(IUCr) Phosphonoacetic acid as a building block in supramolecular chemistry: salts with organic polyamines

Volume 59
Part 1
Pages 87-99
February 2003

Received 1 July 2002
Accepted 6 September 2002

Phosphonoacetic acid as a building block in supramolecular chemistry: salts with organic polyamines

Katharine F. Bowes,^a George Ferguson,^a,^b Alan J. Lough,^c Choudhury M. Zakaria ^a ⁺ and Christopher Glidewell ^a ^*

^aSchool of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST, UK,^bDepartment of Chemistry and Biochemistry, University of Guelph, Ontario N1G 2W1, Canada, and ^cLash Miller Chemical Laboratories, University of Toronto, Ontario M5S 3H6, Canada
Correspondence e-mail: cg@st-andrews.ac.uk

Phosphonoacetic acid, (HO)₂P(O)CH₂COOH, forms adducts with a range of amines. The acid component in these adducts may be the neutral molecule C₂H₅O₅P, the mono-anion (C₂H₄O₅P)^- or the di-anion (C₂H₃O₅P)^2-. The substructure formed by the acid component takes the form of simple chains in compounds (1)-(3), which are the 1:1 adducts formed with 1,4-diazabicyclo[2.2.2]octane, 4,4'-bipyridyl and 1,3-trimethylenedipiperidine, respectively. These adducts contain C₂H₅O₅P, (C₂H₄O₅P)^- and (C₂H₃O₅P)^2-, respectively, although (3) is solvated by a mixture of methanol and water. The (C₂H₄O₅P)^- anion substructure in (4), which is the adduct formed with meso-5,5,7,12,12,14-hexa-C-methyl-1,4,8,11-tetraazacyclotetradecane, is a chain of spiro-fused rings, while the substructure in (5), which is the adduct formed with 2,2'-dipyridylamine, is a chain of edge-fused rings. In (6), the adduct formed with 1,2-bis(4'-pyridyl)ethane, the anion substructure is two-dimensional. The chain substructures are linked by the amine units into two-dimensional structures in (1) and (4) and into three-dimensional frameworks in (2), (3) and (5), while the anion sheets in (6) are likewise linked by the amine units into a three-dimensional framework.

Keywords: phosphonoacetic acid; supramolecular chemistry; organic polyamines.

1. Introduction

Although only a few structures have been reported of salts that contain the mono-anion C₂H₄O₅P^-, which is derived from phosphonoacetic acid, (HO)₂P(O)CH₂COOH, it is clear that this anion is potentially an extremely versatile building block in supramolecular chemistry. In the neutral acid itself, the three-dimensional structure is built from C(4) and C(6) helical chains in space group P2₁2₁2₁, so that small rings are completely absent (Lis, 1997). In this respect, the behaviour of phosphonoacetic acid differs markedly from that of phenylphosphonic acid, PhP(O)(OH)₂ (Weakley, 1976), where it is possible to identify both R²₂(8) rings and C(4) chains, motifs that dominate the aggregation patterns found in salts of the anion [PhP(O)₂OH]^- (Ferguson et al., 1998). In the lithium salt of phosphonoacetic acid [Cambridge Structural Database (CSD; Allen & Kennard, 1993) refcode TERMOS; Lis, 1997], anions [(HO)P(O)₂CH₂COOH]^- are linked into chains that contain alternating R²₂(8) rings, which are formed by the phosphonate units, and R²₂(12) rings, which are formed by a carboxyl donor and phosphonate acceptors. In these chains, the R²₂(8) and R²₂(12) rings are linked in spiro fashion at the P atoms; despite the presence of un-ionized carboxyl groups, the characteristic R²₂(8) carboxyl dimer motif is absent. In the 1:2 salt [{MeNH(CH₂CH₂)₂NHMe}²⁺]·[(C₂H₄O₅P)^-]₂ formed with N,N'-dimethylpiperazine (Farrell et al., 2001), all of the H-atom sites that are bonded to O atoms have 0.5 occupancy at 293 (2) K, and the anions are linked into sheets of alternating R²₂(12) and R⁶₆(28) rings. This salt contains no R²₂(8) rings at all, and the R²₂(12) rings contain phosphonic donors and carboxyl acceptors, in contrast to the corresponding rings in the Li salt (Lis, 1997).

