Bis­(di­cyclo­hexyl­ammonium 3-thienyl­acetate)

The triclinic cell of the title compound contains 2C₁₂H₂₄N⁺·2C₆H₅O₂S^- ion pairs that are linked by four hydrogen bonds [N...O = 2.728 (3) and 2.758 (3) Å] across a centre of inversion.

S1. Comment

The dicyclohexylammonium salts of a number of substituted acetic acids have been structurally documented; the acids include, for example, 2,4-dichlorophenoxyacetic (Subramanian et al., 2000), various dithiocarbamylacetic acids (Ng & Hook, 1999) and trifluoroacetic acid (Ng et al., 1999). With the exceptions of the trifluoroacetate, which adopts a zigzag hydrogen-bonded chain structure and the N,N-dimethyldithocarbamylacetate, which crystallizes as a monohydrate (Ng, 1992), the dicyclohexylammonium carboxylates exists as two ion-pairs that are linked by N···O hydrogen bonds across a centre of inversion; the interactions give rise to the formation of an H—N—H···O—C—O···H—N—H···O—C—O··· ring. The short hydrogen bonds in the title compound [N···O = 2.728 (2), 2.758 (2) Å] are representative of the hydrogen bonds found in other dimeric dicyclohexylammonium carboxylates. \sch

A displacement ellipsoid plot with the numbering scheme of the dimeric title compound is shown in Fig. 1.

Related literature

For related literature, see: Ng (1992); Ng & Hook (1999); Ng, Fun & Raj (1999); Subramanian et al. (2000).

S2. Experimental

The compound was the unexpected product from the attempted condensation of dicyclohexylammonium hydrogen 3-thienylmalonate and dibutyltin oxide in ethanol. The ammonium hydrogen carboxylate was prepared by treating equimolar quantities of dicyclohexylamine and 3-thienylmalonic acid in ethanol; the reagent was heated with dibutyltin oxide (2/1 molar ratio) until the oxide dissolved completely. The title compound separated as crystals when the solution was cooled.

S3. Refinement

All hydrogen atoms, excepting the hydrogen atoms attached to the disordered portion of the molecule, are located from difference maps and isotropically refined. Those attached to the disordered portion (H5 and H5') are geometrically fixed and allowed to ride on the parent atoms with U_iso = 1.2U_eq.

The sulfur at the 3-position of the thiophene ring is disordered with respect to the carbon atom at the 4-position. The occupancy refined to almost 3:1, and this was then fixed as 3:1. Carbon-sulfur distances were restrained to be equal by an SADI 0.01 instruction in SHELXTL. The temperature factor of S1 was set to be equal to that of C5', and that of S1' to that of C5.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 1990).

Figures

Fig. 1. ORTEPII (Johnson, 1976) diagram of the dimeric title compound showing 50% probability displacement ellipsoids and the atom-numbering scheme.

Bis(dicyclohexylammonium 3-thienylacetate)

Crystal data

2C12H24N·2C6H5O2S	Z = 1
Mr = 646.96	F(000) = 352
Triclinic, P1	Dx = 1.158 Mg m^−3
a = 8.8444 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.7581 (2) Å	Cell parameters from 4250 reflections
c = 11.9220 (3) Å	θ = 1.9–28.2°
α = 112.009 (1)°	µ = 0.18 mm^−1
β = 94.990 (1)°	T = 298 K
γ = 99.585 (1)°	Block, colorless
V = 927.98 (4) Å^3	0.48 × 0.44 × 0.34 mm

Data collection

Siemens SMART CCD area detector diffractometer	4299 independent reflections
Radiation source: fine-focus sealed tube	2833 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.047
Detector resolution: 8.33 pixels mm^-1	θmax = 28.2°, θmin = 1.9°
ω scan	h = −11→11
Absorption correction: empirical SADABS (Sheldrick, 1996)	k = −12→12
Tmin = 0.918, Tmax = 0.941	l = −15→7
6549 measured reflections

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)] = 0.060	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.162	H atoms treated by a mixture of independent and constrained refinement
S = 0.93	w = 1/[σ^2(Fo^2) + (0.0865P)^2] where P = (Fo^2 + 2Fc^2)/3
4299 reflections	(Δ/σ)max = 0.001
317 parameters	Δρmax = 0.25 e Å^−3
6 restraints	Δρmin = −0.33 e Å^−3

Special details

Experimental. The data collection covered over a hemisphere of reciprocal space by a combination of three sets of exposures; each set had a different ϕ angle (0, 88 and 180°) for the crystal and each exposure of 10 s covered 0.3° in ω. The crystal-to-detector distance was 4 cm and the detector swing angle was -35°. Crystal decay was monitored by repeating fifty initial frames at the end of data collection and analyzing the duplicate reflections, and was found to be negligible.

