Proton disorder in a short intra­molecular hydrogen bond investigated by single-crystal neutron diffraction at 2.5 and 170 K

The substituted acetyl­acetone 3-[2-(pyridin-4-yl)eth­yl]pentane-2,4-dione, C₁₂H₁₅NO₂, (1), with an ethyl­ene bridge between the acetyl­acetone moiety and the heteroaromatic ring, represents an attractive linker for mixed-metal coordination polymers. In the crystal, (1) adopts an anti­periplanar conformation with respect to the C—C bond in the central ethyl­ene group and almost coplanar acetyl­acetone and pyridyl groups. The ditopic mol­ecule exists as the enol tautomer, with proton disorder in the short intra­molecular hydrogen bond. Single-crystal neutron diffraction at 2.5 K indicated site occupancies of 0.602 (17) and 0.398 (17). The geometry of the acetyl­acetone moiety is in agreement with such a site preference of the bridging hydrogen: the O atom associated with the preferred H-atom site subtends the longer [1.305 (2) Å] and the more carbonyl-like O atom the shorter [1.288 (2) Å] C—O bond. Based on structure-factor calculations for the alternative H-atom sites, reflections particularly sensitive for proton distribution were identified and measured in a second neutron data collection at 170 K. At this temperature, 546 independent neutron intensities were used to refine positional and isotropic displacement parameters for a structure model in which parameters for C and O atoms were constrained to those obtained by single-crystal X-ray diffraction at the same temperature. The site occupancies for the disordered proton do not significantly differ from those at 2.5 K.

Computing details

Data collection: SMART (Bruker, 2001) for (1c). Cell refinement: SMART (Bruker, 2001) for (1c). Data reduction: PRON2013 (Meven, 2013) for (1a), (1b); SAINT-Plus (Bruker, 2009) for (1c). Program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008) for (1c). Program(s) used to refine structure: SHELXL2017 (Sheldrick, 2015) for (1a), (1b); SHELXL2013 (Sheldrick, 2015) for (1c). Molecular graphics: PLATON (Spek, 2009) for (1c). Software used to prepare material for publication: SHELXL2013 (Sheldrick, 2015) for (1c).

3-[2-(Pyridin-4-yl)ethyl]pentane-2,4-dione (1a)

Crystal data

C12H15NO2	F(000) = 35
Mr = 205.26	Dx = 1.255 Mg m^−3
Monoclinic, C2/c	Neutrons radiation, λ = 0.795and 1.171 Å
a = 8.768 (7) Å	Cell parameters from 19 reflections
b = 11.115 (2) Å	θ = 6.0–13.5°
c = 22.30 (4) Å	µ = 0.001 mm^−1
β = 91.59 (13)°	T = 3 K
V = 2172 (5) Å^3	Prism, colourless
Z = 8	4.2 × 3.3 × 3.2 mm

Data collection

Closed Eulerian cradle HEiDi diffractometer	Rint = 0.041
Radiation source: FRM II	θmax = 39.4°, θmin = 2.0°
rocking scan	h = −14→14
4136 measured reflections	k = −12→17
2207 independent reflections	l = −34→34
1978 reflections with I > 2σ(I)