In a continuation of our study of the amine salts formed by phosphonoacetic acid (Farrell et al., 2001), we have now synthesized and characterized the salt-type adducts formed by this acid (A; see scheme above) with each of 1,4-diazabicyclo[2.2.2]octane (DABCO) (B), 4,4'-bipyridyl (C), 1,3-trimethylenedipiperidine (D), tet-a (meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, C₁₆H₃₆N₄) (E), 2,2'-dipyridylamine (F) and 1,2-bis(4'-pyridyl)ethane (G). The resulting adducts have the compositions (C₆H₁₂N₂)·(C₂H₅O₅P) {1; 1,4-diazabicyclo[2.2.2]octane-phosphonoacetic acid (1/1)}, (C₁₀H₈N₂)·(C₂H₅O₅P) [2; 4,4'-bipyridyl-phosphonoacetic acid (1/1)], (C₁₃H₂₆N₂)·(C₂H₅O₅P)·(CH₄O)_0.352·(H₂O)_0.788 [3; 1,3-trimethylenedipiperidine-phosphonoacetic acid (1/1) methanol/water solvate], (C₁₆H₃₆N₄)·(C₂H₅O₅P)₂ [4; tet-a-phosphonoacetic acid (1/2)], (C₁₀H₉N₃)·(C₂H₅O₅P) [5; 2,2'-dipyridylamine-phosphonoacetic acid (1/1)], (C₁₂H₁₂N₂)·- (C₂H₅O₅P)₂ [6; 1,2-bis(4'-pyridyl)ethane-phosphonoacetic acid (1/2)].

2. Experimental

2.1. Syntheses

Equimolar quantities of the appropriate amine and the acid were separately dissolved in methanol. The solutions were mixed, then the mixtures were set aside to crystallize, and they yielded (1)-(6). Analyses: (1) found C 37.7, H 4.9, N 10.6; C₈H₁₇N₂O₅P requires C 38.1, H 6.8, N 11.1%; (2) found C 49.0, H 4.0, N 9.4; C₁₂H₁₂N₂O₅P requires C 48.7, H 4.4, N 9.5%; (3) consistent analysis not obtained; C₃₀H₆₂N₄O₁₀P₂ requires C 51.4, H 8.9, N 8.0%; C_30.70H_67.96N₄O_12.28P₂ (from X-ray analysis) requires C 49.0, H 9.1, N 7.5%; (4) found C 42.4, H 8.3, N 9.7; C₂₀H₄₆N₂O₁₀P₂ requires C 42.5, H 8.2, N 9.9%; (5) found C 46.5, H 4.3, N 13.5; C₁₂H₁₄N₃O₅P requires C 46.3, H 4.5, N 13.5%; (6) found C 41.5, H 4.1, N 6.0; C₁₆H₂₂N₂O₁₀P₂ requires C 41.4, H 4.8, N 6.0%. Crystals suitable for single-crystal X-ray diffraction were selected directly from the analytical samples.

2.2. Data collection, structure solution and refinement

Diffraction data for (1)-(6) were collected at 150 (1) K using a Nonius Kappa-CCD diffractometer with graphite-monochromated Mo K [alpha] radiation ( [lambda] = 0.71073 Å). Other details of cell data, data collection and refinement are summarized in Table 1. The following software was employed: PRPKAPPA (Ferguson, 1999), Kappa-CCD (Nonius, 1997), DENZO-SMN (Otwinowski & Minor, 1997), SHELXL97 (Sheldrick, 1997a), SHELXS97 (Sheldrick, 1997b), PLATON (Spek, 2003).

