N,N-Di­methyl­ammonium N',N'-di­methyl­carbamate

Di­methyl­amine and carbon dioxide form a 2:1 adduct, which is liquid at ambient temperature. Interested in the stabilizing features of the solid, di­methyl­ammonium N,N-di­methyl­carbamate, C₂H₈N⁺·C₃H₆NO₂^-, we grew single crystals from the pure solution; the structure is reported here. The salt crystallizes as dimers, as a result of hydrogen bonding within and across adjacent ion pairs.

Key indicators

• Single-crystal X-ray study
• T = 123 K
• Mean [sigma](N-C) = 0.002 Å
• R factor = 0.043
• wR factor = 0.110
• Data-to-parameter ratio = 19.7

checkCIF results

No syntax errors found



ADDSYM reports no extra symmetry

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Computing details

Data collection: COLLECT (Nonius BV, 1997-2000); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997); data reduction: HKL DENZO (Otwinowski & Minor 1997) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Barbour, 1999); software used to prepare material for publication: X-SEED.

(I)

Crystal data

C2H8N^+·C3H6NO2^−	Dx = 1.181 Mg m^−3
Mr = 134.18	Melting point: 302 K
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.4171 (2) Å	Cell parameters from 5677 reflections
b = 9.2543 (3) Å	θ = 3.5–28.3°
c = 11.0343 (4) Å	µ = 0.09 mm^−1
β = 95.073 (1)°	T = 123 K
V = 754.43 (4) Å^3	Prismatic, colourless
Z = 4	0.20 × 0.20 × 0.10 mm
F(000) = 296

Data collection

Nonius KappaCCD diffractometer	Rint = 0.059
CCD rotation images, thick slices scans	θmax = 28.3°, θmin = 3.5°
5677 measured reflections	h = −7→9
1853 independent reflections	k = −10→12
1262 reflections with I > 2σ(I)	l = −14→10

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.110	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0532P)^2] where P = (Fo^2 + 2Fc^2)/3
1853 reflections	(Δ/σ)max < 0.001
94 parameters	Δρmax = 0.18 e Å^−3
0 restraints	Δρmin = −0.21 e Å^−3

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. H atoms attached to the N atom on the ammonium cation were located and refined. All other H atoms were placed in idealized postions.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.23004 (12)	0.04565 (10)	0.69795 (8)	0.0251 (3)
O2	0.36822 (12)	−0.11594 (10)	0.58676 (8)	0.0250 (3)
N2	0.31244 (14)	0.19177 (12)	0.50167 (10)	0.0198 (3)
C1	0.28655 (15)	−0.08089 (14)	0.67805 (11)	0.0178 (3)
N1	0.25829 (14)	−0.18623 (12)	0.76269 (10)	0.0232 (3)
C2	0.13907 (17)	−0.16328 (16)	0.85808 (11)	0.0255 (3)
H2A	0.1022	−0.0616	0.8586	0.038*
H2B	0.2028	−0.1881	0.9369	0.038*
H2C	0.0316	−0.2246	0.8433	0.038*
C5	0.15899 (17)	0.17156 (17)	0.40836 (12)	0.0300 (4)
H5A	0.0483	0.2098	0.4387	0.045*
H5B	0.1435	0.0684	0.3905	0.045*
H5C	0.1835	0.2232	0.3340	0.045*
C4	0.34569 (17)	0.34500 (15)	0.53192 (13)	0.0269 (3)
H4A	0.3676	0.3984	0.4579	0.040*
H4B	0.4519	0.3531	0.5910	0.040*
H4C	0.2398	0.3855	0.5669	0.040*
C3	0.3046 (2)	−0.33568 (16)	0.74174 (14)	0.0341 (4)
H3A	0.1972	−0.3872	0.7061	0.051*
H3B	0.3479	−0.3810	0.8192	0.051*
H3C	0.3999	−0.3399	0.6857	0.051*
H2	0.413 (2)	0.1576 (17)	0.4721 (13)	0.031 (4)*
H1	0.285 (2)	0.1373 (17)	0.5742 (14)	0.039 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0324 (5)	0.0188 (6)	0.0254 (5)	0.0009 (4)	0.0098 (4)	−0.0004 (4)
O2	0.0266 (5)	0.0263 (6)	0.0239 (5)	0.0015 (4)	0.0117 (4)	0.0002 (4)
N2	0.0198 (6)	0.0185 (6)	0.0219 (6)	0.0016 (4)	0.0059 (4)	0.0008 (5)
C1	0.0140 (6)	0.0215 (7)	0.0177 (7)	−0.0021 (5)	0.0008 (4)	−0.0002 (5)
N1	0.0265 (6)	0.0210 (6)	0.0232 (6)	0.0020 (4)	0.0088 (4)	0.0048 (5)
C2	0.0252 (7)	0.0334 (9)	0.0186 (7)	−0.0048 (6)	0.0056 (5)	0.0036 (6)
C5	0.0272 (7)	0.0381 (9)	0.0246 (8)	−0.0001 (6)	0.0015 (5)	−0.0055 (7)
C4	0.0267 (7)	0.0186 (8)	0.0362 (8)	−0.0013 (5)	0.0074 (6)	0.0005 (6)
C3	0.0410 (8)	0.0229 (8)	0.0398 (9)	0.0057 (6)	0.0124 (7)	0.0089 (7)

Geometric parameters (Å, º)

O1—C1	1.2694 (15)	C2—H2C	0.9800
O2—C1	1.2628 (15)	C5—H5A	0.9800
N2—C4	1.4726 (17)	C5—H5B	0.9800
N2—C5	1.4776 (17)	C5—H5C	0.9800
N2—H2	0.899 (15)	C4—H4A	0.9800
N2—H1	0.983 (16)	C4—H4B	0.9800
C1—N1	1.3788 (17)	C4—H4C	0.9800
N1—C3	1.4485 (19)	C3—H3A	0.9800
N1—C2	1.4490 (16)	C3—H3B	0.9800
C2—H2A	0.9800	C3—H3C	0.9800
C2—H2B	0.9800
C4—N2—C5	112.52 (11)	N2—C5—H5A	109.5
C4—N2—H2	107.0 (10)	N2—C5—H5B	109.5
C5—N2—H2	108.5 (9)	H5A—C5—H5B	109.5
C4—N2—H1	110.6 (9)	N2—C5—H5C	109.5
C5—N2—H1	107.4 (8)	H5A—C5—H5C	109.5
H2—N2—H1	110.8 (13)	H5B—C5—H5C	109.5
O2—C1—O1	124.33 (12)	N2—C4—H4A	109.5
O2—C1—N1	118.10 (12)	N2—C4—H4B	109.5
O1—C1—N1	117.57 (11)	H4A—C4—H4B	109.5
C1—N1—C3	120.97 (11)	N2—C4—H4C	109.5
C1—N1—C2	121.84 (11)	H4A—C4—H4C	109.5
C3—N1—C2	115.11 (11)	H4B—C4—H4C	109.5
N1—C2—H2A	109.5	N1—C3—H3A	109.5
N1—C2—H2B	109.5	N1—C3—H3B	109.5
H2A—C2—H2B	109.5	H3A—C3—H3B	109.5
N1—C2—H2C	109.5	N1—C3—H3C	109.5
H2A—C2—H2C	109.5	H3A—C3—H3C	109.5
H2B—C2—H2C	109.5	H3B—C3—H3C	109.5