Enantio­tropically related polymorphs of gaboxadol hydro­chloride

Gaboxadol hydro­chloride, also known as THIP hydro­chloride (systematic name: 3-hy­droxy-4,5,6,7-tetra­hydro-1,2-oxazolo[5,4-c]pyridin-6-ium chloride), C₆H₉N₂O₂⁺·Cl^-, exists as two enantio­tropically related polymorphs. Transformation between the polymorphs occurs in a single-crystal-to-single-crystal manner at 221 K, and the enthalpy of transformation from the high-temperature form to the low-temperature form is -0.7 kJ mol^-1. Single-crystal structures have been determined at 298 and 220 K. At 298 K, the structure is triclinic (space group P), with two formula units in the crystallographic asymmetric unit. At 220 K, the structure is monoclinic (space group I2/a), with one formula unit in the asymmetric unit. The structures contain identical hydrogen-bonded layers and the transformation between the polymorphs corresponds to a shift of adjacent layers relative to each other. The transformation is shown to be reversible by differential scanning calorimetry and variable-temperature powder X-ray diffraction.

Computing details

Data collection: APEX2 (Bruker, 2010) for RT, LT. Cell refinement: SAINT (Bruker, 2010) for RT, LT. Data reduction: SAINT (Bruker, 2010) for RT, LT. Program(s) used to solve structure: SHELXTL (Sheldrick, 2008) for RT, LT. Program(s) used to refine structure: SHELXTL (Sheldrick, 2008) for RT, LT. Molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2008) for RT, LT. Software used to prepare material for publication: SHELXTL (Sheldrick, 2008) for RT, LT.

(RT) 3-Hydroxy-4,5,6,7-tetrahydro-1,2-oxazolo[5,4-c]pyridin-6-ium chloride

Crystal data

C6H9N2O2^+·Cl^−	Z = 4
Mr = 176.60	F(000) = 368
Triclinic, P1	Dx = 1.541 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.6783 (3) Å	Cell parameters from 3894 reflections
b = 10.8766 (6) Å	θ = 3.0–25.1°
c = 11.2276 (6) Å	µ = 0.45 mm^−1
α = 100.668 (2)°	T = 298 K
β = 101.049 (2)°	Lath, colourless
γ = 101.917 (2)°	0.25 × 0.10 × 0.08 mm
V = 761.43 (7) Å^3

Data collection

Bruker Nonius X8 APEXII CCD area-detector diffractometer	2859 independent reflections
Radiation source: fine-focus sealed tube	2039 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
thin–slice ω and φ scans	θmax = 25.8°, θmin = 3.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −8→7
Tmin = 0.680, Tmax = 0.965	k = −13→13
12968 measured reflections	l = −13→13

