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Acta Cryst. (2008). E64, o667    [ doi:10.1107/S1600536808004339 ]

The low-temperature phase of morpholinium tetrafluoroborate

M. Owczarek, P. Szklarz, R. Jakubas and T. Lis

Abstract top

The crystal structure of the low-temperature form of the title compound, C4H10NO+·BF4-, was determined at 80 K. Two reversible phase transitions, at 158/158 and 124/126 K (heating/cooling), were detected by differential scanning calorimetry for this compound, and the sequence of phase transitions was subsequently confirmed by single-crystal X-ray diffraction experiments. The asymmetric unit at 80 K consists of three BF4- tetrahedral anions and three morpholinium cations (Z' = 3). Hydrogen-bonded morpholinium cations form chains along the [100] direction. The BF4- anions are connected to these chains by N-H...F hydrogen bonds. In the crystal structure, two different layers perpendicular to the [001] direction can be distinguished, which differ in the geometry of the hydrogen bonds between cationic and anionic species.

Comment top

The morpholinium tetrafluoroborate (I) undergoes two reversible phase transitions at 158/158 K and 124/126 K (heating/cooling). At the room temperature it crystallizes in the orthorhombic space group Pnma with Z'=1. The intermediate phase appeared to be incommensurately modulated. The structure of (I) in the low-temperature phase contains ordered BF4- tetrahedral units and morpholinium cations in the chair conformation. The bond distances and angles in the BF4- anions and morpholinium cations are in agreement with the expected values. The N–H morpholinium protons are involved in the hydrogen bonds N–H···O (morpholine-morpholine zigzag chains) and N—H···F with BF4- anions. The tetrahedral BF4- anions occupy voids between morpholinium chains.

The title compound I appeared to be isostructural with morpholinium chlorate(VII) at 100 K (Grigoriev et al., 2008). Both structures are characterized by two independent hydrogen bonded layers and only slight differences in geometry of hydrogen bonds between morpholinium and anionic species are observed.

The room-temperature phase of I is isostructural with the morpholinium hydrogensulfate (Yin et al., 2006). The tetrafluoroborate anions appear to be dynamically disordered in this phase. During the phase transition from modulated to the low temperature phase at 124 K threefold increase of the lattice parameter b is observed.

Related literature top

For the crystal structures of morpholinium chlorate(VII) (isostructural with the title compound) and morpholinium hydrogensulfate, see: Grigoriev et al. (2008); Yin et al. (2006).

Experimental top

The title compound was prepared by reaction of stoichiometric amounts of morpholine and concentrated tetrafluoroboric acid in water. The resulting solid was recrystallized from methanol at room temperature. The crystal for X-ray measurements was slowly cooled from room temperature to 80 K. During cooling, the crystal undergoes phase transition from centrosymmetric (Pnma), through modulated phase, to the non-centrosymmetric P212121 space group.

Refinement top

In the absence of signifiant anomalous scattering effects, Friedel pairs were averaged. All H atoms were found in difference-Fourier maps. In the final refinement, all H atoms were positioned geometrically and treated as riding on their parent atoms, with C–H distances of 0.99 Å and N–H distances of 0.92 Å, and with Uiso(H) values of 1.2Ueq(C) and 1.2Ueq(N).

