Layered structures in proton-transfer compounds of 5-sulfosalicylic acid with the aromatic polyamines 2,6-diamino­pyridine and 1,4-phenyl­ene­diamine

The crystal structures of two proton-transfer compounds of 3-carb­oxy-4-hydroxy­benzene­sulfonic acid (5-sulfosalicylic acid) with the aromatic polyamines 2,6-diamino­pyridine [namely 2,6-diamino­pyridinium 3-carb­oxy-4-hydroxy­benzene­sulfonate monohydrate, C₅H₈N₃⁺·C₇H₅O₆S^-·H₂O, (I)] and 1,4-phenyl­ene­diamine [namely 1,4-phenyl­ene­diaminium 3-carboxyl­ato-4-hydroxy­benzene­sulfonate, C₆H₁₀N₂²⁺·C₇H₄O₆S^2-, (II)] have been determined. Both compounds feature extensively hydrogen-bonded three-dimensional layered polymer structures having significant inter­layer [pi]-[pi] inter­actions between the cation and anion species. In (I), the pyridine N atom of the Lewis base is protonated and forms a direct hydrogen-bonding inter­action with the water mol­ecule, which together with the two amine groups of the cation and the carboxylic acid group of the anion also give additional inter­actions with O-atom acceptors of the sulfonate group. In (II), a dianionic species results from deprotonation of both the sulfonic and the carboxylic acid groups, and all available O-atom acceptors inter­act with all dication donors, which lie about inversion centres.

S1. Comment

The systematics of the solid-state structures of the proton-transfer compounds of 3-carboxy-4-hydroxybenzenesulfonic acid (5-sulfosalicylic acid, 5-SSA) with Lewis bases have been widely studied because of the good crystallinity of many of the compounds. This feature is a result of the presence of sulfonate and potentially carboxyl oxygen acceptors available for hydrogen-bonding interactions. This has been useful for the study of certain difficult-to-crystallize bases, e.g. theophylline (a monohydrate) (Madarasz et al., 2002), trimethoprim (a dihydrate) (Raj et al., 2003) and pyrimethamine (a monohydrate) (Hemamalini et al., 2005). However, examples of the dianionic 5-SSA species are rare, being found only in bis(guanidinium) 5-sulfosalicylate monohydrate (Smith, Wermuth & Healy, 2004). Although anhydrous compounds of 5-SSA are known, for example the 1:1 compounds with guanidine (Zhang et al., 2004) and 1,10-phenanthroline (Fan et al., 2005), the structures usually incorporate at least one water solvate molecule, which acts in a donor/acceptor capacity, usually involving the aminium group in a direct hydrogen-bonding interaction. This, with additional interactions, results in mostly three- dimensional polymer structures, which in only a small number of cases (those compounds with polycyclic heteroaromatic amines) involve π–π stacking effects (Smith, Wermuth & White, 2004).

Aniline-type proton-transfer compounds lend themselves to structure building since the protonated primary amine group will often give up to six interactions with available acceptor atoms. The structures of the 1:1 compounds of 5-SSA with aniline (Bakasova et al., 1991), the 4-X-substituted anilines (X = F, Cl and Br; Smith et al., 2005a) and 4-aminobenzoic acid (Smith et al., 2005b) have been reported. However, apart from the structures of two 5-SSA compounds with diamines [ethylenediaminium bis(5-sulfosalicylate) tetrahydrate (Gao et al., 2004) and 4,4'-bipyridinium bis(5-sulfosalicylate) dihydrate (Muthiah et al., 2003)], no polyfunctional aniline-type compounds are known. We therefore attempted to obtain crystalline compounds of 5-SSA with aromatic polyamines with the aim of maximizing structure enhancement through both hydrogen bonding and possibly π–π interactive effects. The work has yielded limited success to date, but the two compounds whose crystal structures are reported here represent exceptions where good crystalline products were obtained. These compounds resulted from the reaction of 5-SSA with the aromatic polyamines 2,6-diaminopyridine (DAP) and 1,4-phenylenediamine (PDA), respectively, viz. 2,6-diaminopyridinium 5-sulfosalicylate monohydrate, C₅H₈N₃^+. C₇H₅O₆S^-. H₂O, (I), and 1,4-phenylenediaminium 5-sulfosalicylate C₆H₁₀N₂^2+. C₇H₄O₆S²⁻, (II). Figs. 1 and 2 show the atom-numbering schemes used for the 5-sulfosalicylate anion and aminium cations in (I) and (II) and are consistent with those previously employed in 5-SSA structures reported by this group (Smith, Wermuth & Healy, 2004; Smith, Wermuth & White, 2004; Smith et al., 2005a,b). Both (I) and (II) involve proton transfer with subsequent extensive hydrogen bonding involving available H-atom donor and acceptor atoms of both cation and anion species, giving in both three- dimensional layered polymer structures (Tables 1 and 2).

