Table 2. Experimental details.

Crystal data
Chemical formula	C4H12N+·C4H5O6 −·H2O
M r	241.24
Crystal system, space group	Orthorhombic, P21212
Temperature (K)	125
a, b, c (Å)	11.0921 (10), 14.8876 (14), 7.2070 (7)
V (Å3)	1190.13 (19)
Z	4
Radiation type	Mo Kα
μ (mm−1)	0.12
Crystal size (mm)	0.21 × 0.09 × 0.04
Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2008 ▸)
T min, T max	0.567, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	9652, 2925, 2613
R int	0.067
(sin θ/λ)max (Å−1)	0.680
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.040, 0.104, 1.03
No. of reflections	2925
No. of parameters	236
No. of restraints	20
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	0.30, −0.27

Computer programs: APEX2 and SAINT (Bruker, 2008 ▸), SHELXT (Sheldrick, 2015a ▸), SHELXL (Sheldrick, 2015b ▸), DIAMOND (Crystal Impact, 2014 ▸) and OLEX2 (Dolomanov et al., 2009 ▸).