Bis­(diiso­propyl­ammonium) 2,6-naphthalene­di­carboxyl­ate

In the title compound, [{(CH₃)₂CH}₂NH₂]₂ [C₁₀H₆-2,6-(CO₂)₂], two ammonium —NH₂ groups interact with two carboxyl —CO₂ groups around an inversion center to give rise to a ten-membered ←O—C—O...H—N—H...O—C—O...H—N—H← ring. As the di­carboxyl­ato dianion also lies on an inversion center, a linear hydrogen-bonded chain structure is formed.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.059
• wR factor = 0.141
• Data-to-parameter ratio = 19.1

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



ABSMU_01  Alert C The ratio of given/expected absorption coefficient lies
          outside the range 0.99 <> 1.01
          Calculated value of mu =     0.077
          Value of mu given      =     0.080

GOODF_01  Alert C The least squares goodness of fit parameter lies
          outside the range 0.80 <> 2.00
          Goodness of fit given =      0.720

REFLT_03
         From the CIF: _diffrn_reflns_theta_max           28.30
         From the CIF: _reflns_number_total               2756
         TEST2: Reflns within _diffrn_reflns_theta_max
         Count of symmetry unique reflns         3043
         Completeness (_total/calc)             90.57%
          Alert C: < 95% complete


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 3 Alert Level C = Please check

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S1. Comment

Dicyclohexylammonium monocarboxylates typically adopt an arrangement in which two [R₂NH₂]⁺ cations are linked by hydrogen bonds to two [R'CO₂]⁻ anions across a center of inversion, the arrangement giving rise to a ten-membered <-O—C—O···H—N—H···O—C—O···H—N—H<- ring (Ng, 1993; Ng, 1995; Ng, 1996; Ng, 1997, Ng & Hook, 1999, Ramis et al., 2000; Ng et al., 2001); an exception is the trifluoroacetate, which adopts a chain structure (Ng et al., 1999). For the corresponding dicarboxylic acid salts, only the adipate has been verified, but the ammonium dicarboxylate crystallizes as a hydrate (Yang et al., 2000), and it does not display the expected twin 10-membered-ring motif.

This motif is now documented in the bis(diisopropylammonium) derivative of 2,6-naphthalenedicarboxylic acid, (I) (Fig. 1); the crystal structure of the parent acid is known from powder-diffraction measurements (Kaduk & Golab, 1999). N—H···O hydrogen bonds lead to the formation of a chain structure (Fig. 2, Table 2) as the flat dicarboxylato dianion lies at an inversion center.

S2. Experimental

Diisopropylamine (1 g, 10 mmol) was weighed into a beaker, and ethanol (20 ml) was poured into it. 2,6-Naphthalene dicarboxylic acid (1.1 g, 5 mmol) was added to the solution. The mixture was heated until the solid material that had formed dissolved completely. The solvent was allowed to evaporate over several days to furnish a tan-colored syrup from which the desired colorless product separated as parallelepiped-shaped crystals.

S3. Refinement

The ammonium H atoms were located and refined subject to N—H 0.86 (1) Å. The aliphatic and aromatic H atoms were generated geometrically (C—H 0.93 Å for the aromatic H atoms, C—H 0.98 Å for the methine H atom and C—H 0.96 Å for the methyl H atoms), and were included in the refinement in the riding model approximation; their respective temperature factors were set to 1.2, 1.2 and 1.5 times U_eq of the parent C atom.

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SMART; data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. ORTEPII (Johnson, 1976) plot of bis(diisopropylammonium) 2,6-dicarboxylate, with displacement ellipsoids drawn at the 50% probability level. H atoms are drawn as spheres of arbitrary radii.
	Fig. 2. ORTEPII (Johnson, 1976) plot, illustrating the hydrogen-bonded chain structure.

Bis(diisopropylammonium) 2,6-naphthalenedicarboxylate

Crystal data

2C6H16N^+·C12H6O4^2^−	Z = 1
Mr = 418.56	F(000) = 228
Triclinic, P1	Dx = 1.140 Mg m^−3
a = 7.8718 (7) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.5597 (7) Å	Cell parameters from 1895 reflections
c = 10.1327 (9) Å	θ = 2.2–28.3°
α = 67.749 (1)°	µ = 0.08 mm^−1
β = 88.179 (1)°	T = 298 K
γ = 75.389 (1)°	Parallelepiped, colorless
V = 609.92 (9) Å^3	0.30 × 0.20 × 0.20 mm

Data collection

Bruker AXS area-detector diffractometer	1084 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.045
Graphite monochromator	θmax = 28.3°, θmin = 2.2°
ϕ and ω scan	h = −10→10
5309 measured reflections	k = −11→10
2756 independent reflections	l = −12→12