The structure was solved by direct methods and refined by full-matrix least-squares techniques.

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	Occ. (<1)
S1	0.3478 (1)	−0.2480 (1)	0.1187 (1)	0.068 (1)	0.75
S1'	0.451 (1)	−0.1818 (9)	0.0375 (5)	0.071 (1)	0.25
O1	0.7118 (2)	0.3175 (2)	0.3948 (1)	0.065 (1)
O2	0.5385 (2)	0.2468 (2)	0.4979 (1)	0.056 (1)
N1	0.7148 (2)	0.6196 (2)	0.4819 (1)	0.039 (1)
C1	0.6397 (2)	0.2240 (2)	0.4303 (2)	0.041 (1)
C2	0.6764 (2)	0.0652 (2)	0.3851 (2)	0.050 (1)
C3	0.5700 (2)	−0.0397 (2)	0.2688 (2)	0.041 (1)
C4	0.4430 (2)	−0.1461 (2)	0.2632 (2)	0.053 (1)
C5	0.474 (1)	−0.148 (1)	0.0621 (8)	0.071 (1)	0.75
C5'	0.370 (2)	−0.224 (2)	0.149 (1)	0.068 (1)	0.25
C6	0.5868 (2)	−0.0438 (2)	0.1515 (2)	0.056 (1)
C7	0.8026 (2)	0.6889 (2)	0.6111 (2)	0.042 (1)
C8	0.7032 (2)	0.6303 (2)	0.6897 (2)	0.053 (1)
C9	0.7817 (3)	0.6986 (3)	0.8239 (2)	0.066 (1)
C10	0.8176 (3)	0.8704 (3)	0.8740 (2)	0.070 (1)
C11	0.9169 (3)	0.9282 (3)	0.7964 (2)	0.068 (1)
C12	0.8399 (2)	0.8618 (2)	0.6620 (2)	0.051 (1)
C13	0.7879 (2)	0.6623 (2)	0.3868 (2)	0.040 (1)
C14	0.9486 (2)	0.6249 (2)	0.3770 (2)	0.051 (1)
C15	1.0190 (3)	0.6659 (3)	0.2780 (2)	0.065 (1)
C16	0.9121 (3)	0.5903 (3)	0.1555 (2)	0.067 (1)
C17	0.7492 (3)	0.6226 (3)	0.1653 (2)	0.063 (1)
C18	0.6804 (2)	0.5803 (2)	0.2636 (2)	0.050 (1)
H1a	0.701 (3)	0.507 (3)	0.457 (2)	0.09 (1)*
H1b	0.625 (2)	0.656 (2)	0.493 (2)	0.06 (1)*
H2a	0.663 (3)	0.022 (3)	0.451 (2)	0.07 (1)*
H2b	0.779 (3)	0.070 (3)	0.365 (2)	0.08 (1)*
H4	0.416 (3)	−0.164 (3)	0.332 (2)	0.07 (1)*
H5	0.4658	−0.1628	−0.0201	0.085*	0.75
H5'	0.2797	−0.2972	0.1306	0.082*	0.25
H6	0.668 (3)	0.022 (3)	0.135 (2)	0.09 (1)*
H7	0.898 (2)	0.647 (2)	0.604 (2)	0.05 (1)*
H8a	0.690 (3)	0.523 (3)	0.654 (2)	0.07 (1)*
H8b	0.600 (3)	0.659 (3)	0.678 (2)	0.08 (1)*
H9a	0.714 (3)	0.661 (3)	0.870 (2)	0.08 (1)*
H9b	0.878 (3)	0.668 (3)	0.831 (2)	0.08 (1)*
H10a	0.869 (3)	0.920 (3)	0.965 (3)	0.09 (1)*
H10b	0.714 (3)	0.908 (3)	0.875 (2)	0.10 (1)*
H11a	0.938 (3)	1.041 (4)	0.833 (3)	0.11 (1)*
H11b	1.019 (3)	0.896 (3)	0.802 (2)	0.08 (1)*
H12a	0.908 (3)	0.900 (2)	0.616 (2)	0.07 (1)*