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis CCD (Oxford Diffraction, 2006); data reduction: CrysAlis RED (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Asymmetric unit of the title compound with atom labelling scheme. The displacement ellipsoids were drawn at the 50% probability level.
[Figure 2] Fig. 2. Projection of the crystal packing along [100].
[Figure 3] Fig. 3. Two types of chains in the crystal structure of (I). Symmetry codes: (v) 1/2 + x, 1/2 - y, 1 - z; (x) 1 + x, y, z; (xi) 3/2 + x, 1/2 - y,1 - z; (xii) -1/2 + x, 3/2 - y,1 - z; (xiii) -1 + x, y, z; (xiv) -3/2 + x, 3/2 - y, 1 - z.
morpholinium tetrafluoroborate top
Crystal data top
C4H10NO+·BF4–F000 = 1080
Mr = 174.94Dx = 1.598 Mg m−3
Orthorhombic, P212121Mo Kα radiation
λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 14871 reflections
a = 8.106 (4) Åθ = 5–34º
b = 9.417 (4) ŵ = 0.17 mm−1
c = 28.572 (11) ÅT = 80 (2) K
V = 2181.0 (16) Å3Block, colorless
Z = 120.5 × 0.5 × 0.4 mm
Data collection top
Kuma KM-4 CCD κ-geometry
diffractometer		3913 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.033
Monochromator: graphiteθmax = 34.3º
T = 80(2) Kθmin = 4.8º
ω scansh = −12→9
Absorption correction: nonek = −14→14
20616 measured reflectionsl = −44→32
4642 independent reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.037H-atom parameters constrained
wR(F2) = 0.092  w = 1/[σ2(Fo2) + (0.052P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.13(Δ/σ)max = 0.001
4642 reflectionsΔρmax = 0.46 e Å−3
298 parametersΔρmin = −0.31 e Å−3
Primary atom site location: structure-invariant direct methodsExtinction correction: none
Crystal data top
C4H10NO+·BF4–V = 2181.0 (16) Å3
Mr = 174.94Z = 12
Orthorhombic, P212121Mo Kα
a = 8.106 (4) ŵ = 0.17 mm−1
b = 9.417 (4) ÅT = 80 (2) K
c = 28.572 (11) Å0.5 × 0.5 × 0.4 mm
Data collection top
Kuma KM-4 CCD κ-geometry
diffractometer		4642 independent reflections
Absorption correction: none3913 reflections with I > 2σ(I)
20616 measured reflectionsRint = 0.033
Refinement top
R[F2 > 2σ(F2)] = 0.037Δρmax = 0.46 e Å−3
wR(F2) = 0.092Δρmin = −0.31 e Å−3
S = 1.13Absolute structure: ?
4642 reflectionsFlack parameter: ?
298 parametersRogers parameter: ?
H-atom parameters constrained
Special details top