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)] = 0.059	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.141	H atoms treated by a mixture of independent and constrained refinement
S = 0.72	w = 1/[σ^2(Fo^2) + (0.0622P)^2] where P = (Fo^2 + 2Fc^2)/3
2756 reflections	(Δ/σ)max = 0.001
144 parameters	Δρmax = 0.18 e Å^−3
2 restraints	Δρmin = −0.22 e Å^−3

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

	x	y	z	Uiso*/Ueq
O1	0.1618 (2)	0.7424 (2)	0.0754 (2)	0.0718 (5)
O2	0.0445 (2)	0.5200 (2)	0.1817 (2)	0.0703 (5)
N1	−0.0312 (2)	0.7867 (2)	−0.1596 (2)	0.0480 (5)
C1	0.1489 (3)	0.6093 (3)	0.1786 (3)	0.0522 (6)
C2	0.2649 (2)	0.5541 (3)	0.3127 (2)	0.0438 (5)
C3	0.4116 (3)	0.6094 (3)	0.3098 (2)	0.0492 (6)
C4	0.5243 (2)	0.5559 (2)	0.4347 (2)	0.0430 (5)
C5	0.2194 (3)	0.4437 (3)	0.4432 (2)	0.0540 (6)
C6	0.3210 (3)	0.3924 (3)	0.5664 (2)	0.0560 (6)
C7	0.0867 (3)	0.8525 (3)	−0.2746 (2)	0.0557 (6)
C8	0.1107 (4)	1.0249 (3)	−0.2835 (3)	0.0859 (9)
C9	0.2587 (3)	0.7146 (3)	−0.2438 (3)	0.0801 (8)
C10	−0.2124 (3)	0.9000 (3)	−0.1695 (2)	0.0570 (6)
C11	−0.3107 (3)	0.9439 (3)	−0.3092 (3)	0.0828 (9)
C12	−0.3063 (3)	0.8026 (4)	−0.0440 (3)	0.0890 (9)
H1n1	0.028	0.765	−0.077	0.038 (6)*
H1n2	−0.038	0.685	−0.155	0.061 (7)*
H3	0.4400	0.6847	0.2234	0.059*
H5	0.1186	0.4049	0.4459	0.065*
H6	0.2866	0.3219	0.6523	0.067*
H7	0.0326	0.8689	−0.3663	0.067*
H8a	−0.0014	1.1096	−0.3055	0.129*
H8b	0.1878	1.0639	−0.3572	0.129*
H8c	0.1611	1.0113	−0.1935	0.129*
H9a	0.2378	0.6074	−0.2402	0.120*
H9b	0.3125	0.6961	−0.1535	0.120*
H9c	0.3357	0.7523	−0.3179	0.120*
H10	−0.2045	1.0086	−0.1616	0.068*
H11a	−0.2499	1.0069	−0.3867	0.124*
H11b	−0.4274	1.0147	−0.3117	0.124*
H11c	−0.3173	0.8380	−0.3184	0.124*
H12a	−0.2425	0.7780	0.0438	0.134*
H12b	−0.3125	0.6948	−0.0500	0.134*
H12c	−0.4231	0.8732	−0.0466	0.134*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.090 (1)	0.070 (1)	0.052 (1)	−0.031 (1)	−0.021 (1)	−0.011 (1)
O2	0.077 (1)	0.063 (1)	0.080 (1)	−0.023 (1)	−0.022 (1)	−0.030 (1)
N1	0.053 (1)	0.045 (1)	0.046 (1)	−0.012 (1)	−0.010 (1)	−0.017 (1)
C1	0.055 (1)	0.050 (1)	0.058 (2)	−0.008 (1)	−0.011 (1)	−0.030 (1)
C2	0.047 (1)	0.041 (1)	0.047 (1)	−0.012 (1)	−0.002 (1)	−0.020 (1)
C3	0.057 (1)	0.044 (1)	0.047 (1)	−0.013 (1)	−0.002 (1)	−0.017 (1)
C4	0.044 (1)	0.041 (1)	0.047 (1)	−0.012 (1)	0.002 (1)	−0.019 (1)
C5	0.050 (1)	0.061 (2)	0.056 (2)	−0.021 (1)	−0.002 (1)	−0.024 (1)
C6	0.058 (1)	0.061 (2)	0.053 (2)	−0.028 (1)	0.008 (1)	−0.019 (1)
C7	0.067 (1)	0.056 (1)	0.048 (1)	−0.024 (1)	0.005 (1)	−0.019 (1)
C8	0.107 (2)	0.061 (2)	0.099 (2)	−0.042 (2)	0.034 (2)	−0.028 (2)
C9	0.072 (2)	0.075 (2)	0.099 (2)	−0.024 (2)	0.026 (2)	−0.038 (2)
C10	0.054 (1)	0.053 (1)	0.062 (2)	−0.007 (1)	−0.008 (1)	−0.024 (1)
C11	0.067 (2)	0.083 (2)	0.087 (2)	−0.001 (1)	−0.025 (2)	−0.031 (2)
C12	0.062 (2)	0.116 (2)	0.081 (2)	−0.018 (2)	0.014 (2)	−0.033 (2)

