N,N,N′,N′-Tetra­methyl-N′′-[2-(N′,N′,N′′,N′′-tetra­methyl­guanidino)eth­yl]guanidine

Tiritiris, I.; Kantlehner, W.

doi:10.1107/S1600536812027079

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 7| July 2012| Page o2161

https://doi.org/10.1107/S1600536812027079

Open

access

N,N,N′,N′-Tetramethyl-N′′-[2-(N′,N′,N′′,N′′-tetramethylguanidino)ethyl]guanidine

Ioannis Tiritiris ^a and Willi Kantlehner ^b ^*

^aInstitut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany, and ^bFakultät Chemie/Organische Chemie, Hochschule Aalen, Beethovenstrasse 1, D-73430 Aalen, Germany
^*Correspondence e-mail: willi.kantlehner@htw-aalen.de

(Received 11 June 2012; accepted 14 June 2012; online 20 June 2012)

The title compound, C₁₂H₂₈N₆, is located about an inversion center situated at the center of the —CH₂—CH₂— bond. The C—N bond lengths are 1.285 (2), 1.384 (2) and 1.395 (1) Å, indicating double- and single-bond character. The N—C—N angles are 114.1 (1), 119.3 (1) and 126.5 (1)°, showing a deviation of both CN₃ planes from an ideal trigonal–planar geometry.

Related literature

For the crystal structure of N,N,N′,N′-tetramethylchloroformamidinium-chloride, see: Tiritiris & Kantlehner (2008 ). For the synthesis of N,N,N′,N′-tetramethyl-N′′-[2-(N′,N′,N′′,N′′-tetramethylguanidino)-ethyl]-guanidine and the crystal structure of the corresponding diprotonated bisguanidinium dichloride salt, see: Wittmann et al. (2000 ). For the synthesis and characterization of bisguanidine–copper complexes, see: Bienemann et al. (2010 ).

Experimental

Crystal data

C₁₂H₂₈N₆
M_r = 256.40
Monoclinic, P 2₁ /n
a = 8.4189 (6) Å
b = 8.5894 (6) Å
c = 11.0089 (8) Å
β = 106.858 (5)°
V = 761.88 (10) Å³
Z = 2
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 293 K
0.22 × 0.18 × 0.15 mm

Data collection

Bruker–Nonius KappaCCD diffractometer
7247 measured reflections
1835 independent reflections
1120 reflections with I > 2σ(I)
R_int = 0.043

Refinement

R[F² > 2σ(F²)] = 0.036
wR(F²) = 0.096
S = 0.86
1835 reflections
87 parameters
H-atom parameters constrained
Δρ_max = 0.11 e Å⁻³
Δρ_min = −0.13 e Å⁻³

Data collection: COLLECT (Hooft, 2004 ); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 ); data reduction: SCALEPACK; 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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536812027079/kp2426sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812027079/kp2426Isup2.hkl

checkCIF report

Comment top

The synthesis of N,N,N',N'-tetramethyl-N''- [2-(N',N',N'',N''-tetramethylguanidino)-ethyl]- guanidine is well known in literature (Wittmann et al., 2000). The compound was used as a nitrogen donor ligand in reactions with copper halogenides (CuI or CuCl₂), to give mono- or bis-chelate complexes (Bienemann et al., 2010). However, the crystal structure of the free guanidine base was previously unknown. According to the structure analysis, the C1–N3 bond in the bisguanidine is 1.285 (2) Å, indicating double bond character. The bond lengths C1–N2 = 1.384 (2) Å and C1–N1 = 1.395 (1) Å are elongated and characteristic for a C–N imine single bond. The N–C1–N angles are 114.1 (1)° (N1–C1–N2), 126.5 (1)° (N2–C1–N3) and 119.3 (1)° (N1–C1–N3), showing a deviation of both CN₃ planes from an ideal trigonal planar geometry (Fig. 1). The dihedral angle N3—C6—C6ⁱ—N3ⁱ is 180.00 (9). The bonds between the N atoms and the terminal C-methyl groups, all have values close to a typical single bond (1.442 (2)–1.459 (1) Å). This is completely different compared with the geometrical parameters from the crystal structure analysis of the corresponding diprotonated bisguanidinium dichloride salt (Wittmann et al., 2000). Here, the C–N bond lengths of the CN₃ units are in a range between 1.336 (2) and 1.342 (2) Å, the N–C–N angles are 119.5 (1), 120.1 (1) and 120.4 (1)°, indicating also delocalization of the positive charges on both CN₃ planes. The crystal packing in the here presented title compound is through van der Waals interactions, only.