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 (Å2) top
xyzUiso*/Ueq
B10.5748 (2)−0.38148 (19)0.66006 (6)0.0138 (3)
B20.38324 (17)0.16152 (18)0.50547 (6)0.0145 (3)
B30.5721 (2)−0.36435 (19)0.33817 (6)0.0137 (3)
F10.67871 (11)−0.36736 (13)0.69879 (3)0.0272 (2)
F20.52308 (13)−0.24786 (11)0.64441 (4)0.0285 (2)
F30.43715 (11)−0.46227 (11)0.67231 (3)0.0207 (2)
F40.66156 (10)−0.44725 (10)0.62384 (3)0.01512 (17)
F50.35554 (13)0.23160 (12)0.46328 (3)0.0258 (2)
F60.24001 (11)0.09601 (11)0.52149 (4)0.0257 (2)
F70.50716 (11)0.06012 (10)0.50017 (4)0.0244 (2)
F80.43192 (12)0.26312 (10)0.53898 (3)0.01994 (19)
F90.52566 (14)−0.23018 (12)0.35451 (4)0.0333 (3)
F100.67387 (11)−0.35204 (14)0.29913 (3)0.0306 (3)
F110.43177 (11)−0.44221 (11)0.32671 (3)0.0222 (2)
F120.65993 (10)−0.43246 (10)0.37371 (3)0.01573 (18)
O10.69421 (11)0.25053 (12)0.67290 (4)0.0142 (2)
O20.23260 (11)0.76931 (12)0.49397 (4)0.0166 (2)
O30.69339 (11)0.26920 (12)0.32955 (4)0.0151 (2)
N10.45612 (14)0.02870 (13)0.66772 (4)0.0111 (2)
H1C0.4314−0.06640.66540.013*
H1D0.35850.07840.66900.013*
N20.45949 (13)0.54141 (13)0.50542 (4)0.0130 (2)
H2C0.47780.44550.50860.016*
H2D0.55990.58680.50630.016*
N30.45585 (14)0.04709 (13)0.33294 (4)0.0113 (2)
H3C0.4306−0.04800.33500.014*
H3D0.35860.09710.33110.014*
C10.55316 (17)0.05500 (16)0.71154 (5)0.0133 (3)
H1A0.6538−0.00460.71170.016*
H1B0.48610.03000.73930.016*
C20.60018 (17)0.21069 (18)0.71332 (5)0.0154 (3)
H2A0.49890.26930.71490.018*
H2B0.66590.22910.74190.018*
C30.59955 (16)0.22934 (17)0.63068 (5)0.0139 (3)
H3A0.66540.25940.60320.017*
H3B0.49850.28830.63180.017*
C40.55267 (18)0.07415 (16)0.62565 (5)0.0137 (3)
H4A0.48550.06070.59700.016*
H4B0.65350.01550.62280.016*
C50.35391 (17)0.59281 (18)0.54488 (5)0.0160 (3)
H5A0.41220.57910.57500.019*
H5B0.24980.53790.54590.019*
C60.31647 (17)0.74878 (17)0.53769 (5)0.0179 (3)
H6A0.24650.78380.56360.022*
H6B0.42060.80380.53780.022*
C70.33543 (18)0.72648 (17)0.45575 (5)0.0166 (3)
H7A0.43840.78300.45600.020*
H7B0.27770.74500.42580.020*
C80.37715 (17)0.56993 (17)0.45929 (5)0.0149 (3)
H8A0.27510.51260.45670.018*
H8B0.45170.54260.43340.018*
C90.54945 (18)0.09205 (16)0.37573 (5)0.0140 (3)
H9A0.65020.03350.37910.017*
H9B0.48030.07820.40390.017*
C100.59621 (16)0.24721 (16)0.37110 (5)0.0147 (3)
H10A0.49500.30590.36950.018*
H10B0.66010.27710.39890.018*
C110.60280 (17)0.22966 (17)0.28841 (5)0.0153 (3)
H11A0.67070.24840.26030.018*