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.115	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0717P)^2 + 0.0033P] where P = (Fo^2 + 2Fc^2)/3
2859 reflections	(Δ/σ)max < 0.001
224 parameters	Δρmax = 0.57 e Å^−3
6 restraints	Δρmin = −0.24 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.84575 (9)	0.32226 (5)	0.41555 (5)	0.03877 (19)
Cl2	0.17997 (8)	0.17488 (5)	0.07924 (5)	0.03638 (19)
O1A	0.7123 (2)	0.16164 (16)	0.59102 (15)	0.0433 (4)
H1A	0.729 (4)	0.209 (2)	0.542 (2)	0.058 (8)*
O2A	0.1881 (2)	0.16004 (15)	0.57530 (13)	0.0437 (4)
N1A	0.3797 (3)	0.19985 (19)	0.53740 (17)	0.0409 (5)
N2A	0.1326 (3)	−0.07435 (19)	0.76800 (18)	0.0384 (5)
H2AA	0.124 (4)	−0.1430 (16)	0.7046 (16)	0.054 (7)*
H2AB	0.044 (3)	−0.105 (2)	0.815 (2)	0.064 (8)*
C1A	0.5135 (3)	0.1471 (2)	0.59882 (19)	0.0323 (5)
C2A	0.4234 (3)	0.0746 (2)	0.67748 (18)	0.0299 (5)
C3A	0.2273 (4)	0.0865 (2)	0.65797 (19)	0.0338 (5)
C4A	0.0579 (4)	0.0282 (2)	0.7143 (2)	0.0383 (5)
H4AA	−0.0733	−0.0088	0.6512	0.046*
H4AB	0.0353	0.0928	0.7789	0.046*
C5A	0.3550 (3)	−0.0329 (2)	0.84300 (19)	0.0390 (6)
H5AA	0.3863	−0.1010	0.8826	0.047*
H5AB	0.3719	0.0433	0.9083	0.047*
C6A	0.5092 (3)	−0.0027 (2)	0.76307 (19)	0.0347 (5)
H6AA	0.6460	0.0463	0.8155	0.042*
H6AB	0.5257	−0.0822	0.7149	0.042*
O1B	−0.0242 (3)	0.66410 (17)	0.09055 (15)	0.0459 (4)
H1B	−0.056 (4)	0.708 (2)	0.0414 (19)	0.049 (8)*
O2B	0.4876 (2)	0.65808 (15)	0.07513 (14)	0.0460 (4)
N1B	0.2998 (3)	0.70012 (19)	0.03729 (17)	0.0429 (5)
N2B	0.4975 (3)	0.41927 (19)	0.26289 (19)	0.0422 (5)
H2BA	0.425 (4)	0.3514 (17)	0.1958 (16)	0.061 (8)*
H2BB	0.597 (4)	0.387 (3)	0.307 (3)	0.102 (12)*
C1B	0.1697 (4)	0.6487 (2)	0.09850 (19)	0.0341 (5)
C2B	0.2577 (3)	0.5738 (2)	0.17598 (18)	0.0309 (5)
C3B	0.4493 (3)	0.5837 (2)	0.15649 (19)	0.0347 (5)
C4B	0.6118 (4)	0.5234 (2)	0.2128 (2)	0.0420 (6)
H4BA	0.7184	0.5866	0.2794	0.050*
H4BB	0.6796	0.4875	0.1505	0.050*
C5B	0.3531 (4)	0.4620 (2)	0.3393 (2)	0.0428 (6)
H5BA	0.4315	0.5369	0.4055	0.051*
H5BB	0.2983	0.3934	0.3775	0.051*
C6B	0.1715 (4)	0.4960 (2)	0.2602 (2)	0.0370 (5)
H6BA	0.0683	0.4178	0.2110	0.044*
H6BB	0.1032	0.5457	0.3132	0.044*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0435 (4)	0.0375 (3)	0.0425 (4)	0.0131 (3)	0.0151 (3)	0.0186 (3)
Cl2	0.0393 (3)	0.0367 (3)	0.0399 (3)	0.0116 (3)	0.0151 (3)	0.0175 (3)
O1A	0.0428 (10)	0.0477 (10)	0.0500 (10)	0.0119 (8)	0.0211 (8)	0.0265 (9)
O2A	0.0424 (10)	0.0507 (10)	0.0475 (10)	0.0197 (8)	0.0109 (8)	0.0259 (8)
N1A	0.0405 (12)	0.0446 (12)	0.0432 (11)	0.0105 (9)	0.0125 (9)	0.0218 (9)
N2A	0.0435 (12)	0.0399 (12)	0.0417 (11)	0.0123 (9)	0.0253 (10)	0.0158 (10)
C1A	0.0370 (13)	0.0263 (12)	0.0330 (12)	0.0037 (10)	0.0122 (10)	0.0065 (9)
C2A	0.0343 (12)	0.0279 (11)	0.0275 (11)	0.0058 (9)	0.0079 (9)	0.0078 (9)
C3A	0.0399 (13)	0.0324 (12)	0.0304 (11)	0.0115 (10)	0.0066 (9)	0.0096 (9)
C4A	0.0339 (13)	0.0435 (14)	0.0412 (12)	0.0134 (10)	0.0112 (10)	0.0126 (10)
C5A	0.0454 (14)	0.0432 (14)	0.0352 (12)	0.0153 (11)	0.0127 (11)	0.0176 (10)
C6A	0.0355 (12)	0.0374 (13)	0.0364 (12)	0.0127 (10)	0.0113 (10)	0.0147 (10)
O1B	0.0461 (11)	0.0541 (11)	0.0474 (10)	0.0212 (9)	0.0098 (8)	0.0279 (9)
O2B	0.0462 (10)	0.0508 (10)	0.0500 (10)	0.0136 (8)	0.0194 (8)	0.0245 (8)
N1B	0.0484 (13)	0.0453 (12)	0.0417 (11)	0.0150 (10)	0.0120 (10)	0.0217 (9)
N2B	0.0392 (12)	0.0354 (12)	0.0484 (12)	0.0109 (9)	−0.0020 (10)	0.0122 (10)
C1B	0.0424 (14)	0.0320 (12)	0.0293 (11)	0.0119 (10)	0.0067 (10)	0.0093 (10)
C2B	0.0339 (12)	0.0293 (12)	0.0284 (11)	0.0073 (9)	0.0046 (9)	0.0075 (9)
C3B	0.0387 (13)	0.0321 (12)	0.0338 (12)	0.0077 (10)	0.0100 (10)	0.0093 (10)
C4B	0.0360 (13)	0.0454 (14)	0.0478 (14)	0.0123 (11)	0.0131 (11)	0.0132 (11)
C5B	0.0476 (15)	0.0440 (14)	0.0403 (13)	0.0103 (12)	0.0088 (11)	0.0219 (11)
C6B	0.0374 (12)	0.0407 (13)	0.0369 (12)	0.0115 (10)	0.0101 (10)	0.0156 (10)

