Pillared layered hydrogen-bonded network in hexa­methyl­enedi­ammonium hydrogenphosphite

In the structure of the title compound, C₆H₁₈N₂²⁺·2H₂PO₃⁻, the hexa­methyl­enedi­ammonium dication has a center of symmetry and the asymmetric unit contains half of the dication and one hydrogenphosphite anion. The (P—)O—H...O(—P) and N—H...O(—P) hydrogen bonds link ammonium and hydrogenphosphite groups to form a two-dimensional hydrogen-bonded network. Layers are linked covalently into pillars by bifunctional di­ammonium moieties, making a three-dimensional framework.

Key indicators

• Single-crystal X-ray study
• T = 183 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.043
• wR factor = 0.117
• Data-to-parameter ratio = 13.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_420  Alert C D-H Without Acceptor       P(1)   -   H(1)              ?

PLAT_716  Alert C H...A   Unknown or Inconsistent Label ........       O1[A]
                           H3     O1[A]

PLAT_716  Alert C H...A   Unknown or Inconsistent Label ........       O1[B]
                           H11    O1[B]

PLAT_716  Alert C H...A   Unknown or Inconsistent Label ........       O2[C]
                           H12    O2[C]

PLAT_716  Alert C H...A   Unknown or Inconsistent Label ........       O1[D]
                           H13    O1[D]

PLAT_716  Alert C H...A   Unknown or Inconsistent Label ........       O2[E]
                           H13    O2[E]

PLAT_717  Alert C D...A   Unknown or Inconsistent Label ........       O1[A]
                           O3     O1[A]

PLAT_717  Alert C D...A   Unknown or Inconsistent Label ........       O1[B]
                           N1     O1[B]

PLAT_717  Alert C D...A   Unknown or Inconsistent Label ........       O2[C]
                           N1     O2[C]

PLAT_717  Alert C D...A   Unknown or Inconsistent Label ........       O1[D]
                           N1     O1[D]

PLAT_717  Alert C D...A   Unknown or Inconsistent Label ........       O2[E]
                           N1     O2[E]

PLAT_718  Alert C D-H..A  Unknown or Inconsistent label ........       O1[A]
                           O3     H3     O1[A]

PLAT_718  Alert C D-H..A  Unknown or Inconsistent label ........       O1[B]
                           N1     H11    O1[B]

PLAT_718  Alert C D-H..A  Unknown or Inconsistent label ........       O2[C]
                           N1     H12    O2[C]

PLAT_718  Alert C D-H..A  Unknown or Inconsistent label ........       O1[D]
                           N1     H13    O1[D]

PLAT_718  Alert C D-H..A  Unknown or Inconsistent label ........       O2[E]
                           N1     H13    O2[E]


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 16 Alert Level C = Please check

---

S1. Comment

Current interest in supramolecular chemistry and material chemistry has focused on the search for new synthons and the design of building blocks which can be utilized for the engineering of one-, two- or three-dimensional assemblies. These include both organic and organic–inorganic hybrid materials, as well as organometallic moieties. The hydrogen bond plays a key role in this field and a number of hydrogen-bonding synthons have been introduced for the rational design of solids (Braga et al., 1998; Desiraju, 1989; Meleńdez & Hamilton, 1998). It has been found that phosphonic acids are potentially good candidates for the assembly of hydrogen-bonded networks (Ferguson et al., 1998; Gregson et al., 2000; Mahmoudkhani & Langer, 2001a,b; Sharma & Clearfield, 2000; Sharma et al., 2001). Phosphorus acid is the inorganic analogue of phosphonic acids, could thus behave in a similar manner in view of the architecture of the resulting structure and the potential for hydrogen-bonding interactions. This requires a systematic investigation and careful analysis of the already known structures. For example, in the crystal structures of anilinium hydrogenphosphite (Paixäo et al., 2000) and ethylenediammonium hydrogenphosphite (Fleck et al., 2000), the hydrogenphosphite group is involved in hydrogen-bonding networks, forming sheets or layers with a railroad-type section, respectively.

