(1R,3S)-1,2,2-Trimethyl­cyclo­pentane-1,3-diammonium sulfate

In the title salt, C₈H₂₀N₂²⁺·SO₄²⁻, a ten-membered hydrogen-bonded ring (C₃H₂N₂O₂S) is observed involving the two ammonium groups and two O atoms of the sulfate ion. A three-dimensional hydrogen-bond network is constructed whereby every sulfate anion is linked to five adjacent (1R,3S)-1,2,2-trimethyl­cyclo­pentane-1,3-diammonium cations by N—H...O inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 291 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.035
• wR factor = 0.092
• Data-to-parameter ratio = 18.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         S1

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           28.22
           From the CIF: _reflns_number_total               2573
           Count of symmetry unique reflns         1565
           Completeness (_total/calc)            164.41%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1008
           Fraction of Friedel pairs measured     0.644
           Are heavy atom types Z>Si present        yes
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C1     ...          R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C3     ...          S

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 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
   0 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

In our previous studies, we have reported the synetheses and crystal structures of a series of camphoric derivatives and some of their transition metal coordination complexes. Herein, we report the single-crystal structure of (1R,3S)-1,2,2-trimethylcyclopentane-1,3-diammonium sulfate.

The atom-numbering scheme of the title compound is shown in Fig. 1, while selected bond distances and bond angles are given in Table 1. Both of the amine groups are in the protonated form and the bond lengths and bond angles are in the normal ranges compared with the related compounds. A ten-membered hydrogen bonding ring (C₃H₂N₂O₂S) is observed between the two diammonium groups and the two oxygen atoms of divalent sulfate counterion.

In the crystal packing, a three-dimensional hydrogen-bond network is constructed where every sulfate group links five adjacent (1R,3S)-1,2,2-trimethylcyclopentane-1,3-diammonium dications by means of N—H···O hydrogen bonding interactions (Fig. 2).

Related literature

For the synthesis of the title compound, see: Yang et al. (2001). For the structures of related organic camphoric compounds, see: Huang, Qian et al. (2003, 2004); Qian, Liu & Huang (2007). For the structures of other transition metal coordination complexes (enantiomeric and racemic ligands), see: Huang, Zhou et al. (2004); Huang et al. (2005); Qian et al. (2003, 2006); Qian, Chu et al. (2007).

S2. Experimental

The title compound is prepared via a literature method we have mentioned before expect that a dilute sulfuric acid (6.0 mol/L) aqueous solution is used instead of concentrated hydrochloric acid. Single crystals suitable for X-ray diffraction measurement were formed after 1 week in water by slow evaporation at room temperature in air. Anal. Calcd. for C₈H₂₀N₂O₄S: C, 39.98; H, 8.39; O, 11.66%. Found: C, 40.01; H, 8.33; O, 11.74%. FT—IR (KBr pellets, cm^-1): 3441 (s), 2972 (s), 1602 (versus), 1552 (s), 1123 (s), and 1083 (s). ¹H NMR (500 MHz, D₂O): δ = 0.96 (s, 3H), 1.04 (s, 3H), 1.24 (s, 3H), 1.70–1.73 (m, 1H), 1.82–1.87 (m, 1H), 2.03–2.06 (m, 1H), 2.07–2.19 (m, 1H), 3.46–3.49 (t, 1H).

S3. Refinement

The non-hydrogen atoms were refined anisotropically, whereas the H atoms were placed in geometrically idealized positions (C—H = 0.96–0.97 Å and N—H = 0.89 Å) and refined as riding atoms, with U_iso(H) = 1.5U_eq (for methyl C and nitrogen atoms) or U_iso(H) = 1.2U_eq(C) for the other C atoms.

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL (Bruker, 2000); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXTL (Bruker, 2000).

Figures

	Fig. 1. A drawing of the title compound, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. A perspective view of the N—H···O hydrogen-bond contacts in the crystal packing of the title compound. Hydrogen bonds are indicated as dashed lines. [Symmetry codes: (i) -x,1/2 + y,1/2 - z; (ii) - x,-1/2 + y,1/2 - z; (iii) 1 - x,1/2 + y,1/2 - z; (iv) 1 - x,-1/2 + y,1/2 - z.]

(1R,3S)-1,2,2-Trimethylcyclopentane-1,3-diammonium sulfate

Crystal data

C8H20N2^2+·SO4^2^−	F(000) = 520
Mr = 240.32	Dx = 1.477 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 5952 reflections
a = 6.5631 (7) Å	θ = 2.5–28.2°
b = 8.2864 (9) Å	µ = 0.30 mm^−1
c = 19.872 (2) Å	T = 291 K
V = 1080.7 (2) Å^3	Block, colorless
Z = 4	0.14 × 0.12 × 0.10 mm

Data collection

Bruker SMART CCD area-detector diffractometer	2573 independent reflections
Radiation source: fine-focus sealed tube	2530 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.057
ϕ and ω scans	θmax = 28.2°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −8→8
Tmin = 0.961, Tmax = 0.969	k = −10→6
6729 measured reflections	l = −26→26