Refinement

Refinement on F^2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.038	w = 1/[σ^2(Fo^2) + (0.065P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.096	(Δ/σ)max < 0.001
S = 1.15	Δρmax = 0.10 e Å^−3
2207 reflections	Δρmin = −0.10 e Å^−3
271 parameters	Extinction correction: SHELXL2017 (Sheldrick, 2015), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
2 restraints	Extinction coefficient: 0.41 (3)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
O1	0.27745 (18)	0.92797 (15)	0.25978 (7)	0.0080 (3)
H1O	0.3420 (11)	0.9940 (9)	0.2840 (4)	0.0206 (10)*	0.398 (17)
O2	0.43910 (19)	1.03736 (15)	0.33185 (7)	0.0076 (3)
H2O	0.3698 (8)	1.0106 (6)	0.2941 (3)	0.0206 (10)*	0.602 (17)
N1	0.57635 (11)	0.29662 (10)	0.45206 (4)	0.00855 (19)
C1	0.21255 (16)	0.72089 (13)	0.26931 (6)	0.0079 (3)
H1A	0.1634 (5)	0.7371 (4)	0.22494 (16)	0.0316 (8)
H1B	0.2873 (4)	0.6428 (3)	0.26754 (18)	0.0308 (8)
H1C	0.1218 (4)	0.6974 (4)	0.29949 (17)	0.0315 (8)
C2	0.29617 (15)	0.83142 (13)	0.29108 (6)	0.0070 (3)
C3	0.38883 (15)	0.83008 (13)	0.34453 (6)	0.0055 (2)
C4	0.45797 (15)	0.93858 (13)	0.36282 (6)	0.0061 (2)
C5	0.55692 (17)	0.95075 (14)	0.41869 (6)	0.0089 (3)
H5A	0.6719 (4)	0.9199 (5)	0.40956 (19)	0.0433 (11)
H5B	0.5151 (5)	0.8984 (4)	0.45546 (16)	0.0374 (9)
H5C	0.5628 (5)	1.0450 (4)	0.43184 (18)	0.0376 (10)
C6	0.41121 (15)	0.71439 (13)	0.37969 (6)	0.0057 (2)
H6A	0.4279 (4)	0.7341 (3)	0.42756 (13)	0.0229 (7)
H6B	0.3072 (3)	0.6593 (3)	0.37601 (15)	0.0213 (6)
C7	0.54798 (15)	0.63901 (13)	0.35825 (6)	0.0071 (2)
H7A	0.5349 (4)	0.6228 (4)	0.30966 (13)	0.0246 (7)
H7B	0.6542 (4)	0.6907 (3)	0.36532 (16)	0.0240 (7)
C8	0.56046 (15)	0.52005 (13)	0.39059 (6)	0.0060 (3)
C9	0.65396 (15)	0.50452 (14)	0.44198 (6)	0.0067 (2)
H9	0.7237 (4)	0.5786 (3)	0.45946 (15)	0.0245 (7)
C10	0.65882 (15)	0.39257 (14)	0.47048 (6)	0.0076 (3)
H10	0.7332 (4)	0.3781 (3)	0.50958 (14)	0.0235 (7)
C11	0.48603 (16)	0.31230 (13)	0.40292 (6)	0.0076 (3)
H11	0.4223 (4)	0.2328 (3)	0.38753 (16)	0.0261 (7)
C12	0.47455 (16)	0.42059 (13)	0.37119 (6)	0.0067 (3)
H12	0.4012 (4)	0.4267 (3)	0.33085 (15)	0.0233 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0104 (7)	0.0066 (7)	0.0068 (6)	−0.0012 (5)	−0.0030 (5)	0.0022 (5)