In (I) (Fig. 3), single proton transfer to only the pyridine hetero N atom occurs, and this group subsequently participates in a single hydrogen-bonding interaction with the water molecule [N—H···O = 2.775 (5) Å]. The water molecule also provides hydrogen-bonding links between sulfonate O-atom acceptors extending along the c direction [O1W····O53 = 2.897 (5) Å and O1W··· O51ⁱ = 2.789 (5) Å; symmetry code: (i) x, y, 1 + z], giving a total of five interactions for the sulfonate groups, including one with the carboxylic acid group of the 5-SSA anion [O71—H71···O51ⁱⁱ = 2.621 (4) Å; symmetry code: (ii) 1 − x, 1/2 + y, 1 − z]. The result is the formation of an undulating layer structure in which the alternating DAP cations and 5-SSA anions partially superimpose down the c axial direction, with significant π–π ring interactions [ring centroid separation Cg···Cg = 3.54 (1) Å (intra) and 3.56 (1) Å (inter)]. The overall result is a three-dimensional polymer structure. There is no occurrence of the R²₂(8) dimer interaction found in the small number of reported cocrystals of DAP [(1:1) proton-transfer compounds with 2-nitrobenzoic acid (Smith et al., 1999) and 2,4,6-trinitrobenzoic acid (Smith et al., 2000)]. However, this is probably because of the interjection in (I) of the water molecule into the hydrogen-bonding pattern.

The structure of (II), except for the layering, differs markedly from that of (I) and those of the majority of the proton-transfer compounds of 5-SSA. The most unusual feature is the presence of dianionic 5-SSA species despite the use of 1:1 stoichiometric reactant ratios in the preparation. Both amine groups of the PDA molecule are protonated, which is also unusual considering that the second amine group is relatively acidic [pK_a1,2 = 2.67 and 6.60]. The crystallographic repeating unit comprises the 5-SSA²⁻ anion and two centrosymmetric PDA²⁺ half-cations (A and B) (Fig. 2). The A^v and B^ix molecular portions represent the inversion-generated halves of the two molecules [symmetry codes: (v) −x, −y, 1 − z; (ix) 1 − x, 1 − y, −z]. The cation and anion molecules form into two-dimensional sheet structures through a number of hydrogen-bonding interactions involving all potential donor and acceptor atoms of both molecular species [range 2.725 (3)–3.114 (2) Å]. These sheets are interlinked by N⁺—H···O hydrogen-bonding interactions. (Fig. 4) and stack down the c cell direction with the alternating cation A–anion–cation B molecules separation indicating significant π–π interaction [inter-ring centroid distances: cation A–anion = 3.73 (1) Å and cation B–anion = 3.75 (1) Å]. The overall result is a three-dimensional polymer structure.

In the 5-SSA anion species in (I) and (II), similar structural and conformational features to those previously observed (Smith, Wermuth & Healy, 2004; Smith, Wermuth & White, 2004; Smith et al., 2005a,b) are found. An usual intramolecular hydrogen bond is found between the phenol OH group and a carboxyl O atom [O2—H2···O72; 2.606 (4) Å for (I), contracting as expected in (II) to 2.558 (2) Å, where the carboxylic acid group is deprotonated]. This interaction? also results in greater deviation from coplanarity of the overall group with the benzene ring [C2—C1—C7—O71 = 171.1 (2)° for (II) cf. 176.3 (3)° for (I)]. There is no occurrence of the strong intermolecular R²₂(8) cyclic carboxylic acid interaction as is found in the 4-chloro- and 4-bromoanilinium compounds with 5-SSA (Smith et al., 2005a), nor of the anilinium-sulfonate R²₂(8) dimer interaction commonly found in the anhydrous guanidinium sulfonates (Russell et al., 1994; Zhang et al., 2004; Haynes et al., 2004).

S2. Experimental

The title compounds were synthesized by heating 1 mmol quantities of 3-carboxy-4-hydroxybenzenesulfonic acid (5-sulfosalicylic acid = 5-SSA) and, respectively, 2,6-diaminopyridine (DAP) or 1,4-phenylenediamine (PDA) in 50 ml of 50% ethanol–water for 10 min under reflux. After concentration to ca 30 ml, partial room-temperature evaporation of the hot-filtered solutions gave pale brown crystals of both (I) (m.p. 524–526 K) and (II) (m.p. >555 K).

S3. Refinement

H atoms involved in hydrogen-bonding interactions (pyridinium, anilinium, carboxyl, phenol and water) were located by difference methods, and their positional and isotropic displacement parameters were refined. Other H atoms were included in the respective refinements at calculated positions (C—H = 0.95 Å) as riding atoms, with U_eq values fixed at 1.2U_eq(C).

Computing details

For both compounds, data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1999); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN for Windows (Molecular Structure Corporation, 1999); 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: PLATON.

