Hydro­gen-bonding in 4-(hydroxy­methyl)­imidazolium picrate

The title compound, C₄H₇N₂O⁺·C₆H₂N₃O₇⁻, crystallizes in space group P2₁ with one ion pair in the asymmetric unit. Strong N—H...O and O—H...O hydrogen bonds, together with weak C—H...O contacts between the two components, generate a two-dimensional layered structure containing R₁²(6), R₂¹(7), R₃³(10) and R₅⁵(24) rings. These layers are further connected by an additional C—H...O interaction, resulting in an extensive three-dimensional hydrogen-bonding network.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.033
• wR factor = 0.111
• Data-to-parameter ratio = 5.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT089_ALERT_3_B Poor Data / Parameter Ratio (Zmax .LT. 18) .....       5.68

Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT242_ALERT_2_C Check Low    U(eq) as Compared to Neighbors ....         N5
PLAT250_ALERT_2_C Large U3/U1 ratio for average U(i,j) tensor ....       2.11
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          6

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.01
           From the CIF: _reflns_number_total               1187
           Count of symmetry unique reflns         1191
           Completeness (_total/calc)             99.66%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present           no

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

---

Computing details

Data collection: SMART (Siemens, 1998); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Bruker, 1998); software used to prepare material for publication: SHELXL97.

4-hydroxymethylimidazolium picrate

Crystal data

C4H7N2O^+·C6H2N3O7^−	F(000) = 336
Mr = 327.22	Dx = 1.696 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P_2yb	Cell parameters from 2351 reflections
a = 3.7925 (14) Å	θ = 1.7–25.0°
b = 13.916 (5) Å	µ = 0.15 mm^−1
c = 12.141 (4) Å	T = 293 K
β = 90.862 (5)°	Prism, yellow
V = 640.7 (4) Å^3	0.30 × 0.20 × 0.10 mm
Z = 2

Data collection

Bruker SMART 1000 diffractometer	1019 reflections with I > 2σ(I)
ω scans	Rint = 0.022
Absorption correction: multi-scan [SAINT (Bruker 1998) and SADABS (Sheldrick, 1997)]	θmax = 25.0°
Tmin = 0.957, Tmax = 0.983	h = −4→3
2660 measured reflections	k = −9→16
1187 independent reflections	l = −14→13

Refinement

Refinement on F^2	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.033	w = 1/[σ^2(Fo^2) + (0.0716P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.111	(Δ/σ)max < 0.001
S = 1.15	Δρmax = 0.22 e Å^−3
1187 reflections	Δρmin = −0.21 e Å^−3
209 parameters