O2	0.0114 (7)	0.0038 (7)	0.0076 (6)	−0.0008 (5)	−0.0003 (5)	0.0009 (5)
N1	0.0097 (4)	0.0083 (5)	0.0076 (4)	−0.0003 (3)	−0.0007 (3)	0.0023 (3)
C1	0.0102 (6)	0.0054 (6)	0.0079 (5)	−0.0019 (5)	−0.0013 (5)	−0.0006 (5)
H1A	0.044 (2)	0.030 (2)	0.0201 (15)	−0.0085 (16)	−0.0139 (15)	−0.0001 (14)
H1B	0.0286 (18)	0.0207 (19)	0.043 (2)	0.0043 (13)	−0.0013 (16)	−0.0092 (16)
H1C	0.0306 (18)	0.036 (2)	0.0282 (17)	−0.0105 (16)	0.0091 (15)	−0.0044 (15)
C2	0.0075 (6)	0.0085 (7)	0.0050 (6)	−0.0007 (5)	−0.0011 (5)	0.0004 (4)
C3	0.0072 (6)	0.0050 (7)	0.0044 (5)	−0.0002 (4)	0.0005 (4)	0.0009 (4)
C4	0.0066 (6)	0.0067 (7)	0.0050 (5)	−0.0002 (4)	−0.0003 (4)	−0.0013 (5)
C5	0.0102 (6)	0.0086 (7)	0.0078 (6)	−0.0001 (5)	−0.0022 (5)	−0.0025 (5)
H5A	0.0187 (16)	0.073 (3)	0.038 (2)	0.0121 (18)	−0.0070 (15)	−0.015 (2)
H5B	0.047 (2)	0.046 (3)	0.0188 (15)	−0.0175 (19)	−0.0072 (15)	0.0114 (16)
H5C	0.063 (3)	0.0161 (18)	0.0330 (19)	−0.0014 (16)	−0.0185 (19)	−0.0078 (14)
C6	0.0077 (6)	0.0040 (6)	0.0056 (5)	0.0003 (5)	0.0019 (4)	0.0016 (5)
H6A	0.0291 (16)	0.0275 (19)	0.0120 (12)	0.0017 (13)	0.0010 (11)	0.0025 (11)
H6B	0.0149 (14)	0.0212 (17)	0.0279 (15)	−0.0036 (11)	0.0005 (12)	0.0008 (12)
C7	0.0090 (6)	0.0050 (6)	0.0075 (5)	0.0008 (5)	0.0031 (5)	0.0020 (5)
H7A	0.0319 (17)	0.0283 (19)	0.0138 (13)	0.0049 (13)	0.0032 (12)	0.0030 (12)
H7B	0.0170 (13)	0.0203 (16)	0.0345 (18)	−0.0050 (11)	0.0004 (13)	0.0068 (13)
C8	0.0076 (5)	0.0057 (7)	0.0048 (5)	0.0011 (4)	0.0011 (4)	0.0004 (4)
C9	0.0080 (6)	0.0063 (6)	0.0058 (5)	−0.0002 (4)	−0.0005 (4)	0.0008 (4)
H9	0.0301 (16)	0.0191 (17)	0.0237 (15)	−0.0103 (13)	−0.0075 (13)	0.0002 (12)
C10	0.0098 (6)	0.0081 (7)	0.0047 (5)	−0.0003 (5)	−0.0011 (5)	0.0019 (5)
H10	0.0285 (15)	0.0231 (19)	0.0183 (14)	−0.0037 (13)	−0.0103 (12)	0.0044 (12)
C11	0.0090 (6)	0.0062 (7)	0.0077 (6)	−0.0008 (4)	−0.0010 (5)	0.0002 (5)
H11	0.0313 (17)	0.0187 (18)	0.0278 (16)	−0.0091 (13)	−0.0067 (14)	−0.0022 (12)
C12	0.0092 (6)	0.0052 (6)	0.0058 (5)	0.0006 (4)	−0.0007 (5)	0.0004 (4)
H12	0.0268 (16)	0.0238 (18)	0.0186 (14)	−0.0045 (12)	−0.0092 (12)	0.0029 (12)