H11B0.50140.28780.28620.018*
C120.55689 (17)0.07375 (16)0.29006 (5)0.0132 (3)
H12A0.49290.04800.26180.016*
H12B0.65800.01480.29080.016*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
B10.0138 (6)0.0131 (8)0.0143 (7)−0.0009 (6)−0.0009 (5)−0.0013 (6)
B20.0134 (5)0.0142 (7)0.0158 (7)0.0010 (5)−0.0013 (5)−0.0011 (7)
B30.0145 (6)0.0128 (8)0.0139 (7)−0.0011 (6)−0.0002 (5)0.0014 (6)
F10.0194 (4)0.0478 (7)0.0145 (4)−0.0065 (5)−0.0016 (3)−0.0079 (5)
F20.0373 (5)0.0128 (5)0.0353 (6)0.0082 (4)0.0082 (4)0.0009 (4)
F30.0151 (4)0.0218 (5)0.0251 (4)−0.0049 (4)0.0030 (4)0.0001 (4)
F40.0160 (4)0.0152 (4)0.0142 (4)0.0024 (3)0.0004 (3)−0.0005 (4)
F50.0338 (5)0.0305 (6)0.0131 (4)0.0110 (5)−0.0033 (4)0.0005 (4)
F60.0173 (4)0.0230 (5)0.0369 (5)−0.0078 (4)0.0042 (4)−0.0056 (5)
F70.0200 (4)0.0197 (5)0.0334 (5)0.0079 (3)0.0017 (4)0.0011 (5)
F80.0288 (4)0.0143 (5)0.0167 (4)−0.0052 (4)−0.0058 (3)0.0007 (4)
F90.0418 (6)0.0122 (5)0.0458 (6)0.0099 (5)−0.0112 (5)−0.0032 (5)
F100.0210 (5)0.0571 (8)0.0137 (4)−0.0115 (5)0.0012 (3)0.0090 (5)
F110.0148 (4)0.0249 (5)0.0270 (5)−0.0056 (4)−0.0027 (4)0.0019 (5)
F120.0179 (4)0.0160 (4)0.0133 (4)0.0026 (3)−0.0011 (3)0.0001 (4)
O10.0122 (4)0.0166 (5)0.0138 (4)−0.0041 (4)−0.0018 (3)0.0007 (4)
O20.0128 (3)0.0165 (5)0.0205 (5)0.0050 (4)−0.0019 (4)−0.0021 (5)
O30.0126 (4)0.0160 (5)0.0166 (5)−0.0042 (4)0.0008 (3)−0.0005 (4)
N10.0105 (5)0.0092 (5)0.0136 (5)−0.0006 (4)−0.0003 (4)−0.0004 (5)
N20.0112 (4)0.0094 (5)0.0185 (6)0.0002 (4)−0.0001 (4)0.0012 (5)
N30.0113 (5)0.0096 (5)0.0130 (5)−0.0005 (4)0.0011 (4)0.0011 (5)
C10.0156 (6)0.0139 (7)0.0105 (5)−0.0015 (5)−0.0007 (5)−0.0001 (6)
C20.0165 (6)0.0172 (7)0.0124 (6)−0.0027 (5)−0.0005 (4)−0.0031 (6)
C30.0152 (6)0.0147 (7)0.0116 (6)−0.0018 (5)−0.0009 (4)0.0012 (6)
C40.0176 (6)0.0129 (7)0.0105 (5)−0.0011 (5)0.0009 (5)−0.0016 (6)
C50.0139 (5)0.0237 (8)0.0104 (5)−0.0020 (6)−0.0014 (5)−0.0003 (6)
C60.0158 (6)0.0199 (8)0.0182 (6)0.0020 (6)−0.0018 (5)−0.0080 (6)
C70.0170 (6)0.0169 (7)0.0159 (6)0.0017 (5)0.0001 (5)0.0053 (6)
C80.0175 (6)0.0152 (7)0.0120 (6)0.0014 (5)0.0019 (5)−0.0019 (6)
C90.0167 (6)0.0144 (7)0.0109 (5)0.0009 (5)−0.0001 (5)0.0012 (6)
C100.0157 (6)0.0141 (7)0.0144 (6)−0.0009 (5)0.0004 (4)−0.0019 (6)
C110.0161 (6)0.0162 (7)0.0135 (6)−0.0027 (5)0.0014 (4)0.0019 (6)
C120.0140 (5)0.0153 (7)0.0103 (5)−0.0011 (5)0.0008 (5)−0.0010 (6)
Geometric parameters (Å, °) top
B1—F31.3950 (19)C1—C21.516 (2)
