Deuterated γ-malonic acid: its neutron crystal structure in relationship to other polymorphs of aliphatic dicarboxylic acids

McMullan, R.K.; Klooster, W.T.; Weber, H.-P.

doi:10.1107/S0108768108000268

Deuterated γ-malonic acid: its neutron crystal structure in relationship to other polymorphs of aliphatic dicarboxylic acids

R. K. McMullan, W. T. Klooster and H.-P. Weber

Three complete neutron diffraction datasets have been collected for deuterated malonic acid single crystals, DOOC(CD₂)COOD, above (153 K), just below (56 K) and further below (50 K) the low-temperature phase transition (T_c = 57 K). The structural details obtained for this transition, studied previously solely by spectroscopic and calorimetric techniques, clearly establish its first-order nature. At 153 K, the space group is $P\bar 1$ , Z = 2, Z′ = 1. The molecules are packed as linear chains linked end-to-end by asymmetric hydrogen bonds so that the carboxyl groups form cyclic dimers. The deuterons in the carboxyl links are ordered. Neighboring chains are cross-linked through C—D

O hydrogen bonds. Upon cooling through the transition the cell doubles along the a axis. Molecules which are equivalent by symmetry above T_c become independent below T_c owing to conformational changes in alternate chains. At 50 K, the space group is $P\bar 1$ , Z = 4, Z′ = 2. Thermal motion analysis, using for all three temperatures the same segmented rigid-body model, reveals a large torsional motion around the one COOD group associated with the conformational change. Refinements were carried out on all three datasets with an anharmonic structural model, including higher-order displacement tensors (Gram–Charlier expansion up to fourth order). Only atoms involved in torsional motion exhibit a significant anharmonic component which increases with temperature.

Keywords: polymorphism; neutron diffraction; low-temperature phase transition; hydrogen bonding; thermal motion analysis.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768108000268/bk5069sup1.cif Contains datablocks 50K, 56K, 153K
	Structure factor file (CIF format) https://doi.org/10.1107/S0108768108000268/bk506950Ksup2.hkl Contains datablock 50K
	Structure factor file (CIF format) https://doi.org/10.1107/S0108768108000268/bk506956Ksup3.hkl Contains datablock 56K
	Structure factor file (CIF format) https://doi.org/10.1107/S0108768108000268/bk5069153Ksup4.hkl Contains datablock 153K
	Portable Document Format (PDF) file https://doi.org/10.1107/S0108768108000268/bk5069sup5.pdf Supplementary material

CCDC references: 685159; 685160; 685161

Computing details top

Program(s) used to refine structure: UPALS(Lundgren,82)&NOOT(Craven et al.,91) for (50K); UPALS (Lundgren,82)& NOOT(Craven et al.,91) for (56K); UPALS(Lundgren,'82)& NOOT(Craven et al.,91) for 153K. For all compounds, molecular graphics: DIAMOND (Brandenburg, 2006).

Figures top

(50K) top

Crystal data top

C₃D₄O₄	Z = 4
M_r = 108.03	D_x = 1.758 Mg m⁻³
Triclinic, P1	Neutron radiation, λ = 1.1588 Å
a = 10.663 (4) Å	Cell parameters from 32 reflections
b = 5.142 (2) Å	θ = 29–35°
c = 11.234 (2) Å	µ = 0.02 mm⁻¹
α = 103.39 (3)°	T = 50 K
β = 136.81 (2)°	Prism, colourless
γ = 85.19 (3)°	3.0 × 2.4 × 2.0 mm
V = 406.8 (3) Å³

Data collection top

Four-circle diffractometers H6S	2307 independent reflections
Radiation source: steady-state reactor	R_int = 0.019
Ge 022 monochromator	θ_max = 54.2°, θ_min = 1.8°
θ–2θ scans	h = −14→14
Absorption correction: analytical Templeton & Templeton, 1973	k = −7→7
T_min = 0.95, T_max = 0.97	l = −15→15
2653 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	w = 1/[s²(F_o²) + (0.02(F_o²)² + 0.05]
wR(F²) = 0.052
S = 1.53	Δρ_max = 0.27 e Å⁻³
2300 reflections	Δρ_min = −0.40 e Å⁻³
208 parameters	Extinction correction: Becker & Coppens
0 restraints	Extinction coefficient: 0.102 (2)
Primary atom site location: structure-invariant direct methods