Geometric parameters (Å, º)

O1—C1	1.245 (3)	C3—H3	0.93
O2—C1	1.248 (2)	C5—H5	0.93
N1—C7	1.495 (3)	C6—H6	0.93
N1—C10	1.491 (3)	C7—H7	0.98
C1—C2	1.509 (3)	C8—H8a	0.96
C2—C3	1.349 (3)	C8—H8b	0.96
C2—C5	1.402 (3)	C8—H8c	0.96
C3—C4	1.424 (3)	C9—H9a	0.96
C4—C6^i	1.396 (3)	C9—H9b	0.96
C4—C4^i	1.416 (4)	C9—H9c	0.96
C5—C6	1.364 (3)	C10—H10	0.98
C6—C4^i	1.396 (3)	C11—H11a	0.96
C7—C8	1.504 (3)	C11—H11b	0.96
C7—C9	1.505 (3)	C11—H11c	0.96
C10—C11	1.505 (3)	C12—H12a	0.96
C10—C12	1.518 (3)	C12—H12b	0.96
N1—H1n1	0.90	C12—H12c	0.96
N1—H1n2	0.87
C7—N1—C10	117.7 (2)	N1—C7—H7	108.6
O1—C1—O2	125.4 (2)	C8—C7—H7	108.6
O1—C1—C2	117.5 (2)	C9—C7—H7	108.6
O2—C1—C2	117.1 (2)	C7—C8—H8a	109.5
C3—C2—C5	119.2 (2)	C7—C8—H8b	109.5
C3—C2—C1	121.4 (2)	H8a—C8—H8b	109.5
C5—C2—C1	119.5 (2)	C7—C8—H8c	109.5
C2—C3—C4	122.1 (2)	H8a—C8—H8c	109.5
C6^i—C4—C4^i	119.2 (2)	H8b—C8—H8c	109.5
C6^i—C4—C3	123.1 (2)	C7—C9—H9a	109.5
C4^i—C4—C3	117.7 (2)	C7—C9—H9b	109.5
C6—C5—C2	120.9 (2)	H9a—C9—H9b	109.5
C5—C6—C4^i	121.0 (2)	C7—C9—H9c	109.5
N1—C7—C8	110.9 (2)	H9a—C9—H9c	109.5
N1—C7—C9	107.9 (2)	H9b—C9—H9c	109.5
C8—C7—C9	112.2 (2)	N1—C10—H10	109.0
N1—C10—C11	111.4 (2)	C11—C10—H10	109.0
N1—C10—C12	107.5 (2)	C12—C10—H10	109.0
C11—C10—C12	111.0 (2)	C10—C11—H11a	109.5
C10—N1—H1n1	111	C10—C11—H11b	109.5
C7—N1—H1n1	105	H11a—C11—H11b	109.5
C10—N1—H1n2	109	C10—C11—H11c	109.5
C7—N1—H1n2	109	H11a—C11—H11c	109.5
H1n1—N1—H1n2	105	H11b—C11—H11c	109.5
C2—C3—H3	119.0	C10—C12—H12a	109.5
C4—C3—H3	119.0	C10—C12—H12b	109.5
C6—C5—H5	119.6	H12a—C12—H12b	109.5
C2—C5—H5	119.6	C10—C12—H12c	109.5
C5—C6—H6	119.5	H12a—C12—H12c	109.5
C4^i—C6—H6	119.5	H12b—C12—H12c	109.5
O1—C1—C2—C3	−19.8 (3)	C3—C2—C5—C6	0.2 (3)
O2—C1—C2—C3	161.9 (2)	C1—C2—C5—C6	−179.6 (2)
O1—C1—C2—C5	159.9 (2)	C2—C5—C6—C4^i	−1.9 (3)
O2—C1—C2—C5	−18.4 (3)	C10—N1—C7—C8	58.4 (3)
C5—C2—C3—C4	1.5 (3)	C10—N1—C7—C9	−178.4 (2)
C1—C2—C3—C4	−178.8 (2)	C7—N1—C10—C11	56.5 (3)
C2—C3—C4—C6^i	178.3 (2)	C7—N1—C10—C12	178.3 (2)
C2—C3—C4—C4^i	−1.3 (3)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1n1···O1	0.90	1.82	2.716 (2)	173
N1—H1n2···O2^ii	0.87	1.88	2.746 (2)	169

Symmetry code: (ii) −x, −y+1, −z.