Racemic 4-(4-tert-butyl­phen­yl)-2,6-dimethyl­cyclo­hex-3-enecarboxylic acid

Xie, S.; O'Hearn, C.R.; Robinson, P.D.

doi:10.1107/S1600536808003309

organic compounds

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ISSN: 2056-9890

Volume 64| Part 3| March 2008| Page o554

doi:10.1107/S1600536808003309

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Racemic 4-(4-tert-butylphenyl)-2,6-dimethylcyclohex-3-enecarboxylic acid

Songwen Xie,^a Caryn R. O'Hearn ^a and Paul D. Robinson ^b ^*

^aDepartment of Natural, Information, and Mathematical Sciences, Indiana University Kokomo, Kokomo, IN 46904-9003, USA, and ^bDepartment of Geology, Southern Illinois University at Carbondale, Carbondale, IL 62901-4324, USA
^*Correspondence e-mail: robinson@geo.siu.edu

(Received 16 January 2008; accepted 30 January 2008; online 6 February 2008)

The chirality of the title compound, C₁₉H₂₆O₂, is solely generated by the presence of the double bond in the cyclohexene ring. This compound was synthesized to study the interaction of the two enantiomers in the solid state. The resultant racemate is made up of carboxylic acid RS dimers. Intermolecular O—H⋯O hydrogen bonds produce centrosymmetric R₂²(8) rings which dimerize the two chiral enantiomers through their carboxyl groups.

Related literature

In similar compounds previously reported (Xie et al., 2002 , 2007a ), the racemates also consist of carboxylic acid RS dimers. For related literature, see: Xie et al. (2007b , 2004 ); Bernstein et al. (1995 ).

Experimental

Crystal data

C₁₉H₂₆O₂
M_r = 286.40
Monoclinic, P 2₁ /c
a = 24.818 (4) Å
b = 9.4674 (18) Å
c = 7.0105 (12) Å
β = 95.799 (5)°
V = 1638.8 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 100 (2) K
0.36 × 0.29 × 0.09 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.793, T_max = 0.993
24559 measured reflections
2912 independent reflections
2230 reflections with I > 2σ(I)
R_int = 0.062

Refinement

R[F² > 2σ(F²)] = 0.085
wR(F²) = 0.244
S = 1.15
2912 reflections
196 parameters
H-atom parameters constrained
Δρ_max = 0.36 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O1ⁱ	0.82	1.88	2.702 (4)	175
Symmetry code: (i) -x+1, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT and SADABS (Bruker, 2005); program(s) used to solve structure: SIR92 (Altomare et al., 1994 ); program(s) used to refine structure: LS in TEXSAN (Molecular Structure Corporation, 1997 ) and SHELXL97 (Sheldrick, 2008 ); molecular graphics: PLATON (Spek, 2003 ); software used to prepare material for publication: SHELXL97 and PLATON.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808003309/om2210sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808003309/om2210Isup2.hkl

checkCIF report

Comment top

The title carboxylic acid, the structure of whose single enantiomer is unknown, was prepared to study the interaction of the two enantiomers in the solid state. We have previously reported the structure of its precursor, which is achiral and also forms hydrogen-bonded dimers (Xie et al., 2007b). The chirality of the title compound is solely generated by the presence of the double bond in the cyclohexene ring (Xie et al., 2004). The resultant racemate is made up of carboxylic acid RS dimers. The structure and atom numbering are shown in Fig. 1, which illustrates the half-chair conformation of the cyclohexene ring. The torsion angles involving atoms C2, C3, C4, C5, and C6 are all near 180°, as are those involving atoms C8, C2, C1, C6, and C9. The carboxyl group is almost perpendicular to the cyclohexene ring with an angle of 81.6 (5) ° between the O1—C7—O2 plane and the C1—C6 ring. The double bond between C3—C4 is not fully conjugated as shown by the C3—C4—C5 plane to benzene ring angle of 30.4 (5) °.

Fig. 2 shows the hydrogen bonding scheme and molecular packing. Atom O2 acts as a donor in an intermolecular hydrogen bond to atom O1. Inversion of this interaction across (1/2, 1/2, 1/2) produces an R₂²(8) ring (Bernstein et al., 1995), thus creating a hydrogen-bonded RS dimer. There is no evidence to suggest that weak directional interactions interconnect the dimers. Hydrogen bond geometry is given in Table 1.

Related literature top

In similar compounds previously reported (Xie et al., 2002, 2007a), the racemates also consist of carboxylic acid RS dimers. For related literature, see: Xie et al. (2007b, 2004); Bernstein et al. (1995).

