Hydro­gen bonding in calcium-tri­fluoro­methane­sulfonate-1,3-di-4-pyridyl­urea-methanol (1/2/2/4)

The structure of the supramolecular complex calcium-tri­fluoro­methane­sulfonate-1,3-di-4-pyridyl­urea-methanol (1/2/2/4), Ca²⁺·2CF₃SO₃^-·2C₁₁H₁₀N₄O·4CH₄O, is presented. The Ca²⁺ ion lies on an inversion centre and is octahedrally coordinated by four methanol mol­ecules and two tri­fluoro­methane­sulfonate counter-ions. The molecular packing is dominated by hydrogen-bonded sheets in the (110) plane which contain R₄⁴(32) rings; in these rings, significant [pi]-[pi] interactions are observed between inversion-related 1,3-di-4-pyridyl­urea mol­ecules.

S1. Comment

Functional supramolecular architectures as constitutionally dynamic adaptative materials have emerged as a major field in supramolecular chemistry, geared towards the design of self-organizing nanosystems of increasing complexity (Lehn, 2000a,b, 2002; Funeriu et al., 2001). The self-assembly of different entities is based both on the implementation of ligands containing specific molecular information stored in the arrangement of suitable binding sites and on complexed ions reading out the structural information through the algorithm defined by their recognition geometry. Of special interest are so-called hereon–heteroditopic ligand systems, containing different binding units that can combine to form different superstructures according to the specific interaction involved (Funeriu et al., 2001).

We consider in this context the 1,3-di-4-pyridylurea ligand, L, in which the available urea and pyridine moities are covalently linked. We reasoned that, by an appropriate choice of these binding units and of a specific metal salt, we could obtain, under specific conditions, a supramolecular structure (output device). The different interaction types (subprograms) involved are (a) pyridine–metal coordination (Scudder et al., 1999; Lu et al., 2001), (b) metal–anion association (coordination), (c) urea–anion complexation (Scheerder et al., 1996) and (d) urea head-to-tail association (Etter, 1990). These interactions combine either in an independent way (linear combination) or by a crossover with interference between the individual subprograms.

The structure of the complex of L with CaTf₂(methanol)₄ (Tf⁻ = CF₃SO₃⁻) was determined from a crystal obtained in a methanol/diisopropyl ether (1:1) solution at room temperature. This complex proves to be an intriguing coordination polymer with a novel architecture and results from the crossover of the simultaneous independent trifluoromethanesulfonate–urea and trifluoromethanesulfonate–Ca²⁺ complexation subprograms.

The molecular structure of (I) is presented in Fig. 1. The unit cell contains two L ligands, one Ca²⁺ cation on an inversion centre, two trifluoromethanesulfonate counter-ions and four methanol molecules. The unique L ligand has an almost planar conformation; the angle between the two pyridyl rings is 4.28 (10)°. Two inversion-related Tf⁻ ions are coordinated to the Ca²⁺ cation and octahedral coordination at Ca is completed by two pairs of inversion-relate methanol molecules; pertinent dimensions are given in Table 1. The inversion-related L ligands are linked to the Tf⁻ ion by pairs of N—H···O hydrogen bonds, as shown in Fig. 1; hydrogen-bond geometry details are given in Table 2. Possibly assisting the retention of this structure are C—H···O contacts (Table 2) between C3—H3A and O12 (at 2 − x, −y, −z)

The crystal structure contains sheets of molecules lying in the (110) plane (Fig. 2). A feature of this sheet structure is the R(32)⁴₄ (Bernstein et al., 1995) hydrogen-bonded ring system, which is shown in more detail in Fig. 3. Infinite chains are thus generated which are further linked to yield the sheet structure by Tf⁻–Ca²⁺–Tf⁻ moieties. The R(32)⁴₄ ring is stabilized by significant π–π interactions between inversion-related L ligands; details of the overlap are shown in Fig. 4, where the shortest intermolecular C···C distance is 3.388 (2) Å between C14 and C26 at (1 − x, 1 − y, 1 − z).