Related literature top

For the crystal structure of N,N,N',N'- tetramethylchloroformamidinium-chloride, see: Tiritiris & Kantlehner (2008). For the synthesis of N,N,N',N'-tetramethyl-N''-[2-(N',N',N'',N''-tetramethylguanidino)-ethyl]-guanidine and the crystal structure of the corresponding diprotonated bisguanidinium dichloride salt, see: Wittmann et al. (2000). For the synthesis and characterization of bisguanidine–copper complexes, see: Bienemann et al. (2010)

Experimental top

Two equivalents of N,N,N',N'-tetramethylchloroformamidinium-chloride (Tiritiris & Kantlehner, 2008) were reacted with one equivalent of ethane-1,2-diamine in acetonitrile in the presence of triethylamine at 273 K. The obtained protonated bisguanidinium dichloride salt was reacted in a next step with an aqueous sodium hydroxide solution at 273 K. After extraction of the bisguanidine 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.

Structure description top

Computing details top

Data collection: COLLECT (Hooft, 2004); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK (Otwinowski & Minor, 1997); 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 (Sheldrick, 2008).

Figures top

Fig. 1. The structure of the title compound with atom labels and 50% probability displacement ellipsoids.

N,N,N',N'-Tetramethyl-N''-[2- (N',N',N'',N''-tetramethylguanidino)ethyl]guanidine top

Crystal data top

C₁₂H₂₈N₆	F(000) = 284
M_r = 256.40	D_x = 1.118 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 7247 reflections
a = 8.4189 (6) Å	θ = 2.7–28.1°
b = 8.5894 (6) Å	µ = 0.07 mm⁻¹
c = 11.0089 (8) Å	T = 293 K
β = 106.858 (5)°	Polyhedral, colourless
V = 761.88 (10) Å³	0.22 × 0.18 × 0.15 mm
Z = 2

Data collection top

Bruker–Nonius KappaCCD diffractometer	1120 reflections with I > 2σ(I)
Radiation source: sealed tube	R_int = 0.043
Graphite monochromator	θ_max = 28.1°, θ_min = 2.7°
φ scans, and ω scans	h = −11→11
7247 measured reflections	k = −11→11
1835 independent reflections	l = −14→14

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F² > 2σ(F²)] = 0.036	H-atom parameters constrained
wR(F²) = 0.096	w = 1/[σ²(F_o²) + (0.059P)²] where P = (F_o² + 2F_c²)/3
S = 0.86	(Δ/σ)_max < 0.001
1835 reflections	Δρ_max = 0.11 e Å⁻³
87 parameters	Δρ_min = −0.13 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.57 (2)

Crystal data top

C₁₂H₂₈N₆	V = 761.88 (10) Å³
M_r = 256.40	Z = 2
Monoclinic, P2₁/n	Mo Kα radiation
a = 8.4189 (6) Å	µ = 0.07 mm⁻¹
b = 8.5894 (6) Å	T = 293 K
c = 11.0089 (8) Å	0.22 × 0.18 × 0.15 mm
β = 106.858 (5)°