H12b	0.743 (2)	0.897 (2)	0.656 (2)	0.06 (1)*
H13	0.792 (2)	0.772 (2)	0.409 (2)	0.05 (1)*
H14a	1.018 (3)	0.678 (3)	0.458 (2)	0.07 (1)*
H14b	0.938 (2)	0.518 (3)	0.359 (2)	0.06 (1)*
H15a	1.125 (3)	0.634 (3)	0.269 (2)	0.08 (1)*
H15b	1.031 (3)	0.772 (3)	0.298 (2)	0.08 (1)*
H16a	0.950 (3)	0.621 (3)	0.094 (2)	0.08 (1)*
H16b	0.898 (3)	0.471 (3)	0.120 (2)	0.08 (1)*
H17a	0.685 (3)	0.568 (3)	0.085 (2)	0.08 (1)*
H17b	0.754 (3)	0.726 (3)	0.186 (2)	0.08 (1)*
H18a	0.582 (2)	0.606 (2)	0.273 (2)	0.06 (1)*
H18b	0.669 (3)	0.470 (3)	0.244 (2)	0.08 (1)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.073 (1)	0.053 (1)	0.058 (1)	−0.002 (1)	0.003 (1)	0.007 (1)
S1'	0.094 (2)	0.072 (3)	0.048 (2)	0.023 (2)	0.018 (2)	0.023 (2)
O1	0.083 (1)	0.042 (1)	0.074 (1)	0.012 (1)	0.028 (1)	0.024 (1)
O2	0.060 (1)	0.061 (1)	0.056 (1)	0.030 (1)	0.020 (1)	0.024 (1)
N1	0.042 (1)	0.038 (1)	0.036 (1)	0.011 (1)	0.007 (1)	0.012 (1)
C1	0.046 (1)	0.036 (1)	0.037 (1)	0.012 (1)	0.001 (1)	0.010 (1)
C2	0.053 (1)	0.042 (1)	0.056 (1)	0.020 (1)	0.008 (1)	0.017 (1)
C3	0.050 (1)	0.034 (1)	0.047 (1)	0.018 (1)	0.018 (1)	0.018 (1)
C4	0.068 (1)	0.042 (1)	0.050 (1)	0.007 (1)	0.022 (1)	0.018 (1)
C5	0.094 (2)	0.072 (3)	0.048 (2)	0.023 (2)	0.018 (2)	0.023 (2)
C5'	0.073 (1)	0.053 (1)	0.058 (1)	−0.002 (1)	0.003 (1)	0.007 (1)
C6	0.063 (1)	0.059 (1)	0.054 (1)	0.015 (1)	0.019 (1)	0.031 (1)
C7	0.043 (1)	0.044 (1)	0.035 (1)	0.012 (1)	0.005 (1)	0.011 (1)
C8	0.065 (1)	0.049 (1)	0.042 (1)	0.007 (1)	0.007 (1)	0.018 (1)
C9	0.077 (2)	0.079 (2)	0.043 (1)	0.017 (1)	0.008 (1)	0.026 (1)
C10	0.071 (1)	0.078 (2)	0.038 (1)	0.007 (1)	0.005 (1)	0.004 (1)
C11	0.063 (1)	0.068 (1)	0.048 (1)	−0.005 (1)	−0.002 (1)	0.005 (1)
C12	0.052 (1)	0.044 (1)	0.046 (1)	0.002 (1)	0.005 (1)	0.010 (1)
C13	0.049 (1)	0.035 (1)	0.039 (1)	0.012 (1)	0.012 (1)	0.014 (1)
C14	0.043 (1)	0.059 (1)	0.051 (1)	0.011 (1)	0.010 (1)	0.021 (1)
C15	0.059 (1)	0.070 (1)	0.069 (2)	0.012 (1)	0.028 (1)	0.027 (1)
C16	0.082 (2)	0.075 (2)	0.055 (1)	0.029 (1)	0.034 (1)	0.027 (1)
C17	0.084 (2)	0.073 (2)	0.044 (1)	0.037 (1)	0.021 (1)	0.026 (1)
C18	0.049 (1)	0.059 (1)	0.042 (1)	0.021 (1)	0.009 (1)	0.018 (1)