Geometric parameters (Å, º)

O1A—C1A	1.326 (3)	O1B—C1B	1.328 (3)
O1A—H1A	0.830 (17)	O1B—H1B	0.821 (16)
O2A—C3A	1.356 (2)	O2B—C3B	1.353 (2)
O2A—N1A	1.433 (2)	O2B—N1B	1.438 (2)
N1A—C1A	1.313 (3)	N1B—C1B	1.308 (3)
N2A—C4A	1.490 (3)	N2B—C4B	1.492 (3)
N2A—C5A	1.490 (3)	N2B—C5B	1.496 (3)
N2A—H2AA	0.915 (10)	N2B—H2BA	0.924 (10)
N2A—H2AB	0.922 (10)	N2B—H2BB	0.919 (10)
C1A—C2A	1.425 (3)	C1B—C2B	1.425 (3)
C2A—C3A	1.323 (3)	C2B—C3B	1.325 (3)
C2A—C6A	1.499 (3)	C2B—C6B	1.498 (3)
C3A—C4A	1.486 (3)	C3B—C4B	1.480 (3)
C4A—H4AA	0.9700	C4B—H4BA	0.9700
C4A—H4AB	0.9700	C4B—H4BB	0.9700
C5A—C6A	1.516 (3)	C5B—C6B	1.513 (3)
C5A—H5AA	0.9700	C5B—H5BA	0.9700
C5A—H5AB	0.9700	C5B—H5BB	0.9700
C6A—H6AA	0.9700	C6B—H6BA	0.9700
C6A—H6AB	0.9700	C6B—H6BB	0.9700
C1A—O1A—H1A	105.7 (19)	C1B—O1B—H1B	112.8 (18)
C3A—O2A—N1A	106.81 (16)	C3B—O2B—N1B	106.86 (16)
C1A—N1A—O2A	104.67 (16)	C1B—N1B—O2B	104.53 (16)
C4A—N2A—C5A	114.29 (18)	C4B—N2B—C5B	113.78 (18)
C4A—N2A—H2AA	109.2 (15)	C4B—N2B—H2BA	107.4 (16)
C5A—N2A—H2AA	107.1 (16)	C5B—N2B—H2BA	111.4 (17)
C4A—N2A—H2AB	109.5 (17)	C4B—N2B—H2BB	107 (2)
C5A—N2A—H2AB	110.3 (16)	C5B—N2B—H2BB	112 (2)
H2AA—N2A—H2AB	106 (2)	H2BA—N2B—H2BB	104 (3)
N1A—C1A—O1A	123.99 (19)	N1B—C1B—O1B	124.18 (19)
N1A—C1A—C2A	112.6 (2)	N1B—C1B—C2B	112.9 (2)
O1A—C1A—C2A	123.3 (2)	O1B—C1B—C2B	122.89 (19)
C3A—C2A—C1A	103.46 (19)	C3B—C2B—C1B	103.39 (19)
C3A—C2A—C6A	123.86 (19)	C3B—C2B—C6B	123.9 (2)
C1A—C2A—C6A	132.7 (2)	C1B—C2B—C6B	132.71 (19)
C2A—C3A—O2A	112.40 (19)	C2B—C3B—O2B	112.3 (2)
C2A—C3A—C4A	127.3 (2)	C2B—C3B—C4B	127.0 (2)
O2A—C3A—C4A	120.3 (2)	O2B—C3B—C4B	120.74 (19)
C3A—C4A—N2A	105.72 (19)	C3B—C4B—N2B	105.70 (18)
C3A—C4A—H4AA	110.6	C3B—C4B—H4BA	110.6
N2A—C4A—H4AA	110.6	N2B—C4B—H4BA	110.6
C3A—C4A—H4AB	110.6	C3B—C4B—H4BB	110.6
N2A—C4A—H4AB	110.6	N2B—C4B—H4BB	110.6
H4AA—C4A—H4AB	108.7	H4BA—C4B—H4BB	108.7
N2A—C5A—C6A	111.78 (16)	N2B—C5B—C6B	111.34 (18)
