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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 10| October 2010| Page o2481
doi:10.1107/S1600536810033775

N-Ethyl-6-ethyl­amino-4-oxo-1,3,5-triazin-2-aminium chloride (Oxysimazine·HCl)

J. Emery Browna and Russell G. Baughmana*

aDepartment of Chemistry, Truman State University, Kirksville, MO 63501-4221, USA
*Correspondence e-mail: baughman@truman.edu

(Received 24 July 2010; accepted 20 August 2010; online 4 September 2010)

In the title molecular salt, C7H14N5O+·Cl− (the HCl salt of the oxo derivative of the triazine herbicide simazine), the cation and anion are linked by N—H⋯Cl hydrogen bonds. The chloride ion is also involved in a close electrostatic inter­action with an inversion-related triazine ring [Cl⋯centroid distance = 3.201 (1) Å]. A π–π inter­action having a centroid⋯centroid distance of 3.456 (2) Å exists between pairs of rings via another inversion relation. The triazine ring and adjacent non-H atoms are essentially planar (r.m.s. deviation = 0.042 Å), while both methyl groups are approximately perpendicular and on the same side of the plane [torsion angles = 79.3 (3) and −84.6 (3)°]. Upon exposure to X-rays for about two days, the color of the title compound changed from colorless to a pale yellow-orange with no apparent affect on the structure as evidenced by no significant change in the intensities of the standard reflections.

Related literature

The structure determinations of twoherbicides have been reported (Black & Baughman, 2010[Black, H. M. & Baughman, R. G. (2010). Acta Cryst. E66, o2221.]; Baughman & Yu, 1988[Baughman, R. G. & Yu, P.-J. (1988). J. Agric. Food Chem. 36, 1294-1296.] and references cited therein) as has information on the mode of action of this class of herbicides (Roberts, 1998[Roberts, T. R. (1998). Editor. Metabolic Pathways of Agrochemicals, Part 1. Cambridge, England: RSC Publishing.]). For the Gaussian calculation, see: Frisch et al. (2009[Frisch, M. J., et al. (2009). GAUSSIAN09. Gaussian Inc., Wallingsford, Connecticut, USA.]).

[Scheme 1]

Experimental

Crystal data

  • C7H14N5O+·Cl−

  • Mr = 219.68

  • Orthorhombic, P b c a

  • a = 8.2804 (5) Å

  • b = 14.5930 (9) Å

  • c = 17.9924 (11) Å

  • V = 2174.1 (2) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.33 mm−1

  • T = 295 K

  • 0.40 × 0.28 × 0.27 mm
Data collection

  • Bruker P4 diffractometer

  • Absorption correction: integration (XSHELL; Bruker, 1999[Bruker (1999). XSHELL. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.912, Tmax = 0.927

  • 2548 measured reflections

  • 1969 independent reflections

  • 1316 reflections with I > 2σ(I)

  • Rint = 0.026

  • 3 standard reflections every 100 reflections intensity decay: 1.1%
Refinement

  • R[F2 > 2σ(F2)] = 0.037

  • wR(F2) = 0.094

  • S = 1.02

  • 1940 reflections

  • 130 parameters

  • H-atom parameters constrained

  • Δρmax = 0.16 e Å−3

  • Δρmin = −0.15 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N1—H1A⋯Cl1 0.86 2.43 3.225 (2) 154
N2—H2A⋯Cl1i 0.86 2.24 3.080 (2) 167
N4—H4C⋯Cl1 0.86 2.44 3.246 (2) 156
N5—H5D⋯Cl1i 0.86 2.80 3.536 (2) 144
C5—H5A⋯O1ii 0.96 2.53 3.471 (4) 166
Symmetry codes: (i) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, z]; (ii) [-x+{\script{3\over 2}}, -y+1, z+{\script{1\over 2}}].

Data collection: XSCANS (Bruker, 1996[Bruker (1996). XSCANS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS86 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL/PC (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL/PC and SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810033775/fl2312sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810033775/fl2312Isup2.hkl

checkCIF report


Comment top

During an attempt to crystallize simazine (C7H12ClN5) from a dilute HCl(aq) solution exposed to room light, the title compound was produced. The crystal structure of the HCl salt of the oxo derivative of simazine was determined as part of a larger project involving the structure determinations of herbicides (Black & Baughman, 2010; Baughman and Yu, 1988 and references cited therein). Simazine is a selective systemic herbicide that inhibits photosynthesis in annual grasses and broad-leaved weeds (Roberts, 1998).