Geometric parameters (Å, º)

S1—C4	1.689 (2)	C2—H2a	1.02 (2)
S1—C5	1.708 (8)	C2—H2b	0.96 (3)
S1'—C6	1.704 (6)	C4—H4	0.94 (2)
S1'—C5'	1.711 (8)	C5—H5	0.9300
O1—C1	1.249 (2)	C5'—H5'	0.9300
O2—C1	1.248 (2)	C6—H6	0.97 (3)
N1—C7	1.506 (2)	C7—H7	0.99 (2)
N1—C13	1.507 (2)	C8—H8a	0.95 (3)
C1—C2	1.539 (2)	C8—H8b	1.01 (2)
C2—C3	1.498 (3)	C9—H9a	0.97 (2)
C3—C4	1.375 (2)	C9—H9b	0.95 (3)
C3—C6	1.405 (3)	C10—H10a	1.03 (3)
C4—C5'	1.32 (1)	C10—H10b	1.04 (3)
C5—C6	1.352 (9)	C11—H11a	1.00 (3)
C7—C12	1.528 (2)	C11—H11b	1.01 (2)
C7—C8	1.535 (2)	C12—H12a	0.97 (2)
C8—C9	1.530 (3)	C12—H12b	0.98 (2)
C9—C10	1.519 (3)	C13—H13	0.99 (2)
C10—C11	1.521 (3)	C14—H14a	0.99 (2)
C11—C12	1.528 (3)	C14—H14b	0.97 (2)
C13—C18	1.525 (2)	C15—H15a	1.04 (2)
C13—C14	1.528 (2)	C15—H15b	0.95 (3)
C14—C15	1.529 (3)	C16—H16a	0.95 (3)
C15—C16	1.514 (3)	C16—H16b	1.06 (2)
C16—C17	1.530 (3)	C17—H17a	0.97 (2)
C17—C18	1.522 (3)	C17—H17b	0.94 (3)
N1—H1a	1.00 (3)	C18—H18a	0.95 (2)
N1—H1b	0.92 (2)	C18—H18b	0.99 (3)
C4—S1—C5	91.4 (3)	C8—C7—H7	110 (1)
C6—S1'—C5'	87.5 (6)	C9—C8—H8a	113 (1)
C7—N1—C13	117.6 (1)	C7—C8—H8a	105 (1)
O2—C1—O1	125.9 (2)	C9—C8—H8b	113 (1)
O2—C1—C2	116.7 (2)	C7—C8—H8b	105 (1)
O1—C1—C2	117.4 (2)	H8a—C8—H8b	110 (2)
C3—C2—C1	110.9 (1)	C10—C9—H9a	111 (2)
C4—C3—C6	111.1 (2)	C8—C9—H9a	108 (1)
C4—C3—C2	124.0 (2)	C10—C9—H9b	108 (2)
C6—C3—C2	125.0 (2)	C8—C9—H9b	110 (1)
C5'—C4—C3	111.3 (6)	H9a—C9—H9b	109 (2)
C3—C4—S1	112.6 (2)	C9—C10—H10a	113 (2)
C6—C5—S1	111.8 (5)	C11—C10—H10a	111 (2)
C4—C5'—S1'	116.6 (9)	C9—C10—H10b	109 (2)
C5—C6—C3	113.1 (4)	C11—C10—H10b	110 (2)
C3—C6—S1'	113.3 (3)	H10a—C10—H10b	103 (2)
N1—C7—C12	112.1 (1)	C10—C11—H11a	109 (2)
N1—C7—C8	107.5 (1)	C12—C11—H11a	112 (2)
C12—C7—C8	111.3 (2)	C10—C11—H11b	108 (1)
C9—C8—C7	111.1 (2)	C12—C11—H11b	109 (1)
C10—C9—C8	110.9 (2)	H11a—C11—H11b	108 (2)
C9—C10—C11	111.1 (2)	C11—C12—H12a	109 (1)
C10—C11—C12	111.7 (2)	C7—C12—H12a	112 (1)
C11—C12—C7	110.6 (2)	C11—C12—H12b	109 (1)
N1—C13—C18	109.0 (1)	C7—C12—H12b	109 (1)
N1—C13—C14	111.7 (1)	H12a—C12—H12b	108 (2)
C18—C13—C14	110.6 (1)	N1—C13—H13	108 (1)
C13—C14—C15	110.8 (2)	C18—C13—H13	106 (1)