Geometric parameters (Å, º)

O1—C2	1.288 (2)	C5—H5C	1.088 (4)
O1—H1O	1.065 (10)	C6—C7	1.549 (2)
O2—C4	1.305 (2)	C6—H6A	1.096 (4)
O2—H2O	1.067 (8)	C6—H6B	1.100 (3)
N1—C11	1.345 (3)	C7—C8	1.509 (2)
N1—C10	1.3462 (19)	C7—H7A	1.101 (4)
C1—C2	1.504 (2)	C7—H7B	1.102 (4)
C1—H1A	1.083 (4)	C8—C12	1.400 (2)
C1—H1B	1.089 (4)	C8—C9	1.401 (3)
C1—H1C	1.088 (4)	C9—C10	1.397 (2)
C2—C3	1.424 (3)	C9—H9	1.091 (4)
C3—C4	1.405 (2)	C10—H10	1.086 (4)
C3—C6	1.516 (2)	C11—C12	1.399 (2)
C4—C5	1.504 (3)	C11—H11	1.095 (4)
C5—H5A	1.089 (4)	C12—H12	1.093 (4)
C5—H5B	1.078 (4)
C2—O1—H1O	103.9 (6)	C3—C6—H6A	110.3 (2)
C2—O1—H2O	100.5 (3)	C7—C6—H6A	109.0 (2)
C4—O2—H1O	100.1 (4)	C3—C6—H6B	109.8 (2)
C4—O2—H2O	104.1 (4)	C7—C6—H6B	108.9 (2)
C11—N1—C10	116.42 (12)	H6A—C6—H6B	105.8 (3)
C2—C1—H1A	109.7 (3)	C8—C7—C6	111.90 (14)
C2—C1—H1B	112.0 (2)	C8—C7—H7A	109.3 (2)
H1A—C1—H1B	108.9 (3)	C6—C7—H7A	109.4 (2)
C2—C1—H1C	110.8 (3)	C8—C7—H7B	109.8 (2)
H1A—C1—H1C	109.0 (3)	C6—C7—H7B	109.4 (2)
H1B—C1—H1C	106.4 (3)	H7A—C7—H7B	106.9 (3)
O1—C2—C3	121.56 (15)	C12—C8—C9	116.96 (14)
O1—C2—C1	116.86 (15)	C12—C8—C7	120.88 (14)
C3—C2—C1	121.56 (13)	C9—C8—C7	122.14 (13)
C4—C3—C2	117.75 (12)	C10—C9—C8	119.43 (14)
C4—C3—C6	121.95 (14)	C10—C9—H9	120.0 (2)
C2—C3—C6	120.30 (13)	C8—C9—H9	120.6 (2)
O2—C4—C3	121.40 (16)	N1—C10—C9	123.87 (14)
O2—C4—C5	115.10 (15)	N1—C10—H10	115.7 (2)
C3—C4—C5	123.49 (12)	C9—C10—H10	120.5 (2)
C4—C5—H5A	109.4 (3)	N1—C11—C12	123.79 (14)
C4—C5—H5B	112.4 (3)	N1—C11—H11	115.8 (2)
H5A—C5—H5B	108.0 (4)	C12—C11—H11	120.4 (2)
C4—C5—H5C	109.4 (2)	C8—C12—C11	119.52 (15)
H5A—C5—H5C	108.4 (4)	C8—C12—H12	120.3 (2)
H5B—C5—H5C	109.2 (4)	C11—C12—H12	120.1 (2)
C3—C6—C7	112.92 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O···O2	1.07 (1)	1.43 (1)	2.438 (4)	155 (1)
O2—H2O···O1	1.07 (1)	1.43 (1)	2.438 (4)	155 (1)

3-[2-(Pyridin-4-yl)ethyl]pentane-2,4-dione (1b)

Crystal data

C12H15NO2	F(000) = 35
Mr = 205.26	Dx = 1.236 Mg m^−3
Monoclinic, C2/c	Neutron radiation, λ = 0.795and 1.171 Å
a = 8.8583 (7) Å	Cell parameters from 2722 reflections
b = 11.1031 (9) Å	θ = 2.9–29.9°
c = 22.4335 (18) Å	µ = 0.001 mm^−1
β = 91.876 (1)°	T = 170 K
V = 2205.3 (3) Å^3	Prism, colourless
Z = 8	4.2 × 3.3 × 3.2 mm

Data collection

Closed Eulerian cradle HEiDi diffractometer	Rint = 0.040
Radiation source: FRM II	θmax = 39.3°, θmin = 3.3°
rocking scan	h = −12→13
1048 measured reflections	k = 0→16
546 independent reflections	l = −34→34
508 reflections with I > 2σ(I)