N2A—C5A—H5AA	109.3	N2B—C5B—H5BA	109.4
C6A—C5A—H5AA	109.3	C6B—C5B—H5BA	109.4
N2A—C5A—H5AB	109.3	N2B—C5B—H5BB	109.4
C6A—C5A—H5AB	109.3	C6B—C5B—H5BB	109.4
H5AA—C5A—H5AB	107.9	H5BA—C5B—H5BB	108.0
C2A—C6A—C5A	107.86 (18)	C2B—C6B—C5B	108.10 (18)
C2A—C6A—H6AA	110.1	C2B—C6B—H6BA	110.1
C5A—C6A—H6AA	110.1	C5B—C6B—H6BA	110.1
C2A—C6A—H6AB	110.1	C2B—C6B—H6BB	110.1
C5A—C6A—H6AB	110.1	C5B—C6B—H6BB	110.1
H6AA—C6A—H6AB	108.4	H6BA—C6B—H6BB	108.4
C3A—O2A—N1A—C1A	0.4 (2)	C3B—O2B—N1B—C1B	0.3 (2)
O2A—N1A—C1A—O1A	−179.24 (18)	O2B—N1B—C1B—O1B	179.76 (18)
O2A—N1A—C1A—C2A	−0.6 (2)	O2B—N1B—C1B—C2B	0.0 (2)
N1A—C1A—C2A—C3A	0.6 (2)	N1B—C1B—C2B—C3B	−0.2 (2)
O1A—C1A—C2A—C3A	179.3 (2)	O1B—C1B—C2B—C3B	180.0 (2)
N1A—C1A—C2A—C6A	179.3 (2)	N1B—C1B—C2B—C6B	−178.8 (2)
O1A—C1A—C2A—C6A	−2.0 (4)	O1B—C1B—C2B—C6B	1.4 (4)
C1A—C2A—C3A—O2A	−0.3 (2)	C1B—C2B—C3B—O2B	0.4 (2)
C6A—C2A—C3A—O2A	−179.20 (18)	C6B—C2B—C3B—O2B	179.10 (18)
C1A—C2A—C3A—C4A	178.8 (2)	C1B—C2B—C3B—C4B	−179.4 (2)
C6A—C2A—C3A—C4A	0.0 (4)	C6B—C2B—C3B—C4B	−0.7 (4)
N1A—O2A—C3A—C2A	0.0 (2)	N1B—O2B—C3B—C2B	−0.4 (2)
N1A—O2A—C3A—C4A	−179.21 (19)	N1B—O2B—C3B—C4B	179.40 (19)
C2A—C3A—C4A—N2A	−15.4 (3)	C2B—C3B—C4B—N2B	17.0 (3)
O2A—C3A—C4A—N2A	163.69 (19)	O2B—C3B—C4B—N2B	−162.76 (19)
C5A—N2A—C4A—C3A	46.7 (2)	C5B—N2B—C4B—C3B	−48.3 (2)
C4A—N2A—C5A—C6A	−65.6 (2)	C4B—N2B—C5B—C6B	66.3 (2)
C3A—C2A—C6A—C5A	−13.9 (3)	C3B—C2B—C6B—C5B	13.8 (3)
C1A—C2A—C6A—C5A	167.6 (2)	C1B—C2B—C6B—C5B	−167.8 (2)
N2A—C5A—C6A—C2A	43.8 (2)	N2B—C5B—C6B—C2B	−43.7 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2A—H2AA···Cl1^i	0.92 (1)	2.23 (1)	3.123 (2)	167 (2)
N2A—H2AB···Cl2^ii	0.92 (1)	2.18 (1)	3.1015 (19)	177 (2)
N2B—H2BB···Cl1	0.92 (1)	2.18 (1)	3.101 (2)	177 (3)
N2B—H2BA···Cl2	0.92 (1)	2.24 (1)	3.127 (2)	160 (2)
O1A—H1A···Cl1	0.83 (2)	2.19 (2)	3.0053 (17)	166 (3)
O1B—H1B···Cl2^iii	0.82 (2)	2.19 (2)	3.0021 (17)	172 (2)

Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x, −y, −z+1; (iii) −x, −y+1, −z.

(LT) 3-Hydroxy-4,5,6,7-tetrahydro-1,2-oxazolo[5,4-c]pyridin-6-ium chloride

Crystal data

C6H9N2O2^+·Cl^−	F(000) = 736
Mr = 176.60	Dx = 1.589 Mg m^−3
Monoclinic, I2/a	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -I 2ya	Cell parameters from 5388 reflections
a = 13.1489 (5) Å	θ = 2.4–27.3°
b = 6.5780 (2) Å	µ = 0.46 mm^−1
c = 17.0721 (9) Å	T = 220 K
β = 90.420 (1)°	Lath, colourless
V = 1476.59 (11) Å^3	0.25 × 0.10 × 0.08 mm
Z = 8

Data collection

Bruker Nonius X8 APEXII CCD area-detector diffractometer	1643 independent reflections
Radiation source: fine-focus sealed tube	1359 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.025
thin–slice ω and φ scans	θmax = 27.5°, θmin = 3.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −16→16
Tmin = 0.855, Tmax = 0.965	k = −7→8
12044 measured reflections	l = −21→21

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)] = 0.026	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.075	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0369P)^2 + 0.9569P] where P = (Fo^2 + 2Fc^2)/3
1643 reflections	(Δ/σ)max < 0.001
112 parameters	Δρmax = 0.31 e Å^−3
3 restraints	Δρmin = −0.17 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.12433 (3)	0.77808 (5)	0.199929 (19)	0.02848 (13)
O1	0.12661 (9)	−0.10490 (16)	0.53688 (6)	0.0313 (3)
H1	0.1223 (18)	−0.139 (4)	0.5828 (7)	0.074 (7)*
O2	0.11882 (8)	0.42094 (15)	0.54553 (6)	0.0291 (2)
N1	0.11916 (10)	0.22652 (18)	0.58347 (7)	0.0280 (3)
N2	0.09024 (10)	0.46912 (19)	0.33423 (7)	0.0268 (3)
H2A	0.0222 (8)	0.435 (3)	0.3349 (10)	0.041 (5)*
H2B	0.0994 (15)	0.568 (2)	0.2970 (10)	0.058 (6)*
C1	0.12381 (10)	0.0953 (2)	0.52597 (8)	0.0231 (3)
C2	0.12656 (10)	0.1884 (2)	0.45062 (8)	0.0223 (3)
C3	0.12312 (10)	0.3868 (2)	0.46755 (8)	0.0231 (3)
C4	0.12171 (11)	0.5582 (2)	0.41102 (8)	0.0266 (3)
H4A	0.1893	0.6199	0.4072	0.032*
H4B	0.0732	0.6626	0.4275	0.032*
C5	0.15045 (12)	0.2838 (2)	0.31278 (8)	0.0296 (3)
H5A	0.2231	0.3168	0.3141	0.036*
H5B	0.1327	0.2424	0.2593	0.036*
C6	0.12991 (11)	0.1074 (2)	0.36880 (7)	0.0261 (3)
H6A	0.0649	0.0427	0.3554	0.031*
H6B	0.1839	0.0053	0.3644	0.031*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0354 (2)	0.0314 (2)	0.01853 (19)	0.00035 (15)	−0.00293 (13)	0.00197 (13)
O1	0.0460 (7)	0.0268 (6)	0.0213 (5)	−0.0007 (5)	0.0004 (5)	0.0029 (4)