Figures

	Fig. 1. The molecular configuration and atom-numbering scheme for the DAP^+ cation, the 5-SSA^− anion and the water molecule in (I). Non-H atoms are shown as 30% probability displacement ellipsoids, and hydrogen bonds are shown as dashed lines.
	Fig. 2. The atom-numbering scheme for the two centrosymmetric half- PDA^2+ cations (A and B) and the 5-SSA^2− anion in (II) (30% probability displacement ellipsoids). The intramolecular hydrogen bond is shown as a dashed line. [Symmetry codes: (v) −x, −y, 1 − z; (ix) 1 − x, 1 − y, −z.]
	Fig. 3. Structure extension through hydrogen-bonding interactions (shown as broken lines) in (I), viewed along the a cell direction. Hydrogen bonds are shown as dashed lines. [Symmetry code: (v) x, y, z − 1. For other symmetry codes, see Table 1.]
	Fig. 4. A perspective view of the hydrogen-bonding associations in the layered structure of (II), viewed along the a cell direction. Hydrogen bonds are shown as dashed lines. [Symmetry codes: (vii) x, y, 1 + z; (viii) x, 1 + y, z; (ix) 1 − x, 1 − y, −z. For other symmetry codes, see Table 2.]

(I) 2,6-diaminopyridinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate'

Crystal data

C5H8N3^+·C7H5O6S^−·H2O	F(000) = 360
Mr = 345.34	Dx = 1.584 Mg m^−3
Monoclinic, P21	Melting point = 524–526 K
Hall symbol: P 2yb	Mo Kα radiation, λ = 0.71069 Å
a = 8.4778 (15) Å	Cell parameters from 25 reflections
b = 13.085 (2) Å	θ = 12.6–15.8°
c = 6.7562 (11) Å	µ = 0.27 mm^−1
β = 105.001 (14)°	T = 297 K
V = 723.9 (2) Å^3	Prism, pale brown
Z = 2	0.40 × 0.30 × 0.30 mm

Data collection

Rigaku AFC 7R diffractometer	Rint = 0.014
Radiation source: Rigaku rotating anode	θmax = 27.5°, θmin = 2.9°
Graphite monochromator	h = −4→11
ω–2θ scans	k = 0→17
1965 measured reflections	l = −8→8
1726 independent reflections	3 standard reflections every 150 min
1406 reflections with I > 2σ(I)	intensity decay: 0.5%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.034	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.112	w = 1/[σ^2(Fo^2) + (0.1P)^2 + 0.0953P] where P = (Fo^2 + 2Fc^2)/3
S = 0.89	(Δ/σ)max = 0.002
1726 reflections	Δρmax = 0.25 e Å^−3
243 parameters	Δρmin = −0.24 e Å^−3
1 restraint	Absolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.06 (12)