Two intramolecular hydrogen bonds involve the chloride ion (Cl1) with H1a and H4c (Table 1 and Figs. 1 & 2). The same chloride ion is also intermolecularly bonded to the H2a and H5d H atoms present in a symmetry-related molecule. A weak intermolecular interaction was observed between H5a and O1 in another symmetry-related molecule. See Table 1 for the various symmetry operations.

The cation displays a pseudo-vertical mirror perpendicular to Fig. 1 and going through O1, C1, and N3. The C2—N1, N1—C1, C1—N2, and N2—C3 bond lengths are all within 2σ of each other, yet, on the average, are 15σ longer than the C2—N3 and N3—C3 bond lengths which are within 2σ of each other. The values of the torsion angles C2—N4—C4—C5 [79.3 (3)°] and C3—N5—C6—C7 [-84.6 (3)°] show that the ethyl groups are pointed by a comparable amount in the same direction above the triazine ring.

Results from a Gaussian (Frisch et al., 2009) single point calculation at the M06–2X/6–31 G(d) level of theory indicate that the bond orders are largely consistent with the localized structure shown in the Scheme. All three C's in the ring have partially positive charges, with the one on C1 being the largest (+0.85 vs. +0.70 e- for C2 & C3). Since the crystals are initially colorless, then turn to a pale yellow-orange after ~2 days exposure to X-rays, the close [3.201 (1) Å] interactions (Fig. 2) of Cl1···Centroid of the ring at 2 - x, 1 - y, 1 - z) are likely just electrostatic in nature rather than charge-transfer based. However, an interplanar distance of 3.24 (3) Å indicates that a π–π interaction (Fig. 2) exists between pairs of rings via 1 - x, 1 - y 1 - z. This may be the source of the observed color change.

The conversion of simazine to its oxo derivative occurred during the slow evaporation of an HCl(aq) solution in the presence of light. FT—IR analyses of solid samples of the original simazine and the title compound show a C—Cl stretch only for simazine and a C═O stretch only for the salt. The light may have initiated a free-radical reaction between the chlorine in the original simazine and H2O which produced the derivative. In field applications, sunlight might then convert the simazine to the oxo derivative in the presence of acidic soil. The bioactivity of simazine, or other triazines (e.g., the widely-used atrazine), may involve a different free-radical reaction or the oxo versions of the compounds are the active agents.

Related literature top

The structure determinations of two herbicides have been reported (Black & Baughman, 2010; Baughman & Yu, 1988 and references cited therein) as has information on the mode of action of this class of herbicides (Roberts, 1998). For the Gaussian calculation, see: Frisch et al. (2009).

Experimental top

Simazine (99.9%), the parent compound, was purchased from Sigma-Aldrich (Riedel-de Haën) and used without further purification. Crystals of the title compound were grown by slow evaporation of a solution in dilute HCl(aq).

Refinement top

Approximate positions of the all of the H's were first obtained from a difference map, then placed into "ideal" positions and refined as a rotational group. Bond lengths were constrained at 0.93 Å (AFIX 43) for aromatic C—H's; at 0.96 Å (AFIX 137) for methyl C—H's; at 0.97 Å (AFIX 137) for ethyl C—H's; and at 0.86 Å (AFIX 43) for N—H's. Uiso(H) were fixed at 1.5Ueq(parent) for OH and methyl H's, and 1.2 Ueq(parent) for all other H's.

In the final stages of refinement 11 very small or negative Fo's were deemed to be in high disagreement with their Fc's and were eliminated from final refinement.

For the set of standard reflection I's monitored during data collection, an average and standard deviation were calculated, as was the ratio of this standard deviation to the average I for each standard. The average of these 3 ratios, expressed as a percentage, is reported.