S2. Experimental

A solution of L (20 mg, 0.09 mmol) in methanol (1 ml) was added to a solution of CaTf₂ (17.6 mg, 0.09 mmol) in methanol (1 ml) and the mixture was heated for 2 h at 333 K. Single crystals of the LCaTf₂ complex were obtained by slow diffusion of diisopropyl ether as non-solvent into the resulting methanol solution at room temperature.

S3. Refinement

For simplicity, the atoms were positioned in the cell so that the π–π interaction was between molecules of the ligand L related by the inversion centre at (1/2,0.5, 1/2). All H atoms were located in difference maps and subsequently allowed for as riding atoms, with C—H = 0.93 and 0.96 Å, N—H = 0.86 Å and O—H = 0.82 Å.

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2002); cell refinement: CrysAlis RED (Oxford Diffraction, 2002); data reduction: CrysAlis RED (2002); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: CRYSTALS (Watkin et al., 2001), SHELXL97 (Sheldrick, 1997) and WinGX (Version 1.64.05; Farrugia, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: PLATON.

Figures

	Fig. 1. The structure of (I), showing displacement ellipsoids at the 30% probability level. [Symmetry code: (a) 2 − x,-y,-z.]
	Fig. 2. A view of part of the (110) sheet structure. For clarity, F atoms of the CF3 moieties and H atoms not involved in the hydrogen bonding are not shown. [Symmetry codes: (*) 1 − x, 1 − y, 1 − z; ($) x, y, −1 + z; (#) 1 − x, 1 − y, −z; (&) x, y, 1 + z.]
	Fig. 3. A detailed view of the R(32)^44 ring. For clarity, H atoms not involved in the hydrogen bonding and the CF3 moieties are not shown. The symmetry codes are as in Fig. 2.
	Fig. 4. A view normal to the best plane through the L ligand, showing ring overlap. The symmetry code is as in Fig. 2.

(I)

Crystal data

Ca^2+·2CF3O3S^−·2C11H10N4O·4CH4O	Z = 1
Mr = 894.84	F(000) = 462
Triclinic, P1	Dx = 1.497 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 9.157 (1) Å	Cell parameters from 4175 reflections
b = 9.768 (1) Å	θ = 1.8–23.2°
c = 11.366 (2) Å	µ = 0.36 mm^−1
α = 98.95 (1)°	T = 173 K
β = 97.14 (1)°	Prism, colourless
γ = 94.03 (1)°	0.30 × 0.30 × 0.25 mm
V = 992.3 (2) Å^3

Data collection

Xcalibur CCD diffractometer	2931 reflections with I > 2σ(I)
Detector resolution: 17 pixels mm^-1	Rint = 0.030
area–detector scans	θmax = 28.5°, θmin = 3.2°
Absorption correction: gaussian (Schwarzenbach & Flack, 1991)	h = −13→12
Tmin = 0.900, Tmax = 0.910	k = −12→13
17908 measured reflections	l = −17→16
5013 independent reflections

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)] = 0.035	H-atom parameters constrained
wR(F^2) = 0.066	w = 1/[σ^2(Fo^2) + (0.023P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.70	(Δ/σ)max = 0.002
6255 reflections	Δρmax = 0.26 e Å^−3
264 parameters	Δρmin = −0.31 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0018 (4)