Refinement

Refinement on F^2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.060	w = 1/[σ^2(Fo^2) + (0.001P)^2 + 2.P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.147	(Δ/σ)max < 0.001
S = 1.22	Δρmax = 0.08 e Å^−3
546 reflections	Δρmin = −0.08 e Å^−3
75 parameters	Extinction correction: SHELXL2017 (Sheldrick, 2015), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
2 restraints	Extinction coefficient: 0.65 (9)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
N1	0.5750 (9)	0.2957 (6)	0.4521 (3)	0.0340 (16)
O1	0.278418	0.925772	0.260437	0.038
O2	0.442300	1.033999	0.332292	0.038
C1	0.213587	0.720288	0.269852	0.033
C2	0.297701	0.829265	0.291857	0.026
C3	0.390489	0.827223	0.344234	0.023
C4	0.460416	0.935208	0.362497	0.029
C5	0.559039	0.945989	0.417753	0.040
C6	0.412436	0.711889	0.379116	0.026
C7	0.545718	0.635925	0.357908	0.030
C8	0.558361	0.517308	0.390402	0.026
C9	0.651649	0.502265	0.440940	0.030
C10	0.657319	0.391267	0.469346	0.031
C11	0.486482	0.310956	0.403178	0.034
C12	0.474075	0.418150	0.371706	0.032
H1O	0.331 (6)	0.995 (4)	0.286 (3)	0.049 (8)*	0.41 (7)
H2O	0.374 (4)	1.011 (3)	0.2943 (19)	0.049 (8)*	0.59 (7)
H1A	0.169 (3)	0.732 (3)	0.2262 (13)	0.069 (7)*
H1B	0.288 (4)	0.643 (3)	0.2693 (15)	0.076 (8)*
H1C	0.130 (4)	0.693 (3)	0.2990 (16)	0.075 (8)*
H5A	0.663 (6)	0.908 (5)	0.412 (2)	0.125 (17)*
H5B	0.513 (4)	0.906 (4)	0.4561 (17)	0.087 (10)*
H5C	0.563 (4)	1.036 (4)	0.4327 (17)	0.088 (10)*
H6A	0.428 (2)	0.7298 (19)	0.4284 (10)	0.043 (4)*
H6B	0.310 (3)	0.659 (2)	0.3771 (9)	0.043 (4)*
H7A	0.527 (3)	0.619 (2)	0.3099 (11)	0.052 (5)*
H7B	0.650 (3)	0.687 (3)	0.3653 (13)	0.062 (6)*
H9	0.730 (3)	0.575 (3)	0.4567 (11)	0.056 (6)*
H10	0.733 (3)	0.377 (2)	0.5077 (11)	0.051 (5)*
H11	0.426 (3)	0.229 (3)	0.3896 (14)	0.065 (7)*
H12	0.405 (3)	0.423 (3)	0.3306 (13)	0.061 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.049 (4)	0.022 (3)	0.031 (3)	0.001 (3)	−0.006 (3)	0.008 (2)
O1	0.050	0.026	0.037	−0.001	−0.012	0.009
O2	0.049	0.019	0.045	−0.006	−0.006	0.003
C1	0.036	0.029	0.033	−0.004	−0.004	−0.004
C2	0.030	0.020	0.028	0.001	0.000	0.001
C3	0.027	0.017	0.025	0.000	0.000	0.001
C4	0.031	0.023	0.032	0.000	0.000	−0.001
C5	0.040	0.037	0.044	−0.005	−0.011	−0.007
C6	0.031	0.020	0.026	0.003	0.001	0.004
C7	0.032	0.026	0.033	0.006	0.005	0.008
C8	0.027	0.022	0.027	0.007	0.003	0.002
C9	0.030	0.027	0.031	0.001	−0.001	0.001
C10	0.031	0.034	0.029	0.004	−0.003	0.007
C11	0.038	0.023	0.042	0.001	−0.007	−0.002
C12	0.037	0.029	0.031	0.006	−0.008	0.001

Geometric parameters (Å, º)

