4-(2-Hydroxy­ethyl)-4H-1,2,4-triazole, an inter­mediate in the synthesis of iron–triazole spin-crossover compounds

The title 1,2,4-triazole derivative, C₄H₇N₃O, has been synthesized and characterized. Neighboring mol­ecules are connected by inter­molecular O—H...N hydrogen bonds, forming a linear chain arrangement along the crystallographic [101] direction.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C)= 0.002 Å
• R factor = 0.041
• wR factor = 0.100
• Data-to-parameter ratio = 12.9

checkCIF/PLATON results

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Computing details

Data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Mercury (Bruno et al., 2002); software used to prepare material for publication: SHELXL97.

4-(2-Hydroxyethyl)-4H-1,2,4-triazole

Crystal data

C4H7N3O	F(000) = 240
Mr = 113.13	Dx = 1.400 Mg m^−3
Monoclinic, P21/c	Melting point: 84 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 5.5894 (18) Å	Cell parameters from 39 reflections
b = 14.444 (5) Å	θ = 2.8–28.0°
c = 7.013 (4) Å	µ = 0.11 mm^−1
β = 108.56 (3)°	T = 150 K
V = 536.7 (4) Å^3	Block, colourless
Z = 4	0.23 × 0.18 × 0.18 mm

Data collection

Siemens SMART 1K CCD area-detector diffractometer	976 reflections with I > 2σ(I)
Radiation source: normal-focus sealed tube	Rint = 0.095
Graphite monochromator	θmax = 28.0°, θmin = 2.8°
ω scans	h = −7→7
8131 measured reflections	k = −19→18
1301 independent reflections	l = −9→9

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)] = 0.041	Hydrogen site location: difference Fourier map
wR(F^2) = 0.100	All H-atom parameters refined
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0324P)^2 + 0.1227P] where P = (Fo^2 + 2Fc^2)/3
1301 reflections	(Δ/σ)max < 0.001
101 parameters	Δρmax = 0.20 e Å^−3
0 restraints	Δρmin = −0.25 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
N1	0.2141 (2)	0.42318 (8)	0.41199 (18)	0.0269 (3)
N2	0.0005 (2)	0.36840 (8)	0.38340 (18)	0.0283 (3)
C3	−0.0184 (3)	0.35194 (10)	0.5614 (2)	0.0259 (3)
H3	−0.146 (3)	0.3173 (13)	0.586 (3)	0.040 (5)*
N4	0.1714 (2)	0.39259 (8)	0.70715 (16)	0.0210 (3)
C5	0.3098 (3)	0.43582 (9)	0.6055 (2)	0.0233 (3)
H5	0.455 (3)	0.4707 (11)	0.669 (2)	0.027 (4)*
C1	0.2144 (3)	0.39174 (10)	0.9246 (2)	0.0250 (3)
H1A	0.055 (3)	0.3739 (11)	0.944 (2)	0.032 (4)*
H1B	0.253 (3)	0.4556 (12)	0.974 (2)	0.025 (4)*
C2	0.4233 (3)	0.32581 (10)	1.0322 (2)	0.0245 (3)
H2A	0.375 (3)	0.2633 (12)	0.978 (2)	0.026 (4)*
H2B	0.439 (3)	0.3257 (10)	1.173 (2)	0.019 (4)*
O	0.65402 (19)	0.35303 (8)	1.00437 (16)	0.0323 (3)
H1	0.768 (4)	0.3568 (14)	1.129 (3)	0.054 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0267 (6)	0.0278 (6)	0.0258 (7)	−0.0008 (5)	0.0078 (5)	0.0018 (5)
N2	0.0238 (6)	0.0293 (6)	0.0283 (7)	−0.0011 (5)	0.0031 (5)	−0.0007 (5)
C3	0.0193 (7)	0.0266 (7)	0.0307 (8)	−0.0010 (5)	0.0065 (6)	0.0009 (6)
N4	0.0171 (6)	0.0234 (5)	0.0232 (6)	0.0005 (4)	0.0075 (4)	0.0006 (5)
C5	0.0220 (7)	0.0243 (7)	0.0244 (7)	−0.0034 (5)	0.0084 (5)	−0.0004 (5)
C1	0.0226 (7)	0.0323 (8)	0.0238 (7)	0.0003 (6)	0.0125 (6)	−0.0013 (6)
C2	0.0232 (7)	0.0306 (7)	0.0217 (7)	−0.0026 (6)	0.0101 (6)	0.0024 (6)
O	0.0185 (5)	0.0553 (7)	0.0235 (6)	−0.0020 (5)	0.0072 (4)	0.0046 (5)

Geometric parameters (Å, º)

N1—N2	1.3923 (17)	C1—C2	1.509 (2)
N2—C3	1.308 (2)	C1—H1A	0.979 (18)
C3—N4	1.3505 (19)	C1—H1B	0.985 (17)
C3—H3	0.932 (18)	C2—O	1.4197 (17)
N4—C5	1.3594 (17)	C2—H2A	0.983 (17)
N1—C5	1.3031 (19)	C2—H2B	0.962 (15)
N4—C1	1.466 (2)	O—H1	0.90 (2)
C5—H5	0.939 (16)
C5—N1—N2	106.17 (12)	N4—C1—H1A	107.0 (10)
C3—N2—N1	106.98 (12)	C2—C1—H1A	111.0 (10)
N2—C3—N4	111.12 (13)	N4—C1—H1B	107.6 (9)
N2—C3—H3	125.2 (11)	C2—C1—H1B	111.5 (9)
N4—C3—H3	123.7 (11)	H1A—C1—H1B	107.8 (13)
C3—N4—C5	104.12 (12)	O—C2—C1	110.40 (12)
C3—N4—C1	127.76 (12)	O—C2—H2A	110.7 (9)
C5—N4—C1	128.10 (12)	C1—C2—H2A	108.2 (9)
N1—C5—N4	111.61 (12)	O—C2—H2B	110.5 (9)
N1—C5—H5	124.9 (10)	C1—C2—H2B	108.5 (8)
N4—C5—H5	123.5 (10)	H2A—C2—H2B	108.4 (12)
N4—C1—C2	111.69 (12)	C2—O—H1	106.0 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O—H1···N2^i	0.90 (2)	1.85 (2)	2.754 (2)	178.3 (19)

Symmetry code: (i) x+1, y, z+1.