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Ca1	1.0000	0.0000	0.0000	0.02014 (11)
O2	1.13628 (12)	0.20800 (12)	−0.01142 (11)	0.0316 (3)
H2	1.1087	0.2472	−0.0679	0.047*
C2	1.28346 (19)	0.26111 (19)	0.03850 (17)	0.0423 (5)
H2B	1.3085	0.2300	0.1139	0.063*
H2C	1.2907	0.3610	0.0511	0.063*
H2D	1.3504	0.2282	−0.0159	0.063*
O3	0.85768 (12)	0.01471 (11)	−0.18068 (10)	0.0302 (3)
H3	0.8003	0.0748	−0.1867	0.045*
C3	0.8362 (2)	−0.08435 (19)	−0.28842 (16)	0.0440 (5)
H3A	0.8893	−0.1634	−0.2762	0.066*
H3B	0.8719	−0.0429	−0.3518	0.066*
H3C	0.7327	−0.1137	−0.3100	0.066*
S1	0.75716 (5)	0.20720 (4)	0.18066 (4)	0.02909 (11)
F1	0.56130 (14)	0.12817 (13)	0.30814 (11)	0.0658 (4)
F2	0.69659 (14)	−0.03200 (12)	0.24689 (12)	0.0649 (4)
F3	0.52539 (13)	0.02686 (12)	0.12473 (11)	0.0585 (3)
O11	0.82191 (13)	0.13343 (12)	0.08232 (11)	0.0384 (3)
O12	0.85742 (13)	0.24608 (13)	0.29065 (11)	0.0479 (4)
O13	0.66623 (13)	0.31371 (12)	0.14929 (11)	0.0397 (3)
C4	0.6278 (2)	0.07484 (19)	0.21640 (17)	0.0372 (4)
O1	0.68198 (14)	0.62088 (12)	0.57166 (10)	0.0406 (3)
N1	0.80701 (14)	0.44014 (13)	0.49423 (12)	0.0264 (3)
H1	0.8211	0.3903	0.4280	0.032*
N2	0.64656 (14)	0.54022 (13)	0.36927 (11)	0.0247 (3)
H2A	0.6717	0.4784	0.3148	0.030*
C1	0.70925 (17)	0.54100 (16)	0.48560 (14)	0.0249 (4)
N11	1.04683 (17)	0.33489 (17)	0.80203 (15)	0.0443 (4)
C12	1.0463 (2)	0.2641 (2)	0.69164 (19)	0.0440 (5)
H12	1.1012	0.1875	0.6834	0.053*
C13	0.97008 (19)	0.29712 (18)	0.58935 (17)	0.0366 (4)
H13	0.9749	0.2445	0.5146	0.044*
C14	0.88485 (18)	0.41131 (16)	0.59933 (15)	0.0273 (4)
C15	0.8866 (2)	0.48728 (18)	0.71277 (16)	0.0369 (4)
H15A	0.8344	0.5655	0.7239	0.044*
C16	0.9673 (2)	0.4449 (2)	0.80916 (17)	0.0453 (5)
H16	0.9665	0.4968	0.8849	0.054*
N21	0.34134 (15)	0.80415 (13)	0.23998 (12)	0.0290 (3)
C22	0.39556 (18)	0.70308 (17)	0.16774 (15)	0.0298 (4)
H22	0.3638	0.6915	0.0856	0.036*
C23	0.49556 (18)	0.61560 (16)	0.20837 (14)	0.0268 (4)
H23	0.5292	0.5473	0.1544	0.032*
C24	0.54559 (17)	0.63065 (15)	0.33099 (14)	0.0221 (3)
C25	0.49125 (17)	0.73559 (16)	0.40699 (15)	0.0274 (4)
H25	0.5216	0.7505	0.4895	0.033*
C26	0.39121 (18)	0.81690 (17)	0.35664 (15)	0.0309 (4)
H26	0.3558	0.8862	0.4085	0.037*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ca1	0.0210 (2)	0.0206 (2)	0.0195 (2)	0.00650 (19)	0.00356 (19)	0.00260 (19)
O2	0.0278 (6)	0.0319 (7)	0.0356 (7)	−0.0010 (5)	−0.0039 (5)	0.0152 (5)