Experimental top

The title carboxylic acid was synthesized following a similar method previously reported by Xie et al., 2002. Purified compound was recrystallized from hexane-ethyl acetate as colorless crystals (m.p. 467–468 K).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT and SADABS (Bruker, 2005); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: LS in TEXSAN (Molecular Structure Corporation, 1997) and SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2003).

Figures top

	Fig. 1. The molecular structure and atom numbering scheme, with displacement ellipsoids drawn at the 50% probablilty level.
	Fig. 2. Molecular packing and hydrogen bonding as viewed down [001]. Dashed lines represent hydrogen bonds. Most H atoms not involved in hydrogen bonding have been omitted to improve clarity. [Symmetry code: (i) -x + 1, -y + 1, -z + 1.]

(RS)-4-(4-tert-butylphenyl)-2,6-dimethylcyclohex-3-enecarboxylic acid top

Crystal data top

C₁₉H₂₆O₂	F(000) = 624
M_r = 286.40	D_x = 1.161 Mg m⁻³
Monoclinic, P2₁/c	Melting point = 467–468 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71069 Å
a = 24.818 (4) Å	Cell parameters from 5539 reflections
b = 9.4674 (18) Å	θ = 3.3–25.0°
c = 7.0105 (12) Å	µ = 0.07 mm⁻¹
β = 95.799 (5)°	T = 100 K
V = 1638.8 (5) Å³	Plate, colorless
Z = 4	0.36 × 0.29 × 0.09 mm

Data collection top

Bruker Kappa-APEXII CCD diffractometer	2912 independent reflections
Radiation source: X-ray tube	2230 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.062
ϕ and ω scans	θ_max = 25.1°, θ_min = 1.6°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −29→29
T_min = 0.793, T_max = 0.993	k = −11→11
24559 measured reflections	l = −8→8

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.085	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.244	H-atom parameters constrained
S = 1.15	w = 1/[σ²(F_o²) + (0.0701P)² + 6.4307P] where P = (F_o² + 2F_c²)/3
2912 reflections	(Δ/σ)_max < 0.001
196 parameters	Δρ_max = 0.36 e Å⁻³
0 restraints	Δρ_min = −0.34 e Å⁻³

Crystal data top

C₁₉H₂₆O₂	V = 1638.8 (5) Å³
M_r = 286.40	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 24.818 (4) Å	µ = 0.07 mm⁻¹
b = 9.4674 (18) Å	T = 100 K
c = 7.0105 (12) Å	0.36 × 0.29 × 0.09 mm
β = 95.799 (5)°