Crystal data top

C₃D₄O₄	γ = 85.19 (3)°
M_r = 108.03	V = 406.8 (3) Å³
Triclinic, P1	Z = 4
a = 10.663 (4) Å	Neutron radiation, λ = 1.1588 Å
b = 5.142 (2) Å	µ = 0.02 mm⁻¹
c = 11.234 (2) Å	T = 50 K
α = 103.39 (3)°	3.0 × 2.4 × 2.0 mm
β = 136.81 (2)°

Data collection top

Four-circle diffractometers H6S	2653 measured reflections
Absorption correction: analytical Templeton & Templeton, 1973	2307 independent reflections
T_min = 0.95, T_max = 0.97	R_int = 0.019

Refinement top

wR(F²) = 0.052	0 restraints
S = 1.53	Δρ_max = 0.27 e Å⁻³
2300 reflections	Δρ_min = −0.40 e Å⁻³
208 parameters

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

	x	y	z	U_iso*/U_eq
C0A	0.03930 (9)	0.11744 (12)	0.23688 (8)	0.0148 (2)
C1A	0.03043 (8)	0.29771 (12)	0.35716 (8)	0.0111 (2)
C2A	0.01821 (8)	0.27417 (12)	0.12644 (8)	0.0122 (2)
O11A	0.03285 (10)	0.54168 (14)	0.37702 (9)	0.0169 (2)
O12A	0.02100 (10)	0.16141 (14)	0.43609 (10)	0.0218 (2)
O21A	0.14782 (10)	0.35536 (17)	0.16073 (11)	0.0318 (2)
O22A	−0.15367 (10)	0.31321 (16)	−0.01041 (10)	0.0236 (2)
D12A	0.01040 (13)	0.28907 (17)	0.51169 (12)	0.0334 (2)
D21A	−0.15710 (12)	0.43044 (18)	−0.07171 (12)	0.0336 (2)
D01A	0.17288 (13)	0.04118 (19)	0.32179 (12)	0.0487 (2)
D02A	−0.07034 (13)	−0.05104 (17)	0.15137 (12)	0.0314 (2)
C0B	0.55989 (9)	0.12874 (12)	0.25322 (8)	0.0142 (2)
C1B	0.54465 (8)	0.30473 (12)	0.36932 (8)	0.0119 (2)
C2B	0.53347 (8)	0.28585 (12)	0.13977 (8)	0.0113 (2)
O11B	0.52689 (10)	0.54377 (14)	0.37533 (9)	0.0192 (2)
O12B	0.55247 (11)	0.17081 (14)	0.46038 (10)	0.0239 (2)
O21B	0.65638 (10)	0.44400 (15)	0.19758 (10)	0.0213 (2)
O22B	0.36557 (10)	0.23937 (15)	−0.02523 (10)	0.0186 (2)
D12B	0.52762 (12)	0.28434 (17)	0.52534 (12)	0.0408 (2)
D21B	0.35396 (12)	0.35973 (18)	−0.09028 (12)	0.0331 (2)
D01B	0.69712 (13)	0.06327 (18)	0.34140 (12)	0.0488 (2)
D02B	0.45644 (17)	−0.04789 (17)	0.17098 (12)	0.0248 (2)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C0A	0.0091 (3)	0.0058 (2)	0.0074 (2)	0.0015 (2)	0.0071 (2)	0.0016 (2)
C1A	0.0067 (2)	0.0051 (2)	0.0057 (2)	0.0004 (2)	0.0053 (2)	0.0010 (2)
C2A	0.0065 (3)	0.0067 (2)	0.0057 (2)	0.0010 (2)	0.0050 (2)	0.0013 (2)
O11A	0.0096 (3)	0.0052 (3)	0.0077 (3)	0.0009 (2)	0.0072 (3)	0.0010 (2)
O12A	0.0140 (3)	0.0057 (3)	0.0097 (3)	0.0016 (2)	0.0105 (3)	0.0021 (2)
O21A	0.0076 (3)	0.0184 (3)	0.0120 (3)	0.0029 (2)	0.0072 (3)	0.0089 (3)
O22A	0.0072 (3)	0.0143 (3)	0.0087 (3)	0.0004 (2)	0.0051 (3)	0.0052 (2)
D12A	0.0219 (5)	0.0134 (4)	0.0167 (4)	0.0019 (3)	0.0168 (4)	0.0020 (3)
D21A	0.0157 (4)	0.0210 (5)	0.0156 (5)	0.0033 (3)	0.0109 (4)	0.0094 (3)
D01A	0.0181 (5)	0.0207 (5)	0.0192 (5)	0.0105 (3)	0.0150 (4)	0.0108 (3)
D02A	0.0222 (5)	0.0121 (4)	0.0175 (5)	−0.0053 (3)	0.0153 (4)	−0.0019 (3)
C0B	0.0083 (2)	0.0061 (2)	0.0063 (2)	0.0014 (2)	0.0060 (2)	0.0015 (2)
C1B	0.0065 (2)	0.0056 (2)	0.0057 (2)	0.0009 (2)	0.0051 (2)	0.0012 (2)
C2B	0.0069 (2)	0.0063 (2)	0.0060 (2)	0.0005 (2)	0.0055 (2)	0.0010 (2)
O11B	0.0102 (3)	0.0058 (3)	0.0087 (3)	0.0017 (2)	0.0080 (3)	0.0019 (2)
O12B	0.0145 (3)	0.0067 (3)	0.0110 (3)	0.0033 (2)	0.0116 (3)	0.0036 (2)
O21B	0.0071 (3)	0.0128 (3)	0.0079 (3)	−0.0003 (2)	0.0048 (2)	0.0038 (2)
O22B	0.0076 (3)	0.0119 (3)	0.0070 (3)	−0.0013 (2)	0.0045 (3)	0.0027 (2)
D12B	0.0211 (5)	0.0151 (4)	0.0167 (4)	0.0039 (3)	0.0165 (4)	0.0041 (3)
D21B	0.0157 (4)	0.0201 (5)	0.0130 (4)	0.0006 (3)	0.0095 (4)	0.0070 (3)
D01B	0.0181 (5)	0.0212 (5)	0.0187 (5)	0.0093 (3)	0.0146 (4)	0.0097 (3)
D02B	0.0229 (5)	0.0120 (4)	0.0173 (5)	−0.0046 (3)	0.0155 (4)	−0.0010 (3)