N1—C10	1.337 (7)	C5—H5C	1.06 (4)
N1—C11	1.339 (7)	C6—C7	1.5390
O1—C2	1.2909	C6—H6A	1.13 (2)
O1—H1O	1.06 (4)	C6—H6B	1.08 (2)
O2—C4	1.2965	C7—C8	1.5077
O2—H2O	1.06 (4)	C7—H7A	1.10 (3)
C1—C2	1.4963	C7—H7B	1.10 (3)
C1—H1A	1.05 (3)	C8—C12	1.3874
C1—H1B	1.08 (4)	C8—C9	1.3910
C1—H1C	1.05 (3)	C9—C10	1.3876
C2—C3	1.4119	C9—H9	1.11 (3)
C3—C4	1.4044	C10—H10	1.08 (3)
C3—C6	1.5100	C11—C12	1.3864
C4—C5	1.4977	C11—H11	1.09 (3)
C5—H5A	1.02 (6)	C12—H12	1.09 (3)
C5—H5B	1.06 (4)
C10—N1—C11	115.9 (4)	C3—C6—H6A	111.6 (11)
C2—O1—H1O	105 (2)	C7—C6—H6A	109.0 (11)
C2—O1—H2O	100.8 (13)	C3—C6—H6B	110.1 (12)
C4—O2—H1O	100.6 (17)	C7—C6—H6B	110.0 (12)
C4—O2—H2O	105.8 (18)	H6A—C6—H6B	102.5 (15)
C2—C1—H1A	111.9 (18)	C8—C7—C6	112.0
C2—C1—H1B	110.5 (19)	C8—C7—H7A	109.1 (14)
H1A—C1—H1B	107 (3)	C6—C7—H7A	107.9 (14)
C2—C1—H1C	112 (2)	C8—C7—H7B	109.4 (15)
H1A—C1—H1C	112 (3)	C6—C7—H7B	108.8 (15)
H1B—C1—H1C	103 (3)	H7A—C7—H7B	110 (2)
O1—C2—C3	122.1	C12—C8—C9	116.8
O1—C2—C1	115.8	C12—C8—C7	121.1
C3—C2—C1	122.1	C9—C8—C7	122.1
C4—C3—C2	117.9	C10—C9—C8	119.5
C4—C3—C6	121.7	C10—C9—H9	118.9 (14)
C2—C3—C6	120.4	C8—C9—H9	121.3 (14)
O2—C4—C3	121.6	N1—C10—C9	124.1 (3)
O2—C4—C5	115.1	N1—C10—H10	115.6 (14)
C3—C4—C5	123.3	C9—C10—H10	120.3 (13)
C4—C5—H5A	111 (3)	N1—C11—C12	124.1 (3)
C4—C5—H5B	114 (2)	N1—C11—H11	112.9 (16)
H5A—C5—H5B	108 (4)	C12—C11—H11	122.9 (16)
C4—C5—H5C	111 (2)	C11—C12—C8	119.6
H5A—C5—H5C	114 (4)	C11—C12—H12	120.4 (16)
H5B—C5—H5C	99 (3)	C8—C12—H12	119.8 (16)
C3—C6—C7	113.1

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O···O2	1.06 (4)	1.47 (4)	2.449	151 (4)
O2—H2O···O1	1.06 (4)	1.47 (4)	2.449	151 (3)

3-[2-(Pyridin-4-yl)ethyl]pentane-2,4-dione (1c)

Crystal data

C12H15NO2	F(000) = 880
Mr = 205.25	Dx = 1.236 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 8.8583 (7) Å	Cell parameters from 2722 reflections
b = 11.1031 (9) Å	θ = 2.9–29.9°
c = 22.4335 (18) Å	µ = 0.08 mm^−1
β = 91.876 (1)°	T = 170 K
V = 2205.3 (3) Å^3	Block, colourless
Z = 8	0.19 × 0.18 × 0.18 mm

Data collection

Bruker APEX CCD area detector diffractometer	3290 independent reflections
Radiation source: Incoatec microsource	2517 reflections with I > 2σ(I)
Multilayer optics monochromator	Rint = 0.033
/w scans	θmax = 30.7°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −12→12
Tmin = 0.656, Tmax = 0.746	k = −15→15
16619 measured reflections	l = −31→31