B1—F41.3964 (19)C1—H1A0.9900
B1—F11.3971 (18)C1—H1B0.9900
B1—F21.400 (2)C2—H2A0.9900
B2—F61.3921 (18)C2—H2B0.9900
B2—F51.3926 (19)C3—C41.517 (2)
B2—F71.3942 (18)C3—H3A0.9900
B2—F81.4098 (19)C3—H3B0.9900
B3—F101.3919 (18)C4—H4A0.9900
B3—F111.3926 (19)C4—H4B0.9900
B3—F121.3962 (19)C5—C61.514 (2)
B3—F91.399 (2)C5—H5A0.9900
O1—C21.4338 (18)C5—H5B0.9900
O1—C31.4435 (17)C6—H6A0.9900
O2—C71.4318 (18)C6—H6B0.9900
O2—C61.4354 (18)C7—C81.516 (2)
O3—C111.4350 (18)C7—H7A0.9900
O3—C101.4397 (18)C7—H7B0.9900
N1—C41.4968 (18)C8—H8A0.9900
N1—C11.4992 (17)C8—H8B0.9900
N1—H1C0.9200C9—C101.515 (2)
N1—H1D0.9200C9—H9A0.9900
N2—C51.4960 (18)C9—H9B0.9900
N2—C81.5014 (18)C10—H10A0.9900
N2—H2C0.9200C10—H10B0.9900
N2—H2D0.9200C11—C121.515 (2)
N3—C121.4950 (17)C11—H11A0.9900
N3—C91.4998 (18)C11—H11B0.9900
N3—H3C0.9200C12—H12A0.9900
N3—H3D0.9200C12—H12B0.9900
F3—B1—F4110.30 (13)H3A—C3—H3B108.1
F3—B1—F1109.61 (13)N1—C4—C3109.29 (11)
F4—B1—F1109.00 (12)N1—C4—H4A109.8
F3—B1—F2109.32 (13)C3—C4—H4A109.8
F4—B1—F2108.22 (13)N1—C4—H4B109.8
F1—B1—F2110.37 (14)C3—C4—H4B109.8
F6—B2—F5111.11 (12)H4A—C4—H4B108.3
F6—B2—F7109.46 (13)N2—C5—C6109.05 (12)
F5—B2—F7110.28 (12)N2—C5—H5A109.9
F6—B2—F8108.12 (12)C6—C5—H5A109.9
F5—B2—F8108.14 (13)N2—C5—H5B109.9
F7—B2—F8109.69 (11)C6—C5—H5B109.9
F10—B3—F11109.85 (13)H5A—C5—H5B108.3
F10—B3—F12108.61 (13)O2—C6—C5110.10 (12)
F11—B3—F12110.21 (13)O2—C6—H6A109.6
F10—B3—F9110.60 (14)C5—C6—H6A109.6
F11—B3—F9109.52 (13)O2—C6—H6B109.6
F12—B3—F9108.03 (13)C5—C6—H6B109.6
C2—O1—C3110.75 (10)H6A—C6—H6B108.2
C7—O2—C6110.50 (10)O2—C7—C8110.66 (12)
C11—O3—C10110.98 (10)O2—C7—H7A109.5
C4—N1—C1110.43 (11)C8—C7—H7A109.5
C4—N1—H1C109.6O2—C7—H7B109.5
C1—N1—H1C109.6C8—C7—H7B109.5
C4—N1—H1D109.6H7A—C7—H7B108.1
C1—N1—H1D109.6N2—C8—C7109.38 (12)
H1C—N1—H1D108.1N2—C8—H8A109.8
C5—N2—C8110.45 (10)C7—C8—H8A109.8
C5—N2—H2C109.6N2—C8—H8B109.8
C8—N2—H2C109.6C7—C8—H8B109.8
C5—N2—H2D109.6H8A—C8—H8B108.2
C8—N2—H2D109.6N3—C9—C10109.12 (12)
H2C—N2—H2D108.1N3—C9—H9A109.9
C12—N3—C9110.09 (11)C10—C9—H9A109.9
C12—N3—H3C109.6N3—C9—H9B109.9
C9—N3—H3C109.6C10—C9—H9B109.9
C12—N3—H3D109.6H9A—C9—H9B108.3
C9—N3—H3D109.6O3—C10—C9110.34 (12)
H3C—N3—H3D108.2O3—C10—H10A109.6
N1—C1—C2108.65 (11)C9—C10—H10A109.6
N1—C1—H1A110.0O3—C10—H10B109.6
C2—C1—H1A110.0C9—C10—H10B109.6
N1—C1—H1B110.0H10A—C10—H10B108.1
C2—C1—H1B110.0O3—C11—C12110.59 (12)
H1A—C1—H1B108.3O3—C11—H11A109.5
O1—C2—C1111.08 (12)C12—C11—H11A109.5