Computing details top

Data collection: XSCANS (Bruker, 1996); cell refinement: XSCANS (Bruker, 1996); data reduction: XSCANS (Bruker, 1996); program(s) used to solve structure: SHELXS86 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL/PC (Sheldrick, 2008); software used to prepare material for publication: SHELXTL/PC (Sheldrick, 2008) and SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The asymmetric unit of the title compound, showing the labeling of the non-H atoms and H atoms involved in intramolecular hydrogen bonding (dashed lines). Displacement ellipsoids are drawn at the 50% probability levels and H atoms are drawn as small spheres of arbitrary radius.
[Figure 2] Fig. 2. View of inversion-related molecules at (1-x, 1-y, 1-z) and (2-x, 1-x, 1-z) showing Cl···ring and ring···ring (π–π) interactions. Only 4 Cl's are shown for charge balance; four others (not shown) are H-bonded to H2 and H5-type H's on the periphery of this view. To minimize congestion, displacement ellipsoids are drawn at the 30% probability levels.
N-Ethyl-6-ethylamino-4-oxo-1,3,5-triazin-2-aminium chloride top
Crystal data top
C7H14N5O+·Cl−F(000) = 928
Mr = 219.68Dx = 1.342 Mg m−3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 100 reflections
a = 8.2804 (5) Åθ = 10.9–20.4°
b = 14.5930 (9) ŵ = 0.33 mm−1
c = 17.9924 (11) ÅT = 295 K
V = 2174.1 (2) Å3Parallelpiped, colorless
Z = 80.40 × 0.28 × 0.27 mm
Data collection top
Bruker P4
diffractometer		1316 reflections with I > 2σ(I)
Radiation source: normal-focus sealed tubeRint = 0.026
Graphite monochromatorθmax = 25.3°, θmin = 2.3°
θ/2θ scansh = −9→1
Absorption correction: integration
(XSHELL; Bruker, 1999)		k = −1→17
Tmin = 0.912, Tmax = 0.927l = −1→21
2548 measured reflections3 standard reflections every 100 reflections
1969 independent reflections intensity decay: A value of 1.1% for the average ratio of σ(I):(average I) for the three standards.
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.037H-atom parameters constrained
wR(F2) = 0.094 w = 1/[σ2(Fo2) + (0.0341P)2 + 0.8482P]
where P = (Fo2 + 2Fc2)/3
S = 1.02(Δ/σ)max = 0.001
1940 reflectionsΔρmax = 0.16 e Å−3
130 parametersΔρmin = −0.15 e Å−3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0061 (6)
Crystal data top
C7H14N5O+·Cl−V = 2174.1 (2) Å3
Mr = 219.68Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 8.2804 (5) ŵ = 0.33 mm−1
b = 14.5930 (9) ÅT = 295 K
c = 17.9924 (11) Å0.40 × 0.28 × 0.27 mm
Data collection top
Bruker P4
diffractometer		1316 reflections with I > 2σ(I)
Absorption correction: integration
(XSHELL; Bruker, 1999)		Rint = 0.026
Tmin = 0.912, Tmax = 0.9273 standard reflections every 100 reflections
2548 measured reflections intensity decay: A value of 1.1% for the average ratio of σ(I):(average I) for the three standards.
1969 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0370 restraints
wR(F2) = 0.094H-atom parameters constrained
S = 1.02Δρmax = 0.16 e Å−3
1940 reflectionsΔρmin = −0.15 e Å−3
130 parameters
Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
xyzUiso*/Ueq
Cl10.99717 (7)0.66337 (4)0.44093 (3)0.0479 (2)
O10.7993 (2)0.37960 (13)0.38752 (9)0.0624 (5)
N10.7703 (2)0.48903 (13)0.47604 (9)0.0416 (5)
H1A0.82800.52800.45190.050*
N20.6260 (2)0.35562 (13)0.48312 (10)0.0413 (5)
H2A0.59080.30550.46390.050*
N30.6097 (2)0.46066 (12)0.58214 (10)0.0402 (5)
N40.7645 (3)0.59006 (13)0.57336 (10)0.0499 (5)
H4C0.82580.62450.54670.060*
