H7A	0.2051 (10)	0.5516 (7)	0.5665 (9)	0.048 (4)*
H7B	0.2525 (8)	0.6534 (12)	0.5769 (9)	0.050 (5)*
H5A	−0.0593 (11)	0.5475 (8)	0.4593 (10)	0.061 (5)*
H5B	−0.1003 (8)	0.6483 (13)	0.4321 (10)	0.058 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0631 (10)	0.0362 (7)	0.0423 (8)	−0.0015 (7)	0.0035 (7)	0.0051 (6)
C2	0.0372 (7)	0.0385 (7)	0.0461 (7)	−0.0032 (6)	−0.0005 (6)	0.0041 (6)
C3	0.0350 (7)	0.0346 (6)	0.0398 (7)	−0.0048 (5)	−0.0051 (5)	0.0045 (5)
C4	0.0369 (8)	0.0514 (8)	0.0542 (8)	−0.0108 (6)	−0.0080 (7)	0.0107 (7)
C5	0.0587 (10)	0.0596 (10)	0.0608 (10)	−0.0195 (8)	−0.0260 (9)	0.0123 (8)
C6	0.0849 (13)	0.0476 (9)	0.0433 (8)	−0.0136 (8)	−0.0168 (9)	0.0063 (7)
C7	0.0258 (6)	0.0459 (7)	0.0293 (6)	0.0013 (5)	−0.0018 (5)	0.0003 (5)
C8	0.0298 (6)	0.0419 (7)	0.0295 (6)	0.0021 (5)	0.0051 (5)	0.0018 (5)
C9	0.0252 (6)	0.0416 (7)	0.0300 (6)	0.0001 (5)	−0.0010 (5)	0.0011 (5)
C10	0.0370 (7)	0.0373 (6)	0.0405 (7)	−0.0007 (5)	−0.0052 (6)	0.0000 (5)
C11	0.0469 (9)	0.0779 (11)	0.0391 (7)	0.0020 (8)	0.0061 (7)	−0.0013 (7)
C12	0.0330 (8)	0.0935 (13)	0.0520 (9)	0.0002 (8)	0.0107 (7)	−0.0027 (9)
C13	0.0281 (7)	0.0632 (9)	0.0479 (8)	−0.0024 (6)	−0.0015 (6)	−0.0034 (7)
C14	0.0300 (7)	0.0396 (6)	0.0399 (7)	−0.0037 (5)	0.0012 (5)	−0.0049 (5)
C15	0.0271 (6)	0.0389 (6)	0.0447 (7)	−0.0028 (5)	0.0000 (5)	−0.0056 (5)
N1	0.0904 (13)	0.0530 (8)	0.0543 (9)	0.0022 (8)	0.0230 (9)	0.0047 (7)
N2	0.0293 (6)	0.0447 (6)	0.0342 (5)	0.0039 (5)	−0.0022 (4)	0.0046 (4)
N3	0.0287 (5)	0.0406 (6)	0.0370 (6)	−0.0036 (4)	−0.0031 (4)	0.0018 (4)
N4	0.0259 (5)	0.0399 (6)	0.0377 (6)	0.0000 (4)	−0.0052 (4)	0.0012 (4)
N5	0.0306 (6)	0.0515 (7)	0.0561 (7)	−0.0013 (6)	−0.0156 (6)	0.0033 (6)
N6	0.0431 (8)	0.0406 (6)	0.0535 (7)	0.0022 (6)	0.0009 (6)	0.0055 (5)
N7	0.0294 (6)	0.0457 (7)	0.0585 (8)	−0.0017 (5)	−0.0150 (6)	0.0062 (6)
N8	0.0481 (8)	0.0436 (6)	0.0460 (7)	0.0003 (6)	−0.0104 (6)	−0.0007 (5)
O1	0.0350 (5)	0.0563 (6)	0.0386 (5)	−0.0122 (5)	−0.0010 (4)	0.0022 (4)
O2	0.1446 (16)	0.1092 (13)	0.0480 (8)	0.0043 (11)	0.0257 (9)	−0.0016 (8)
O3	0.0729 (10)	0.1297 (15)	0.0876 (11)	−0.0121 (10)	0.0340 (9)	−0.0054 (10)
O4	0.0298 (5)	0.0893 (8)	0.0421 (6)	−0.0117 (5)	0.0014 (4)	−0.0207 (5)
O5	0.0396 (6)	0.0704 (8)	0.0648 (7)	0.0011 (5)	−0.0132 (5)	−0.0101 (6)
O6	0.0719 (9)	0.1012 (10)	0.0417 (6)	0.0024 (8)	−0.0125 (6)	−0.0077 (6)