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All e.s.d.'s are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
S5	0.96025 (9)	0.09870 (7)	0.30700 (14)	0.0386 (3)
O2	0.4791 (4)	−0.2341 (2)	0.0940 (5)	0.0468 (9)
O51	1.0254 (3)	0.1158 (3)	0.1284 (5)	0.0524 (9)
O52	1.0837 (4)	0.0619 (3)	0.4803 (5)	0.0605 (10)
O53	0.8771 (4)	0.1898 (2)	0.3517 (6)	0.0559 (10)
O71	0.3248 (3)	0.0659 (2)	0.1281 (5)	0.0474 (9)
O72	0.2513 (3)	−0.0964 (2)	0.0559 (5)	0.0518 (9)
C1	0.5333 (4)	−0.0540 (3)	0.1445 (5)	0.0310 (9)
C2	0.5846 (4)	−0.1551 (3)	0.1372 (5)	0.0337 (10)
C3	0.7516 (5)	−0.1774 (3)	0.1769 (6)	0.0406 (11)
C4	0.8645 (4)	−0.0999 (3)	0.2260 (6)	0.0370 (10)
C5	0.8132 (4)	0.0014 (3)	0.2375 (5)	0.0323 (9)
C6	0.6490 (4)	0.0237 (3)	0.1961 (5)	0.0306 (9)
C7	0.3567 (4)	−0.0310 (3)	0.1056 (5)	0.0365 (10)
N11	0.6697 (4)	−0.0305 (3)	0.6979 (5)	0.0350 (9)
N21	0.4379 (5)	0.0680 (3)	0.6615 (6)	0.0478 (11)
N61	0.9169 (4)	−0.1142 (4)	0.7403 (7)	0.0511 (11)
C21	0.5036 (4)	−0.0244 (3)	0.6536 (5)	0.0333 (9)
C31	0.4141 (4)	−0.1134 (3)	0.6040 (6)	0.0382 (10)
C41	0.4959 (5)	−0.2037 (3)	0.6034 (6)	0.0410 (11)
C51	0.6640 (5)	−0.2084 (3)	0.6466 (6)	0.0406 (11)
C61	0.7528 (4)	−0.1194 (3)	0.6953 (5)	0.0367 (10)
O1W	0.8131 (4)	0.1616 (3)	0.7491 (6)	0.0576 (11)
H2	0.397 (9)	−0.208 (6)	0.092 (10)	0.10 (2)*
H3	0.786100	−0.246400	0.169100	0.0490*
H4	0.978200	−0.114700	0.252400	0.0440*
H6	0.611800	0.092100	0.204100	0.0370*
H71	0.214 (7)	0.076 (5)	0.111 (8)	0.067 (15)*
H11	0.714 (5)	0.022 (3)	0.706 (5)	0.023 (9)*
H21A	0.486 (7)	0.114 (5)	0.713 (8)	0.061 (17)*
H21B	0.324 (6)	0.070 (4)	0.634 (6)	0.039 (11)*
H31	0.298400	−0.112000	0.568900	0.0450*
H41	0.434500	−0.265300	0.570700	0.0480*
H51	0.719000	−0.271800	0.644600	0.0500*
H61A	0.941 (7)	−0.060 (5)	0.777 (8)	0.054 (16)*
H61B	0.965 (7)	−0.168 (5)	0.749 (8)	0.061 (17)*
H1A	0.887 (7)	0.155 (5)	0.847 (8)	0.063 (16)*
H1B	0.833 (7)	0.188 (5)	0.643 (8)	0.073 (17)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S5	0.0214 (4)	0.0424 (4)	0.0510 (5)	−0.0041 (4)	0.0074 (3)	0.0013 (4)
O2	0.0388 (14)	0.0384 (14)	0.0614 (17)	−0.0052 (12)	0.0095 (13)	0.0025 (13)
O51	0.0268 (11)	0.069 (2)	0.0646 (16)	−0.0042 (13)	0.0176 (11)	0.0144 (16)
O52	0.0386 (14)	0.068 (2)	0.0625 (17)	−0.0117 (15)	−0.0090 (13)	0.0044 (16)
O53	0.0382 (15)	0.0416 (16)	0.091 (2)	−0.0067 (13)	0.0225 (15)	−0.0119 (16)
O71	0.0245 (13)	0.0460 (15)	0.0730 (18)	0.0001 (11)	0.0149 (12)	−0.0074 (13)
O72	0.0279 (12)	0.0506 (17)	0.0720 (19)	−0.0086 (12)	0.0042 (12)	−0.0076 (15)
C1	0.0254 (15)	0.0369 (17)	0.0301 (15)	−0.0005 (12)	0.0063 (12)	0.0023 (13)
C2	0.0306 (16)	0.0359 (18)	0.0352 (16)	−0.0058 (13)	0.0095 (13)	0.0044 (14)
C3	0.0371 (18)	0.0338 (17)	0.052 (2)	0.0070 (15)	0.0134 (16)	0.0003 (15)
C4	0.0247 (15)	0.0411 (19)	0.0445 (19)	0.0030 (14)	0.0077 (13)	0.0016 (16)
C5	0.0254 (14)	0.0411 (18)	0.0307 (15)	−0.0049 (13)	0.0076 (12)	0.0027 (13)
C6	0.0250 (14)	0.0342 (16)	0.0340 (15)	−0.0020 (12)	0.0099 (12)	−0.0020 (13)
C7	0.0253 (15)	0.046 (2)	0.0377 (17)	−0.0046 (14)	0.0075 (13)	−0.0030 (15)
N11	0.0328 (15)	0.0372 (17)	0.0330 (14)	−0.0078 (13)	0.0048 (11)	0.0020 (12)
N21	0.040 (2)	0.0431 (19)	0.0548 (19)	0.0052 (15)	0.0024 (15)	−0.0035 (16)
N61	0.0326 (17)	0.056 (2)	0.061 (2)	−0.0022 (18)	0.0057 (15)	0.001 (2)
C21	0.0300 (15)	0.0398 (18)	0.0284 (15)	0.0017 (14)	0.0044 (12)	0.0013 (14)
C31	0.0298 (16)	0.045 (2)	0.0377 (18)	−0.0046 (15)	0.0051 (13)	0.0012 (15)
C41	0.0429 (19)	0.0388 (19)	0.0390 (18)	−0.0093 (16)	0.0064 (15)	−0.0017 (15)
C51	0.043 (2)	0.0352 (18)	0.0441 (19)	0.0048 (15)	0.0123 (16)	0.0027 (15)
C61	0.0309 (17)	0.045 (2)	0.0335 (17)	−0.0020 (15)	0.0072 (14)	−0.0006 (14)
O1W	0.0498 (18)	0.059 (2)	0.060 (2)	−0.0101 (17)	0.0069 (16)	−0.0014 (17)

Geometric parameters (Å, º)