Data collection top

Bruker Kappa-APEXII CCD diffractometer	2912 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	2230 reflections with I > 2σ(I)
T_min = 0.793, T_max = 0.993	R_int = 0.062
24559 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.085	0 restraints
wR(F²) = 0.244	H-atom parameters constrained
S = 1.15	Δρ_max = 0.36 e Å⁻³
2912 reflections	Δρ_min = −0.34 e Å⁻³
196 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.44630 (12)	0.4071 (3)	0.5431 (5)	0.0292 (8)
O2	0.46014 (12)	0.6355 (3)	0.6148 (5)	0.0292 (8)
H2	0.4875	0.6225	0.5606	0.044*
C1	0.38217 (16)	0.5270 (4)	0.7216 (6)	0.0185 (9)
H1	0.3818	0.6204	0.7818	0.022*
C2	0.38377 (16)	0.4141 (4)	0.8808 (6)	0.0196 (9)
H2A	0.3872	0.3212	0.8215	0.024*
C3	0.33177 (17)	0.4167 (5)	0.9728 (6)	0.0264 (10)
H3	0.3321	0.3814	1.0967	0.032*
C4	0.28418 (16)	0.4675 (4)	0.8859 (5)	0.0169 (9)
C5	0.28100 (17)	0.5288 (5)	0.6930 (6)	0.0254 (10)
H5A	0.2737	0.6290	0.7038	0.030*
H5B	0.2501	0.4872	0.6175	0.030*
C6	0.33030 (16)	0.5119 (5)	0.5815 (6)	0.0201 (9)
H6	0.3296	0.4172	0.5249	0.024*
C7	0.43253 (17)	0.5160 (5)	0.6182 (6)	0.0222 (10)
C8	0.43195 (18)	0.4343 (5)	1.0310 (6)	0.0289 (11)
H8A	0.4325	0.5299	1.0768	0.043*
H8B	0.4649	0.4149	0.9748	0.043*
H8C	0.4288	0.3708	1.1361	0.043*
C9	0.32793 (19)	0.6213 (5)	0.4201 (6)	0.0295 (11)
H9A	0.2949	0.6096	0.3377	0.044*
H9B	0.3583	0.6084	0.3473	0.044*
H9C	0.3291	0.7146	0.4742	0.044*
C10	0.23456 (15)	0.4701 (4)	0.9897 (5)	0.0155 (8)
C11	0.22526 (16)	0.3688 (4)	1.1286 (6)	0.0188 (9)
H11	0.2501	0.2961	1.1543	0.023*
C12	0.18002 (16)	0.3744 (4)	1.2283 (6)	0.0193 (9)
H12	0.1754	0.3056	1.3199	0.023*
C13	0.14075 (16)	0.4812 (4)	1.1952 (6)	0.0184 (9)
C14	0.15024 (17)	0.5810 (5)	1.0570 (6)	0.0210 (9)
H14	0.1253	0.6536	1.0310	0.025*
C15	0.19560 (16)	0.5761 (5)	0.9565 (6)	0.0208 (9)
H15	0.2002	0.6450	0.8649	0.025*
C16	0.09164 (16)	0.4845 (4)	1.3099 (5)	0.0180 (9)
C17	0.05339 (17)	0.6074 (5)	1.2524 (6)	0.0243 (10)
H17A	0.0725	0.6951	1.2741	0.036*
H17B	0.0232	0.6049	1.3279	0.036*
H17C	0.0405	0.5994	1.1190	0.036*
C18	0.05936 (17)	0.3457 (5)	1.2774 (6)	0.0254 (10)
H18A	0.0473	0.3358	1.1436	0.038*
H18B	0.0286	0.3478	1.3500	0.038*
H18C	0.0821	0.2672	1.3184	0.038*
C19	0.11093 (18)	0.4982 (5)	1.5252 (6)	0.0234 (10)
H19A	0.1315	0.4160	1.5670	0.035*
H19B	0.0801	0.5065	1.5967	0.035*
H19C	0.1332	0.5808	1.5458	0.035*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0299 (17)	0.0191 (17)	0.0421 (19)	−0.0048 (14)	0.0203 (14)	−0.0079 (14)
O2	0.0269 (18)	0.0221 (17)	0.0423 (19)	−0.0054 (14)	0.0215 (15)	−0.0045 (14)
C1	0.021 (2)	0.015 (2)	0.021 (2)	−0.0007 (17)	0.0055 (17)	−0.0055 (17)
C2	0.020 (2)	0.017 (2)	0.023 (2)	0.0000 (18)	0.0073 (17)	0.0010 (17)
C3	0.026 (2)	0.026 (2)	0.029 (2)	0.004 (2)	0.0145 (19)	0.0088 (19)
C4	0.020 (2)	0.012 (2)	0.019 (2)	−0.0038 (17)	0.0034 (16)	−0.0011 (16)
C5	0.019 (2)	0.036 (3)	0.022 (2)	−0.007 (2)	0.0055 (17)	0.0002 (19)
C6	0.023 (2)	0.020 (2)	0.018 (2)	−0.0015 (18)	0.0058 (17)	−0.0021 (17)
C7	0.024 (2)	0.020 (2)	0.023 (2)	−0.0027 (19)	0.0079 (18)	−0.0017 (18)
C8	0.028 (2)	0.027 (3)	0.032 (2)	−0.004 (2)	0.0022 (19)	0.005 (2)
C9	0.034 (3)	0.031 (3)	0.025 (2)	−0.001 (2)	0.0059 (19)	0.0080 (19)
C10	0.0137 (19)	0.016 (2)	0.0166 (19)	−0.0021 (17)	0.0015 (15)	−0.0039 (16)
C11	0.018 (2)	0.016 (2)	0.022 (2)	0.0001 (17)	0.0020 (16)	0.0003 (16)
C12	0.021 (2)	0.018 (2)	0.020 (2)	−0.0021 (17)	0.0074 (16)	0.0030 (16)
C13	0.017 (2)	0.016 (2)	0.021 (2)	−0.0036 (17)	−0.0008 (16)	−0.0031 (17)
C14	0.022 (2)	0.019 (2)	0.022 (2)	0.0035 (18)	0.0040 (17)	0.0032 (17)
C15	0.021 (2)	0.019 (2)	0.021 (2)	−0.0008 (18)	−0.0009 (17)	0.0040 (17)
C16	0.019 (2)	0.018 (2)	0.018 (2)	0.0020 (17)	0.0046 (16)	0.0004 (16)
C17	0.020 (2)	0.027 (3)	0.026 (2)	0.0053 (19)	0.0032 (17)	0.0034 (19)
C18	0.020 (2)	0.026 (2)	0.032 (2)	−0.0058 (19)	0.0082 (18)	−0.0069 (19)
C19	0.023 (2)	0.023 (2)	0.024 (2)	0.0021 (19)	0.0011 (17)	−0.0031 (18)