Data collection top

Bruker–Nonius KappaCCD diffractometer	1120 reflections with I > 2σ(I)
7247 measured reflections	R_int = 0.043
1835 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.036	0 restraints
wR(F²) = 0.096	H-atom parameters constrained
S = 0.86	Δρ_max = 0.11 e Å⁻³
1835 reflections	Δρ_min = −0.13 e Å⁻³
87 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
N1	−0.04772 (12)	0.18588 (12)	0.32603 (9)	0.0485 (3)
N2	0.20678 (12)	0.08543 (13)	0.31899 (10)	0.0556 (3)
N3	−0.01179 (12)	0.13388 (11)	0.12955 (9)	0.0484 (3)
C1	0.05014 (13)	0.13573 (13)	0.25085 (10)	0.0434 (3)
C2	−0.22265 (16)	0.20743 (17)	0.26375 (13)	0.0607 (4)
H2A	−0.2392	0.3035	0.2173	0.091*
H2B	−0.2819	0.2105	0.3262	0.091*
H2C	−0.2631	0.1226	0.2064	0.091*
C3	0.01949 (17)	0.29870 (15)	0.42638 (12)	0.0571 (3)
H3A	0.1384	0.2914	0.4535	0.086*
H3B	−0.0228	0.2775	0.4968	0.086*
H3C	−0.0128	0.4017	0.3950	0.086*
C4	0.24173 (19)	0.01111 (18)	0.44203 (13)	0.0688 (4)
H4A	0.2972	0.0835	0.5069	0.103*
H4B	0.3116	−0.0778	0.4444	0.103*
H4C	0.1396	−0.0216	0.4563	0.103*
C5	0.35164 (16)	0.12927 (18)	0.28218 (14)	0.0664 (4)
H5A	0.3186	0.1914	0.2065	0.100*
H5B	0.4073	0.0373	0.2663	0.100*
H5C	0.4254	0.1883	0.3492	0.100*
C6	0.06621 (15)	0.04024 (13)	0.05215 (10)	0.0488 (3)
H6A	0.1385	−0.0369	0.1049	0.059*
H6B	0.1331	0.1064	0.0150	0.059*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0438 (5)	0.0632 (6)	0.0376 (5)	−0.0024 (4)	0.0103 (4)	−0.0085 (4)
N2	0.0442 (5)	0.0785 (7)	0.0409 (6)	0.0042 (5)	0.0074 (4)	0.0036 (5)
N3	0.0528 (6)	0.0556 (6)	0.0351 (5)	0.0067 (4)	0.0099 (4)	−0.0028 (4)
C1	0.0434 (6)	0.0495 (6)	0.0357 (6)	−0.0011 (4)	0.0090 (5)	−0.0028 (4)
C2	0.0463 (7)	0.0865 (9)	0.0482 (7)	0.0030 (6)	0.0121 (6)	−0.0075 (6)
C3	0.0635 (8)	0.0643 (8)	0.0439 (7)	−0.0071 (6)	0.0162 (6)	−0.0122 (5)
C4	0.0686 (9)	0.0823 (9)	0.0476 (8)	0.0144 (7)	0.0043 (7)	0.0078 (7)
C5	0.0458 (7)	0.0868 (10)	0.0662 (9)	−0.0047 (6)	0.0155 (7)	−0.0165 (7)
C6	0.0518 (7)	0.0576 (7)	0.0361 (6)	0.0056 (5)	0.0115 (5)	−0.0016 (5)

Geometric parameters (Å, º) top

N1—C1	1.3945 (14)	C3—H3B	0.9600
N1—C2	1.4449 (16)	C3—H3C	0.9600
N1—C3	1.4550 (15)	C4—H4A	0.9600
N2—C1	1.3837 (15)	C4—H4B	0.9600
N2—C5	1.4422 (16)	C4—H4C	0.9600
N2—C4	1.4483 (17)	C5—H5A	0.9600
N3—C1	1.2852 (15)	C5—H5B	0.9600
N3—C6	1.4589 (13)	C5—H5C	0.9600
C2—H2A	0.9600	C6—C6ⁱ	1.516 (2)
C2—H2B	0.9600	C6—H6A	0.9700
C2—H2C	0.9600	C6—H6B	0.9700
C3—H3A	0.9600