S5—O51	1.468 (3)	N61—H61A	0.76 (6)
S5—O52	1.437 (4)	C1—C7	1.482 (5)
S5—O53	1.456 (3)	C1—C6	1.393 (5)
S5—C5	1.759 (4)	C1—C2	1.397 (5)
O2—C2	1.349 (5)	C2—C3	1.402 (6)
O71—C7	1.313 (5)	C3—C4	1.375 (6)
O72—C7	1.220 (5)	C4—C5	1.403 (6)
O2—H2	0.77 (8)	C5—C6	1.378 (5)
O71—H71	0.93 (6)	C3—H3	0.9547
O1W—H1A	0.79 (6)	C4—H4	0.9537
O1W—H1B	0.85 (6)	C6—H6	0.9551
N11—C21	1.364 (5)	C21—C31	1.383 (5)
N11—C61	1.362 (5)	C31—C41	1.371 (6)
N21—C21	1.338 (6)	C41—C51	1.380 (6)
N61—C61	1.347 (5)	C51—C61	1.379 (6)
N11—H11	0.78 (4)	C31—H31	0.9478
N21—H21A	0.76 (6)	C41—H41	0.9539
N21—H21B	0.94 (5)	C51—H51	0.9535
N61—H61B	0.81 (6)
O51—S5—O52	111.79 (19)	C4—C5—C6	120.0 (3)
O51—S5—O53	110.6 (2)	S5—C5—C4	119.3 (3)
O51—S5—C5	106.40 (18)	C1—C6—C5	120.3 (4)
O52—S5—O53	113.3 (2)	O71—C7—C1	113.8 (3)
O52—S5—C5	106.9 (2)	O72—C7—C1	122.7 (4)
O53—S5—C5	107.48 (18)	O71—C7—O72	123.4 (3)
C2—O2—H2	102 (6)	C4—C3—H3	120.45
C7—O71—H71	111 (4)	C2—C3—H3	119.67
H1A—O1W—H1B	118 (6)	C3—C4—H4	120.15
C21—N11—C61	123.7 (4)	C5—C4—H4	119.61
C61—N11—H11	121 (3)	C5—C6—H6	121.19
C21—N11—H11	115 (3)	C1—C6—H6	118.47
H21A—N21—H21B	118 (6)	N21—C21—C31	124.2 (4)
C21—N21—H21A	124 (5)	N11—C21—C31	118.3 (4)
C21—N21—H21B	116 (3)	N11—C21—N21	117.4 (4)
H61A—N61—H61B	134 (6)	C21—C31—C41	118.7 (3)
C61—N61—H61A	107 (5)	C31—C41—C51	122.2 (4)
C61—N61—H61B	116 (4)	C41—C51—C61	118.9 (4)
C6—C1—C7	120.6 (3)	N11—C61—C51	118.1 (3)
C2—C1—C6	119.6 (3)	N11—C61—N61	117.5 (4)
C2—C1—C7	119.7 (3)	N61—C61—C51	124.4 (4)
O2—C2—C1	122.6 (3)	C41—C31—H31	120.50
O2—C2—C3	117.5 (3)	C21—C31—H31	120.78
C1—C2—C3	119.9 (3)	C31—C41—H41	118.88
C2—C3—C4	119.9 (4)	C51—C41—H41	118.89
C3—C4—C5	120.2 (3)	C41—C51—H51	121.18
S5—C5—C6	120.7 (3)	C61—C51—H51	119.95
O51—S5—C5—C4	74.2 (3)	C2—C1—C6—C5	0.7 (5)
O51—S5—C5—C6	−106.3 (3)	C7—C1—C6—C5	178.2 (3)
O52—S5—C5—C4	−45.4 (3)	C7—C1—C2—O2	0.6 (5)
O52—S5—C5—C6	134.1 (3)	O2—C2—C3—C4	−178.6 (3)
O53—S5—C5—C4	−167.4 (3)	C1—C2—C3—C4	1.0 (5)
O53—S5—C5—C6	12.1 (3)	C2—C3—C4—C5	0.3 (6)
C21—N11—C61—C51	−0.5 (5)	C3—C4—C5—S5	178.4 (3)
C61—N11—C21—N21	−179.8 (3)	C3—C4—C5—C6	−1.1 (5)
C61—N11—C21—C31	0.3 (5)	S5—C5—C6—C1	−178.9 (3)
C21—N11—C61—N61	179.4 (4)	C4—C5—C6—C1	0.6 (5)
C6—C1—C7—O72	178.4 (3)	N11—C21—C31—C41	0.6 (5)
C6—C1—C7—O71	−1.1 (5)	N21—C21—C31—C41	−179.3 (4)
C2—C1—C7—O72	−4.1 (5)	C21—C31—C41—C51	−1.3 (6)
C2—C1—C7—O71	176.4 (3)	C31—C41—C51—C61	1.1 (6)
C6—C1—C2—O2	178.1 (3)	C41—C51—C61—N61	180 (2)
C6—C1—C2—C3	−1.5 (5)	C41—C51—C61—N11	−0.2 (5)
C7—C1—C2—C3	−179.0 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O72	0.77 (8)	1.89 (8)	2.605 (4)	154 (8)
O1W—H1A···O51^i	0.79 (6)	2.02 (5)	2.789 (5)	163 (6)
O1W—H1B···O53	0.85 (6)	2.10 (5)	2.897 (5)	157 (6)
N11—H11···O1W	0.78 (4)	2.00 (4)	2.775 (5)	173 (4)
N21—H21A···O2^ii	0.76 (6)	2.35 (6)	3.054 (5)	154 (6)
N21—H21B···O52^iii	0.94 (5)	2.04 (5)	2.936 (6)	161 (4)
N61—H61B···O53^iv	0.81 (6)	2.49 (6)	3.252 (6)	158 (5)
O71—H71···O51^iii	0.93 (6)	1.71 (6)	2.621 (4)	166 (6)
C6—H6···O53	0.96	2.55	2.918 (5)	103
C6—H6···O71	0.96	2.38	2.723 (4)	101