Geometric parameters (Å, º) top

O1—C7	1.222 (5)	C2—H2A	0.9800
O2—C7	1.325 (5)	C3—H3	0.9300
C1—C7	1.510 (5)	C5—H5A	0.9700
C1—C2	1.544 (6)	C5—H5B	0.9700
C1—C6	1.545 (6)	C6—H6	0.9800
C2—C3	1.500 (5)	C8—H8A	0.9600
C2—C8	1.523 (6)	C8—H8B	0.9600
C3—C4	1.361 (6)	C8—H8C	0.9600
C4—C5	1.466 (6)	C9—H9A	0.9600
C4—C10	1.493 (5)	C9—H9B	0.9600
C5—C6	1.525 (5)	C9—H9C	0.9600
C6—C9	1.531 (6)	C11—H11	0.9300
C10—C15	1.397 (6)	C12—H12	0.9300
C10—C11	1.402 (6)	C14—H14	0.9300
C11—C12	1.382 (5)	C15—H15	0.9300
C12—C13	1.407 (6)	C17—H17A	0.9600
C13—C14	1.390 (6)	C17—H17B	0.9600
C13—C16	1.527 (5)	C17—H17C	0.9600
C14—C15	1.388 (6)	C18—H18A	0.9600
C16—C17	1.530 (6)	C18—H18B	0.9600
C16—C19	1.542 (6)	C18—H18C	0.9600
C16—C18	1.544 (6)	C19—H19A	0.9600
O2—H2	0.8200	C19—H19B	0.9600
C1—H1	0.9800	C19—H19C	0.9600

C7—C1—C2	109.7 (3)	C2—C3—H3	118.0
C7—C1—C6	111.4 (3)	C4—C5—H5A	108.0
C2—C1—C6	110.7 (3)	C6—C5—H5A	108.0
C3—C2—C8	110.5 (4)	C4—C5—H5B	108.0
C3—C2—C1	109.8 (3)	C6—C5—H5B	108.0
C8—C2—C1	112.0 (3)	H5A—C5—H5B	107.2
C4—C3—C2	124.0 (4)	C2—C8—H8A	109.5
C3—C4—C5	121.1 (4)	C2—C8—H8B	109.5
C3—C4—C10	120.6 (4)	C2—C8—H8C	109.5
C5—C4—C10	118.2 (4)	H8A—C8—H8B	109.5
C4—C5—C6	117.4 (4)	H8A—C8—H8C	109.5
C5—C6—C9	109.6 (4)	H8B—C8—H8C	109.5
C5—C6—C1	108.9 (3)	C6—C9—H9A	109.5
C9—C6—C1	112.0 (3)	C6—C9—H9B	109.5
C5—C6—H6	108.8	C6—C9—H9C	109.5
C9—C6—H6	108.8	H9A—C9—H9B	109.5
C1—C6—H6	108.8	H9A—C9—H9C	109.5
O1—C7—O2	123.1 (4)	H9B—C9—H9C	109.5
O1—C7—C1	123.1 (4)	C12—C11—H11	119.2
O2—C7—C1	113.8 (3)	C10—C11—H11	119.2
C15—C10—C11	116.6 (4)	C11—C12—H12	119.0
C15—C10—C4	121.5 (4)	C13—C12—H12	119.0
C11—C10—C4	122.0 (4)	C15—C14—H14	118.9
C12—C11—C10	121.6 (4)	C13—C14—H14	118.9
C11—C12—C13	121.9 (4)	C14—C15—H15	119.2
C14—C13—C12	116.1 (4)	C10—C15—H15	119.2
C14—C13—C16	123.6 (4)	C16—C17—H17A	109.5
C12—C13—C16	120.2 (4)	C16—C17—H17B	109.5
C15—C14—C13	122.3 (4)	H17A—C17—H17B	109.5
C14—C15—C10	121.5 (4)	C16—C17—H17C	109.5
C13—C16—C17	112.5 (3)	H17A—C17—H17C	109.5
C13—C16—C19	109.4 (3)	H17B—C17—H17C	109.5
C17—C16—C19	108.5 (3)	C16—C18—H18A	109.5
C13—C16—C18	109.6 (3)	C16—C18—H18B	109.5
C17—C16—C18	108.0 (3)	H18A—C18—H18B	109.5
C19—C16—C18	108.8 (3)	C16—C18—H18C	109.5
C7—O2—H2	109.5	H18A—C18—H18C	109.5
C7—C1—H1	108.3	H18B—C18—H18C	109.5
C2—C1—H1	108.3	C16—C19—H19A	109.5
C6—C1—H1	108.3	C16—C19—H19B	109.5
C3—C2—H2A	108.1	H19A—C19—H19B	109.5
C8—C2—H2A	108.1	C16—C19—H19C	109.5
C1—C2—H2A	108.1	H19A—C19—H19C	109.5
C4—C3—H3	118.0	H19B—C19—H19C	109.5