O2	0.0418 (6)	0.0268 (5)	0.0188 (5)	0.0000 (4)	0.0010 (4)	−0.0030 (4)
N1	0.0354 (7)	0.0286 (6)	0.0200 (6)	−0.0006 (5)	0.0005 (5)	0.0023 (5)
N2	0.0308 (7)	0.0285 (6)	0.0210 (6)	−0.0013 (5)	−0.0020 (5)	0.0052 (5)
C1	0.0221 (7)	0.0271 (7)	0.0202 (7)	−0.0007 (6)	−0.0008 (5)	0.0008 (5)
C2	0.0220 (7)	0.0260 (7)	0.0188 (7)	0.0005 (6)	−0.0005 (5)	0.0000 (5)
C3	0.0242 (8)	0.0285 (7)	0.0166 (7)	−0.0002 (5)	0.0000 (5)	−0.0015 (5)
C4	0.0314 (8)	0.0246 (7)	0.0236 (7)	−0.0020 (6)	−0.0002 (6)	−0.0002 (6)
C5	0.0362 (8)	0.0338 (8)	0.0189 (7)	0.0017 (7)	0.0022 (6)	−0.0003 (6)
C6	0.0342 (8)	0.0260 (7)	0.0181 (7)	0.0025 (6)	−0.0018 (6)	−0.0020 (5)

Geometric parameters (Å, º)

O1—C1	1.3303 (18)	C2—C3	1.338 (2)
O1—H1	0.817 (10)	C2—C6	1.4959 (18)
O2—C3	1.3518 (16)	C3—C4	1.484 (2)
O2—N1	1.4336 (15)	C4—H4A	0.9800
N1—C1	1.3091 (18)	C4—H4B	0.9800
N2—C4	1.4915 (18)	C5—C6	1.5288 (19)
N2—C5	1.5006 (19)	C5—H5A	0.9800
N2—H2A	0.923 (9)	C5—H5B	0.9800
N2—H2B	0.917 (9)	C6—H6A	0.9800
C1—C2	1.4255 (19)	C6—H6B	0.9800
C1—O1—H1	113.6 (18)	C3—C4—N2	105.99 (11)
C3—O2—N1	107.27 (10)	C3—C4—H4A	110.5
C1—N1—O2	104.45 (11)	N2—C4—H4A	110.5
C4—N2—C5	112.96 (11)	C3—C4—H4B	110.5
C4—N2—H2A	110.4 (11)	N2—C4—H4B	110.5
C5—N2—H2A	108.6 (11)	H4A—C4—H4B	108.7
C4—N2—H2B	107.1 (13)	N2—C5—C6	111.59 (11)
C5—N2—H2B	109.5 (13)	N2—C5—H5A	109.3
H2A—N2—H2B	108.2 (16)	C6—C5—H5A	109.3
N1—C1—O1	123.31 (13)	N2—C5—H5B	109.3
N1—C1—C2	113.26 (12)	C6—C5—H5B	109.3
O1—C1—C2	123.43 (12)	H5A—C5—H5B	108.0
C3—C2—C1	102.90 (12)	C2—C6—C5	108.69 (11)
C3—C2—C6	123.40 (12)	C2—C6—H6A	110.0
C1—C2—C6	133.68 (12)	C5—C6—H6A	110.0
C2—C3—O2	112.12 (12)	C2—C6—H6B	110.0
C2—C3—C4	126.94 (13)	C5—C6—H6B	110.0
O2—C3—C4	120.94 (12)	H6A—C6—H6B	108.3
C3—O2—N1—C1	0.16 (14)	C6—C2—C3—C4	0.2 (2)
O2—N1—C1—O1	179.36 (12)	N1—O2—C3—C2	−0.19 (16)
O2—N1—C1—C2	−0.08 (15)	N1—O2—C3—C4	178.66 (12)
N1—C1—C2—C3	−0.03 (16)	C2—C3—C4—N2	18.4 (2)
O1—C1—C2—C3	−179.46 (13)	O2—C3—C4—N2	−160.22 (12)
N1—C1—C2—C6	−178.66 (15)	C5—N2—C4—C3	−49.92 (15)
O1—C1—C2—C6	1.9 (2)	C4—N2—C5—C6	66.15 (16)
C1—C2—C3—O2	0.14 (16)	C3—C2—C6—C5	11.38 (19)
C6—C2—C3—O2	178.95 (12)	C1—C2—C6—C5	−170.22 (15)
C1—C2—C3—C4	−178.63 (13)	N2—C5—C6—C2	−42.02 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2B···Cl1	0.92 (1)	2.19 (1)	3.0990 (12)	174 (2)
N2—H2A···Cl1^i	0.92 (1)	2.26 (1)	3.1393 (13)	159 (2)
O1—H1···Cl1^ii	0.82 (1)	2.20 (1)	3.0080 (11)	170 (2)