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

(II) 1,4-phenylenediaminium 3-carboxylato-4-hydroxybenzenesolfonate

Crystal data

C6H10N2^2+·C7H4O6S^2^−	Z = 2
Mr = 326.32	F(000) = 340
Triclinic, P1	Dx = 1.621 Mg m^−3
Hall symbol: -P 1	Melting point: greater than 555 K K
a = 6.9800 (14) Å	Mo Kα radiation, λ = 0.71069 Å
b = 9.1573 (15) Å	Cell parameters from 25 reflections
c = 10.849 (2) Å	θ = 12.7–17.2°
α = 84.618 (14)°	µ = 0.28 mm^−1
β = 97.698 (16)°	T = 297 K
γ = 102.879 (14)°	Prism, pale brown
V = 668.4 (2) Å^3	0.40 × 0.30 × 0.25 mm

Data collection

Rigaku AFC 7R diffractometer	Rint = 0.034
Radiation source: Rigaku rotating anode	θmax = 27.5°, θmin = 2.9°
Graphite monochromator	h = −3→9
ω–2θ scans	k = −11→11
3477 measured reflections	l = −14→13
3067 independent reflections	3 standard reflections every 150 min
2678 reflections with F^2 > 2σ(F^2)	intensity decay: 0.8%

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.111	H atoms treated by a mixture of independent and constrained refinement
S = 0.83	w = 1/[σ^2(Fo^2) + (0.1P)^2 + 2.7752P] where P = (Fo^2 + 2Fc^2)/3
3067 reflections	(Δ/σ)max = 0.002
227 parameters	Δρmax = 0.28 e Å^−3
0 restraints	Δρmin = −0.30 e Å^−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All e.s.d.'s are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
S5	0.24133 (6)	−0.07178 (5)	0.17261 (4)	0.0220 (1)
O2	0.2200 (2)	0.53368 (17)	0.30520 (17)	0.0382 (5)
O51	0.0443 (2)	−0.16497 (16)	0.18292 (15)	0.0332 (4)
O52	0.3917 (2)	−0.12624 (16)	0.25917 (15)	0.0338 (4)
O53	0.2911 (2)	−0.05407 (17)	0.04508 (14)	0.0345 (5)
O71	0.7443 (2)	0.38757 (18)	0.38199 (16)	0.0382 (5)
O72	0.5953 (2)	0.58001 (17)	0.36193 (16)	0.0389 (5)
C1	0.4086 (3)	0.3451 (2)	0.29678 (17)	0.0214 (5)
C2	0.2298 (3)	0.3953 (2)	0.27685 (18)	0.0244 (5)
C3	0.0565 (3)	0.3015 (2)	0.2271 (2)	0.0288 (6)
C4	0.0594 (3)	0.1595 (2)	0.19590 (19)	0.0269 (5)
C5	0.2359 (3)	0.1086 (2)	0.21482 (17)	0.0220 (5)
C6	0.4085 (3)	0.2011 (2)	0.26493 (17)	0.0228 (5)
C7	0.5962 (3)	0.4427 (2)	0.35162 (18)	0.0256 (5)
N1A	0.0053 (3)	0.29317 (19)	0.56513 (18)	0.0282 (5)
C1A	0.0033 (3)	0.1417 (2)	0.53136 (17)	0.0232 (5)
C2A	0.1793 (3)	0.0934 (2)	0.54190 (19)	0.0263 (5)
C3A	0.1758 (3)	−0.0505 (2)	0.51007 (19)	0.0272 (5)
N1B	0.3612 (3)	0.21705 (19)	−0.10300 (18)	0.0269 (5)
C1B	0.4327 (3)	0.3632 (2)	−0.04953 (17)	0.0230 (5)