Geometric parameters (Å, º)

C1—C6	1.376 (2)	C10—N8	1.4712 (18)
C1—C2	1.382 (2)	C11—C12	1.375 (2)
C1—N1	1.476 (2)	C11—H11	0.9300
C2—C3	1.383 (2)	C12—C13	1.385 (2)
C2—H2	0.9300	C12—H12	0.9300
C3—O1	1.3644 (16)	C13—C14	1.3865 (19)
C3—C4	1.3938 (19)	C13—H13	0.9300
C4—C5	1.380 (2)	C14—O4	1.3599 (16)
C4—H4	0.9300	C14—C15	1.3842 (18)
C5—C6	1.374 (3)	C15—H15	0.9300
C5—H5	0.9300	N1—O3	1.208 (2)
C6—H6	0.9300	N1—O2	1.218 (2)
C7—N5	1.3356 (17)	N5—H5A	0.888 (9)
C7—N4	1.3434 (16)	N5—H5B	0.874 (9)
C7—N2	1.3469 (18)	N6—H6A	0.863 (9)
C8—N2	1.3385 (16)	N6—H6B	0.875 (9)
C8—N3	1.3429 (16)	N7—H7A	0.881 (9)
C8—N6	1.3456 (19)	N7—H7B	0.878 (9)
C9—N7	1.3364 (17)	N8—O5	1.2226 (16)
C9—N4	1.3380 (16)	N8—O6	1.2238 (17)
C9—N3	1.3498 (17)	O1—H1	0.835 (9)
C10—C15	1.3756 (19)	O4—H4A	0.830 (9)
C10—C11	1.382 (2)
C6—C1—C2	123.05 (15)	C11—C12—C13	121.09 (14)
C6—C1—N1	118.84 (15)	C11—C12—H12	119.5
C2—C1—N1	118.10 (15)	C13—C12—H12	119.5
C1—C2—C3	118.25 (14)	C12—C13—C14	120.01 (14)
C1—C2—H2	120.9	C12—C13—H13	120.0
C3—C2—H2	120.9	C14—C13—H13	120.0
O1—C3—C2	117.97 (12)	O4—C14—C15	117.63 (12)
O1—C3—C4	122.19 (13)	O4—C14—C13	122.51 (12)
C2—C3—C4	119.83 (13)	C15—C14—C13	119.86 (13)
C5—C4—C3	119.82 (15)	C10—C15—C14	118.47 (12)
C5—C4—H4	120.1	C10—C15—H15	120.8
C3—C4—H4	120.1	C14—C15—H15	120.8
C6—C5—C4	121.37 (15)	O3—N1—O2	123.13 (18)
C6—C5—H5	119.3	O3—N1—C1	118.81 (16)
C4—C5—H5	119.3	O2—N1—C1	118.04 (19)
C5—C6—C1	117.66 (15)	C8—N2—C7	115.13 (11)
C5—C6—H6	121.2	C8—N3—C9	115.05 (11)
C1—C6—H6	121.2	C9—N4—C7	114.76 (11)
N5—C7—N4	116.71 (12)	C7—N5—H5A	118.0 (12)
N5—C7—N2	118.20 (12)	C7—N5—H5B	117.7 (12)
N4—C7—N2	125.08 (11)	H5A—N5—H5B	120.4 (17)
N2—C8—N3	124.74 (12)	C8—N6—H6A	115.2 (13)
N2—C8—N6	117.95 (12)	C8—N6—H6B	116.3 (12)
N3—C8—N6	117.30 (12)	H6A—N6—H6B	121.5 (19)
N7—C9—N4	117.24 (12)	C9—N7—H7A	119.3 (11)
N7—C9—N3	117.65 (12)	C9—N7—H7B	119.0 (11)
N4—C9—N3	125.09 (11)	H7A—N7—H7B	119.2 (15)