Table 1
Experimental details

	(1)	(2)	(3)	(4)	(5)	(6)
Crystal data
Chemical formula	C₆H₁₂N₂·-C₂H₅O₅P	C₁₀H₉N₂·-C₂H₄O₅P	2(C₁₃H₂₈N₂)·-2(C₂H₃O₅P)·-1.58(H₂O)·-0.70(CH₄O)	C₁₆H₃₈N₄·-2(C₂H₄O₅P)	C₁₀H₁₀N₃·-C₂H₄O₅P	C₁₂H₁₄N₂·2(C₂H₄O₅P)
Chemical formula weight	252.21	296.21	745.67	564.55	311.23	464.3
Cell setting, space group	Orthorhombic, Pca2₁	Monoclinic, P2₁/n	Triclinic, $[P\overline 1]$	Triclinic, $[P\overline 1]$	Triclinic, $[P\overline 1]$	Monoclinic, P2₁/c
a, b, c (Å)	20.3011 (17), 6.7692 (5), 8.0158 (6)	4.6225 (2), 17.2421 (6), 15.6529 (7)	11.7486 (3), 13.3913 (4), 13.8206 (5)	8.7219 (2), 9.8947 (1), 9.9343 (2)	7.0706 (2), 10.6500 (3), 10.7020 (4)	8.8501 (3), 15.1862 (6), 7.3741 (3)
$[\alpha]$ , $[\beta]$ , $[\gamma]$ $[(^{\circ})]$	90, 90, 90	90, 95.7190 (15), 90	96.9260 (17), 109.4140 (16), 105.4830 (15)	62.5110 (9), 85.6800 (8), 67.1910 (9)	115.8690 (13), 98.8120 (15), 104.0040 (13)	90, 90.761 (2), 90
V (Å³)	1101.55 (15)	1241.35 (9)	1923.2 (1)	695.42 (2)	671.96 (4)	990.99 (7)
Z	4	4	2	1	2	2
D_x (Mg m^-3)	1.521	1.585	1.288	1.348	1.538	1.556
Radiation type	Mo K $[\alpha]$	Mo K $[\alpha]$	Mo K $[\alpha]$	Mo K $[\alpha]$	Mo K $[\alpha]$	Mo K $[\alpha]$
No. of reflections for cell parameters	1987	2390	8765	2923	3079	5037
$[\theta]$ range ( $[^{\circ}]$ )	3.6-25.5	2.6-27.5	3.1-27.6	2.6-27.4	3.1-27.6	2.7-27.5
$[\mu]$ (mm^-1)	0.259	0.244	0.176	0.213	0.232	0.279
Temperature (K)	150 (1)	150 (1)	150 (1)	150 (1)	150 (1)	150 (1)
Crystal form, colour	Plate, colourless	Block, colourless	Plate, colourless	Needle, colourless	Plate, colourless	Plate, colourless
Crystal size (mm)	0.18 × 0.10 × 0.03	0.34 × 0.20 × 0.15	0.16 × 0.10 × 0.06	0.40 × 0.24 × 0.20	0.34 × 0.16 × 0.16	0.28 × 0.12 × 0.08