N50.4670 (2)0.32663 (13)0.58517 (11)0.0461 (5)
H5D0.44220.27570.56400.055*
C10.7374 (3)0.40559 (16)0.44432 (13)0.0443 (6)
C20.7138 (3)0.51210 (15)0.54523 (12)0.0387 (5)
C30.5681 (3)0.38174 (16)0.55095 (12)0.0384 (5)
C40.7206 (4)0.62068 (19)0.64822 (14)0.0600 (7)
H4A0.60730.60770.65700.072*
H4B0.73590.68640.65180.072*
C50.8195 (4)0.5745 (2)0.70630 (15)0.0788 (10)
H5A0.78920.59720.75440.118*
H5B0.93180.58710.69770.118*
H5C0.80140.50960.70420.118*
C60.3943 (3)0.34737 (18)0.65733 (12)0.0505 (6)
H6A0.29250.31490.66150.061*
H6B0.37140.41250.65990.061*
C70.4998 (4)0.3215 (2)0.72113 (15)0.0802 (10)
H7A0.44790.33840.76690.120*
H7B0.60120.35300.71710.120*
H7C0.51810.25660.72050.120*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0491 (3)0.0455 (3)0.0491 (3)0.0041 (3)0.0000 (3)0.0024 (3)
O10.0758 (13)0.0704 (12)0.0409 (9)−0.0070 (11)0.0160 (10)−0.0152 (9)
N10.0469 (12)0.0426 (11)0.0352 (10)0.0009 (9)0.0028 (9)0.0033 (9)
N20.0429 (11)0.0423 (11)0.0387 (10)−0.0019 (10)−0.0029 (9)−0.0069 (9)
N30.0397 (11)0.0419 (10)0.0390 (9)0.0006 (9)0.0019 (9)−0.0032 (9)
N40.0600 (13)0.0450 (12)0.0449 (11)−0.0072 (11)0.0063 (11)−0.0032 (10)
N50.0458 (13)0.0460 (11)0.0466 (10)−0.0068 (10)0.0017 (9)−0.0033 (9)
C10.0483 (14)0.0479 (14)0.0368 (12)0.0032 (12)−0.0040 (12)−0.0026 (12)
C20.0392 (13)0.0393 (13)0.0376 (12)0.0035 (11)−0.0030 (11)0.0001 (10)
C30.0352 (12)0.0447 (13)0.0354 (11)0.0051 (11)−0.0048 (10)−0.0002 (11)
C40.0691 (19)0.0547 (15)0.0563 (15)−0.0076 (15)0.0082 (15)−0.0177 (14)
C50.097 (2)0.091 (2)0.0476 (16)−0.010 (2)−0.0022 (17)−0.0057 (16)
C60.0467 (14)0.0576 (15)0.0473 (13)−0.0061 (13)0.0062 (12)0.0008 (12)
C70.091 (2)0.101 (3)0.0486 (15)0.023 (2)−0.0016 (17)0.0070 (16)
Geometric parameters (Å, º) top
O1—C11.204 (3)N5—H5D0.8600
N1—C21.372 (3)C4—C51.489 (4)
N1—C11.372 (3)C4—H4A0.9700
N1—H1A0.8600C4—H4B0.9700
N2—C31.366 (3)C5—H5A0.9600
N2—C11.368 (3)C5—H5B0.9600
N2—H2A0.8600C5—H5C0.9600
N3—C21.322 (3)C6—C71.491 (4)
N3—C31.327 (3)C6—H6A0.9700
N4—C21.314 (3)C6—H6B0.9700
N4—C41.465 (3)C7—H7A0.9600
N4—H4C0.8600C7—H7B0.9600
N5—C31.314 (3)C7—H7C0.9600
N5—C61.463 (3)
C2—N1—C1121.8 (2)N4—C4—H4A109.3
C2—N1—H1A119.1C5—C4—H4A109.3
C1—N1—H1A119.1N4—C4—H4B109.3
C3—N2—C1123.0 (2)C5—C4—H4B109.3
C3—N2—H2A118.5H4A—C4—H4B107.9
C1—N2—H2A118.5C4—C5—H5A109.5
C2—N3—C3116.73 (19)C4—C5—H5B109.5
C2—N4—C4122.6 (2)H5A—C5—H5B109.5
C2—N4—H4C118.7C4—C5—H5C109.5
C4—N4—H4C118.7H5A—C5—H5C109.5
C3—N5—C6123.5 (2)H5B—C5—H5C109.5
C3—N5—H5D118.3N5—C6—C7113.0 (2)
C6—N5—H5D118.3N5—C6—H6A109.0
O1—C1—N2123.5 (2)C7—C6—H6A109.0
O1—C1—N1123.2 (2)N5—C6—H6B109.0
N2—C1—N1113.3 (2)C7—C6—H6B109.0
N4—C2—N3120.4 (2)H6A—C6—H6B107.8
N4—C2—N1116.9 (2)C6—C7—H7A109.5
N3—C2—N1122.6 (2)C6—C7—H7B109.5
N5—C3—N3119.9 (2)H7A—C7—H7B109.5
N5—C3—N2118.1 (2)C6—C7—H7C109.5
N3—C3—N2122.0 (2)H7A—C7—H7C109.5
N4—C4—C5111.8 (2)H7B—C7—H7C109.5
C3—N2—C1—O1173.6 (2)C1—N1—C2—N3−8.0 (3)
C3—N2—C1—N1−7.2 (3)C6—N5—C3—N30.4 (3)
C2—N1—C1—O1−171.7 (2)C6—N5—C3—N2−178.9 (2)
C2—N1—C1—N29.1 (3)C2—N3—C3—N5179.0 (2)
C4—N4—C2—N35.1 (4)C2—N3—C3—N2−1.8 (3)
C4—N4—C2—N1−176.6 (2)C1—N2—C3—N5−176.8 (2)
C3—N3—C2—N4−178.1 (2)C1—N2—C3—N33.9 (3)
C3—N3—C2—N13.8 (3)C2—N4—C4—C579.3 (3)
C1—N1—C2—N4173.9 (2)C3—N5—C6—C7−84.6 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···Cl10.862.433.225 (2)154
N2—H2A···Cl1i0.862.243.080 (2)167
N4—H4C···Cl10.862.443.246 (2)156
N5—H5D···Cl1i0.862.803.536 (2)144
C5—H5A···O1ii0.962.533.471 (4)166
Symmetry codes: (i) −x+3/2, y−1/2, z; (ii) −x+3/2, −y+1, z+1/2.