(56K) top

Crystal data top

C₃D₄O₄	Z = 4
M_r = 108.03	D_x = 1.747 Mg m⁻³
Triclinic, P1	Neutron radiation, λ = 1.0411 Å
a = 10.675 (1) Å	Cell parameters from 32 reflections
b = 5.152 (1) Å	θ = 29–35°
c = 11.238 (1) Å	µ = 0.02 mm⁻¹
α = 103.35 (1)°	T = 56 K
β = 136.68 (1)°	Prism, colourless
γ = 85.07 (1)°	3.0 × 2.4 × 2.0 mm
V = 409.45 (13) Å³

Data collection top

Four-circle diffractometers H6M	3203 independent reflections
Radiation source: steady-state reactor	R_int = 0.022
Be 002 monochromator	θ_max = 55.3°, θ_min = 1.8°
θ–2θ scans	h = −14→14
Absorption correction: analytical Templeton & Templeton, 1973	k = −7→7
T_min = 0.95, T_max = 0.97	l = −15→15
4641 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	w = 1/[s²(F_o²) + (0.02(F_o²))²]
wR(F²) = 0.049
S = 1.02	Δρ_max = 0.45 e Å⁻³
3205 reflections	Δρ_min = −0.50 e Å⁻³
208 parameters	Extinction correction: Becker & Coppens
0 restraints	Extinction coefficient: 0.103 (3)
Primary atom site location: structure-invariant direct methods

Crystal data top

C₃D₄O₄	γ = 85.07 (1)°
M_r = 108.03	V = 409.45 (13) Å³
Triclinic, P1	Z = 4
a = 10.675 (1) Å	Neutron radiation, λ = 1.0411 Å
b = 5.152 (1) Å	µ = 0.02 mm⁻¹
c = 11.238 (1) Å	T = 56 K
α = 103.35 (1)°	3.0 × 2.4 × 2.0 mm
β = 136.68 (1)°

Data collection top

Four-circle diffractometers H6M	4641 measured reflections
Absorption correction: analytical Templeton & Templeton, 1973	3203 independent reflections
T_min = 0.95, T_max = 0.97	R_int = 0.022

Refinement top

wR(F²) = 0.049	0 restraints
S = 1.02	Δρ_max = 0.45 e Å⁻³
3205 reflections	Δρ_min = −0.50 e Å⁻³
208 parameters