Data collection
Diffractometer	Kappa-CCD	Kappa-CCD	Kappa-CCD	Kappa-CCD	Kappa-CCD	Kappa-CCD
Data collection method	$[\varphi]$ scans, and $[\omega]$ scans with $[\kappa]$ offsets	$[\varphi]$ scans, and $[\omega]$ scans with $[\kappa]$ offsets	$[\varphi]$ scans, and $[\omega]$ scans with $[\kappa]$ offsets	$[\varphi]$ scans, and $[\omega]$ scans with $[\kappa]$ offsets	$[\varphi]$ scans, and $[\omega]$ scans with $[\kappa]$ offsets	$[\varphi]$ scans, and $[\omega]$ scans with $[\kappa]$ offsets
No. of measured, independent and observed reflections	7195, 1987, 1462	8078, 2824, 2194	24 179, 8765, 5307	9161, 3148, 2745	9556, 3079, 2471	6047, 2263, 1883
Criterion for observed reflections	$[I \, \gt\, 2 \sigma (I\,)]$	$[I \, \gt\, 2 \sigma (I\,)]$	$[I \, \gt\, 2 \sigma (I\,)]$	$[I \, \gt\, 2 \sigma (I\,)]$	$[I \, \gt\, 2 \sigma (I\,)]$	$[I\, \gt\, 2\sigma(I\,)]$
R_int	0.119	0.034	0.108	0.026	0.056	0.035
$[\theta_{\rm max}]$ ( $[^{\circ}]$ )	25.5	27.5	27.6	27.4	27.6	27.5
Range of h, k, l	-21 $[\rightarrow]$ h $[\rightarrow]$ 24	0 $[\rightarrow]$ h $[\rightarrow]$ 6	-15 $[\rightarrow]$ h $[\rightarrow]$ 15	0 $[\rightarrow]$ h $[\rightarrow]$ 11	-9 $[\rightarrow]$ h $[\rightarrow]$ 9	-11 $[\rightarrow]$ h $[\rightarrow]$ 11
	-8 $[\rightarrow]$ k $[\rightarrow]$ 8	0 $[\rightarrow]$ k $[\rightarrow]$ 22	-17 $[\rightarrow]$ k $[\rightarrow]$ 17	-11 $[\rightarrow]$ k $[\rightarrow]$ 12	-13 $[\rightarrow]$ k $[\rightarrow]$ 13	-19 $[\rightarrow]$ k $[\rightarrow]$ 19
	-9 $[\rightarrow]$ l $[\rightarrow]$ 9	-20 $[\rightarrow]$ l $[\rightarrow]$ 20	-17 $[\rightarrow]$ l $[\rightarrow]$ 17	-12 $[\rightarrow]$ l $[\rightarrow]$ 12	-13 $[\rightarrow]$ l $[\rightarrow]$ 13	-9 $[\rightarrow]$ l $[\rightarrow]$ 9

Refinement
Refinement on	F ²	F ²	F ²	F ²	F ²	F ²
$[R[F\,^{2} \gt 2 \sigma (F\,^{2})]]$ , wR(F ²), S	0.055, 0.141, 1.02	0.039, 0.102, 1.03	0.080, 0.228, 1.03	0.036, 0.0978, 1.05	0.041, 0.110, 1.07	0.038, 0.103, 1.06
No. of reflections and parameters used in refinement	1987, 148	2824, 183	8765, 466	3148, 174	3079, 198	2263, 139
H-atom treatment	H-atom parameters constrained	H-atom parameters constrained	H-atom parameters constrained	H-atom parameters constrained	H-atom parameters constrained	H-atom parameters constrained
Weighting scheme	w = 1/[ $[\sigma]$ ²(F_o²) + (0.0527P)² + 0.0408P] where P = (F_o² + 2F_c²)/3	w = 1/[ $[\sigma]$ ²(F_o²) + (0.0414P)² + 0.5382P] where P = (F_o² + 2F_c²)/3	w = 1/[ $[\sigma]$ ²(F_o²) + (0.0954P)² + 1.4703P] where P = (F_o² + 2F_c²)/3	w = 1/[ $[\sigma]$ ²(F_o²) + (0.0375P)² + 0.3032P] where P = (F_o² + 2F_c²)/3	w = 1/[ $[\sigma]$ ²(F_o²) + (0.0437P)² + 0.2307P] where P = (F_o² + 2F_c²)/3	w = 1/[ $[\sigma]$ ²(F_o²) + (0.0431P)² + 0.3391P] where P = (F_o² + 2F_c²)/3
$[(\Delta/\sigma)_{\rm max}]$	0.016	0.001	0.000	0.000	0.000	0.001
$[\Delta\rho_{\rm max}]$ , $[\Delta\rho_{\rm min}]$ (e Å^-3)	0.301, -0.525	0.259, -0.367	0.683, -0.433	0.273, -0.413	0.314, -0.359	0.308, -0.438
Extinction method	None	None	SHELXL	None	SHELXL	SHELXL
Extinction coefficient	0	0	0.028 (4)	0	0.015 (4)	0.011 (3)