In the crystal structure of the title compound, (I), the hexamethylenediammonium cation is centrosymmetric and the asymmetric unit contains half of the dication and a hydrogenphosphite anion (Fig. 1). The structure exhibits a pillared-layered hydrogen-bonded network, as shown in Fig. 2. The anion acts as both hydrogen-bond donor (through the O3 atom) and acceptor (through the O1 and O2 atoms). The O2 atom is a bifurcated acceptor of hydrogen bonds via the H12 and H13 atoms, while the N1 atom acts as a bifurcated hydrogen-bond donor through the H13 atom. The O1 atom acts as an acceptor of three hydrogen bonds via the H3, H11 and H13 atoms (see Table 2 for the hydrogen-bond geometry and notations). The hydrogen-bonding pattern is presented in Fig. 3. Although the first-level graph set, based on the methodology of Bernstein et al. (1995) and Grell et al. (1999), contains only D and C(4) descriptors, the second and higher levels comprise several motifs, including chains and rings. The assignment of graph-set descriptors were performed using PLUTO, as described by Motherwell et al. (1999). The O3 atom acts only as a donor to the O1 atom, hydrogen bond [a], thus forming C(4) chain motifs along the a axis. A R₁²(4) ring motif is formed by the combination of [d] and [e] hydrogen bonds. A pair of hydrogenphosphite anions and an ammonium cation are linked together via [a], [c] and [d] hydrogen bonds, forming a R₃²(8) ring motif. A R₃³(10) motif is also formed by [a], [c] and [e] hydrogen bonds. A combination of [a], [b], [e], [c] and [b] hydrogen bonds gives a R₅³(12) ring motif.

S2. Experimental

The title compound was prepared by the reaction of a solution of phosphorus acid in water and 1,6-hexamethylenediamine in water with the molar ratio 2:1 at ambient temperature. Crystals suitable for X-ray diffraction analysis were obtained by very slow evaporation of the solution over a period of several days.

S3. Refinement

The H atom bonded to the P atom was refined isotropically without restraints. The H atoms of the ammonium and hydroxyl groups were refined isotropically with restrained bond distances of 0.85 and 0.80 Å, respectively, whereas the other H atoms were constrained to idealized geometries using the appropriate riding model.

Computing details

Data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT and SADABS (Sheldrick, 2001); program(s) used to solve structure: SHELXTL (Bruker, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: DIAMOND (Brandenburg, 2000).

Figures

	Fig. 1. The molecular structure of (I). Displacement ellipsoids are shown at the 50% probability level. Only symmetry-independent atoms are labelled.
	Fig. 2. Top: the alternating arrangement of organic dications and hydrogenphosphite tetrahedra. Notice the orientation of hydrogen on the P atom pointing out from the layers. Bottom: a view onto a layer showing the arrangement of polyhedra to form chains parallel to the a axis.
	Fig. 3. The pattern of the hydrogen-bonding network. The hydrogen-bond notations are given in Table 2. C atoms are not shown for clarity.

Hexamethylenediammonium hydrogenphosphite

Crystal data

C6H18N2^2+·2H2PO3^−	F(000) = 300
Mr = 280.20	Dx = 1.432 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 4.9330 (3) Å	Cell parameters from 2831 reflections
b = 8.9074 (5) Å	θ = 1–25°
c = 14.8407 (8) Å	µ = 0.35 mm^−1
β = 94.751 (1)°	T = 183 K
V = 649.86 (6) Å^3	Parallelipide, colorless
Z = 2	0.16 × 0.08 × 0.02 mm

Data collection

Siemens SMART CCD diffractometer	1284 independent reflections
Radiation source: fine-focus sealed tube	1049 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.042
Detector resolution: no pixels mm^-1	θmax = 26.1°, θmin = 2.7°
ω scans	h = −6→6
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	k = −11→9
Tmin = 0.946, Tmax = 0.993	l = −16→18
4004 measured reflections

