N-(n-Dec­yl)-4-nitro­aniline

Yonkey, M.M.; Walczak, C.P.; Squattrito, P.J.; Mohanty, D.K.; Kirschbaum, K.

doi:10.1107/S1600536808003310

organic compounds

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ISSN: 2056-9890

Volume 64| Part 3| March 2008| Page o549

doi:10.1107/S1600536808003310

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N-(n-Decyl)-4-nitroaniline

Matthew M. Yonkey,^a Christopher P. Walczak,^a Philip J. Squattrito,^a ^* Dillip K. Mohanty ^a ^* and Kristin Kirschbaum ^b

^aDepartment of Chemistry, Central Michigan University, Mount Pleasant, Michigan 48859, USA, and ^bDepartment of Chemistry, University of Toledo, Toledo, Ohio 43606-3390, USA
^*Correspondence e-mail: p.squattrito@cmich.edu, mohan1dk@cmich.edu

(Received 29 January 2008; accepted 30 January 2008; online 6 February 2008)

N-(n-Decyl)-4-nitroaniline, C₁₆H₂₆N₂O₂, crystallizes with two essentially planar molecules in the asymmetric unit. The decyl chains are fully extended in an anti conformation. The molecules pack in planar layers, within which molecules are linked into chains by two approximately linear N—H⋯O hydrogen bonds between the amine N atom and one O atom of the nitro group of an adjacent molecule. These molecular chains propagate via interleaving of the decyl chains to form the two dimensional sheets. The sheets are associated exclusively via non-bonded contacts. The structure has features in common with those of other N-alkyl-4-nitroanilines, but also subtle differences in packing.

Related literature

For the structures of other N-alkyl-4-nitroanilines, see: Panunto et al. (1987 ); Gangopadhyay et al. (1999 ); Teng et al. (2006 ).

Experimental

Crystal data

C₁₆H₂₆N₂O₂
M_r = 278.39
Monoclinic, P 2₁ /c
a = 13.291 (6) Å
b = 29.117 (12) Å
c = 8.279 (4) Å
β = 91.457 (7)°
V = 3203 (2) Å³
Z = 8
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 140 (2) K
0.40 × 0.35 × 0.28 mm

Data collection

Bruker SMART 6000 CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ; Blessing, 1995 ) T_min = 0.94, T_max = 0.98
28685 measured reflections
6310 independent reflections
4359 reflections with I > 2σ(I)
R_int = 0.041

Refinement

R[F² > 2σ(F²)] = 0.053
wR(F²) = 0.140
S = 1.03
6310 reflections
569 parameters
All H-atom parameters refined
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2N⋯O3ⁱ	0.873 (18)	2.234 (19)	3.101 (2)	171.7 (16)
N4—H4N⋯O1ⁱⁱ	0.869 (19)	2.265 (19)	3.121 (2)	168.3 (17)
Symmetry codes: (i) $[-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (ii) $[-x, y-{\script{1\over 2}}, -z-{\script{1\over 2}}]$ .

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT (Bruker, 2003 ); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: DIAMOND (Brandenberg & Berndt, 2006 ) and Crystal Maker (Crystal Maker, 2006 ); software used to prepare material for publication: SHELTXL and local programs.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808003310/lh2595sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808003310/lh2595Isup2.hkl

checkCIF report

Comment top

Recently we have reported the preparation and characteristics of highly solvent-resistant polyamines containing two aromatic nitro groups in the polymer repeat units (Teng et al., 2006). These polymers were prepared by the nucleophilic displacement of fluorine atoms from 1,5-difluoro-2,4-dinitrobenzene, using aliphatic diamines. The aforementioned solvent resistance of these polymers is a direct consequence of inter- and intrachain hydrogen bonding interactions between the secondary amine and nitro groups in the polymer repeat units. In order to further understand the importance of these interactions, we have undertaken the preparation of polyamines containing one aromatic nitro group in contrast to two such groups. The syntheses and properties of these polymers using both 2,6-difluoronitrobenzene and isomeric 2,4-difluoronitrobenzene, and a series of aliphatic diamines, will be reported elsewhere. In the course of these studies, it was necessary to prepare model compounds prior to the preparation of the polymers. This was accomplished by the reactions of either mono- or difluoro-substituted nitrobenzene with a homologous series of n-alkyl amines. The X-ray crystal structures of N-methyl-4-nitroaniline (Panunto et al., 1987) and N-alkyl-4-nitroanilines with alkyl groups ranging from n-propyl to n-pentyl (Gangopadhyay et al., 1999) have been reported. The N-decyl-4-nitroaniline (I) reported herein represents the longest chain N-alkyl-4-nitroaniline derivative thus far characterized by single-crystal X-ray methods.