For (2) the space group P2₁/n was uniquely assigned from the systematic absences: space group P2₁/c was similarly assigned for (6). Compounds (3), (4) and (5) are all triclinic: in each case space group P $[\bar 1]$ was chosen and confirmed by the successful structure analysis. For (1), the systematic absences permitted Pca2₁ and Pcam (= Pbcm, No. 57) as possible space groups: Pca2₁ was selected and confirmed by the successful analysis. The structures were solved by direct methods and refined with all data on F². A weighting scheme based on P = (F_o² + 2F_c²)/3 was employed in order to reduce statistical bias (Wilson, 1976). The asymmetric unit in (3) contains two cations, two anions, three water molecules with partial occupancies and one methanol with partial occupancy; the occupancies refined to the values water O71 0.297 (9), methanol O81 C82 0.703 (9), water O91 0.434 (15), water O92 0.845 (19). No allowance was made for H atoms on the molecules with partial occupancy. The cations in each of (4) and (6) lie across inversion centres. In (4), the cation exhibits some disorder of the axial methyl groups with the groups containing C52 and C72 having site-occupation factors of 0.711 (4) and 0.289 (4), respectively. This behaviour is most readily interpreted in terms of a 180° rotation of the cation, in a fraction of the sites, about a line joining the mid-points of the C2-C3 and C2ⁱ-C3ⁱ bonds [i = (1 - x, 1 - y, 1 - z)]. Because of the small partial occupancy of C72, an apparently short intermolecular C72C72ⁱⁱ [ii = (1 - x, -y, 1 - z)] contact of 2.639 (10) Å may be ignored. The cation in (5) exhibits orientational disorder and the location of the amino N was modelled over two sites (denoted N1 and N1A) with site-occupation factors of 0.916 (4) and 0.084 (4): possibly because of the very low occupancy of the minor orientation, it was not possible to determine coordinates for the C atoms of the minor orientation (all of these would be very close to the sites of the major-form C atoms). All full-occupancy H atoms were located from difference maps and included in the refinements as riding atoms with distances O-H 0.82-0.84 Å, N-H 0.88-93 Å and C-H 0.92-1.00 Å. For (1) the anomalous dispersion terms are on the borderline of being significant (heaviest atom P); Friedel reflections were not merged and refinement with 988 Friedel pairs led to a Flack value of 0.1 (2), which does not really allow any meaningful comment.

The diagrams were prepared with the aid of PLATON (Spek, 2003). Details of hydrogen-bond dimensions and of molecular conformations are given in Tables 2 and 3. Figs. 1 -18 show the molecular components, with the atom-labelling schemes and aspects of the supramolecular structures.¹

Table 2
Hydrogen-bond parameters (Å, °)