C1—N1—C2	117.02 (10)	H3A—C3—H3C	109.5
C1—N1—C3	119.32 (9)	H3B—C3—H3C	109.5
C2—N1—C3	113.16 (10)	N2—C4—H4A	109.5
C1—N2—C5	121.12 (11)	N2—C4—H4B	109.5
C1—N2—C4	123.22 (10)	H4A—C4—H4B	109.5
C5—N2—C4	114.76 (11)	N2—C4—H4C	109.5
C1—N3—C6	119.87 (10)	H4A—C4—H4C	109.5
N3—C1—N2	126.52 (10)	H4B—C4—H4C	109.5
N3—C1—N1	119.28 (11)	N2—C5—H5A	109.5
N2—C1—N1	114.14 (10)	N2—C5—H5B	109.5
N1—C2—H2A	109.5	H5A—C5—H5B	109.5
N1—C2—H2B	109.5	N2—C5—H5C	109.5
H2A—C2—H2B	109.5	H5A—C5—H5C	109.5
N1—C2—H2C	109.5	H5B—C5—H5C	109.5
H2A—C2—H2C	109.5	N3—C6—C6ⁱ	109.70 (12)
H2B—C2—H2C	109.5	N3—C6—H6A	109.7
N1—C3—H3A	109.5	C6ⁱ—C6—H6A	109.7
N1—C3—H3B	109.5	N3—C6—H6B	109.7
H3A—C3—H3B	109.5	C6ⁱ—C6—H6B	109.7
N1—C3—H3C	109.5	H6A—C6—H6B	108.2

C6—N3—C1—N2	15.52 (18)	C2—N1—C1—N3	10.45 (16)
C6—N3—C1—N1	−161.37 (10)	C3—N1—C1—N3	−132.01 (12)
C5—N2—C1—N3	46.34 (18)	C2—N1—C1—N2	−166.81 (11)
C4—N2—C1—N3	−145.11 (14)	C3—N1—C1—N2	50.74 (15)
C5—N2—C1—N1	−136.65 (12)	C1—N3—C6—C6ⁱ	138.63 (13)
C4—N2—C1—N1	31.90 (17)

Symmetry code: (i) −x, −y, −z.

Experimental details

Crystal data
Chemical formula	C₁₂H₂₈N₆
M_r	256.40
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	293
a, b, c (Å)	8.4189 (6), 8.5894 (6), 11.0089 (8)
β (°)	106.858 (5)
V (Å³)	761.88 (10)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.22 × 0.18 × 0.15

Data collection
Diffractometer	Bruker–Nonius KappaCCD
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	7247, 1835, 1120
R_int	0.043
(sin θ/λ)_max (Å⁻¹)	0.663

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.036, 0.096, 0.86
No. of reflections	1835
No. of parameters	87
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.11, −0.13

Computer programs: COLLECT (Hooft, 2004), SCALEPACK (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg & Putz, 2005).

Acknowledgements

The authors thank Dr F. Lissner (Institut für Anorganische Chemie, Universität Stuttgart) for measuring the crystal data.

References

Bienemann, O., Haase, R., Flörke, U., Döring, A., Kuckling, D. & Herres-Pawlis, S. (2010). Z. Naturforsch. Teil B, 65, 798–806. CAS Google Scholar
Brandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Hooft, R. W. W. (2004). COLLECT. Bruker–Nonius BV, Delft, The Netherlands. Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Tiritiris, I. & Kantlehner, W. (2008). Z. Kristallogr. 223, 345–346. CAS Google Scholar
Wittmann, H., Schorm, A. & Sundermeyer, J. (2000). Z. Anorg. Allg. Chem. 626, 1583–1590. CrossRef CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.