2-Carb­oxy-4-(hydroxy­meth­yl)pyridinium chloride hemihydrate

The title compound, C₇H₈NO₃⁺·Cl⁻·0.5H₂O, features inter- and intra­molecular O—H...Cl and N—H...O hydrogen bonds, linking the mol­ecules into a three-dimensional network. The water mol­ecule is located on a crystallographic twofold rotation axis.

Key indicators

• Single-crystal X-ray study
• T = 110 K
• Mean [sigma](C-C) = 0.001 Å
• R factor = 0.035
• wR factor = 0.101
• Data-to-parameter ratio = 25.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.50 Ratio
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.96
PLAT417_ALERT_2_C Short Inter D-H..H-D       H1N    ..  H3O     ..       2.13 Ang.
PLAT432_ALERT_2_C Short Inter X...Y Contact  C2     ..  C2      ..       3.19 Ang.

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

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check


checkCIF publication errors

Alert level A
PUBL024_ALERT_1_A The number of authors is greater than 5.
              Please specify the role of each of the co-authors
              for your paper.

Author Response: L. S. von Chrzanowski paper write up M. Lutz data collection, structure determination A. L. Spek crystallographic supervisor A. R. McDonald compound synthesis G. P. M. van Klink supervisor of the chemist G. van Koten project supervisor of the chemist

   1 ALERT level A = Data missing that is essential or data in wrong format
   0 ALERT level G = General alerts. Data that may be required is missing

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Computing details

Data collection: COLLECT (Nonius, 1999); cell refinement: PEAKREF (Schreurs, 2005); data reduction: EVALCCD (Duisenberg et al., 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

2-Carboxy-4-(hydroxymethyl)pyridinium chloride hemihydrate

Crystal data

C7H8NO3^+·Cl^−·0.5H2O	F(000) = 824
Mr = 198.60	Dx = 1.548 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 22552 reflections
a = 8.1935 (4) Å	θ = 2.7–35.0°
b = 13.5699 (6) Å	µ = 0.42 mm^−1
c = 15.5198 (15) Å	T = 110 K
β = 98.990 (3)°	Block, colourless
V = 1704.36 (19) Å^3	0.42 × 0.30 × 0.24 mm
Z = 8

Data collection

Nonius KappaCCD area-detector diffractometer	3753 independent reflections
Radiation source: rotating anode	3274 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.024
φ and ω scans	θmax = 35.0°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −13→13
Tmin = 0.83, Tmax = 0.90	k = −21→21
40008 measured reflections	l = −25→25

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)] = 0.035	Hydrogen site location: difference Fourier map
wR(F^2) = 0.101	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0525P)^2 + 1.7395P] where P = (Fo^2 + 2Fc^2)/3
3753 reflections	(Δ/σ)max = 0.001
146 parameters	Δρmax = 1.13 e Å^−3
0 restraints	Δρmin = −0.70 e Å^−3

Special details

Experimental. Spectroscopic analysis: ¹H NMR (300 MHz, D₂O, δ, p.p.m.): 4.88 (s, 2H, CH₂), 7.99 (d, 1H, CH), 8.26 (s, 1H, CH), 8.59 (d, 1H, CH); ¹³C NMR (75 MHz, D₂O, δ, p.p.m): 62.1, 123.7, 125.7, 141.1, 143.7, 162.9, 164.5. Elemental analysis, calculated for C₇H₈O₃NCl: C 44.34, H 4.25, N 7.39%; found: C 44.31, H 4.21, N 7.35%.