The asymmetric unit of the title compound (I) contains two independent molecules which do not differ significantly in conformation (Figure 1). Both molecules are essentially planar and have the decyl tails in the characteristic zigzag anti conformations. The molecules are packed into layers that are parallel to and at the same intervals as the (202) lattice planes (Figure 2). Within each of these layers, the molecules are linked by two N—H···O hydrogen bonds between the amine N atom of one molecule and one of the nitro O atoms of another (Figure 3). As a consequence of these interactions, the N—O bond that participates in the hydrogen bond is about 0.01 Å longer than the other N—O bond on each nitro group. Also, the relative shortness of the H···O interactions and the linearity of the N—H···O bonds (Table 1) clearly demonstrate that these are classic single-acceptor hydrogen bonds, unlike the three-center interactions found in many nitroaniline derivatives including N-methyl-4-nitroaniline (Panunto et al., 1987). The hydrogen bonding links the molecules into chains that run along the 101 direction with the decyl chains on adjacent molecules oriented up and down, with an angle between the chains of about 77°. To complete the two-dimensional layers, these molecular chains then stack along the b axis with the decyl tails interleaved in parallel fashion so as to maximize favorable non-bonded contacts.

The series of N-alkyl-4-nitroanilines where alkyl = propyl-octyl has been examined for potential optical second harmonic generation (SHG) behavior (Gangopadhyay et al., 1999). SHG effects require the absence of a center of inversion, although this condition alone does not guarantee activity. Physical measurements of this series showed that only the butyl compound is active, and single-crystal structure analyses of the propyl, butyl and pentyl derivatives confirmed that only the butyl crystallizes in an noncentrosymmetric space group. The authors report that poor crystal quality prevented structure determinations of the longer chain derivatives, however, our successful crystallization of the decyl compound demonstrates that at least some of these may be characterized. The N—H···O hydrogen bonding in (I) is very similar to that found in the shorter chain analogs in terms of involving only one of the nitro O atoms. The packing in (I) is subtly different. In the propyl and pentyl compounds, the molecules stack in one direction in identical orientation so that both the rings and chains are parallel and in close contact. By contrast, in (I), the layers are staggered so that rings in adjacent layers are not directly over one another but rather have an alkyl chain in between. This indicates that the fully interleaved packing of the decyl chains within the layer, which is unique to (I), is more important than the π-π interactions between the rings in determining the overall packing.

Related literature top

For the structures of other N-alkyl-4-nitroanilines, see: Panunto et al. (1987); Gangopadhyay et al. (1999); Teng et al. (2006).

Experimental top

Anhydrous potassium carbonate (2.0811 g, 0.015 mol) and a solution of 4-nitrofluorobenzene (0.9993 g, 0.007 mol) in 8 ml of dimethyacetamide (DMAC) were combined in a three-necked 100 ml round-bottomed flask, fitted with a nitrogen inlet, a thermometer, a magnetic stirring bar, and a Dean-Stark trap fitted with a condenser. To the clear yellow solution, n-decylamine (1.1767 g, 0.0075 mol) dissolved in DMAC (5 ml) was added with stirring. Additional DMAC (8 ml) was used to wash the transfer container and this was added to the reaction mixture, followed by the addition of 20 ml of toluene. The temperature of the reaction mixture was raised to 403 K, and the reaction was allowed to continue at this temperature for one hour. Water, the by-product of the reaction, was removed via azeotropic distillation with toluene. After the removal of water, toluene was removed via the Dean-Stark trap, and the temperature of the reaction mixture was allowed to rise to 433 K. The reaction was allowed to continue at this temperature for three hours, after which it was allowed to cool to room temperature and then diluted with 20 ml of dichloromethane. The resulting heterogeneous mixture was then filtered through celite at reduced pressure, and the solvents from the filtrate were removed under high vacuum to yield a bright orange liquid residue. This crude product was dissolved in trichloromethane (15 ml), transferred to a separatory funnel, and washed repeatedly with deionized water. The organic layer was collected, dried over anhydrous magnesium sulfate, filtered, and the filtrate was evaporated using a rotary evaporator to yield a bright yellow solid. Crystals suitable for X-ray diffraction were obtained by recrystallization from hexane. Yield 56%, m.p. 332–333 K. IR (KBr, ν > 1400 cm^-1): 3353, 3064, 2952, 2925, 2850, 1602, 1541, 1475, 1466. ¹H NMR [400 MHz, δ p.p.m., CDCl₃], 8.12 (m, 2H), 6.53 (m, 2H), 4.44 (s, 1H), 1.65 (m, 2H), 1.30 (m, 14H), 0.92 (t, 3H). ¹³C NMR [δ, CDCl₃], 153.63, 137.74, 129.69.111.11, 43.66, 32.09, 29.75, 29.54, 29.51, 29.36, 27.21, 22.89, 14.33. MS (M/Z) (% base peak), 278 (11.6), 151 (100), 105 (19.7).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenberg & Berndt, 2006) and Crystal Maker (Crystal Maker, 2006); software used to prepare material for publication: SHELTXL (Sheldrick, 2008) and local programs.

Figures top

	Fig. 1. The asymmetric unit of (I) showing two independent molecules with atom labels and 50% probability displacement ellipsoids for non-hydrogen atoms.
	Fig. 2. Packing diagram of (I) as viewed along the b axis. Note the planar layers parallel to (202).
	Fig. 3. View onto a single layer of molecules with hydrogen bonds shown as dashed lines.