D-HA	HA	DA	D-HA
(1)
O1-H1N1	1.79	2.605 (5)	164
O3-H3O5ⁱ	1.74	2.538 (5)	157
O4-H4N2ⁱⁱ	2.00	2.606 (5)	129
(2)
O1-H1AN2	1.81	2.645 (2)	176
O3-H3O4ⁱⁱⁱ	1.70	2.515 (2)	162
N1-H1O5^iv	1.74	2.582 (2)	158
C12-H12O2^iv	2.22	2.978 (2)	135
C13-H13O3^v	2.46	3.369 (2)	159
C15-H15O4^vi	2.36	3.269 (2)	153
C26-H26O1^vii	2.54	3.430 (2)	155
(3)
N11-H11AO22	1.81	2.716 (5)	168
N11-H11BO12	1.83	2.659 (5)	149
N21-H21AO14^viii	2.08	2.806 (4)	134
N21-H21BO14^ix	1.81	2.722 (4)	174
N31-H31AO21	2.34	2.834 (4)	113
N31-H31AO25	2.01	2.840 (4)	150
N31-H31BO15	1.90	2.797 (4)	166
N41-H41AO24^x	1.81	2.721 (4)	171
N41-H41BO24^xi	2.12	2.976 (4)	154
O13-H13O21	1.70	2.533 (4)	171
O23-H23O11ⁱⁱⁱ	1.72	2.524 (4)	160
(4)
N1-H11AN4^vii	2.08	2.817 (2)	137
O1-H1O5^xii	1.69	2.517 (2)	167
O3-H3O4^xiii	1.74	2.581 (2)	174
N1-H1BO4	1.91	2.799 (2)	160
N4-H4O1ⁱⁱⁱ	2.57	3.428 (2)	155^#
N4-H4O2^vii	2.56	3.198 (2)	127^#
C2-H2AO5ⁱⁱⁱ	2.50	3.426 (2)	156
(5)
N12-H12N22	1.97	2.632 (2)	131
O1-H1AO5^xiv	1.76	2.570 (2)	163
O3-H3O4^vii	1.80	2.604 (2)	161
N1-H1O4	1.87	2.743 (2)	171
N12-H12O5	2.34	3.062 (2)	140
C24-H24O2^xv	2.53	3.312 (3)	140
C26-H26O2^vii	2.48	3.201 (3)	132
(6)
O1-H1O4^vii	1.81	2.640 (2)	169
O3-H3O5^xvi	1.71	2.521 (2)	163
N11-H11O4	1.73	2.613 (2)	178
C13-H13O3^xvii	2.52	3.349 (2)	146
C15-H15O3^xviii	2.48	3.329 (2)	148
C16-H16O2^vii	2.38	3.256 (2)	154
Symmetry codes: (i) $[{{3}\over{2}}]$ - x, y, $[{{1}\over{2}}]$ + z; (ii) $[{{1}\over{2}}]$ + x, -y, z; (iii) 1 + x, y, z; (iv) $[{{5}\over{2}}]$ - x, $[{{1}\over{2}}]$ + y, $[{{1}\over{2}}]$ - z; (v) 2 - x, 1 - y, 1 - z; (vi) $[{{3}\over{2}}]$ + x, $[{{1}\over{2}}]$ - y, - $[{{1}\over{2}}]$ + z; (vii) 1 - x, 1 - y, 1 - z; (viii) x, -1 + y, -1 + z; (ix) -x, -y, -z; (x) 1 - x, 2 - y, 1 - z; (xi) x, 1 + y, 1 + z; (xii) -x, 1 - y, 1 - z; (xiii) -x, 2 - y, -z; (xiv) -1 + x, y, z; (xv) 1 + x, y, 1 + z; (xvi) x, $[{{1}\over{2}}]$ - y, - $[{{1}\over{2}}]$ + z; (xvii) 1 - x, - $[{{1}\over{2}}]$ + y, $[{{1}\over{2}}]$ - z; (xviii) -1 + x, $[{{1}\over{2}}]$ - y, $[{{1}\over{2}}]$ + z.

^#Three-centre N-H

(O)₂ system: sum of angles at H4, 358°.

Table 3
Selected torsional and dihedral angles (°)

(a) Amine components
(1)
N1-C11-C21-N2	2.8 (6)
N1-C12-C22-N2	3.1 (6)
N1-C13-C23-N2	3.0 (6)
(2)
(N1, C12-C16)
^(N2, C22-C26)	5.5 (2)
(3)
C16-C15-C14-C17	-177.3 (3)	C32-C33-C34-C37	175.5 (3)
C15-C14-C17-C18	175.2 (3)	C33-C34-C37-C38	166.6 (3)
C14-C17-C17-C27	-173.5 (3)	C34-C37-C38-C47	177.4 (3)
C17-C18-C27-C24	-177.4 (3)	C37-C38-C47-C44	169.5 (3)
C18-C27-C24-C23	179.3 (3)	C38-C47-C44-C45	-174.1 (3)
C27-C24-C23-C22	-179.8 (3)	C47-C44-C45-C46	178.8 (3)

(4)
N1-C2-C3-N4	-69.3 (2)	C5-C6-N7-N1ⁱ	-71.1 (2)
C2-C3-N4-C5	-176.2 (2)	C6-C7-N1ⁱ-C2ⁱ	173.6 (2)
C3-N4-C5-C6	-174.4 (2)	C7-N1ⁱ-C2ⁱ-C3ⁱ	-175.0 (2)
N4-C5-C6-C7	63.3 (2)
(5)
C11-N1-C21-N22	6.7 (3)	C21-N1-C11-N12	-9.3 (3)
(6)
C13-C14-C17-C17ⁱⁱ	-92.4 (2)

(b) Acid components^#
(1)

research papers

Phosphonoacetic acid as a building block in supramolecular chemistry: salts with organic polyamines

1. Introduction

2. Experimental

2.1. Syntheses

2.2. Data collection, structure solution and refinement