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
O1	0.07702 (10)	0.65605 (5)	0.01642 (4)	0.01750 (14)
H1O	0.039 (3)	0.7105 (17)	−0.0088 (15)	0.045 (6)*
O2	0.04751 (10)	0.72276 (5)	0.14613 (4)	0.01725 (13)
O3	0.20061 (9)	0.51296 (5)	0.41022 (4)	0.01373 (12)
H3O	0.271 (2)	0.5546 (13)	0.4149 (11)	0.027 (4)*
N1	0.21100 (9)	0.49412 (5)	0.08935 (4)	0.01117 (12)
H1N	0.205 (2)	0.5040 (12)	0.0321 (11)	0.020 (4)*
C1	0.16738 (10)	0.56437 (6)	0.14237 (5)	0.01002 (13)
C2	0.18607 (10)	0.54898 (6)	0.23129 (5)	0.01064 (13)
H2	0.156 (2)	0.6001 (12)	0.2676 (10)	0.019 (4)*
C3	0.24403 (10)	0.45802 (6)	0.26538 (5)	0.01114 (13)
C4	0.29005 (12)	0.38698 (7)	0.20857 (5)	0.01382 (14)
H4	0.331 (2)	0.3246 (12)	0.2283 (11)	0.020 (4)*
C5	0.27348 (11)	0.40721 (6)	0.12035 (5)	0.01329 (14)
H5	0.301 (2)	0.3640 (13)	0.0794 (11)	0.021 (4)*
C6	0.09164 (11)	0.65739 (6)	0.10211 (5)	0.01143 (13)
C7	0.25194 (12)	0.43389 (7)	0.36075 (5)	0.01484 (15)
H7A	0.365 (2)	0.4128 (13)	0.3865 (11)	0.027 (4)*
H7B	0.175 (2)	0.3804 (12)	0.3661 (11)	0.023 (4)*
Cl1	0.47957 (3)	0.656638 (19)	0.429264 (16)	0.02286 (7)
O4	0.5000	0.76419 (11)	0.2500	0.0395 (3)
H4O	0.4885	0.7241	0.2934	0.050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0313 (4)	0.0143 (3)	0.0072 (2)	0.0086 (2)	0.0040 (2)	0.0027 (2)
O2	0.0284 (3)	0.0120 (3)	0.0116 (3)	0.0045 (2)	0.0039 (2)	−0.0017 (2)
O3	0.0209 (3)	0.0136 (3)	0.0074 (2)	−0.0008 (2)	0.0044 (2)	−0.00112 (19)
N1	0.0163 (3)	0.0115 (3)	0.0060 (2)	0.0023 (2)	0.0029 (2)	0.0003 (2)
C1	0.0139 (3)	0.0097 (3)	0.0067 (3)	0.0006 (2)	0.0023 (2)	0.0002 (2)
C2	0.0147 (3)	0.0110 (3)	0.0065 (3)	0.0006 (2)	0.0026 (2)	0.0000 (2)
C3	0.0151 (3)	0.0120 (3)	0.0064 (3)	0.0010 (2)	0.0023 (2)	0.0007 (2)
C4	0.0213 (4)	0.0127 (3)	0.0079 (3)	0.0042 (3)	0.0034 (3)	0.0012 (2)
C5	0.0200 (4)	0.0122 (3)	0.0081 (3)	0.0043 (3)	0.0036 (3)	0.0004 (2)
C6	0.0162 (3)	0.0102 (3)	0.0080 (3)	0.0006 (2)	0.0022 (2)	0.0008 (2)
C7	0.0252 (4)	0.0135 (3)	0.0063 (3)	0.0029 (3)	0.0039 (3)	0.0010 (2)
Cl1	0.03037 (13)	0.01878 (11)	0.01996 (11)	−0.00810 (8)	0.00561 (9)	−0.00835 (8)
O4	0.0639 (10)	0.0283 (6)	0.0299 (7)	0.000	0.0183 (7)	0.000

Geometric parameters (Å, º)

O1—C6	1.3166 (10)	C2—C3	1.3966 (12)
O1—H1O	0.87 (2)	C2—H2	0.953 (16)
O2—C6	1.2090 (10)	C3—C4	1.3974 (12)
O3—C7	1.4208 (11)	C3—C7	1.5074 (11)
O3—H3O	0.805 (18)	C4—C5	1.3821 (11)
N1—C1	1.3436 (10)	C4—H4	0.943 (17)
N1—C5	1.3444 (11)	C5—H5	0.918 (17)
N1—H1N	0.893 (17)	C7—H7A	0.990 (18)
C1—C2	1.3804 (11)	C7—H7B	0.971 (17)
C1—C6	1.4992 (11)	O4—H4O	0.8822
C6—O1—H1O	114.3 (15)	C5—C4—H4	118.4 (10)
C7—O3—H3O	108.0 (13)	C3—C4—H4	122.1 (10)
C1—N1—C5	121.74 (7)	N1—C5—C4	120.12 (8)
C1—N1—H1N	121.6 (10)	N1—C5—H5	115.7 (11)
C5—N1—H1N	116.6 (10)	C4—C5—H5	124.2 (11)
N1—C1—C2	120.42 (7)	O2—C6—O1	126.37 (8)
N1—C1—C6	118.33 (7)	O2—C6—C1	121.54 (7)
C2—C1—C6	121.21 (7)	O1—C6—C1	112.07 (7)
C1—C2—C3	119.38 (7)	O3—C7—C3	113.30 (7)
C1—C2—H2	118.9 (10)	O3—C7—H7A	109.7 (10)
C3—C2—H2	121.7 (10)	C3—C7—H7A	110.7 (10)
C2—C3—C4	118.68 (7)	O3—C7—H7B	105.6 (10)
C2—C3—C7	121.60 (7)	C3—C7—H7B	108.5 (10)
C4—C3—C7	119.68 (7)	H7A—C7—H7B	108.8 (14)
C5—C4—C3	119.57 (8)
C5—N1—C1—C2	0.10 (13)	C1—N1—C5—C4	1.85 (14)
C5—N1—C1—C6	−177.30 (8)	C3—C4—C5—N1	−1.06 (14)
N1—C1—C2—C3	−2.78 (12)	N1—C1—C6—O2	178.89 (9)
C6—C1—C2—C3	174.54 (8)	C2—C1—C6—O2	1.51 (13)
C1—C2—C3—C4	3.47 (13)	N1—C1—C6—O1	0.58 (11)
C1—C2—C3—C7	−174.27 (8)	C2—C1—C6—O1	−176.80 (8)
C2—C3—C4—C5	−1.59 (13)	C2—C3—C7—O3	−1.93 (12)
C7—C3—C4—C5	176.20 (9)	C4—C3—C7—O3	−179.65 (8)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1	0.893 (17)	2.309 (16)	2.6318 (10)	101.1 (12)
N1—H1N···O3^i	0.893 (17)	1.900 (17)	2.7697 (9)	164.2 (15)
O1—H1O···Cl1^ii	0.87 (2)	2.06 (2)	2.9309 (7)	173 (2)
O3—H3O···Cl1	0.805 (18)	2.181 (18)	2.9836 (7)	174.7 (17)
O4—H4O···Cl1	0.88	2.31	3.1692 (8)	165

Symmetry codes: (i) x, −y+1, z−1/2; (ii) x−1/2, −y+3/2, z−1/2.