N,N-Dimethyl O-p-tolyl phospho­ramido­cyanidate

The P—N bond in the title compound, C₁₀H₁₃N₂O₂P, is shorter [at 1.6104 (15) Å] than a normal P—N single bond. The N atom deviates slightly from the plane of the three atoms to which it is bonded. The sum of the angles surrounding this N atom is 358°. In the crystal structure, weak C—H...O hydrogen bonds link mol­ecules into one-dimensional chains along the a-axis direction.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.034
• wR factor = 0.084
• Data-to-parameter ratio = 20.1

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)        300 Deg.
PLAT230_ALERT_2_C Hirshfeld Test Diff for    P1     -   C1      ..       6.79 su

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           29.00
           From the CIF: _reflns_number_total               2791
           Count of symmetry unique reflns         1471
           Completeness (_total/calc)            189.73%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1320
           Fraction of Friedel pairs measured     0.897
           Are heavy atom types Z>Si present        yes
PLAT791_ALERT_1_G Confirm the Absolute Configuration of P1     = .          S
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          3

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 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
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Organophosphorus compounds (henceforth OPs for convenience) are one of the most widely used classes of pesticides in the world (Fulton & Key, 2001). For some phosphoramido acid, esters inhibiting acetylcholinesterase (AChE) activity was reported, resulting in an accumulation of acetylcholine (ACh) in neural and non-neural tissues (Ghadimi et al., 2007). Tabun (O-ethyl N,N-dimethyl-phosphoramidocyanidate, (CH₃)₂NP(O)CN(OC₂H₅)) is one of the well known nerve agent with very high toxicity (Munro et al., 1994). The crystal structure of dimethyl N-phenylphosphoramidate has already been reported (du Plessis et al., 1982). In this work, the synthesis and crystal structure of (CH₃)2NP(O)CN(p—OC₆H₄—CH₃) is presented. The molecular structure of the title compound is shown in Fig. 1 Four different groups are linked to atom P1 giving a distorted tetrahedral configuration. The bond angles around P atom are in the range of 101.14 (8)° [O2—P1—C1] to 118.26 (7)° [O1—P1—O2]. The O atom (of the 4-CH₃—C₆H₄—O group) has sp2 character (P1—O2—C2= 119.88 (10)°). The P1—O2 bond length (1.5799 (13) Å) is smaller than a P—O normal single bond length (1.64 Å, Corbridge, 1995). Also, the P—N bond length (1.6104 (15) Å) is shorter than the normal P—N single bond length (1.77 Å, Corbridge, 1995). The N atom in the title molecule indicates a slight deviation from planarity. This fact can be shown by the torsion angle P1—C9—C10—N1, which is ca 9.07°. Furthermore, sum of the surrounding angles around N atom is 358.01° which is less than that for an sp2 hybridized atom. The P1—C1 bond length is longer than the P—N and P—O bond lengths (1.8096 (18) Å) and the cyanide group has nearly linear configuration (N2—C1—P1 = 175.43 (17)°). Each molecule is surrounded with by neighboring molecules via weak C—H···O interactions leading to a 1-D chain in the network. A view of the unit cell packing of title compound is given in Figure 2.

Related literature

For a review of organophosphorus compounds as used as pesticides, see: Fulton & Key (2001).

For related literature, see: Corbridge (1995); Ghadimi et al. (2007); Munro et al. (1994); du Plessis et al. (1982).

S2. Experimental

To a solution of N, N-dimethyl phosphoramidochloridic acid 4-methyl phenyl ester (0.82 g, 3.5 mmol) in 30 ml dry acetonitrile KCN (0.45 g, 7 mmol) was added and stirred 4 h at 330 K. The mixture was cooled at room temperature, and filtered. The solvent was evaporated under vacuum. The solid product was washed with n-hexane and crystallized in hexane/ethyl acetate 9:1 at room temperature. ¹H NMR (CDCl₃), δ(p.p.m.): 2.34 (s, 3 H, p-CH₃), 2.88 (d, 3JPNCH = 11.4 Hz, 6 H, NMe2), 7.10–7.21 (m, 4 H, Ar—H); ¹³C NMR (CDCl₃), δ(p.p.m.): 20.71 (s, 1 C, p-CH₃), 35.64 (s, 2 C, N(CH₃)₂), 114.34 (d, 1JP-C = 186.8 Hz, 2 C, CN), 120.12 (d, 3JP-C = 4.90 Hz, 1 C, Cortho), 130.70 (s, 1 C, Cmeta), 136.32 (s, 1 C, Cpara), 146.32 (d, 2JP-C = 7.4 Hz, 1 C, Cipso); ³¹P{¹H} NMR δ (p.p.m.): -11.824 (s); ³¹P NMR, δ(p.p.m.): -11.94 to -11.71 (hept., 3JP-H = 11.3 Hz).

S3. Refinement

All hydrogen atoms were found in difference Fourier maps but were placed in calculated positions [C—H = 0.95–0.98 Å] and refined in the riding-model approximation with U_iso(H)=1.2U_eq(C) or 1.5U_eq(C) for methyl groups.