C15—C10—C11	122.99 (13)	O5—N8—O6	123.30 (13)
C15—C10—N8	118.25 (12)	O5—N8—C10	118.19 (12)
C11—C10—N8	118.76 (13)	O6—N8—C10	118.50 (13)
C12—C11—C10	117.58 (14)	C3—O1—H1	107.5 (14)
C12—C11—H11	121.2	C14—O4—H4A	113.1 (13)
C10—C11—H11	121.2
C6—C1—C2—C3	−0.9 (2)	C6—C1—N1—O3	−177.46 (17)
N1—C1—C2—C3	178.75 (12)	C2—C1—N1—O3	2.9 (2)
C1—C2—C3—O1	−179.35 (12)	C6—C1—N1—O2	0.8 (2)
C1—C2—C3—C4	1.5 (2)	C2—C1—N1—O2	−178.81 (16)
O1—C3—C4—C5	179.91 (14)	N3—C8—N2—C7	3.86 (18)
C2—C3—C4—C5	−1.0 (2)	N6—C8—N2—C7	−174.73 (12)
C3—C4—C5—C6	−0.2 (3)	N5—C7—N2—C8	177.70 (12)
C4—C5—C6—C1	0.8 (3)	N4—C7—N2—C8	−3.47 (18)
C2—C1—C6—C5	−0.3 (2)	N2—C8—N3—C9	−1.28 (18)
N1—C1—C6—C5	−179.92 (14)	N6—C8—N3—C9	177.32 (12)
C15—C10—C11—C12	−0.4 (3)	N7—C9—N3—C8	179.61 (12)
N8—C10—C11—C12	179.86 (15)	N4—C9—N3—C8	−2.16 (18)
C10—C11—C12—C13	0.1 (3)	N7—C9—N4—C7	−179.26 (12)
C11—C12—C13—C14	−0.1 (3)	N3—C9—N4—C7	2.50 (18)
C12—C13—C14—O4	179.52 (15)	N5—C7—N4—C9	179.35 (12)
C12—C13—C14—C15	0.3 (2)	N2—C7—N4—C9	0.50 (18)
C11—C10—C15—C14	0.6 (2)	C15—C10—N8—O5	0.72 (19)
N8—C10—C15—C14	−179.63 (12)	C11—C10—N8—O5	−179.50 (14)
O4—C14—C15—C10	−179.81 (12)	C15—C10—N8—O6	−177.97 (14)
C13—C14—C15—C10	−0.6 (2)	C11—C10—N8—O6	1.8 (2)

Hydrogen-bond geometry (Å, º)

Cg3 is the centroid of the melamine triamine ring.

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N3^i	0.84 (1)	1.86 (1)	2.6907 (14)	176 (2)
O4—H4A···N2^ii	0.83 (1)	1.87 (1)	2.6876 (14)	170 (2)
N5—H5A···N4^iii	0.89 (1)	2.17 (1)	3.0594 (18)	178 (17)
N5—H5B···O1^iv	0.87 (1)	2.25 (1)	2.9613 (16)	138 (15)
N7—H7A···O1^v	0.88 (1)	2.32 (1)	3.1600 (17)	159 (14)
N7—H7B···O4^vi	0.88 (1)	2.13 (1)	2.9180 (16)	149 (15)
C6—H6···Cg3^vii	0.93	2.95	3.7504 (18)	145

Symmetry codes: (i) −x+1/2, −y+1, z−1/2; (ii) x, −y+3/2, z+1/2; (iii) −x, −y+1, −z+1; (iv) −x, y+1/2, −z+1/2; (v) x, −y+1/2, z+1/2; (vi) x+1/2, y, −z+3/2; (vii) −x+1/2, y−1/2, z.