N-(n-Decyl)-4-nitroaniline top

Crystal data top

C₁₆H₂₆N₂O₂	F(000) = 1216
M_r = 278.39	D_x = 1.155 Mg m⁻³
Monoclinic, P2₁/c	Melting point = 332–333 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 13.291 (6) Å	Cell parameters from 950 reflections
b = 29.117 (12) Å	θ = 2.6–25.8°
c = 8.279 (4) Å	µ = 0.08 mm⁻¹
β = 91.457 (7)°	T = 140 K
V = 3203 (2) Å³	Pyramidal, yellow
Z = 8	0.40 × 0.35 × 0.28 mm

Data collection top

Bruker SMART 6000 CCD diffractometer	6310 independent reflections
Radiation source: fine-focus sealed tube	4359 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.041
ω scans	θ_max = 26.1°, θ_min = 1.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995)	h = −16→16
T_min = 0.94, T_max = 0.98	k = −32→35
28685 measured reflections	l = −10→10

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)] = 0.053	Hydrogen site location: difference Fourier map
wR(F²) = 0.140	All H-atom parameters refined
S = 1.03	w = 1/[σ²(F_o²) + (0.0796P)² + 0.231P] where P = (F_o² + 2F_c²)/3
6310 reflections	(Δ/σ)_max = 0.001
569 parameters	Δρ_max = 0.19 e Å⁻³
0 restraints	Δρ_min = −0.26 e Å⁻³

Crystal data top

C₁₆H₂₆N₂O₂	V = 3203 (2) Å³
M_r = 278.39	Z = 8
Monoclinic, P2₁/c	Mo Kα radiation
a = 13.291 (6) Å	µ = 0.08 mm⁻¹
b = 29.117 (12) Å	T = 140 K
c = 8.279 (4) Å	0.40 × 0.35 × 0.28 mm
β = 91.457 (7)°