C16—C15—C14	111.6 (2)	C14—C13—H13	112 (1)
C15—C16—C17	111.9 (2)	C13—C14—H14a	110 (1)
C18—C17—C16	111.4 (2)	C15—C14—H14a	111 (1)
C17—C18—C13	110.6 (2)	C13—C14—H14b	108 (1)
C7—N1—H1a	105 (2)	C15—C14—H14b	111 (1)
C13—N1—H1a	109 (1)	H14a—C14—H14b	106 (2)
C7—N1—H1b	102 (1)	C16—C15—H15a	110 (1)
C13—N1—H1b	109 (1)	C14—C15—H15a	110 (1)
H1a—N1—H1b	115 (2)	C16—C15—H15b	105 (1)
C3—C2—H2a	109 (1)	C14—C15—H15b	110 (1)
C1—C2—H2a	110 (1)	H15a—C15—H15b	111 (2)
C3—C2—H2b	105 (1)	C15—C16—H16a	113 (2)
C1—C2—H2b	110 (2)	C17—C16—H16a	108 (1)
H2a—C2—H2b	112 (2)	C15—C16—H16b	112 (1)
C5'—C4—H4	125 (2)	C17—C16—H16b	106 (1)
C3—C4—H4	124 (1)	H16a—C16—H16b	106 (2)
S1—C4—H4	124 (1)	C18—C17—H17a	112 (1)
C6—C5—H5	124.1	C16—C17—H17a	108 (1)
S1—C5—H5	124.1	C18—C17—H17b	108 (1)
C4—C5'—H5'	121.7	C16—C17—H17b	110 (2)
S1'—C5'—H5'	121.7	H17a—C17—H17b	108 (2)
C5—C6—H6	123 (2)	C17—C18—H18a	112 (1)
C3—C6—H6	124 (1)	C13—C18—H18a	108 (1)
S1'—C6—H6	122 (1)	C17—C18—H18b	111 (1)
N1—C7—H7	104 (1)	C13—C18—H18b	106 (1)
C12—C7—H7	112 (1)	H18a—C18—H18b	109 (2)
O2—C1—C2—C3	87.8 (2)	C13—N1—C7—C8	179.0 (1)
O1—C1—C2—C3	−91.3 (2)	N1—C7—C8—C9	−178.4 (2)
C1—C2—C3—C4	−101.4 (2)	C12—C7—C8—C9	−55.4 (2)
C1—C2—C3—C6	79.1 (2)	C7—C8—C9—C10	55.7 (2)
C6—C3—C4—C5'	0 (1)	C8—C9—C10—C11	−56.1 (3)
C2—C3—C4—C5'	−180 (1)	C9—C10—C11—C12	56.4 (3)
C6—C3—C4—S1	0.2 (2)	C10—C11—C12—C7	−55.6 (3)
C2—C3—C4—S1	−179.4 (1)	N1—C7—C12—C11	175.4 (2)
C5—S1—C4—C3	−1.2 (5)	C8—C7—C12—C11	55.0 (2)
C4—S1—C5—C6	1.9 (9)	C7—N1—C13—C18	−179.9 (1)
C3—C4—C5'—S1'	3 (2)	C7—N1—C13—C14	57.6 (2)
C6—S1'—C5'—C4	−3 (2)	N1—C13—C14—C15	178.8 (2)
S1—C5—C6—C3	−2 (1)	C18—C13—C14—C15	57.2 (2)
C4—C3—C6—C5	1.3 (7)	C13—C14—C15—C16	−55.1 (3)
C2—C3—C6—C5	−179.2 (7)	C14—C15—C16—C17	53.5 (3)
C4—C3—C6—S1'	−2.3 (4)	C15—C16—C17—C18	−54.1 (3)
C2—C3—C6—S1'	177.3 (4)	C16—C17—C18—C13	56.0 (2)
C5'—S1'—C6—C3	3.0 (9)	N1—C13—C18—C17	179.1 (1)
C13—N1—C7—C12	56.5 (2)	C14—C13—C18—C17	−57.8 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1a···O1	1.01 (3)	1.74 (3)	2.728 (3)	167 (2)
N1—H1b···O2^i	0.92 (2)	1.85 (2)	2.758 (3)	169 (2)

Symmetry code: (i) −x+1, −y+1, −z+1.