Benzene-1,2-diaminium bis­(hydrogen phospho­nate)

The asymmetric unit of the title mol­ecular salt, C₆H₁₀N₂²⁺·2H₂PO₃⁻, contains half of a benzene-1,2-diaminium cation and a phosphite anion, the complete cation being generated by a crystallographic mirror plane. In the crystal, N—H...O hydrogen bonds generate R₂²(9) and R₂²(8) ring motifs and O—H...O hydrogen bonds generate an R₂²(8) ring motif. Overall, these generate a three-dimensional framework. The crystal structure also features π–π inter­actions [centroid-to-centroid distance = 3.8642 (7) Å].

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.030
• wR factor = 0.092
• Data-to-parameter ratio = 22.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT934_ALERT_3_C Number of (Iobs-Icalc)/SigmaW > 10 Outliers ....          1 Check

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          6 Note
PLAT128_ALERT_4_G Alternate Setting for Input Space Group     C2/c       I2/a Note
PLAT172_ALERT_4_G The CIF-Embedded .res File Contains DFIX Records          4 Report
PLAT860_ALERT_3_G Number of Least-Squares Restraints .............          4 Note
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600        117 Note
PLAT933_ALERT_2_G Number of OMIT records in Embedded RES .........          1 Note
PLAT978_ALERT_2_G Number C-C Bonds with Positive Residual Density           2 Note

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   1 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   7 ALERT level G = General information/check it is not something unexpected

   0 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
   2 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL2016 (Sheldrick, 2015) and PLATON (Spek, 2009).

Benzene-1,2-diaminium bis(hydrogen phosphonate)

Crystal data

C6H10N2^2+·2H2PO3^−	F(000) = 568
Mr = 272.13	Dx = 1.561 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 13.6564 (6) Å	Cell parameters from 4562 reflections
b = 12.3755 (4) Å	θ = 2.9–32.4°
c = 7.7281 (3) Å	µ = 0.39 mm^−1
β = 117.586 (1)°	T = 295 K
V = 1157.61 (8) Å^3	Block, colourless
Z = 4	0.26 × 0.24 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer	1822 reflections with I > 2σ(I)
ω and φ scan	Rint = 0.021
Absorption correction: multi-scan (SADABS; Bruker, 2004)	θmax = 33.0°, θmin = 2.4°
Tmin = 0.699, Tmax = 0.747	h = −18→20
8958 measured reflections	k = −18→18
2065 independent reflections	l = −11→11

Refinement

Refinement on F^2	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.030	w = 1/[σ^2(Fo^2) + (0.0546P)^2 + 0.3312P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.092	(Δ/σ)max < 0.001
S = 1.07	Δρmax = 0.35 e Å^−3
2065 reflections	Δρmin = −0.28 e Å^−3
93 parameters	Extinction correction: SHELXL2016 (Sheldrick 2015), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
4 restraints	Extinction coefficient: 0.0168 (18)

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
C1	0.44886 (8)	0.40189 (8)	0.66686 (14)	0.02418 (18)
C2	0.39713 (9)	0.49869 (9)	0.58591 (17)	0.0325 (2)
H2	0.328163	0.498858	0.476438	0.039*
C3	0.44871 (12)	0.59530 (9)	0.6689 (2)	0.0408 (3)
H3	0.414075	0.660483	0.615223	0.049*
N1	0.39441 (7)	0.30090 (7)	0.57724 (13)	0.02768 (18)
O1	0.00568 (7)	0.64051 (7)	0.50188 (13)	0.0394 (2)
O2	0.15544 (8)	0.49792 (7)	0.63278 (16)	0.0452 (2)
O3	0.20193 (7)	0.68978 (7)	0.73819 (12)	0.0366 (2)
P1	0.12641 (2)	0.61846 (2)	0.57358 (4)	0.02759 (10)
H1	0.1469 (14)	0.6272 (12)	0.429 (2)	0.040 (4)*
H1A	0.4365 (11)	0.2541 (11)	0.558 (2)	0.039 (4)*
H1B	0.3384 (9)	0.3133 (11)	0.4632 (14)	0.031 (3)*
H1C	0.3696 (12)	0.2700 (12)	0.649 (2)	0.040 (4)*
H2A	0.1013 (12)	0.4605 (15)	0.573 (3)	0.059*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0213 (4)	0.0239 (4)	0.0272 (4)	0.0007 (3)	0.0111 (3)	0.0009 (3)
C2	0.0324 (5)	0.0294 (5)	0.0371 (5)	0.0081 (4)	0.0172 (4)	0.0080 (4)
C3	0.0518 (7)	0.0244 (5)	0.0538 (7)	0.0067 (4)	0.0308 (6)	0.0068 (5)
N1	0.0201 (4)	0.0267 (4)	0.0277 (4)	−0.0007 (3)	0.0039 (3)	0.0014 (3)
O1	0.0259 (4)	0.0282 (4)	0.0485 (5)	0.0018 (3)	0.0041 (3)	−0.0065 (3)
O2	0.0287 (4)	0.0268 (4)	0.0617 (6)	0.0019 (3)	0.0053 (4)	0.0001 (4)
O3	0.0281 (4)	0.0352 (4)	0.0350 (4)	−0.0029 (3)	0.0048 (3)	−0.0104 (3)
P1	0.02555 (15)	0.02557 (15)	0.02480 (14)	−0.00026 (8)	0.00585 (10)	−0.00370 (8)

Geometric parameters (Å, º)

C1—C2	1.3843 (13)	N1—H1B	0.872 (9)
C1—C1^i	1.3928 (19)	N1—H1C	0.861 (9)
C1—N1	1.4552 (12)	O1—P1	1.5012 (9)
C2—C3	1.3852 (17)	O2—P1	1.5569 (9)
C2—H2	0.9300	O2—H2A	0.811 (9)
C3—C3^i	1.381 (3)	O3—P1	1.4987 (8)
C3—H3	0.9300	P1—H1	1.276 (16)
N1—H1A	0.876 (9)
C2—C1—C1^i	120.05 (6)	H1A—N1—H1B	106.3 (14)
C2—C1—N1	119.13 (9)	C1—N1—H1C	110.0 (11)
C1^i—C1—N1	120.81 (5)	H1A—N1—H1C	107.5 (15)
C1—C2—C3	119.61 (11)	H1B—N1—H1C	107.8 (14)
C1—C2—H2	120.2	P1—O2—H2A	109.8 (15)
C3—C2—H2	120.2	O3—P1—O1	114.38 (5)
C3^i—C3—C2	120.32 (7)	O3—P1—O2	109.47 (5)
C3^i—C3—H3	119.8	O1—P1—O2	111.67 (5)
C2—C3—H3	119.8	O3—P1—H1	110.5 (7)
C1—N1—H1A	114.7 (10)	O1—P1—H1	108.1 (8)
C1—N1—H1B	110.2 (9)	O2—P1—H1	102.1 (7)
C1^i—C1—C2—C3	1.30 (18)	C1—C2—C3—C3^i	0.2 (2)
N1—C1—C2—C3	−179.38 (10)

Symmetry code: (i) −x+1, y, −z+3/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1^ii	0.88 (2)	1.85 (2)	2.7217 (14)	171 (2)
N1—H1B···O3^iii	0.87 (1)	1.87 (1)	2.7220 (13)	165 (1)
N1—H1C···O3^iv	0.86 (2)	1.87 (2)	2.7193 (14)	169 (1)
O2—H2A···O1^v	0.81 (2)	1.80 (2)	2.5959 (14)	166 (2)

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