Data collection top

Bruker SMART 6000 CCD diffractometer	6310 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995)	4359 reflections with I > 2σ(I)
T_min = 0.94, T_max = 0.98	R_int = 0.041
28685 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.053	0 restraints
wR(F²) = 0.140	All H-atom parameters refined
S = 1.03	Δρ_max = 0.19 e Å⁻³
6310 reflections	Δρ_min = −0.26 e Å⁻³
569 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
O1	−0.60160 (9)	0.67377 (4)	−0.86284 (15)	0.0412 (3)
O2	−0.67258 (9)	0.60818 (4)	−0.90706 (16)	0.0453 (4)
O3	1.10779 (9)	0.09460 (4)	0.85523 (15)	0.0406 (3)
O4	1.17105 (10)	0.16069 (4)	0.91774 (17)	0.0484 (4)
N1	−0.60284 (10)	0.63137 (5)	−0.85126 (16)	0.0302 (3)
N2	−0.27827 (10)	0.54358 (5)	−0.54454 (16)	0.0295 (3)
N3	1.10435 (10)	0.13712 (5)	0.85407 (16)	0.0320 (3)
N4	0.77760 (11)	0.22343 (5)	0.54846 (17)	0.0312 (3)
C1	−0.51989 (11)	0.60874 (6)	−0.77006 (18)	0.0256 (4)
C2	−0.51950 (12)	0.56106 (6)	−0.75980 (19)	0.0276 (4)
C3	−0.44015 (12)	0.53898 (6)	−0.68323 (19)	0.0265 (4)
C4	−0.35872 (11)	0.56424 (5)	−0.61648 (18)	0.0246 (4)
C5	−0.36234 (12)	0.61265 (6)	−0.62760 (19)	0.0274 (4)
C6	−0.44100 (12)	0.63459 (6)	−0.70329 (19)	0.0273 (4)
C7	−0.26796 (13)	0.49425 (6)	−0.5227 (2)	0.0283 (4)
C8	−0.16565 (13)	0.48362 (6)	−0.4446 (2)	0.0300 (4)
C9	−0.14962 (13)	0.43315 (6)	−0.4047 (2)	0.0295 (4)
C10	−0.04873 (13)	0.42560 (6)	−0.3167 (2)	0.0317 (4)
C11	−0.02331 (13)	0.37619 (6)	−0.2754 (2)	0.0292 (4)
C12	0.07786 (13)	0.37202 (6)	−0.1859 (2)	0.0296 (4)
C13	0.10972 (13)	0.32300 (6)	−0.1464 (2)	0.0290 (4)
C14	0.20989 (13)	0.31956 (6)	−0.0544 (2)	0.0310 (4)
C15	0.24269 (14)	0.27065 (6)	−0.0180 (2)	0.0354 (4)
C16	0.34653 (16)	0.26753 (8)	0.0615 (3)	0.0499 (6)
C17	1.01992 (12)	0.15945 (6)	0.77582 (18)	0.0271 (4)
C18	1.01434 (12)	0.20703 (6)	0.77712 (19)	0.0289 (4)
C19	0.93436 (12)	0.22876 (6)	0.70194 (19)	0.0289 (4)
C20	0.85730 (11)	0.20307 (6)	0.62333 (18)	0.0264 (4)
C21	0.86534 (12)	0.15453 (6)	0.62463 (19)	0.0283 (4)
C22	0.94510 (12)	0.13317 (6)	0.69935 (19)	0.0275 (4)
C23	0.76177 (13)	0.27270 (6)	0.5393 (2)	0.0295 (4)
C24	0.66360 (13)	0.28244 (6)	0.4467 (2)	0.0312 (4)
C25	0.64562 (13)	0.33306 (6)	0.4121 (2)	0.0297 (4)
C26	0.54838 (13)	0.34037 (6)	0.3138 (2)	0.0310 (4)
C27	0.52284 (13)	0.39032 (6)	0.2770 (2)	0.0307 (4)
C28	0.42175 (13)	0.39529 (6)	0.1880 (2)	0.0294 (4)
C29	0.39176 (13)	0.44438 (6)	0.1484 (2)	0.0286 (4)
C30	0.29031 (13)	0.44809 (6)	0.0593 (2)	0.0292 (4)
C31	0.26026 (14)	0.49683 (6)	0.0147 (2)	0.0323 (4)
C32	0.15712 (16)	0.49976 (7)	−0.0678 (3)	0.0420 (5)
H2N	−0.2325 (13)	0.5606 (6)	−0.496 (2)	0.032 (5)*
H2	−0.5723 (13)	0.5437 (6)	−0.8041 (19)	0.027 (4)*
H3	−0.4412 (13)	0.5071 (7)	−0.679 (2)	0.035 (5)*
H4N	0.7319 (14)	0.2059 (7)	0.504 (2)	0.037 (5)*
H5	−0.3087 (13)	0.6296 (6)	−0.5867 (19)	0.030 (5)*
H6	−0.4425 (13)	0.6666 (7)	−0.7100 (19)	0.031 (5)*
H7B	−0.3219 (13)	0.4826 (6)	−0.453 (2)	0.031 (4)*
H7A	−0.2746 (12)	0.4790 (6)	−0.630 (2)	0.027 (4)*
H8B	−0.1144 (13)	0.4933 (6)	−0.519 (2)	0.034 (5)*
H8A	−0.1593 (13)	0.5016 (6)	−0.347 (2)	0.039 (5)*
H9B	−0.2026 (13)	0.4221 (6)	−0.334 (2)	0.035 (5)*
H9A	−0.1528 (12)	0.4146 (6)	−0.507 (2)	0.033 (5)*
H10B	0.0036 (13)	0.4388 (6)	−0.385 (2)	0.034 (5)*
H10A	−0.0496 (13)	0.4451 (6)	−0.220 (2)	0.038 (5)*
H11B	−0.0757 (13)	0.3637 (6)	−0.205 (2)	0.030 (4)*
H11A	−0.0216 (12)	0.3566 (6)	−0.376 (2)	0.033 (5)*
H12B	0.1303 (13)	0.3863 (6)	−0.251 (2)	0.035 (5)*
H12A	0.0726 (12)	0.3896 (6)	−0.083 (2)	0.031 (4)*
H13B	0.0577 (13)	0.3094 (6)	−0.083 (2)	0.033 (5)*
H13A	0.1142 (12)	0.3066 (6)	−0.246 (2)	0.036 (5)*
H14B	0.2036 (12)	0.3372 (6)	0.047 (2)	0.031 (4)*
H14A	0.2602 (14)	0.3339 (6)	−0.121 (2)	0.044 (5)*
H15B	0.2401 (15)	0.2530 (7)	−0.116 (3)	0.054 (6)*
H15A	0.1955 (14)	0.2567 (6)	0.052 (2)	0.039 (5)*
H16C	0.3993 (16)	0.2807 (8)	−0.007 (3)	0.064 (7)*
H16B	0.3464 (18)	0.2856 (9)	0.166 (3)	0.079 (8)*
H16A	0.3665 (16)	0.2361 (9)	0.085 (3)	0.063 (7)*
H18	1.0663 (14)	0.2236 (6)	0.829 (2)	0.037 (5)*
H19	0.9313 (13)	0.2604 (7)	0.705 (2)	0.038 (5)*
H21	0.8145 (13)	0.1366 (6)	0.578 (2)	0.036 (5)*