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

	x	y	z	U_iso*/U_eq
C0A	0.04205 (7)	0.11896 (9)	0.23879 (6)	0.0194 (3)
C1A	0.03183 (6)	0.29815 (9)	0.35818 (6)	0.0138 (2)
C2A	0.02027 (6)	0.27620 (9)	0.12820 (6)	0.0165 (2)
O11A	0.03222 (8)	0.54172 (11)	0.37671 (7)	0.0188 (3)
O12A	0.02349 (8)	0.16217 (11)	0.43784 (8)	0.0233 (4)
O21A	0.15011 (8)	0.36856 (15)	0.16683 (9)	0.0406 (7)
O22A	−0.15193 (8)	0.30361 (14)	−0.01291 (8)	0.0231 (4)
D12A	0.01138 (10)	0.28128 (14)	0.51244 (9)	0.0360 (5)
D21A	−0.15632 (10)	0.42136 (16)	−0.07479 (10)	0.0391 (6)
D01A	0.17582 (11)	0.04376 (16)	0.32382 (10)	0.0533 (8)
D02A	−0.06682 (11)	−0.05039 (14)	0.15360 (10)	0.0295 (6)
C0B	0.55955 (7)	0.12864 (9)	0.25266 (6)	0.0168 (2)
C1B	0.54391 (6)	0.30411 (9)	0.36861 (6)	0.0154 (2)
C2B	0.53307 (6)	0.28594 (9)	0.13935 (6)	0.0135 (2)
O11B	0.52746 (8)	0.54355 (11)	0.37560 (7)	0.0228 (3)
O12B	0.54962 (8)	0.16994 (11)	0.45802 (8)	0.0284 (4)
O21B	0.65628 (8)	0.43881 (12)	0.19565 (8)	0.0169 (3)
O22B	0.36412 (8)	0.24381 (12)	−0.02455 (7)	0.0148 (2)
D12B	0.52587 (10)	0.28417 (14)	0.52391 (10)	0.0413 (7)
D21B	0.35296 (10)	0.36400 (10)	−0.08948 (9)	0.0308 (5)
D01B	0.69645 (10)	0.06306 (15)	0.34061 (10)	0.0454 (7)
D02B	0.45652 (11)	−0.04779 (14)	0.17057 (10)	0.0272 (4)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C0A	0.0125 (2)	0.0079 (2)	0.0092 (2)	0.0021 (2)	0.0092 (2)	0.0030 (1)
C1A	0.0087 (2)	0.0071 (2)	0.0068 (2)	0.0009 (1)	0.0063 (1)	0.0023 (1)
C2A	0.0097 (2)	0.0091 (2)	0.0077 (2)	0.0015 (1)	0.0072 (2)	0.0010 (2)
O11A	0.0125 (2)	0.0073 (2)	0.0098 (2)	0.0014 (2)	0.0094 (2)	0.0027 (2)
O12A	0.0161 (2)	0.0077 (2)	0.0109 (2)	0.0022 (2)	0.0118 (2)	0.0036 (2)
O21A	0.0102 (2)	0.0290 (3)	0.0176 (3)	0.0058 (2)	0.0101 (2)	0.0166 (2)
O22A	0.0096 (2)	0.0214 (3)	0.0106 (2)	−0.0004 (2)	0.0056 (2)	0.0086 (2)
D12A	0.0244 (4)	0.0155 (3)	0.0181 (3)	0.0028 (2)	0.0183 (3)	0.0040 (2)
D21A	0.0176 (3)	0.0271 (4)	0.0173 (3)	0.0031 (2)	0.0117 (3)	0.0128 (3)
D01A	0.0233 (4)	0.0244 (4)	0.0224 (4)	0.0125 (2)	0.0187 (3)	0.0134 (3)
D02A	0.0283 (4)	0.0152 (3)	0.0198 (4)	−0.0054 (2)	0.0186 (3)	−0.0007 (2)
C0B	0.0113 (2)	0.0077 (2)	0.0082 (2)	0.0013 (1)	0.0081 (2)	0.0023 (1)
C1B	0.0088 (2)	0.0079 (2)	0.0073 (2)	0.0015 (1)	0.0066 (2)	0.0030 (1)
C2B	0.0085 (2)	0.0087 (2)	0.0066 (2)	0.0004 (1)	0.0060 (2)	0.0021 (1)
O11B	0.0139 (2)	0.0080 (2)	0.0115 (2)	0.0026 (2)	0.0110 (2)	0.0039 (2)
O12B	0.0171 (2)	0.0090 (2)	0.0130 (2)	0.0041 (2)	0.0134 (2)	0.0055 (2)
O21B	0.0087 (2)	0.0150 (2)	0.0084 (2)	−0.0010 (2)	0.0055 (2)	0.0048 (2)
O22B	0.0094 (2)	0.0133 (2)	0.0069 (2)	−0.0013 (2)	0.0049 (2)	0.0038 (2)
D12B	0.0252 (4)	0.0171 (3)	0.0197 (3)	0.0052 (2)	0.0196 (3)	0.0063 (2)
D21B	0.0179 (3)	0.0217 (4)	0.0143 (3)	0.0008 (2)	0.0107 (3)	0.0079 (2)
D01B	0.0198 (3)	0.0233 (4)	0.0199 (3)	0.0098 (2)	0.0156 (3)	0.0111 (2)
D02B	0.0252 (4)	0.0144 (3)	0.0186 (3)	−0.0050 (2)	0.0166 (3)	0.0000 (2)