Experimental details

Crystal data
Chemical formulaC7H14N5O+·Cl−
Mr219.68
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)295
a, b, c (Å)8.2804 (5), 14.5930 (9), 17.9924 (11)
V (Å3)2174.1 (2)
Z8
Radiation typeMo Kα
µ (mm−1)0.33
Crystal size (mm)0.40 × 0.28 × 0.27
Data collection
DiffractometerBruker P4
diffractometer
Absorption correctionIntegration
(XSHELL; Bruker, 1999)
Tmin, Tmax0.912, 0.927
No. of measured, independent and
observed [I > 2σ(I)] reflections		2548, 1969, 1316
Rint0.026
(sin θ/λ)max (Å−1)0.600
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.094, 1.02
No. of reflections1940
No. of parameters130
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.16, −0.15

Computer programs: XSCANS (Bruker, 1996), SHELXS86 (Sheldrick, 2008), SHELXTL/PC (Sheldrick, 2008) and SHELXL97 (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···Cl10.862.4303.225 (2)154
N2—H2A···Cl1i0.862.2373.080 (2)167
N4—H4C···Cl10.862.4413.246 (2)156
N5—H5D···Cl1i0.862.8013.536 (2)144
C5—H5A···O1ii0.962.5273.471 (4)166
Symmetry codes: (i) −x+3/2, y−1/2, z; (ii) −x+3/2, −y+1, z+1/2.
 

Acknowledgements

This material is based upon work supported by the National Science Foundation under grant No. DUE-0431664. The authors thank Eric V. Patterson for the quantum calculations.

References

First citationBaughman, R. G. & Yu, P.-J. (1988). J. Agric. Food Chem. 36, 1294–1296.  CSD CrossRef CAS Web of Science Google Scholar
 First citationBlack, H. M. & Baughman, R. G. (2010). Acta Cryst. E66, o2221.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationBruker (1996). XSCANS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationBruker (1999). XSHELL. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationFrisch, M. J., et al. (2009). GAUSSIAN09. Gaussian Inc., Wallingsford, Connecticut, USA.  Google Scholar
 First citationRoberts, T. R. (1998). Editor. Metabolic Pathways of Agrochemicals, Part 1. Cambridge, England: RSC Publishing.  Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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Journal logoCRYSTALLOGRAPHIC
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ISSN: 2056-9890
Volume 66| Part 10| October 2010| Page o2481
doi:10.1107/S1600536810033775
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