H22	0.9501 (12)	0.1018 (6)	0.6989 (18)	0.021 (4)*
H23A	0.7597 (13)	0.2854 (6)	0.650 (2)	0.035 (5)*
H23B	0.8176 (12)	0.2866 (6)	0.4814 (19)	0.026 (4)*
H24A	0.6678 (13)	0.2668 (6)	0.346 (2)	0.035 (5)*
H24B	0.6091 (13)	0.2712 (6)	0.511 (2)	0.037 (5)*
H25A	0.6444 (12)	0.3504 (6)	0.512 (2)	0.029 (4)*
H25B	0.7028 (14)	0.3458 (6)	0.351 (2)	0.041 (5)*
H26B	0.5542 (13)	0.3223 (6)	0.212 (2)	0.038 (5)*
H26A	0.4937 (14)	0.3258 (6)	0.375 (2)	0.039 (5)*
H27A	0.5216 (13)	0.4080 (6)	0.380 (2)	0.035 (5)*
H27B	0.5763 (14)	0.4048 (6)	0.210 (2)	0.035 (5)*
H28B	0.3706 (13)	0.3813 (6)	0.257 (2)	0.032 (5)*
H28A	0.4228 (13)	0.3761 (6)	0.087 (2)	0.037 (5)*
H29B	0.4433 (13)	0.4581 (6)	0.0850 (19)	0.034 (5)*
H29A	0.3906 (12)	0.4617 (6)	0.252 (2)	0.030 (4)*
H30B	0.2386 (13)	0.4343 (6)	0.131 (2)	0.033 (5)*
H30A	0.2948 (13)	0.4291 (6)	−0.039 (2)	0.034 (5)*
H31B	0.2590 (13)	0.5154 (6)	0.110 (2)	0.031 (4)*
H31A	0.3098 (14)	0.5093 (7)	−0.057 (2)	0.045 (5)*
H32C	0.1556 (15)	0.4806 (7)	−0.168 (2)	0.054 (6)*
H32B	0.1019 (17)	0.4875 (8)	0.003 (3)	0.066 (7)*
H32A	0.1373 (15)	0.5321 (8)	−0.101 (2)	0.057 (6)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0429 (8)	0.0236 (7)	0.0564 (8)	0.0058 (5)	−0.0149 (6)	0.0077 (6)
O2	0.0334 (7)	0.0367 (8)	0.0647 (9)	−0.0033 (6)	−0.0236 (6)	0.0049 (6)
O3	0.0417 (7)	0.0266 (8)	0.0528 (8)	0.0096 (6)	−0.0097 (6)	0.0047 (6)
O4	0.0381 (8)	0.0369 (8)	0.0688 (9)	−0.0005 (6)	−0.0288 (7)	0.0033 (6)
N1	0.0289 (8)	0.0277 (9)	0.0339 (7)	0.0015 (6)	−0.0054 (6)	0.0025 (6)
N2	0.0261 (8)	0.0215 (8)	0.0402 (8)	−0.0022 (6)	−0.0109 (6)	0.0010 (6)
N3	0.0307 (8)	0.0276 (9)	0.0373 (8)	0.0045 (7)	−0.0060 (6)	0.0035 (6)
N4	0.0268 (8)	0.0247 (8)	0.0416 (8)	0.0013 (6)	−0.0113 (6)	−0.0014 (6)
C1	0.0257 (8)	0.0236 (9)	0.0273 (8)	0.0026 (7)	−0.0036 (7)	0.0023 (6)
C2	0.0243 (9)	0.0242 (10)	0.0340 (9)	−0.0036 (7)	−0.0044 (7)	−0.0016 (7)
C3	0.0274 (9)	0.0175 (9)	0.0345 (9)	0.0004 (7)	−0.0048 (7)	0.0010 (7)
C4	0.0229 (8)	0.0241 (9)	0.0265 (8)	0.0007 (7)	−0.0023 (6)	0.0011 (6)
C5	0.0258 (9)	0.0252 (10)	0.0308 (9)	−0.0049 (7)	−0.0039 (7)	−0.0005 (7)
C6	0.0318 (9)	0.0195 (9)	0.0304 (8)	−0.0006 (7)	−0.0015 (7)	0.0011 (7)
C7	0.0263 (9)	0.0216 (9)	0.0367 (9)	0.0006 (7)	−0.0049 (7)	0.0015 (7)
C8	0.0287 (9)	0.0241 (9)	0.0369 (10)	0.0006 (7)	−0.0060 (8)	0.0031 (8)
C9	0.0285 (9)	0.0231 (9)	0.0366 (10)	0.0006 (7)	−0.0039 (8)	0.0009 (7)
C10	0.0305 (9)	0.0235 (10)	0.0408 (10)	0.0002 (7)	−0.0062 (8)	0.0019 (8)
C11	0.0294 (9)	0.0237 (10)	0.0343 (9)	0.0020 (7)	−0.0033 (8)	0.0017 (7)
C12	0.0300 (9)	0.0216 (9)	0.0371 (9)	−0.0001 (7)	−0.0032 (8)	0.0031 (7)
C13	0.0293 (9)	0.0222 (9)	0.0352 (9)	0.0014 (7)	−0.0028 (7)	0.0016 (7)
C14	0.0286 (9)	0.0254 (10)	0.0388 (10)	0.0008 (7)	−0.0028 (8)	0.0050 (8)
C15	0.0352 (10)	0.0241 (10)	0.0466 (11)	0.0016 (8)	−0.0081 (9)	0.0049 (8)
C16	0.0400 (12)	0.0368 (13)	0.0719 (16)	0.0049 (10)	−0.0178 (11)	0.0130 (11)
C17	0.0253 (9)	0.0258 (10)	0.0301 (8)	0.0034 (7)	−0.0029 (7)	0.0031 (7)
C18	0.0263 (9)	0.0258 (10)	0.0343 (9)	−0.0030 (7)	−0.0076 (7)	0.0007 (7)
C19	0.0300 (9)	0.0204 (10)	0.0361 (9)	0.0009 (7)	−0.0056 (7)	0.0008 (7)
C20	0.0238 (8)	0.0276 (10)	0.0277 (8)	0.0030 (7)	−0.0014 (6)	0.0017 (6)
C21	0.0260 (9)	0.0261 (10)	0.0325 (9)	−0.0031 (7)	−0.0041 (7)	−0.0024 (7)
C22	0.0312 (9)	0.0179 (10)	0.0334 (9)	0.0018 (7)	−0.0011 (7)	−0.0002 (7)
C23	0.0292 (9)	0.0250 (10)	0.0339 (9)	0.0028 (7)	−0.0046 (7)	0.0013 (7)
C24	0.0285 (9)	0.0277 (10)	0.0372 (10)	0.0030 (7)	−0.0039 (8)	−0.0004 (8)
C25	0.0291 (9)	0.0269 (10)	0.0330 (9)	0.0042 (7)	−0.0027 (7)	−0.0012 (7)
C26	0.0330 (10)	0.0255 (10)	0.0342 (9)	0.0049 (8)	−0.0056 (8)	−0.0015 (7)
C27	0.0315 (10)	0.0262 (10)	0.0342 (9)	0.0030 (7)	−0.0042 (8)	0.0003 (7)
C28	0.0325 (9)	0.0231 (9)	0.0323 (9)	0.0025 (7)	−0.0053 (7)	−0.0004 (7)
C29	0.0299 (9)	0.0234 (10)	0.0322 (9)	0.0001 (7)	−0.0041 (7)	−0.0003 (7)
C30	0.0315 (9)	0.0212 (9)	0.0344 (9)	0.0002 (7)	−0.0056 (8)	0.0004 (7)
C31	0.0352 (10)	0.0239 (10)	0.0374 (10)	0.0016 (8)	−0.0067 (8)	−0.0018 (8)
C32	0.0398 (11)	0.0317 (12)	0.0536 (12)	0.0067 (9)	−0.0155 (9)	−0.0001 (9)