Refinement

Refinement on F^2	2 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.052	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.146	w = 1/[σ^2(Fo^2) + (0.0612P)^2 + 1.752P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max < 0.001
3290 reflections	Δρmax = 0.33 e Å^−3
145 parameters	Δρmin = −0.19 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
O1	0.27842 (13)	0.92577 (9)	0.26044 (5)	0.0380 (3)
O2	0.44230 (13)	1.03400 (9)	0.33229 (5)	0.0378 (3)
H1O	0.323 (4)	0.989 (3)	0.2812 (16)	0.045*	0.52 (4)
H2O	0.387 (4)	1.006 (4)	0.2999 (14)	0.045*	0.48 (4)
N1	0.57646 (14)	0.29558 (10)	0.45184 (6)	0.0331 (3)
C1	0.21359 (16)	0.72029 (12)	0.26985 (7)	0.0329 (3)
H1A	0.1324	0.7017	0.2970	0.049*
H1B	0.2831	0.6518	0.2683	0.049*
H1C	0.1703	0.7361	0.2299	0.049*
C2	0.29770 (15)	0.82926 (11)	0.29186 (6)	0.0262 (3)
C3	0.39049 (14)	0.82722 (10)	0.34423 (6)	0.0234 (2)
C4	0.46042 (15)	0.93521 (11)	0.36250 (6)	0.0286 (3)
C5	0.55904 (18)	0.94599 (14)	0.41775 (7)	0.0404 (4)
H5A	0.6584	0.9112	0.4105	0.061*
H5B	0.5126	0.9026	0.4505	0.061*
H5C	0.5706	1.0311	0.4285	0.061*
C6	0.41244 (15)	0.71189 (11)	0.37912 (6)	0.0256 (3)
H6A	0.3188	0.6634	0.3754	0.031*
H6B	0.4298	0.7318	0.4218	0.031*
C7	0.54572 (15)	0.63592 (12)	0.35791 (6)	0.0304 (3)
H7A	0.5323	0.6206	0.3146	0.036*
H7B	0.6407	0.6818	0.3644	0.036*
C8	0.55836 (14)	0.51731 (11)	0.39040 (6)	0.0255 (3)
C9	0.65165 (15)	0.50226 (12)	0.44094 (6)	0.0295 (3)
H9	0.7110	0.5675	0.4559	0.035*
C10	0.65732 (15)	0.39127 (13)	0.46935 (6)	0.0314 (3)
H10	0.7230	0.3829	0.5034	0.038*
C11	0.48648 (17)	0.31096 (12)	0.40318 (7)	0.0345 (3)
H11	0.4277	0.2444	0.3894	0.041*
C12	0.47408 (16)	0.41815 (12)	0.37171 (6)	0.0323 (3)
H12	0.4082	0.4237	0.3375	0.039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0505 (6)	0.0258 (5)	0.0370 (6)	−0.0012 (4)	−0.0122 (5)	0.0088 (4)
O2	0.0488 (6)	0.0187 (4)	0.0454 (6)	−0.0057 (4)	−0.0056 (5)	0.0033 (4)
N1	0.0365 (6)	0.0254 (6)	0.0371 (7)	0.0055 (5)	−0.0018 (5)	0.0067 (5)
C1	0.0364 (7)	0.0285 (7)	0.0335 (7)	−0.0039 (5)	−0.0043 (6)	−0.0044 (5)
C2	0.0303 (6)	0.0203 (6)	0.0280 (6)	0.0011 (5)	0.0000 (5)	0.0009 (5)
C3	0.0272 (6)	0.0174 (5)	0.0254 (6)	0.0002 (4)	−0.0002 (4)	0.0012 (4)
C4	0.0308 (6)	0.0229 (6)	0.0322 (7)	−0.0004 (5)	−0.0001 (5)	−0.0010 (5)
C5	0.0397 (8)	0.0366 (8)	0.0442 (9)	−0.0051 (6)	−0.0114 (7)	−0.0067 (6)
C6	0.0307 (6)	0.0202 (5)	0.0260 (6)	0.0032 (5)	0.0008 (5)	0.0035 (4)
C7	0.0319 (6)	0.0261 (6)	0.0334 (7)	0.0062 (5)	0.0047 (5)	0.0084 (5)
C8	0.0273 (6)	0.0223 (6)	0.0271 (6)	0.0066 (5)	0.0027 (5)	0.0024 (5)
C9	0.0303 (6)	0.0269 (6)	0.0312 (7)	0.0007 (5)	−0.0015 (5)	0.0011 (5)
C10	0.0308 (6)	0.0338 (7)	0.0293 (7)	0.0040 (5)	−0.0033 (5)	0.0067 (5)
C11	0.0380 (7)	0.0233 (6)	0.0416 (8)	0.0013 (5)	−0.0066 (6)	−0.0016 (5)
C12	0.0366 (7)	0.0288 (6)	0.0309 (7)	0.0065 (5)	−0.0079 (5)	0.0008 (5)