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)] = 0.035	H-atom parameters constrained
wR(F^2) = 0.092	w = 1/[σ^2(Fo^2) + (0.0502P)^2 + 0.3153P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max = 0.001
2573 reflections	Δρmax = 0.36 e Å^−3
141 parameters	Δρmin = −0.55 e Å^−3
0 restraints	Absolute structure: Flack (1983), 1008 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.05 (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
C1	0.2929 (3)	0.41806 (19)	0.40485 (7)	0.0187 (3)
C2	0.4177 (2)	0.5784 (2)	0.39285 (7)	0.0175 (3)
C3	0.2489 (2)	0.71107 (19)	0.38443 (8)	0.0193 (3)
H3	0.2431	0.7725	0.4265	0.023*
C4	0.0464 (3)	0.6245 (2)	0.37648 (9)	0.0231 (3)
H4A	0.0220	0.5949	0.3299	0.028*
H4B	−0.0657	0.6905	0.3924	0.028*
C5	0.0756 (3)	0.4757 (2)	0.42052 (9)	0.0243 (3)
H5A	−0.0234	0.3930	0.4093	0.029*
H5B	0.0617	0.5029	0.4678	0.029*
C6	0.3777 (3)	0.3036 (2)	0.45777 (9)	0.0282 (4)
H6A	0.3794	0.3566	0.5007	0.042*
H6B	0.5139	0.2727	0.4457	0.042*
H6C	0.2933	0.2092	0.4603	0.042*
C7	0.5424 (3)	0.6224 (2)	0.45556 (8)	0.0271 (4)
H7A	0.6522	0.5469	0.4608	0.041*
H7B	0.4562	0.6186	0.4946	0.041*
H7C	0.5968	0.7293	0.4506	0.041*
C8	0.5608 (2)	0.5688 (2)	0.33204 (8)	0.0208 (3)
H8A	0.6351	0.6681	0.3280	0.031*
H8B	0.4822	0.5512	0.2919	0.031*
H8C	0.6546	0.4811	0.3381	0.031*
N1	0.2824 (2)	0.31718 (16)	0.34122 (7)	0.0212 (3)
H1A	0.4036	0.2727	0.3334	0.032*
H1B	0.2480	0.3798	0.3067	0.032*
H1C	0.1896	0.2398	0.3463	0.032*
N2	0.2841 (2)	0.82886 (17)	0.32852 (8)	0.0257 (3)
H2A	0.2823	0.7770	0.2893	0.039*
H2B	0.4046	0.8763	0.3341	0.039*
H2C	0.1863	0.9032	0.3290	0.039*
O1	0.0145 (2)	0.57816 (18)	0.12914 (7)	0.0317 (3)
O2	0.3575 (2)	0.4812 (2)	0.12373 (9)	0.0499 (4)
O3	0.1540 (3)	0.43956 (19)	0.22259 (7)	0.0467 (4)
O4	0.2805 (3)	0.70567 (17)	0.19494 (7)	0.0414 (4)
S1	0.20253 (6)	0.55228 (4)	0.167780 (18)	0.01945 (12)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0178 (7)	0.0197 (7)	0.0185 (6)	−0.0011 (7)	−0.0009 (5)	0.0010 (5)
C2	0.0129 (6)	0.0203 (7)	0.0192 (6)	0.0008 (6)	−0.0018 (5)	−0.0008 (5)
C3	0.0145 (7)	0.0191 (7)	0.0244 (7)	0.0008 (6)	0.0020 (6)	−0.0017 (5)
C4	0.0127 (7)	0.0245 (8)	0.0322 (8)	0.0008 (6)	0.0009 (6)	0.0030 (7)
C5	0.0162 (7)	0.0244 (8)	0.0322 (8)	−0.0001 (6)	0.0053 (6)	0.0036 (7)
C6	0.0307 (9)	0.0286 (9)	0.0253 (8)	0.0019 (8)	−0.0039 (7)	0.0077 (7)
C7	0.0226 (8)	0.0345 (9)	0.0243 (7)	−0.0029 (7)	−0.0058 (6)	−0.0038 (7)
C8	0.0152 (6)	0.0218 (7)	0.0256 (7)	−0.0003 (6)	0.0035 (6)	−0.0011 (7)
N1	0.0240 (7)	0.0184 (6)	0.0213 (6)	−0.0022 (6)	−0.0013 (6)	−0.0006 (5)
N2	0.0192 (7)	0.0184 (6)	0.0395 (8)	0.0022 (6)	0.0026 (7)	0.0049 (5)
O1	0.0241 (6)	0.0329 (7)	0.0381 (7)	0.0073 (6)	−0.0106 (5)	−0.0032 (6)
O2	0.0323 (8)	0.0544 (10)	0.0629 (10)	0.0159 (8)	0.0124 (7)	−0.0010 (8)
O3	0.0689 (11)	0.0422 (8)	0.0290 (6)	−0.0259 (9)	−0.0123 (7)	0.0151 (6)
O4	0.0549 (10)	0.0275 (7)	0.0417 (8)	−0.0168 (7)	−0.0111 (7)	−0.0010 (5)
S1	0.01899 (19)	0.01784 (18)	0.02151 (17)	−0.00102 (14)	−0.00342 (14)	0.00292 (13)