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 1998); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. Ellipsoid plot.
	Fig. 2. Packing diagram.

N,N-Dimethyl O-p-tolyl phosphoramidocyanidate

Crystal data

C10H13N2O2P	Z = 1
Mr = 224.19	F(000) = 118
Triclinic, P1	Dx = 1.349 Mg m^−3
Hall symbol: P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.0322 (9) Å	Cell parameters from 1809 reflections
b = 6.8532 (10) Å	θ = 2.9–33.7°
c = 7.3820 (11) Å	µ = 0.23 mm^−1
α = 105.604 (3)°	T = 100 K
β = 95.800 (3)°	Prism, colourless
γ = 106.802 (3)°	0.60 × 0.12 × 0.10 mm
V = 276.03 (7) Å^3

Data collection

Bruker APEX II diffractometer	2688 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.020
Graphite monochromator	θmax = 29.0°, θmin = 2.9°
ω scans	h = −8→8
3289 measured reflections	k = −9→9
2791 independent reflections	l = −9→10

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)] = 0.034	H-atom parameters constrained
wR(F^2) = 0.084	w = 1/[σ^2(Fo^2) + (0.0486P)^2 + ] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.001
2791 reflections	Δρmax = 0.48 e Å^−3
139 parameters	Δρmin = −0.41 e Å^−3
3 restraints	Absolute structure: Flack (1983), 1332 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.03 (7)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
P1	0.82244 (6)	0.58868 (5)	0.72672 (5)	0.01572 (11)
O1	1.0453 (2)	0.5443 (2)	0.7274 (2)	0.0239 (3)
O2	0.6317 (2)	0.48682 (18)	0.53457 (17)	0.0175 (2)
N1	0.8366 (2)	0.8366 (2)	0.7906 (2)	0.0186 (3)
N2	0.5735 (3)	0.4022 (3)	0.9964 (2)	0.0244 (3)
C1	0.6641 (3)	0.4674 (3)	0.8858 (3)	0.0180 (3)
C2	0.5178 (3)	0.2614 (3)	0.4632 (2)	0.0157 (3)
C3	0.6336 (3)	0.1317 (3)	0.3651 (2)	0.0177 (3)
H3A	0.7893	0.1921	0.3468	0.021*
C4	0.5173 (3)	−0.0891 (3)	0.2938 (3)	0.0193 (3)
H4A	0.5943	−0.1799	0.2255	0.023*
C5	0.2882 (3)	−0.1790 (3)	0.3214 (2)	0.0175 (3)
C6	0.1780 (3)	−0.0424 (3)	0.4193 (3)	0.0189 (3)
H6A	0.0219	−0.1013	0.4375	0.023*
C7	0.2907 (3)	0.1783 (3)	0.4912 (2)	0.0179 (3)
H7A	0.2136	0.2699	0.5580	0.021*
C8	0.1680 (4)	−0.4192 (3)	0.2471 (3)	0.0246 (4)
H8A	0.0071	−0.4544	0.2726	0.037*
H8B	0.2569	−0.4885	0.3119	0.037*
H8C	0.1618	−0.4704	0.1087	0.037*
C9	0.6234 (3)	0.8978 (3)	0.7893 (3)	0.0208 (4)
H9A	0.6312	0.9986	0.7160	0.031*
H9B	0.6118	0.9661	0.9213	0.031*
H9C	0.4844	0.7695	0.7299	0.031*
C10	1.0552 (3)	1.0079 (3)	0.9003 (3)	0.0246 (4)
H10A	1.0802	1.1293	0.8498	0.037*
H10B	1.1886	0.9538	0.8889	0.037*
H10C	1.0430	1.0549	1.0354	0.037*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P1	0.01261 (18)	0.01389 (19)	0.0204 (2)	0.00529 (14)	0.00426 (14)	0.00354 (15)
O1	0.0163 (6)	0.0243 (7)	0.0313 (7)	0.0107 (5)	0.0062 (5)	0.0044 (6)
O2	0.0189 (6)	0.0122 (5)	0.0206 (6)	0.0049 (5)	0.0032 (5)	0.0045 (5)
N1	0.0151 (7)	0.0142 (7)	0.0258 (8)	0.0049 (6)	0.0048 (6)	0.0050 (6)
N2	0.0245 (8)	0.0232 (8)	0.0241 (8)	0.0062 (6)	0.0058 (6)	0.0066 (6)
C1	0.0168 (8)	0.0139 (8)	0.0213 (8)	0.0056 (6)	0.0010 (6)	0.0027 (6)
C2	0.0168 (8)	0.0140 (7)	0.0159 (7)	0.0046 (6)	0.0018 (6)	0.0052 (6)
C3	0.0152 (8)	0.0181 (8)	0.0188 (8)	0.0047 (6)	0.0050 (6)	0.0045 (6)
C4	0.0211 (9)	0.0180 (8)	0.0193 (8)	0.0084 (7)	0.0054 (7)	0.0038 (6)
C5	0.0173 (8)	0.0173 (8)	0.0168 (8)	0.0051 (6)	−0.0006 (6)	0.0056 (6)
C6	0.0130 (8)	0.0210 (8)	0.0224 (8)	0.0049 (6)	0.0028 (6)	0.0076 (7)
C7	0.0163 (8)	0.0193 (8)	0.0187 (8)	0.0085 (7)	0.0024 (6)	0.0046 (6)
C8	0.0222 (9)	0.0156 (8)	0.0311 (10)	0.0030 (7)	−0.0009 (7)	0.0050 (7)
C9	0.0209 (9)	0.0184 (8)	0.0247 (9)	0.0111 (7)	0.0031 (7)	0.0048 (7)
C10	0.0168 (8)	0.0197 (9)	0.0293 (10)	0.0011 (7)	0.0036 (7)	0.0005 (7)