Geometric parameters (Å, º) top

O1—N1	1.2383 (18)	C15—C16	1.516 (3)
O2—N1	1.2275 (17)	C15—H15B	0.96 (2)
O3—N3	1.2389 (19)	C15—H15A	0.954 (19)
O4—N3	1.2293 (18)	C16—H16C	0.99 (2)
N1—C1	1.437 (2)	C16—H16B	1.01 (2)
N2—C4	1.352 (2)	C16—H16A	0.97 (2)
N2—C7	1.454 (2)	C17—C18	1.387 (2)
N2—H2N	0.873 (18)	C17—C22	1.394 (2)
N3—C17	1.437 (2)	C18—C19	1.373 (2)
N4—C20	1.351 (2)	C18—H18	0.938 (19)
N4—C23	1.452 (2)	C19—C20	1.414 (2)
N4—H4N	0.869 (19)	C19—H19	0.92 (2)
C1—C2	1.391 (2)	C20—C21	1.417 (2)
C1—C6	1.394 (2)	C21—C22	1.364 (2)
C2—C3	1.376 (2)	C21—H21	0.930 (18)
C2—H2	0.933 (17)	C22—H22	0.916 (18)
C3—C4	1.410 (2)	C23—C24	1.523 (2)
C3—H3	0.930 (19)	C23—H23A	0.987 (17)
C4—C5	1.413 (2)	C23—H23B	0.982 (17)
C5—C6	1.364 (2)	C24—C25	1.519 (2)
C5—H5	0.924 (17)	C24—H24A	0.957 (18)
C6—H6	0.935 (19)	C24—H24B	0.966 (18)
C7—C8	1.523 (2)	C25—C26	1.524 (2)
C7—H7B	0.989 (17)	C25—H25A	0.970 (17)
C7—H7A	0.997 (16)	C25—H25B	0.995 (19)
C8—C9	1.520 (2)	C26—C27	1.522 (2)
C8—H8B	0.973 (18)	C26—H26B	1.000 (18)
C8—H8A	0.965 (18)	C26—H26A	0.992 (18)
C9—C10	1.526 (2)	C27—C28	1.523 (2)
C9—H9B	0.982 (18)	C27—H27A	0.999 (18)
C9—H9A	1.002 (17)	C27—H27B	1.003 (18)
C10—C11	1.515 (2)	C28—C29	1.518 (2)
C10—H10B	0.986 (17)	C28—H28B	0.988 (17)
C10—H10A	0.984 (18)	C28—H28A	1.008 (17)
C11—C12	1.524 (2)	C29—C30	1.524 (2)
C11—H11B	0.989 (17)	C29—H29B	0.961 (18)
C11—H11A	1.012 (17)	C29—H29A	0.995 (17)
C12—C13	1.522 (2)	C30—C31	1.518 (2)
C12—H12B	0.985 (18)	C30—H30B	1.003 (17)
C12—H12A	1.000 (17)	C30—H30A	0.983 (18)
C13—C14	1.520 (2)	C31—C32	1.518 (3)
C13—H13B	0.964 (17)	C31—H31B	0.957 (17)
C13—H13A	0.959 (18)	C31—H31A	0.968 (19)
C14—C15	1.517 (3)	C32—H32C	1.00 (2)
C14—H14B	0.988 (17)	C32—H32B	1.02 (2)
C14—H14A	0.973 (19)	C32—H32A	1.01 (2)