Geometric parameters (Å, º)

C1—N1	1.5173 (19)	C6—H6C	0.9600
C1—C6	1.522 (2)	C7—H7A	0.9600
C1—C5	1.536 (2)	C7—H7B	0.9600
C1—C2	1.579 (2)	C7—H7C	0.9600
C2—C8	1.532 (2)	C8—H8A	0.9600
C2—C7	1.535 (2)	C8—H8B	0.9600
C2—C3	1.570 (2)	C8—H8C	0.9600
C3—N2	1.497 (2)	N1—H1A	0.8900
C3—C4	1.519 (2)	N1—H1B	0.8900
C3—H3	0.9800	N1—H1C	0.8900
C4—C5	1.524 (2)	N2—H2A	0.8900
C4—H4A	0.9700	N2—H2B	0.8900
C4—H4B	0.9700	N2—H2C	0.8900
C5—H5A	0.9700	O1—S1	1.4693 (13)
C5—H5B	0.9700	O2—S1	1.4654 (16)
C6—H6A	0.9600	O3—S1	1.4697 (13)
C6—H6B	0.9600	O4—S1	1.4728 (14)
N1—C1—C6	104.42 (13)	C1—C6—H6C	109.5
N1—C1—C5	107.34 (13)	H6A—C6—H6C	109.5
C6—C1—C5	113.15 (14)	H6B—C6—H6C	109.5
N1—C1—C2	111.18 (12)	C2—C7—H7A	109.5
C6—C1—C2	116.06 (14)	C2—C7—H7B	109.5
C5—C1—C2	104.52 (13)	H7A—C7—H7B	109.5
C8—C2—C7	109.03 (13)	C2—C7—H7C	109.5
C8—C2—C3	112.63 (13)	H7A—C7—H7C	109.5
C7—C2—C3	107.24 (13)	H7B—C7—H7C	109.5
C8—C2—C1	113.15 (13)	C2—C8—H8A	109.5
C7—C2—C1	110.72 (13)	C2—C8—H8B	109.5
C3—C2—C1	103.84 (12)	H8A—C8—H8B	109.5
N2—C3—C4	111.46 (13)	C2—C8—H8C	109.5
N2—C3—C2	115.27 (13)	H8A—C8—H8C	109.5
C4—C3—C2	107.34 (13)	H8B—C8—H8C	109.5
N2—C3—H3	107.5	C1—N1—H1A	109.5
C4—C3—H3	107.5	C1—N1—H1B	109.5
C2—C3—H3	107.5	H1A—N1—H1B	109.5
C3—C4—C5	102.27 (13)	C1—N1—H1C	109.5
C3—C4—H4A	111.3	H1A—N1—H1C	109.5
C5—C4—H4A	111.3	H1B—N1—H1C	109.5
C3—C4—H4B	111.3	C3—N2—H2A	109.5
C5—C4—H4B	111.3	C3—N2—H2B	109.5
H4A—C4—H4B	109.2	H2A—N2—H2B	109.5
C4—C5—C1	104.57 (13)	C3—N2—H2C	109.5
C4—C5—H5A	110.8	H2A—N2—H2C	109.5
C1—C5—H5A	110.8	H2B—N2—H2C	109.5
C4—C5—H5B	110.8	O2—S1—O1	109.23 (10)
C1—C5—H5B	110.8	O2—S1—O3	109.73 (11)
H5A—C5—H5B	108.9	O1—S1—O3	107.35 (9)
C1—C6—H6A	109.5	O2—S1—O4	108.94 (11)
C1—C6—H6B	109.5	O1—S1—O4	110.95 (9)
H6A—C6—H6B	109.5	O3—S1—O4	110.62 (8)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O4^i	0.89	2.22	3.098 (2)	169
N1—H1B···O3	0.89	1.85	2.7011 (19)	160
N1—H1C···O1^ii	0.89	1.96	2.840 (2)	172
N2—H2A···O4	0.89	1.97	2.844 (2)	169
N2—H2B···O2^iii	0.89	1.97	2.833 (2)	162
N2—H2C···O1^iv	0.89	2.13	2.969 (2)	157
N2—H2C···O3^iv	0.89	2.48	3.185 (2)	137
C7—H7C···O2^iii	0.96	2.57	3.428 (3)	148
C8—H8C···O4^i	0.96	2.41	3.229 (2)	143

Symmetry codes: (i) −x+1, y−1/2, −z+1/2; (ii) −x, y−1/2, −z+1/2; (iii) −x+1, y+1/2, −z+1/2; (iv) −x, y+1/2, −z+1/2.