(153K) top

Crystal data top

C₃D₄O₄	Z = 2
M_r = 108.03	D_x = 1.733 Mg m⁻³
Triclinic, P1	Neutron radiation, λ = 1.1588 Å
a = 5.333 (2) Å	Cell parameters from 32 reflections
b = 5.158 (2) Å	θ = 29–35°
c = 11.250 (2) Å	µ = 0.02 mm⁻¹
α = 103.33 (3)°	T = 153 K
β = 136.40 (2)°	Prism, colourless
γ = 84.76 (3)°	3.0 × 2.4 × 2.0 mm
V = 206.34 (15) Å³

Data collection top

Four-circle diffractometers H6S	1169 independent reflections
Radiation source: steady-state reactor	R_int = 0.011
Ge 022 monochromator	θ_max = 54.2°, θ_min = 1.8°
θ–2θ scans	h = −7→7
Absorption correction: analytical Templeton & Templeton, 1973	k = −7→7
T_min = 0.95, T_max = 0.97	l = −15→15
1345 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	w = 1/[σ²(F_o²) + (0.020 (F_o²))² + 514]
wR(F²) = 0.040
S = 1.04	Δρ_max = 0.53 e Å⁻³
1177 reflections	Δρ_min = −0.60 e Å⁻³
105 parameters	Extinction correction: Becker & Coppens
0 restraints	Extinction coefficient: 0.125 (3)
Primary atom site location: structure-invariant direct methods

Crystal data top

C₃D₄O₄	γ = 84.76 (3)°
M_r = 108.03	V = 206.34 (15) Å³
Triclinic, P1	Z = 2
a = 5.333 (2) Å	Neutron radiation, λ = 1.1588 Å
b = 5.158 (2) Å	µ = 0.02 mm⁻¹
c = 11.250 (2) Å	T = 153 K
α = 103.33 (3)°	3.0 × 2.4 × 2.0 mm
β = 136.40 (2)°

Data collection top

Four-circle diffractometers H6S	1345 measured reflections
Absorption correction: analytical Templeton & Templeton, 1973	1169 independent reflections
T_min = 0.95, T_max = 0.97	R_int = 0.011

Refinement top

wR(F²) = 0.040	0 restraints
S = 1.04	Δρ_max = 0.53 e Å⁻³
1177 reflections	Δρ_min = −0.60 e Å⁻³
105 parameters