C2B	0.3014 (3)	0.4556 (2)	−0.0464 (2)	0.0289 (6)
C3B	0.3700 (3)	0.5945 (2)	0.0037 (2)	0.0296 (6)
H2	0.343 (6)	0.578 (4)	0.331 (4)	0.080 (12)*
H3	−0.064500	0.335800	0.213300	0.0340*
H4	−0.059900	0.095800	0.162100	0.0310*
H6	0.528700	0.166000	0.278300	0.0270*
H2A	0.301300	0.157800	0.570100	0.0300*
H3A	0.301100	−0.081600	0.518300	0.0210*
H11A	0.143 (5)	0.349 (4)	0.583 (3)	0.062 (9)*
H12A	−0.072 (4)	0.340 (3)	0.507 (3)	0.041 (7)*
H13A	−0.041 (5)	0.287 (3)	0.639 (3)	0.051 (8)*
H2B	0.165400	0.424400	−0.077900	0.0340*
H3B	0.288200	0.662200	0.017400	0.0210*
H11B	0.370 (5)	0.136 (4)	−0.041 (3)	0.054 (8)*
H12B	0.425 (5)	0.201 (4)	−0.165 (3)	0.063 (10)*
H13B	0.240 (4)	0.203 (3)	−0.130 (3)	0.041 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S5	0.0189 (2)	0.0168 (2)	0.0301 (3)	0.0022 (2)	0.0006 (2)	−0.0079 (2)
O2	0.0287 (8)	0.0241 (7)	0.0651 (10)	0.0088 (6)	0.0006 (7)	−0.0194 (7)
O51	0.0235 (7)	0.0235 (7)	0.0505 (9)	−0.0023 (5)	0.0033 (6)	−0.0110 (6)
O52	0.0327 (8)	0.0265 (7)	0.0434 (8)	0.0125 (6)	−0.0078 (6)	−0.0106 (6)
O53	0.0447 (9)	0.0274 (7)	0.0337 (8)	0.0066 (6)	0.0108 (6)	−0.0081 (6)
O71	0.0241 (7)	0.0354 (8)	0.0534 (10)	0.0065 (6)	−0.0104 (6)	−0.0156 (7)
O72	0.0304 (8)	0.0232 (7)	0.0616 (10)	0.0003 (6)	−0.0025 (7)	−0.0196 (7)
C1	0.0198 (8)	0.0188 (8)	0.0249 (9)	0.0018 (6)	0.0003 (6)	−0.0062 (6)
C2	0.0245 (9)	0.0194 (8)	0.0307 (9)	0.0061 (7)	0.0023 (7)	−0.0065 (7)
C3	0.0198 (9)	0.0272 (9)	0.0407 (11)	0.0082 (7)	−0.0019 (7)	−0.0085 (8)
C4	0.0195 (9)	0.0226 (9)	0.0369 (10)	0.0021 (7)	−0.0033 (7)	−0.0087 (7)
C5	0.0207 (8)	0.0177 (8)	0.0273 (9)	0.0029 (6)	0.0004 (7)	−0.0062 (6)
C6	0.0196 (8)	0.0202 (8)	0.0289 (9)	0.0048 (7)	−0.0004 (7)	−0.0064 (7)
C7	0.0234 (9)	0.0236 (9)	0.0283 (9)	0.0008 (7)	0.0004 (7)	−0.0087 (7)
N1A	0.0290 (9)	0.0190 (8)	0.0359 (9)	0.0044 (7)	−0.0023 (7)	−0.0092 (7)
C1A	0.0257 (9)	0.0171 (8)	0.0259 (9)	0.0031 (7)	−0.0002 (7)	−0.0053 (6)
C2A	0.0207 (9)	0.0229 (9)	0.0322 (10)	−0.0005 (7)	−0.0034 (7)	−0.0081 (7)
C3A	0.0205 (9)	0.0240 (9)	0.0365 (10)	0.0045 (7)	−0.0018 (7)	−0.0071 (7)
N1B	0.0235 (8)	0.0227 (8)	0.0346 (9)	0.0046 (6)	−0.0015 (7)	−0.0097 (7)
C1B	0.0246 (9)	0.0191 (8)	0.0251 (9)	0.0034 (7)	0.0021 (7)	−0.0046 (6)
C2B	0.0202 (9)	0.0278 (10)	0.0387 (11)	0.0053 (7)	−0.0020 (7)	−0.0094 (8)
C3B	0.0233 (9)	0.0266 (9)	0.0408 (11)	0.0087 (7)	−0.0007 (8)	−0.0098 (8)