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. Full-MATRIX

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

	x	y	z	Uiso*/Ueq
C1	0.3398 (12)	0.2336 (3)	1.0354 (3)	0.0327 (10)
H1A	0.5919	0.2226	1.0320	0.039*
H1B	0.2628	0.2149	1.1081	0.039*
C2	0.2669 (11)	0.3381 (3)	1.0186 (3)	0.0281 (9)
C3	0.1264 (12)	0.4065 (3)	1.0835 (3)	0.0340 (10)
H3A	0.0430	0.3981	1.1545	0.041*
C4	0.2654 (13)	0.4752 (3)	0.9281 (3)	0.0373 (10)
H4A	0.2952	0.5209	0.8732	0.045*
C5	0.3166 (11)	0.7037 (3)	0.5575 (3)	0.0297 (9)
C6	0.4439 (11)	0.6288 (3)	0.4952 (3)	0.0308 (9)
H6A	0.4988	0.5700	0.5276	0.037*
C7	0.4878 (11)	0.6429 (3)	0.3844 (3)	0.0275 (9)
C8	0.4163 (11)	0.7323 (3)	0.3266 (3)	0.0264 (9)
C9	0.2678 (11)	0.8037 (3)	0.3988 (3)	0.0262 (9)
C10	0.2227 (11)	0.7906 (3)	0.5113 (3)	0.0311 (10)
H10A	0.1310	0.8396	0.5544	0.037*
N1	0.3532 (10)	0.3835 (3)	0.9216 (3)	0.0324 (8)
H1C	0.4488	0.3564	0.8658	0.039*
N2	0.1298 (10)	0.4909 (2)	1.0247 (3)	0.0365 (9)
H2B	0.0545	0.5455	1.0479	0.044*
N3	0.2819 (11)	0.6919 (3)	0.6759 (3)	0.0436 (10)
N4	0.6127 (11)	0.5596 (2)	0.3215 (3)	0.0361 (9)
N5	0.1571 (9)	0.8965 (2)	0.3559 (3)	0.0318 (8)
O1	0.1655 (9)	0.1752 (2)	0.9549 (2)	0.0419 (8)
H1	0.2452	0.1868	0.8939	0.063*
O2	0.4681 (9)	0.7443 (2)	0.2259 (2)	0.0380 (8)
O3	0.1231 (13)	0.7532 (3)	0.7278 (3)	0.0662 (12)
O4	0.4120 (12)	0.6201 (3)	0.7189 (3)	0.0609 (11)
O5	0.5193 (13)	0.4799 (3)	0.3528 (3)	0.0673 (12)
O6	0.7978 (12)	0.5722 (3)	0.2423 (3)	0.0575 (10)
O7	0.2442 (12)	0.9219 (3)	0.2643 (3)	0.0574 (11)
O8	−0.0235 (11)	0.9479 (3)	0.4141 (3)	0.0594 (11)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.038 (2)	0.029 (2)	0.031 (2)	0.0042 (19)	0.0034 (18)	0.0016 (17)
C2	0.028 (2)	0.029 (2)	0.028 (2)	−0.0028 (17)	0.0030 (17)	0.0009 (17)
C3	0.039 (3)	0.033 (2)	0.029 (2)	−0.0037 (18)	0.0075 (18)	−0.0021 (17)
C4	0.051 (3)	0.027 (2)	0.033 (2)	−0.002 (2)	0.003 (2)	0.0004 (19)
C5	0.037 (2)	0.028 (2)	0.0236 (18)	−0.0070 (17)	0.0027 (16)	0.0021 (16)
C6	0.036 (2)	0.027 (2)	0.030 (2)	−0.0008 (18)	−0.0009 (17)	0.0062 (17)
C7	0.031 (2)	0.027 (2)	0.0248 (19)	0.0015 (16)	0.0039 (17)	−0.0022 (16)
C8	0.032 (2)	0.0231 (19)	0.024 (2)	−0.0015 (16)	0.0013 (16)	−0.0015 (15)
C9	0.027 (2)	0.025 (2)	0.027 (2)	−0.0003 (16)	0.0009 (16)	0.0014 (15)
C10	0.032 (2)	0.031 (2)	0.030 (2)	−0.0027 (17)	0.0025 (18)	−0.0045 (17)
N1	0.045 (2)	0.0284 (18)	0.0244 (16)	0.0004 (16)	0.0070 (15)	−0.0007 (14)
N2	0.049 (2)	0.0211 (18)	0.039 (2)	0.0016 (16)	0.0028 (17)	−0.0071 (15)
N3	0.062 (3)	0.045 (2)	0.0244 (18)	−0.013 (2)	0.0029 (17)	0.0004 (18)
N4	0.054 (2)	0.0246 (19)	0.0296 (19)	0.0084 (17)	−0.0011 (16)	−0.0004 (16)
N5	0.038 (2)	0.0253 (18)	0.0321 (18)	0.0036 (16)	0.0025 (15)	−0.0015 (15)
O1	0.067 (2)	0.0265 (16)	0.0321 (16)	−0.0129 (15)	0.0119 (15)	−0.0015 (12)
O2	0.059 (2)	0.0314 (16)	0.0241 (14)	0.0089 (14)	0.0132 (13)	0.0045 (12)
O3	0.104 (3)	0.065 (3)	0.0309 (18)	0.008 (2)	0.0249 (19)	−0.0064 (17)
O4	0.107 (3)	0.049 (2)	0.0266 (17)	−0.004 (2)	−0.0059 (19)	0.0104 (15)
O5	0.112 (4)	0.0272 (19)	0.063 (2)	−0.001 (2)	0.020 (2)	0.0025 (17)
O6	0.088 (3)	0.044 (2)	0.0411 (18)	0.0215 (18)	0.0267 (19)	0.0034 (16)
O7	0.098 (3)	0.039 (2)	0.0366 (18)	0.0216 (19)	0.0176 (18)	0.0097 (15)
O8	0.078 (3)	0.044 (2)	0.058 (2)	0.0309 (19)	0.024 (2)	0.0045 (17)

Geometric parameters (Å, º)