Symmetry codes: (i) −x, y−1/2, −z+1/2; (ii) x, −y+1/2, z+1/2.

(RT_I-1) 4,5,6,7-Tetrahydroisoxazolo[5,4-c]pyridin-3-ol hydrochloride

Crystal data

C6H9N2O2^+·Cl^−	c = 17.0168 Å
Mr = 176.60	α = 89.683°
Triclinic, I1	β = 92.077°
Hall symbol: -I 1	γ = 99.652°
a = 13.6018 Å	V = 1522.86 Å^3
b = 6.6783 Å	Z = 8

Data collection

h = →	l = →
k = →

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

	x	y	z	Biso*/Beq
Cl1	0.61890	0.27314	0.20336
Cl2	0.62294	0.30291	0.70219
O1A	0.37367	0.58597	−0.03535
H1A	0.37409	0.60337	−0.08477
O2A	0.38238	0.07047	−0.04236
N1A	0.38138	0.26106	−0.08123
N2A	0.40315	0.03589	0.17111
H2AA	0.39208	−0.05957	0.20877
H2AB	0.46857	0.08863	0.17376
C1A	0.37697	0.39044	−0.02417
C2A	0.37394	0.29745	0.05144
C3A	0.37781	0.10502	0.03578
C4A	0.37880	−0.06327	0.09301
H4AA	0.42878	−0.14444	0.08000
H4AB	0.31414	−0.15046	0.09304
C5A	0.34499	0.19992	0.18801
H5AA	0.35938	0.24554	0.24185
H5AB	0.27426	0.14619	0.18263
C6A	0.36983	0.37894	0.13290
H6AA	0.31915	0.46500	0.13464
H6AB	0.43366	0.45922	0.14854
O1B	0.37268	−0.15151	0.46322
H1B	0.37544	−0.18094	0.41646
O2B	0.38337	0.37104	0.45852
N1B	0.38129	0.18109	0.41858
N2B	0.40896	0.40649	0.67166
H2BA	0.40030	0.49290	0.71022
H2BB	0.47408	0.39589	0.67234
C1B	0.37643	0.04618	0.47493
C2B	0.37508	0.13265	0.55106
C3B	0.37984	0.32928	0.53641
C4B	0.38179	0.49369	0.59467
H4BA	0.31691	0.53525	0.59640
H4BB	0.43087	0.61070	0.58144
C5B	0.34938	0.20223	0.68867
H5BA	0.27881	0.21008	0.68452
H5BB	0.36478	0.16275	0.74205
C6B	0.37183	0.04330	0.63208
H6BA	0.43546	0.00359	0.64656
H6BB	0.32046	−0.07629	0.63371