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.117	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0641P)^2 + 0.4391P] where P = (Fo^2 + 2Fc^2)/3
1284 reflections	(Δ/σ)max < 0.001
93 parameters	Δρmax = 0.40 e Å^−3
4 restraints	Δρmin = −0.34 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
P1	0.05324 (12)	0.12340 (7)	0.61326 (4)	0.0182 (2)
O1	−0.2067 (3)	0.0477 (2)	0.63477 (13)	0.0272 (5)
O2	0.1354 (4)	0.2562 (2)	0.67105 (12)	0.0267 (5)
O3	0.2752 (4)	−0.0031 (2)	0.61785 (15)	0.0302 (5)
N1	−0.1298 (5)	−0.2250 (3)	0.72491 (15)	0.0219 (5)
C1	−0.1121 (5)	−0.3440 (3)	0.65508 (17)	0.0222 (6)
H1A	−0.0475	−0.4384	0.6848	0.027*
H1B	0.0222	−0.3137	0.6125	0.027*
C2	−0.3850 (5)	−0.3714 (3)	0.60280 (17)	0.0220 (6)
H2A	−0.4570	−0.2751	0.5775	0.026*
H2B	−0.5151	−0.4101	0.6446	0.026*
C3	−0.3630 (5)	−0.4838 (3)	0.52585 (18)	0.0224 (6)
H3A	−0.2366	−0.4436	0.4833	0.027*
H3B	−0.2853	−0.5788	0.5511	0.027*
H1	0.027 (5)	0.154 (3)	0.5297 (16)	0.011 (6)*
H13	−0.269 (5)	−0.240 (3)	0.7564 (17)	0.021 (7)*
H12	0.021 (5)	−0.225 (4)	0.7608 (19)	0.039 (9)*
H11	−0.152 (7)	−0.138 (2)	0.699 (2)	0.034 (9)*
H3	0.432 (4)	0.022 (4)	0.624 (2)	0.041 (10)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P1	0.0164 (4)	0.0182 (4)	0.0200 (4)	0.0012 (2)	0.0003 (2)	0.0002 (3)
O1	0.0167 (9)	0.0277 (11)	0.0374 (11)	0.0023 (7)	0.0039 (8)	0.0064 (9)
O2	0.0295 (10)	0.0208 (10)	0.0284 (10)	0.0024 (8)	−0.0051 (8)	−0.0053 (8)
O3	0.0166 (10)	0.0204 (10)	0.0535 (13)	0.0011 (8)	0.0027 (9)	−0.0037 (9)
N1	0.0207 (11)	0.0224 (13)	0.0223 (12)	−0.0025 (9)	0.0000 (9)	0.0022 (9)
C1	0.0217 (13)	0.0207 (13)	0.0239 (13)	0.0021 (10)	0.0002 (10)	−0.0002 (10)
C2	0.0173 (12)	0.0226 (14)	0.0258 (13)	0.0027 (10)	0.0004 (10)	−0.0028 (11)
C3	0.0172 (13)	0.0219 (13)	0.0279 (13)	0.0035 (10)	0.0002 (10)	−0.0016 (11)

Geometric parameters (Å, º)

P1—O1	1.5060 (19)	C1—C2	1.517 (3)
P1—O2	1.4974 (19)	C1—H1A	0.99
P1—O3	1.5686 (19)	C1—H1B	0.99
P1—H1	1.27 (2)	C2—C3	1.529 (4)
O3—H3	0.80 (2)	C2—H2A	0.99
N1—C1	1.490 (3)	C2—H2B	0.99
N1—H13	0.87 (2)	C3—C3^i	1.526 (5)
N1—H12	0.87 (2)	C3—H3A	0.99
N1—H11	0.87 (2)	C3—H3B	0.99
O1—P1—H1	106.4 (11)	N1—C1—H1B	109.3
O1—P1—O3	105.82 (11)	C2—C1—H1B	109.3
O2—P1—H1	113.1 (11)	H1A—C1—H1B	107.9
O2—P1—O1	115.29 (12)	C1—C2—C3	111.9 (2)
O2—P1—O3	112.83 (10)	C1—C2—H2A	109.2
O3—P1—H1	102.3 (11)	C3—C2—H2A	109.2
P1—O3—H3	118 (3)	C1—C2—H2B	109.2
C1—N1—H13	110.9 (19)	C3—C2—H2B	109.2
C1—N1—H12	109 (2)	H2A—C2—H2B	107.9
H13—N1—H12	110 (3)	C3^i—C3—C2	112.6 (3)
C1—N1—H11	110 (2)	C3^i—C3—H3A	109.1
H13—N1—H11	108 (3)	C2—C3—H3A	109.1
H12—N1—H11	110 (3)	C3^i—C3—H3B	109.1
N1—C1—C2	111.7 (2)	C2—C3—H3B	109.1
N1—C1—H1A	109.3	H3A—C3—H3B	107.8
C2—C1—H1A	109.3

Symmetry code: (i) −x−1, −y−1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O1[a]^ii	0.80 (2)	1.79 (2)	2.587 (3)	171 (4)
N1—H11···O1[b]	0.87 (2)	1.91 (2)	2.784 (3)	177 (3)
N1—H12···O2[c]^iii	0.87 (2)	1.91 (2)	2.781 (3)	173 (3)
N1—H13···O1[d]^iv	0.87 (2)	2.50 (3)	3.060 (3)	123 (2)
N1—H13···O2[e]^iv	0.87 (2)	2.18 (2)	3.045 (3)	171 (3)

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