N,N,N′-Trimethyl-N′′-(4-nitro­phen­yl)-N′-phenyl­guanidine

Ioannis Tiritiris; Wolfgang Frey; Willi Kantlehner

doi:10.1107/S160053681400693X

. 2014 Apr 5;70(Pt 5):o516–o517. doi: 10.1107/S160053681400693X

N,N,N′-Trimethyl-N′′-(4-nitrophenyl)-N′-phenylguanidine

Ioannis Tiritiris ^a, Wolfgang Frey ^b, Willi Kantlehner ^a,^*

PMCID: PMC4011204 PMID: 24860331

Abstract

The C—N bond lengths in the guanidine unit of the title compound, C₁₆H₁₈N₄O₂, are 1.298 (2), 1.353 (2) and 1.401 (3) Å, indicating double- and single-bond character. The N—C—N angles are 115.81 (16), 118.90 (18) and 125.16 (18)°, showing a deviation of the CN₃ plane from an ideal trigonal–planar geometry. In the crystal, C—H⋯O hydrogen bonds are observed between the methyl- and aromatic-H atoms and nitro-O atoms. One H atom of the phenyl ring and of the NMe₂ group associate with the O atoms of the nitro group, giving chains along the a- and b-axis directions. Cross-linking of these two chains results in a two-dimensional network along bc.

Related literature

For the synthesis and characterization of compounds for blue OLEDs, see: Agarwal et al. (2011 ▶). For the crystal structures of N-methylated diphenylguanidines, see: Tanatani et al. (1998 ▶). For non-classical hydrogen bonds, see: Desiraju & Steiner (1999 ▶). For the crystal structure of N′′-(4-carbazol-9-yl-phenyl)-N,N′-diethyl-N,N′-diphenylguanidine, see: Tiritiris & Kantlehner (2013 ▶), and of N′′-(4-methoxyphenyl)-N,N,N′-trimethyl-N′-phenylguanidine, see: Tiritiris et al. (2014 ▶).

Experimental

Crystal data

C₁₆H₁₈N₄O₂
M _r = 298.34
Monoclinic,
a = 18.409 (2) Å
b = 7.7140 (8) Å
c = 22.493 (3) Å
β = 109.503 (7)°
V = 3010.9 (6) Å³
Z = 8
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.35 × 0.25 × 0.20 mm

Data collection

Nicolet P3/F diffractometer
2974 measured reflections
2974 independent reflections
2237 reflections with I > 2σ(I)
3 standard reflections every 50 reflections intensity decay: 3%

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.124
S = 1.06
2974 reflections
203 parameters
H-atom parameters constrained
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: XSCANS (Siemens, 1996 ▶); cell refinement: XSCANS; data reduction: SHELXTL (Sheldrick, 2008 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S160053681400693X/nr2049sup1.cif

e-70-0o516-sup1.cif^{(24KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681400693X/nr2049Isup2.hkl

e-70-0o516-Isup2.hkl^{(146.1KB, hkl)}

Click here for additional data file.^{(6.2KB, cml)}

Supporting information file. DOI: 10.1107/S160053681400693X/nr2049Isup3.cml

CCDC reference: 994178

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C12—H12⋯O2ⁱ	0.93	2.49	3.416 (3)	173
C2—H2A⋯O1ⁱⁱ	0.96	2.72	3.064 (3)	102

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The authors thank Dr B. Iliev (IoLiTec GmbH) for the synthesis of the title compound.

supplementary crystallographic information

1. Comment

We were interested in the synthesis and characterization of aromatic guanidines to examine their suitability in OLEDs (Agarwal et al., 2011). Because the crystal structure of the title compound was not known so far, it was decided to carry out an appropriate investigation. According to the structure analysis, the C1–N3 bond in the guanidine unit is 1.298 (2) Å, indicating double bond character. The bond lengths C1–N2 = 1.401 (3) Å and C1–N1 = 1.353 (2) Å are elongated and characteristic for C–N imine single bonds. The N–C1–N angles are 115.81 (16)° (N1–C1–N2), 125.16 (18)° (N2–C1–N3) and 118.90 (18)° (N1–C1–N3), showing a deviation of the CN₃ plane from an ideal trigonal planar geometry (Fig. 1). Similar bond lengths and angles of the guanidine CN₃ part have been found by structure analysis for N''-(4-Carbazol-9-yl-phenyl)- N,N'-diethyl-N,N'-diphenyl-guanidine (Tiritiris & Kantlehner, 2013), several N-methylated diphenylguanidines (Tanatani et al., 1998) and N''- (4-methoxyphenyl)-N,N,N'-trimethyl-N'- phenylguanidine (Tiritiris et al., 2014). Non-classical C–H···O hydrogen bonds (Desiraju & Steiner, 1999) between methyl hydrogen atoms, aromatic hydrogen atoms and oxygen atoms of the nitro groups are present [d(H···O) = 2.49 and 2.72 Å] (Tab. 1). One hydrogen atom of the phenyl ring (H12) is associated with the oxygen atom (O2) of the nitro group, resulting in chains along the b axis. A second hydrogen atom of the NMe₂ group (H2A) is connected with O1, giving chains along the a axis. By crosslinking of both chains, a two-dimensional network along bc results (Fig. 2).

2. Experimental

One equivalent of N,N-dimethyl-N',N'-methylphenyl- chloroformamidinium-chloride (synthesized from N,N-dimethyl- N',N'-methylphenylthiourea and phosgene) was reacted with one equivalent of 4-nitroaniline (Sigma-Aldrich) in acetonitrile, in the presence of one equivalent triethylamine, at 273 K. The obtained mixture consisting of the guanidinium chloride and triethylammonium chloride was reacted in the next step with an excess of an aqueous sodium hydroxide solution at 273 K. After extraction of the guanidine with diethyl ether from the water phase, the solvent was evaporated and the title compound was isolated in form of a colourless solid. Single crystals have been obtained by recrystallization from a saturated acetonitrile solution at room temperature.