O1—C2—H2A109.4O3—C11—H11B109.5
C1—C2—H2A109.4C12—C11—H11B109.5
O1—C2—H2B109.4H11A—C11—H11B108.1
C1—C2—H2B109.4N3—C12—C11108.82 (11)
H2A—C2—H2B108.0N3—C12—H12A109.9
O1—C3—C4110.22 (12)C11—C12—H12A109.9
O1—C3—H3A109.6N3—C12—H12B109.9
C4—C3—H3A109.6C11—C12—H12B109.9
O1—C3—H3B109.6H12A—C12—H12B108.3
C4—C3—H3B109.6
C4—N1—C1—C256.30 (14)C6—O2—C7—C861.49 (15)
C3—O1—C2—C161.00 (14)C5—N2—C8—C754.94 (14)
N1—C1—C2—O1−58.22 (14)O2—C7—C8—N2−57.26 (14)
C2—O1—C3—C4−60.55 (14)C12—N3—C9—C1057.02 (14)
C1—N1—C4—C3−56.75 (15)C11—O3—C10—C960.49 (15)
O1—C3—C4—N158.12 (14)N3—C9—C10—O3−58.07 (14)
C8—N2—C5—C6−55.96 (14)C10—O3—C11—C12−60.89 (14)
C7—O2—C6—C5−62.45 (15)C9—N3—C12—C11−57.07 (14)
N2—C5—C6—O259.27 (14)O3—C11—C12—N358.66 (14)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N1—H1C···F20.921.962.742 (2)142
N1—H1D···O3i0.921.962.857 (2)164
N2—H2C···F80.921.962.799 (2)151
N2—H2D···O2ii0.921.952.842 (2)164
N3—H3C···F90.921.962.742 (2)141
N3—H3D···O1i0.921.962.856 (2)164
C1—H1B···F1iii0.992.423.261 (2)143
C2—H2B···F10iv0.992.393.337 (2)160
C3—H3A···F5v0.992.453.413 (2)165
C5—H5A···F4vi0.992.473.384 (2)154
C5—H5B···F7i0.992.543.410 (2)147
C6—H6A···F12i0.992.383.318 (2)158
C8—H8B···F12vi0.992.413.352 (2)159
C9—H9B···F50.992.453.233 (2)136
C11—H11A···F1vii0.992.413.373 (2)163
C12—H12A···F10viii0.992.403.237 (2)142
C12—H12B···F3ix0.992.543.429 (2)149
Symmetry codes: (i) x−1/2, −y+1/2, −z+1; (ii) x+1/2, −y+3/2, −z+1; (iii) −x+1, y+1/2, −z+3/2; (iv) −x+3/2, −y, z+1/2; (v) x+1/2, −y+1/2, −z+1; (vi) x, y+1, z; (vii) −x+3/2, −y, z−1/2; (viii) −x+1, y+1/2, −z+1/2; (ix) x+1/2, −y−1/2, −z+1.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N1—H1C···F20.921.962.742 (2)142
N1—H1D···O3i0.921.962.857 (2)164
N2—H2C···F80.921.962.799 (2)151
N2—H2D···O2ii0.921.952.842 (2)164
N3—H3C···F90.921.962.742 (2)141
N3—H3D···O1i0.921.962.856 (2)164
Symmetry codes: (i) x−1/2, −y+1/2, −z+1; (ii) x+1/2, −y+3/2, −z+1.
Acknowledgements top

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references
References top

Brandenburg, K. (1998). DIAMOND. University of Bonn, Germany

Grigoriev, M. S., German, K. E. & Maruk, A. Y. (2008). Acta Cryst. E64, o390–?.

Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Versions 1.171. Oxford Diffraction, Abingdon, Oxfordshire, England.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Yin, C.-X., Huo, F.-J. & Yang, P. (2006). Acta Cryst. E62, o2084–o2085.