C2—C3—C4—C5	−2.0 (7)	C3—C4—C10—C15	147.3 (4)
C3—C4—C5—C6	9.7 (6)	C5—C4—C10—C15	−29.1 (6)
C7—C1—C2—C3	−175.2 (4)	C3—C4—C10—C11	−31.1 (6)
C7—C1—C6—C5	−178.2 (4)	C5—C4—C10—C11	152.6 (4)
C2—C1—C6—C9	−179.2 (3)	C15—C10—C11—C12	−0.4 (6)
C4—C5—C6—C9	−160.8 (4)	C4—C10—C11—C12	178.0 (4)
C6—C1—C2—C8	−175.0 (3)	C10—C11—C12—C13	0.4 (6)
C8—C2—C3—C4	147.4 (4)	C11—C12—C13—C14	−0.3 (6)
C6—C1—C2—C3	−51.8 (4)	C11—C12—C13—C16	−179.4 (4)
C7—C1—C2—C8	61.6 (4)	C12—C13—C14—C15	0.2 (6)
C1—C2—C3—C4	23.4 (6)	C16—C13—C14—C15	179.3 (4)
C2—C3—C4—C10	−178.2 (4)	C13—C14—C15—C10	−0.3 (7)
C10—C4—C5—C6	−174.0 (4)	C11—C10—C15—C14	0.4 (6)
C4—C5—C6—C1	−38.0 (5)	C4—C10—C15—C14	−178.1 (4)
C2—C1—C6—C5	59.4 (4)	C14—C13—C16—C17	1.5 (6)
C7—C1—C6—C9	−56.8 (5)	C12—C13—C16—C17	−179.5 (4)
C2—C1—C7—O1	55.7 (6)	C14—C13—C16—C19	−119.2 (4)
C6—C1—C7—O1	−67.3 (6)	C12—C13—C16—C19	59.9 (5)
C2—C1—C7—O2	−124.9 (4)	C14—C13—C16—C18	121.7 (4)
C6—C1—C7—O2	112.0 (4)	C12—C13—C16—C18	−59.3 (5)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1ⁱ	0.82	1.88	2.702 (4)	175

Symmetry code: (i) −x+1, −y+1, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₉H₂₆O₂
M_r	286.40
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	24.818 (4), 9.4674 (18), 7.0105 (12)
β (°)	95.799 (5)
V (Å³)	1638.8 (5)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.36 × 0.29 × 0.09

Data collection
Diffractometer	Bruker Kappa-APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.793, 0.993
No. of measured, independent and observed [I > 2σ(I)] reflections	24559, 2912, 2230
R_int	0.062
(sin θ/λ)_max (Å⁻¹)	0.597

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.085, 0.244, 1.15
No. of reflections	2912
No. of parameters	196
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.36, −0.34

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SAINT and SADABS (Bruker, 2005), SIR92 (Altomare et al., 1994), LS in TEXSAN (Molecular Structure Corporation, 1997) and SHELXL97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2003).

Selected geometric parameters (Å, º) top

C3—C4	1.361 (6)	C4—C5	1.466 (6)

C2—C3—C4—C5	−2.0 (7)	C2—C1—C6—C9	−179.2 (3)
C3—C4—C5—C6	9.7 (6)	C4—C5—C6—C9	−160.8 (4)
C7—C1—C2—C3	−175.2 (4)	C6—C1—C2—C8	−175.0 (3)
C7—C1—C6—C5	−178.2 (4)	C8—C2—C3—C4	147.4 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1ⁱ	0.82	1.88	2.702 (4)	175

Symmetry code: (i) −x+1, −y+1, −z+1.

Acknowledgements

SX and CO are grateful to the departmental fund and for a Grant-in-Aid for Faculty Research from Indiana University Kokomo, as well as a Senior Research Grant from Indiana Academy of Science. The authors thank Professor Nigam P. Rath of the University of Missouri – St. Louis for kindly collecting the low-temperature data set using a diffractometer whose purchase was made possible by funding from the National Science Foundation (CHE-0420497).

References

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