Geometric parameters (Å, º)

O1—C2	1.2909 (15)	C5—H5C	0.9800
O1—H1O	0.923 (19)	C6—C7	1.5390 (18)
O2—C4	1.2965 (16)	C6—H6A	0.9900
O2—H2O	0.919 (19)	C6—H6B	0.9900
N1—C10	1.3333 (19)	C7—C8	1.5077 (17)
N1—C11	1.3413 (18)	C7—H7A	0.9900
C1—C2	1.4963 (18)	C7—H7B	0.9900
C1—H1A	0.9800	C8—C12	1.3874 (19)
C1—H1B	0.9800	C8—C9	1.3910 (18)
C1—H1C	0.9800	C9—C10	1.3876 (18)
C2—C3	1.4119 (18)	C9—H9	0.9500
C3—C4	1.4044 (17)	C10—H10	0.9500
C3—C6	1.5100 (16)	C11—C12	1.3864 (19)
C4—C5	1.498 (2)	C11—H11	0.9500
C5—H5A	0.9800	C12—H12	0.9500
C5—H5B	0.9800
C2—O1—H1O	108 (3)	C7—C6—H6A	109.0
C4—O2—H2O	100 (3)	C3—C6—H6B	109.0
C10—N1—C11	115.95 (12)	C7—C6—H6B	109.0
C2—C1—H1A	109.5	H6A—C6—H6B	107.8
C2—C1—H1B	109.5	C8—C7—C6	112.02 (11)
H1A—C1—H1B	109.5	C8—C7—H7A	109.2
C2—C1—H1C	109.5	C6—C7—H7A	109.2
H1A—C1—H1C	109.5	C8—C7—H7B	109.2
H1B—C1—H1C	109.5	C6—C7—H7B	109.2
O1—C2—C3	122.06 (11)	H7A—C7—H7B	107.9
O1—C2—C1	115.82 (12)	C12—C8—C9	116.78 (12)
C3—C2—C1	122.11 (11)	C12—C8—C7	121.08 (12)
C4—C3—C2	117.92 (11)	C9—C8—C7	122.12 (12)
C4—C3—C6	121.65 (11)	C10—C9—C8	119.51 (13)
C2—C3—C6	120.43 (11)	C10—C9—H9	120.2
O2—C4—C3	121.60 (12)	C8—C9—H9	120.2
O2—C4—C5	115.07 (12)	N1—C10—C9	124.15 (13)
C3—C4—C5	123.33 (12)	N1—C10—H10	117.9
C4—C5—H5A	109.5	C9—C10—H10	117.9
C4—C5—H5B	109.5	N1—C11—C12	123.97 (13)
H5A—C5—H5B	109.5	N1—C11—H11	118.0
C4—C5—H5C	109.5	C12—C11—H11	118.0
H5A—C5—H5C	109.5	C11—C12—C8	119.63 (13)
H5B—C5—H5C	109.5	C11—C12—H12	120.2
C3—C6—C7	113.06 (10)	C8—C12—H12	120.2
C3—C6—H6A	109.0

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O···O2	0.92 (2)	1.61 (3)	2.4488 (15)	149 (4)
O2—H2O···O1	0.92 (2)	1.56 (2)	2.4488 (15)	161 (4)