Geometric parameters (Å, º)

S5—O51	1.4602 (15)	C1—C6	1.394 (3)
S5—O52	1.4538 (16)	C2—C3	1.393 (3)
S5—O53	1.4570 (16)	C3—C4	1.379 (3)
S5—C5	1.7646 (19)	C4—C5	1.396 (3)
O2—C2	1.350 (2)	C5—C6	1.386 (3)
O71—C7	1.242 (3)	C3—H3	0.9539
O72—C7	1.274 (2)	C4—H4	0.9539
O2—H2	0.88 (4)	C6—H6	0.9524
N1A—C1A	1.464 (3)	C1A—C3A^i	1.384 (3)
N1A—H13A	0.90 (3)	C1A—C2A	1.383 (3)
N1A—H12A	0.91 (3)	C2A—C3A	1.387 (3)
N1A—H11A	0.99 (4)	C2A—H2A	0.9522
N1B—C1B	1.465 (3)	C3A—H3A	0.9692
N1B—H12B	0.89 (3)	C1B—C2B	1.384 (3)
N1B—H11B	0.96 (3)	C1B—C3B^ii	1.382 (3)
N1B—H13B	0.84 (3)	C2B—C3B	1.390 (3)
C1—C2	1.407 (3)	C2B—H2B	0.9540
C1—C7	1.496 (3)	C3B—H3B	0.9645
O51—S5—O52	111.82 (9)	C4—C5—C6	119.87 (17)
O51—S5—O53	112.17 (9)	C1—C6—C5	120.84 (19)
O51—S5—C5	106.72 (9)	O72—C7—C1	117.39 (18)
O52—S5—O53	111.75 (9)	O71—C7—O72	123.64 (19)
O52—S5—C5	107.23 (9)	O71—C7—C1	118.95 (17)
O53—S5—C5	106.75 (9)	C2—C3—H3	120.10
C2—O2—H2	105 (2)	C4—C3—H3	119.64
H12A—N1A—H13A	109 (3)	C5—C4—H4	120.09
H11A—N1A—H12A	115 (3)	C3—C4—H4	119.79
C1A—N1A—H12A	111.1 (18)	C1—C6—H6	119.36
C1A—N1A—H13A	109.0 (17)	C5—C6—H6	119.80
C1A—N1A—H11A	110 (2)	N1A—C1A—C2A	119.39 (18)
H11A—N1A—H13A	103 (3)	N1A—C1A—C3A^i	118.80 (19)
H11B—N1B—H13B	104 (3)	C2A—C1A—C3A^i	121.82 (17)
C1B—N1B—H11B	111 (2)	C1A—C2A—C3A	118.96 (19)
H12B—N1B—H13B	107 (3)	C1A^i—C3A—C2A	119.22 (19)
C1B—N1B—H12B	115 (2)	C3A—C2A—H2A	120.31
C1B—N1B—H13B	111.7 (19)	C1A—C2A—H2A	120.73
H11B—N1B—H12B	106 (3)	C2A—C3A—H3A	117.33
C2—C1—C7	121.28 (16)	C1A^i—C3A—H3A	123.45
C2—C1—C6	118.74 (18)	N1B—C1B—C2B	119.32 (19)
C6—C1—C7	119.98 (19)	N1B—C1B—C3B^ii	119.07 (18)
C1—C2—C3	120.17 (17)	C2B—C1B—C3B^ii	121.62 (17)
O2—C2—C1	121.69 (18)	C1B—C2B—C3B	119.15 (19)
O2—C2—C3	118.14 (18)	C1B^ii—C3B—C2B	119.23 (19)
C2—C3—C4	120.25 (19)	C1B—C2B—H2B	120.57
C3—C4—C5	120.12 (19)	C3B—C2B—H2B	120.28
S5—C5—C4	120.31 (15)	C2B—C3B—H3B	125.22
S5—C5—C6	119.80 (16)	C1B^ii—C3B—H3B	115.25
O51—S5—C5—C4	−28.54 (18)	O2—C2—C3—C4	179.57 (18)
O51—S5—C5—C6	152.61 (15)	C2—C3—C4—C5	0.4 (3)
O52—S5—C5—C4	−148.51 (16)	C3—C4—C5—C6	−0.1 (3)
O52—S5—C5—C6	32.64 (18)	C3—C4—C5—S5	−178.92 (16)
O53—S5—C5—C4	91.59 (17)	S5—C5—C6—C1	178.78 (14)
O53—S5—C5—C6	−87.26 (17)	C4—C5—C6—C1	−0.1 (3)
C6—C1—C2—O2	−179.73 (18)	C3A^i—C1A—C2A—C3A	0.0 (3)
C6—C1—C2—C3	0.5 (3)	N1A—C1A—C2A—C3A	179.79 (19)
C2—C1—C6—C5	−0.1 (3)	C2A—C1A—C3A^i—C2A^i	0.0 (3)
C7—C1—C6—C5	179.55 (17)	N1A—C1A—C3A^i—C2A^i	−179.79 (18)
C7—C1—C2—C3	−179.18 (18)	C1A—C2A—C3A—C1A^i	0.0 (3)
C6—C1—C7—O72	169.88 (18)	N1B—C1B—C2B—C3B	−179.62 (19)
C2—C1—C7—O71	171.06 (19)	C2B—C1B—C3B^ii—C2B^ii	−0.2 (3)
C7—C1—C2—O2	0.6 (3)	C3B^ii—C1B—C2B—C3B	0.2 (3)
C2—C1—C7—O72	−10.4 (3)	N1B—C1B—C3B^ii—C2B^ii	179.62 (18)
C6—C1—C7—O71	−8.6 (3)	C1B—C2B—C3B—C1B^ii	−0.2 (3)
C1—C2—C3—C4	−0.7 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O72	0.88 (4)	1.74 (4)	2.558 (2)	152 (4)
N1A—H11A···O71^iii	0.99 (4)	2.41 (4)	3.114 (2)	128 (3)
N1A—H11A···O72^iii	0.99 (4)	1.84 (4)	2.808 (3)	168 (3)
N1B—H11B···O53	0.96 (3)	1.90 (3)	2.812 (2)	157 (3)
N1A—H12A···O71^iv	0.91 (3)	1.83 (3)	2.725 (3)	166 (3)
N1B—H12B···O52^v	0.89 (3)	2.01 (4)	2.868 (3)	161 (3)
N1A—H13A···O2^vi	0.90 (3)	2.43 (3)	3.015 (3)	123 (2)
N1A—H13A···O51^i	0.90 (3)	2.14 (3)	2.905 (3)	143 (3)
N1B—H13B···O51^vii	0.84 (3)	1.95 (3)	2.794 (3)	177 (3)
C2A—H2A···O72^iii	0.95	2.50	3.249 (2)	136
C3—H3···O71^iv	0.95	2.54	3.192 (3)	126
C4—H4···O53^vii	0.95	2.59	3.385 (3)	141

Symmetry codes: (i) −x, −y, −z+1; (iii) −x+1, −y+1, −z+1; (iv) x−1, y, z; (v) −x+1, −y, −z; (vi) −x, −y+1, −z+1; (vii) −x, −y, −z.