Geometric parameters (Å, º)

P1—O1	1.4613 (13)	C5—C6	1.390 (2)
P1—O2	1.5799 (13)	C5—C8	1.510 (2)
P1—N1	1.6104 (15)	C6—C7	1.390 (2)
P1—C1	1.8096 (18)	C6—H6A	0.9500
O2—C2	1.4181 (19)	C7—H7A	0.9500
N1—C9	1.463 (2)	C8—H8A	0.9800
N1—C10	1.467 (2)	C8—H8B	0.9800
N2—C1	1.145 (2)	C8—H8C	0.9800
C2—C7	1.383 (2)	C9—H9A	0.9800
C2—C3	1.385 (2)	C9—H9B	0.9800
C3—C4	1.394 (2)	C9—H9C	0.9800
C3—H3A	0.9500	C10—H10A	0.9800
C4—C5	1.401 (2)	C10—H10B	0.9800
C4—H4A	0.9500	C10—H10C	0.9800
O1—P1—O2	118.26 (7)	C5—C6—H6A	119.2
O1—P1—N1	117.32 (7)	C7—C6—H6A	119.2
O2—P1—N1	102.87 (7)	C2—C7—C6	118.46 (16)
O1—P1—C1	108.72 (8)	C2—C7—H7A	120.8
O2—P1—C1	101.14 (8)	C6—C7—H7A	120.8
N1—P1—C1	106.88 (8)	C5—C8—H8A	109.5
C2—O2—P1	119.88 (10)	C5—C8—H8B	109.5
C9—N1—C10	115.30 (14)	H8A—C8—H8B	109.5
C9—N1—P1	121.52 (11)	C5—C8—H8C	109.5
C10—N1—P1	121.19 (13)	H8A—C8—H8C	109.5
N2—C1—P1	175.43 (17)	H8B—C8—H8C	109.5
C7—C2—C3	121.95 (15)	N1—C9—H9A	109.5
C7—C2—O2	118.45 (15)	N1—C9—H9B	109.5
C3—C2—O2	119.60 (15)	H9A—C9—H9B	109.5
C2—C3—C4	118.69 (16)	N1—C9—H9C	109.5
C2—C3—H3A	120.7	H9A—C9—H9C	109.5
C4—C3—H3A	120.7	H9B—C9—H9C	109.5
C3—C4—C5	120.86 (16)	N1—C10—H10A	109.5
C3—C4—H4A	119.6	N1—C10—H10B	109.5
C5—C4—H4A	119.6	H10A—C10—H10B	109.5
C6—C5—C4	118.46 (16)	N1—C10—H10C	109.5
C6—C5—C8	121.62 (17)	H10A—C10—H10C	109.5
C4—C5—C8	119.92 (17)	H10B—C10—H10C	109.5
C5—C6—C7	121.58 (16)
O1—P1—O2—C2	67.61 (14)	C7—C2—C3—C4	−0.3 (3)
N1—P1—O2—C2	−161.29 (12)	O2—C2—C3—C4	−179.12 (15)
C1—P1—O2—C2	−50.89 (13)	C2—C3—C4—C5	−0.4 (3)
O1—P1—N1—C9	178.18 (13)	C3—C4—C5—C6	0.9 (3)
O2—P1—N1—C9	46.52 (14)	C3—C4—C5—C8	−178.47 (15)
C1—P1—N1—C9	−59.52 (15)	C4—C5—C6—C7	−0.8 (3)
O1—P1—N1—C10	−18.64 (18)	C8—C5—C6—C7	178.61 (16)
O2—P1—N1—C10	−150.30 (15)	C3—C2—C7—C6	0.5 (3)
C1—P1—N1—C10	103.65 (16)	O2—C2—C7—C6	179.28 (14)
P1—O2—C2—C7	101.96 (16)	C5—C6—C7—C2	0.1 (3)
P1—O2—C2—C3	−79.22 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7A···O1^i	0.95	2.50	3.441 (2)	174

Symmetry code: (i) x−1, y, z.