C4—N2	1.306 (6)	C7—C8	1.452 (6)
C4—N1	1.322 (6)	C7—N4	1.470 (6)
C4—H4A	0.9300	C8—O2	1.252 (5)
C3—C2	1.350 (6)	C8—C9	1.445 (5)
C3—N2	1.375 (6)	C9—C10	1.390 (6)
C3—H3A	0.9300	C9—N5	1.453 (6)
C2—N1	1.379 (5)	C10—H10A	0.9300
C2—C1	1.494 (6)	N1—H1C	0.8600
C1—O1	1.426 (6)	N2—H2B	0.8600
C1—H1A	0.9700	N3—O4	1.224 (6)
C1—H1B	0.9700	N3—O3	1.228 (6)
C5—C6	1.379 (6)	N4—O6	1.211 (5)
C5—C10	1.379 (6)	N4—O5	1.226 (6)
C5—N3	1.456 (4)	N5—O7	1.217 (4)
C6—C7	1.373 (4)	N5—O8	1.223 (5)
C6—H6A	0.9300	O1—H1	0.8200
N2—C4—N1	108.6 (4)	O2—C8—C7	123.7 (4)
N2—C4—H4A	125.7	C9—C8—C7	111.6 (3)
N1—C4—H4A	125.7	C10—C9—C8	124.1 (4)
C2—C3—N2	107.0 (4)	C10—C9—N5	115.4 (4)
C2—C3—H3A	126.5	C8—C9—N5	120.4 (3)
N2—C3—H3A	126.5	C5—C10—C9	118.7 (4)
C3—C2—N1	106.1 (4)	C5—C10—H10A	120.7
C3—C2—C1	132.9 (4)	C9—C10—H10A	120.7
N1—C2—C1	121.1 (4)	C4—N1—C2	109.1 (4)
O1—C1—C2	112.3 (4)	C4—N1—H1C	125.4
O1—C1—H1A	109.2	C2—N1—H1C	125.4
C2—C1—H1A	109.2	C4—N2—C3	109.3 (4)
O1—C1—H1B	109.2	C4—N2—H2B	125.4
C2—C1—H1B	109.2	C3—N2—H2B	125.4
H1A—C1—H1B	107.9	O3—N3—O4	123.2 (4)
C6—C5—C10	122.0 (4)	O3—N3—C5	118.8 (4)
C6—C5—N3	119.7 (4)	O4—N3—C5	118.0 (4)
C10—C5—N3	118.3 (4)	O6—N4—O5	123.4 (4)
C7—C6—C5	118.6 (4)	O6—N4—C7	119.6 (4)
C7—C6—H6A	120.7	O5—N4—C7	117.1 (4)
C5—C6—H6A	120.7	O7—N5—O8	121.4 (4)
C6—C7—C8	124.9 (4)	O7—N5—C9	120.3 (3)
C6—C7—N4	116.2 (3)	O8—N5—C9	118.3 (3)
C8—C7—N4	118.9 (3)	C1—O1—H1	109.5
O2—C8—C9	124.7 (4)
N2—C3—C2—N1	0.2 (5)	N5—C9—C10—C5	178.9 (4)
N2—C3—C2—C1	179.0 (4)	N2—C4—N1—C2	0.5 (5)
C3—C2—C1—O1	122.2 (5)	C3—C2—N1—C4	−0.4 (5)
N1—C2—C1—O1	−59.2 (5)	C1—C2—N1—C4	−179.4 (4)
C10—C5—C6—C7	2.0 (6)	N1—C4—N2—C3	−0.4 (5)
N3—C5—C6—C7	−177.4 (4)	C2—C3—N2—C4	0.1 (5)
C5—C6—C7—C8	1.2 (6)	C6—C5—N3—O3	−169.7 (4)
C5—C6—C7—N4	−178.0 (4)	C10—C5—N3—O3	10.8 (6)
C6—C7—C8—O2	177.8 (4)	C6—C5—N3—O4	9.7 (6)
N4—C7—C8—O2	−3.0 (6)	C10—C5—N3—O4	−169.7 (4)
C6—C7—C8—C9	−4.1 (6)	C6—C7—N4—O6	−147.9 (4)
N4—C7—C8—C9	175.1 (3)	C8—C7—N4—O6	32.9 (6)
O2—C8—C9—C10	−177.7 (4)	C6—C7—N4—O5	32.5 (6)
C7—C8—C9—C10	4.3 (6)	C8—C7—N4—O5	−146.8 (4)
O2—C8—C9—N5	1.7 (6)	C10—C9—N5—O7	166.3 (4)
C7—C8—C9—N5	−176.3 (4)	C8—C9—N5—O7	−13.2 (6)
C6—C5—C10—C9	−1.9 (6)	C10—C9—N5—O8	−13.5 (6)
N3—C5—C10—C9	177.6 (4)	C8—C9—N5—O8	167.0 (4)
C8—C9—C10—C5	−1.6 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4A···O4	0.93	2.37	3.294 (5)	172
O1—H1···O2^i	0.82	2.00	2.787 (4)	162
O1—H1···O6^i	0.82	2.30	2.797 (4)	120
N1—H1C···O2^i	0.86	1.95	2.730 (5)	151
N1—H1C···O7^i	0.86	2.18	2.796 (4)	129
C3—H3A···O3^ii	0.93	2.56	3.280 (4)	135
C1—H1B···O3^ii	0.97	2.55	3.402 (5)	147
N2—H2B···O1^iii	0.86	1.99	2.811 (5)	160
C1—H1A···O1^iv	0.97	2.47	3.393 (5)	159

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