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

	x	y	z	U_iso*/U_eq
C0	0.60455 (14)	0.12563 (10)	0.24685 (7)	0.0309 (5)
C1	0.57591 (13)	0.30175 (10)	0.36341 (6)	0.0247 (4)
C2	0.55587 (14)	0.28324 (10)	0.13513 (7)	0.0255 (4)
O11	0.55832 (17)	0.54299 (12)	0.37553 (8)	0.0362 (6)
O12	0.5723 (5)	0.1654 (4)	0.4458 (3)	0.0531 (8)
O21	0.8066 (5)	0.4133 (4)	0.1845 (3)	0.0436 (7)
O22	0.2170 (5)	0.2676 (5)	−0.0190 (3)	0.0343 (6)
D12	0.5371 (2)	0.28112 (18)	0.51686 (12)	0.0552 (8)
D21	0.1988 (2)	0.3852 (2)	−0.08380 (13)	0.0451 (7)
D01	0.8758 (2)	0.05620 (15)	0.33327 (10)	0.0742 (10)
D02	0.3974 (2)	−0.04627 (14)	0.16512 (10)	0.0431 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C0	0.0195 (2)	0.0123 (2)	0.0155 (2)	0.0034 (2)	0.0145 (2)	0.0043 (2)
C1	0.0136 (2)	0.0114 (2)	0.0126 (2)	0.0025 (2)	0.0106 (2)	0.0043 (2)
C2	0.0152 (2)	0.0136 (2)	0.0126 (2)	0.0017 (2)	0.0112 (2)	0.0035 (2)
O11	0.0207 (3)	0.0115 (2)	0.0184 (3)	0.0035 (2)	0.0167 (3)	0.0047 (2)
O12	0.0285 (3)	0.0131 (3)	0.0215 (3)	0.0055 (2)	0.0220 (3)	0.0070 (2)
O21	0.0145 (3)	0.0379 (4)	0.0210 (3)	0.0019 (3)	0.0110 (2)	0.0171 (3)
O22	0.0172 (3)	0.0313 (3)	0.0154 (3)	−0.0051 (3)	0.0082 (3)	0.0094 (3)
D12	0.0337 (5)	0.0204 (4)	0.0268 (4)	0.0055 (3)	0.0258 (4)	0.0076 (3)
D21	0.0239 (4)	0.0374 (5)	0.0211 (4)	−0.0013 (3)	0.0135 (3)	0.0123 (3)
D01	0.0318 (5)	0.0314 (4)	0.0325 (4)	0.0177 (3)	0.0266 (4)	0.0188 (3)
D02	0.0410 (5)	0.0197 (4)	0.0285 (4)	−0.0066 (3)	0.0269 (4)	−0.0006 (3)

Experimental details

	(50K)	(56K)	(153K)
Crystal data
Chemical formula	C₃D₄O₄	C₃D₄O₄	C₃D₄O₄
M_r	108.03	108.03	108.03
Crystal system, space group	Triclinic, P1	Triclinic, P1	Triclinic, P1
Temperature (K)	50	56	153
a, b, c (Å)	10.663 (4), 5.142 (2), 11.234 (2)	10.675 (1), 5.152 (1), 11.238 (1)	5.333 (2), 5.158 (2), 11.250 (2)
α, β, γ (°)	103.39 (3), 136.81 (2), 85.19 (3)	103.35 (1), 136.68 (1), 85.07 (1)	103.33 (3), 136.40 (2), 84.76 (3)
V (Å³)	406.8 (3)	409.45 (13)	206.34 (15)
Z	4	4	2
Radiation type	Neutron, λ = 1.1588 Å	Neutron, λ = 1.0411 Å	Neutron, λ = 1.1588 Å
µ (mm⁻¹)	0.02	0.02	0.02
Crystal size (mm)	3.0 × 2.4 × 2.0	3.0 × 2.4 × 2.0	3.0 × 2.4 × 2.0

Data collection
Diffractometer	Four-circle diffractometers H6S	Four-circle diffractometers H6M	Four-circle diffractometers H6S
Absorption correction	Analytical Templeton & Templeton, 1973	Analytical Templeton & Templeton, 1973	Analytical Templeton & Templeton, 1973
T_min, T_max	0.95, 0.97	0.95, 0.97	0.95, 0.97
No. of measured, independent and observed reflections	2653, 2307, ? [I > 2σ(I)]	4641, 3203, ? [ > 0*σ(I)]	1345, 1169, ? [ > 0*σ(I)]
R_int	0.019	0.022	0.011
(sin θ/λ)_max (Å⁻¹)	0.700	0.790	0.700

Refinement
R[F² > 2σ(F²)], wR(F²), S	?, 0.052, 1.53	?, 0.049, 1.02	?, 0.040, 1.04
No. of reflections	2300	3205	1177
No. of parameters	208	208	105
Δρ_max, Δρ_min (e Å⁻³)	0.27, −0.40	0.45, −0.50	0.53, −0.60

Computer programs: UPALS(Lundgren,82)&NOOT(Craven et al.,91), UPALS (Lundgren,82)& NOOT(Craven et al.,91), UPALS(Lundgren,'82)& NOOT(Craven et al.,91), DIAMOND (Brandenburg, 2006).

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