O2—N1—O1	122.05 (13)	C15—C16—H16C	112.1 (12)
O2—N1—C1	119.14 (14)	C15—C16—H16B	108.6 (14)
O1—N1—C1	118.81 (13)	H16C—C16—H16B	107.8 (19)
C4—N2—C7	124.44 (14)	C15—C16—H16A	112.5 (13)
C4—N2—H2N	119.0 (12)	H16C—C16—H16A	106.6 (18)
C7—N2—H2N	116.1 (12)	H16B—C16—H16A	109.1 (19)
O4—N3—O3	121.91 (14)	C18—C17—C22	120.94 (14)
O4—N3—C17	119.14 (15)	C18—C17—N3	119.32 (14)
O3—N3—C17	118.95 (14)	C22—C17—N3	119.74 (15)
C20—N4—C23	124.66 (15)	C19—C18—C17	119.84 (15)
C20—N4—H4N	118.1 (12)	C19—C18—H18	121.6 (11)
C23—N4—H4N	117.3 (12)	C17—C18—H18	118.6 (11)
C2—C1—C6	120.88 (14)	C18—C19—C20	120.58 (16)
C2—C1—N1	119.20 (14)	C18—C19—H19	118.8 (11)
C6—C1—N1	119.91 (15)	C20—C19—H19	120.6 (11)
C3—C2—C1	119.74 (15)	N4—C20—C19	121.98 (16)
C3—C2—H2	119.2 (11)	N4—C20—C21	119.95 (15)
C1—C2—H2	121.1 (10)	C19—C20—C21	118.07 (14)
C2—C3—C4	120.57 (16)	C22—C21—C20	121.05 (15)
C2—C3—H3	118.2 (11)	C22—C21—H21	118.6 (11)
C4—C3—H3	121.2 (11)	C20—C21—H21	120.3 (11)
N2—C4—C3	122.09 (15)	C21—C22—C17	119.53 (16)
N2—C4—C5	119.85 (14)	C21—C22—H22	120.5 (10)
C3—C4—C5	118.06 (14)	C17—C22—H22	119.9 (10)
C6—C5—C4	121.42 (15)	N4—C23—C24	109.36 (14)
C6—C5—H5	119.6 (11)	N4—C23—H23A	109.2 (10)
C4—C5—H5	119.0 (11)	C24—C23—H23A	110.7 (10)
C5—C6—C1	119.31 (16)	N4—C23—H23B	108.9 (10)
C5—C6—H6	120.6 (11)	C24—C23—H23B	109.0 (9)
C1—C6—H6	120.0 (11)	H23A—C23—H23B	109.7 (14)
N2—C7—C8	109.51 (13)	C25—C24—C23	113.85 (14)
N2—C7—H7B	110.0 (10)	C25—C24—H24A	108.0 (11)
C8—C7—H7B	109.6 (10)	C23—C24—H24A	106.4 (11)
N2—C7—H7A	108.8 (9)	C25—C24—H24B	108.5 (10)
C8—C7—H7A	110.3 (9)	C23—C24—H24B	107.9 (10)
H7B—C7—H7A	108.5 (13)	H24A—C24—H24B	112.3 (15)
C9—C8—C7	114.04 (14)	C24—C25—C26	111.31 (14)
C9—C8—H8B	108.7 (10)	C24—C25—H25A	110.4 (10)
C7—C8—H8B	107.6 (10)	C26—C25—H25A	110.5 (10)
C9—C8—H8A	109.4 (11)	C24—C25—H25B	109.9 (11)
C7—C8—H8A	107.7 (11)	C26—C25—H25B	108.9 (10)
H8B—C8—H8A	109.2 (15)	H25A—C25—H25B	105.6 (14)
C8—C9—C10	111.07 (14)	C27—C26—C25	114.96 (14)
C8—C9—H9B	110.3 (10)	C27—C26—H26B	110.8 (10)
C10—C9—H9B	107.6 (10)	C25—C26—H26B	107.1 (10)
C8—C9—H9A	109.6 (10)	C27—C26—H26A	110.3 (11)
C10—C9—H9A	110.0 (10)	C25—C26—H26A	106.8 (10)
H9B—C9—H9A	108.1 (14)	H26B—C26—H26A	106.4 (14)
C11—C10—C9	115.65 (14)	C26—C27—C28	112.15 (14)
C11—C10—H10B	110.1 (10)	C26—C27—H27A	109.2 (10)
C9—C10—H10B	107.1 (10)	C28—C27—H27A	109.4 (10)
C11—C10—H10A	111.7 (11)	C26—C27—H27B	110.7 (10)
C9—C10—H10A	106.2 (10)	C28—C27—H27B	108.9 (10)
H10B—C10—H10A	105.6 (14)	H27A—C27—H27B	106.4 (14)
C10—C11—C12	111.98 (14)	C29—C28—C27	114.68 (14)
C10—C11—H11B	109.0 (10)	C29—C28—H28B	109.4 (10)
C12—C11—H11B	108.0 (9)	C27—C28—H28B	106.9 (9)
C10—C11—H11A	111.0 (10)	C29—C28—H28A	110.6 (10)
C12—C11—H11A	108.6 (9)	C27—C28—H28A	108.6 (10)
H11B—C11—H11A	108.1 (14)	H28B—C28—H28A	106.2 (14)
C13—C12—C11	114.60 (14)	C28—C29—C30	113.29 (14)
C13—C12—H12B	108.4 (10)	C28—C29—H29B	108.8 (11)
C11—C12—H12B	109.0 (10)	C30—C29—H29B	109.9 (10)
C13—C12—H12A	108.7 (10)	C28—C29—H29A	107.5 (9)
C11—C12—H12A	107.2 (10)	C30—C29—H29A	110.4 (9)
H12B—C12—H12A	108.7 (14)	H29B—C29—H29A	106.7 (14)
C14—C13—C12	113.87 (14)	C31—C30—C29	114.08 (14)
C14—C13—H13B	109.3 (10)	C31—C30—H30B	109.7 (10)
C12—C13—H13B	107.6 (10)	C29—C30—H30B	107.2 (9)
C14—C13—H13A	109.1 (10)	C31—C30—H30A	110.2 (10)
C12—C13—H13A	107.7 (11)	C29—C30—H30A	106.7 (10)
H13B—C13—H13A	109.2 (14)	H30B—C30—H30A	108.7 (14)
C15—C14—C13	113.89 (15)	C30—C31—C32	113.01 (15)
C15—C14—H14B	110.5 (10)	C30—C31—H31B	109.7 (10)
C13—C14—H14B	107.4 (10)	C32—C31—H31B	107.8 (10)
C15—C14—H14A	108.6 (11)	C30—C31—H31A	108.8 (12)
C13—C14—H14A	107.0 (11)	C32—C31—H31A	108.9 (11)
H14B—C14—H14A	109.4 (15)	H31B—C31—H31A	108.6 (16)
C16—C15—C14	113.34 (16)	C31—C32—H32C	110.0 (12)
C16—C15—H15B	110.3 (12)	C31—C32—H32B	112.1 (12)
C14—C15—H15B	109.3 (12)	H32C—C32—H32B	106.6 (17)
C16—C15—H15A	108.5 (11)	C31—C32—H32A	113.5 (12)
C14—C15—H15A	109.2 (11)	H32C—C32—H32A	106.9 (16)
H15B—C15—H15A	106.0 (17)	H32B—C32—H32A	107.3 (17)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2N···O3ⁱ	0.873 (18)	2.234 (19)	3.101 (2)	171.7 (16)
N4—H4N···O1ⁱⁱ	0.869 (19)	2.265 (19)	3.121 (2)	168.3 (17)

Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x, y−1/2, −z−1/2.

Experimental details

Crystal data
Chemical formula	C₁₆H₂₆N₂O₂
M_r	278.39
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	140
a, b, c (Å)	13.291 (6), 29.117 (12), 8.279 (4)
β (°)	91.457 (7)
V (Å³)	3203 (2)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.40 × 0.35 × 0.28

Data collection
Diffractometer	Bruker SMART 6000 CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996; Blessing, 1995)
T_min, T_max	0.94, 0.98
No. of measured, independent and observed [I > 2σ(I)] reflections	28685, 6310, 4359
R_int	0.041
(sin θ/λ)_max (Å⁻¹)	0.618

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.053, 0.140, 1.03
No. of reflections	6310
No. of parameters	569
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.19, −0.26

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2003), SHELXTL (Sheldrick, 2008), DIAMOND (Brandenberg & Berndt, 2006) and Crystal Maker (Crystal Maker, 2006), SHELTXL (Sheldrick, 2008) and local programs.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2N···O3ⁱ	0.873 (18)	2.234 (19)	3.101 (2)	171.7 (16)
N4—H4N···O1ⁱⁱ	0.869 (19)	2.265 (19)	3.121 (2)	168.3 (17)

Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x, y−1/2, −z−1/2.

Acknowledgements

DKM acknowledges financial support for this project from the Research Excellence Fund of Michigan and a President's Bridge to Commercialization Grant from Central Michigan University. We thank the College of Arts and Sciences of the University of Toledo and the Ohio Board of Regents for generous financial support of the X-ray diffraction facility.

References

Blessing, R. H. (1995). Acta Cryst. A51, 33–38. CrossRef CAS Web of Science IUCr Journals Google Scholar
Brandenberg, K. & Berndt, M. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2001). SMART. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2003). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Crystal Maker (2006). Crystal Maker. Crystal Maker Software, Yarnton, England. Google Scholar
Gangopadhyay, P., Venugopal Rao, S., Narayana Rao, D. & Radhakrishnan, T. P. (1999). J. Mater. Chem. 9, 1699–1705. Web of Science CSD CrossRef CAS Google Scholar
Panunto, T. W., Urbanczyk-Lipkowska, Z., Johnson, R. & Etter, M. C. (1987). J. Amer. Chem. Soc. 109, 7786–7797. CSD CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Teng, Y. H., Kaminski, G., Zhang, Z., Sharma, A. & Mohanty, D. K. (2006). Polymer, 47, 4004–4011. Web of Science CrossRef CAS Google Scholar