C2	0.0313 (10)	0.0484 (12)	0.0451 (12)	−0.0030 (9)	−0.0015 (9)	0.0096 (10)
O3	0.0346 (7)	0.0272 (6)	0.0269 (6)	0.0134 (5)	−0.0039 (5)	0.0005 (5)
C3	0.0479 (12)	0.0412 (11)	0.0366 (11)	0.0204 (10)	−0.0074 (9)	−0.0102 (9)
S1	0.0281 (2)	0.0289 (2)	0.0310 (2)	0.01003 (19)	0.00934 (19)	−0.00035 (19)
F1	0.0703 (9)	0.0724 (9)	0.0609 (8)	0.0060 (7)	0.0448 (7)	0.0022 (7)
F2	0.0687 (9)	0.0522 (8)	0.0868 (10)	0.0212 (7)	0.0182 (8)	0.0386 (7)
F3	0.0474 (7)	0.0568 (8)	0.0645 (8)	−0.0099 (6)	−0.0034 (6)	0.0042 (6)
O11	0.0409 (7)	0.0378 (7)	0.0403 (7)	0.0154 (6)	0.0215 (6)	0.0006 (6)
O12	0.0359 (8)	0.0566 (9)	0.0434 (8)	0.0092 (7)	−0.0030 (6)	−0.0116 (7)
O13	0.0471 (8)	0.0317 (7)	0.0452 (8)	0.0209 (6)	0.0145 (6)	0.0073 (6)
C4	0.0368 (11)	0.0424 (11)	0.0369 (11)	0.0136 (9)	0.0131 (9)	0.0090 (9)
O1	0.0569 (9)	0.0375 (7)	0.0254 (7)	0.0237 (7)	−0.0039 (6)	−0.0026 (6)
N1	0.0299 (8)	0.0268 (7)	0.0235 (7)	0.0098 (6)	0.0020 (6)	0.0058 (6)
N2	0.0290 (8)	0.0246 (7)	0.0207 (7)	0.0120 (6)	0.0018 (6)	0.0017 (6)
C1	0.0271 (9)	0.0214 (8)	0.0267 (9)	0.0038 (7)	0.0005 (7)	0.0070 (7)
N11	0.0397 (10)	0.0460 (10)	0.0483 (11)	−0.0028 (8)	−0.0086 (8)	0.0262 (9)
C12	0.0330 (11)	0.0436 (12)	0.0604 (14)	0.0092 (9)	−0.0010 (10)	0.0273 (11)
C13	0.0324 (10)	0.0391 (11)	0.0418 (11)	0.0109 (9)	0.0022 (9)	0.0162 (9)
C14	0.0252 (9)	0.0257 (9)	0.0326 (10)	−0.0001 (7)	0.0007 (7)	0.0136 (7)
C15	0.0460 (12)	0.0319 (10)	0.0322 (10)	0.0040 (9)	−0.0047 (9)	0.0108 (8)
C16	0.0584 (13)	0.0417 (12)	0.0336 (11)	−0.0018 (10)	−0.0090 (10)	0.0141 (9)
N21	0.0297 (8)	0.0268 (8)	0.0321 (8)	0.0086 (6)	0.0021 (7)	0.0088 (6)
C22	0.0339 (10)	0.0293 (9)	0.0264 (9)	0.0053 (8)	0.0007 (8)	0.0069 (7)
C23	0.0323 (9)	0.0242 (8)	0.0243 (9)	0.0085 (7)	0.0031 (7)	0.0031 (7)
C24	0.0228 (8)	0.0194 (8)	0.0249 (9)	0.0027 (6)	0.0039 (7)	0.0053 (7)
C25	0.0299 (9)	0.0286 (9)	0.0234 (9)	0.0087 (7)	0.0013 (7)	0.0026 (7)
C26	0.0338 (10)	0.0268 (9)	0.0335 (10)	0.0111 (8)	0.0070 (8)	0.0032 (8)

Geometric parameters (Å, º)

Ca1—O2	2.3384 (11)	N2—C1	1.3731 (19)
Ca1—O3	2.3215 (11)	N2—C24	1.3996 (18)
Ca1—O11	2.3521 (11)	N2—H2A	0.86
O2—C2	1.4239 (19)	N11—C12	1.334 (2)
O2—H2	0.82	N11—C16	1.337 (2)
C2—H2B	0.96	C12—C13	1.375 (2)
C2—H2C	0.96	C12—H12	0.93
C2—H2D	0.96	C13—C14	1.404 (2)
O3—C3	1.4209 (19)	C13—H13	0.93
O3—H3	0.82	C14—C15	1.382 (2)
C3—H3A	0.96	C15—C16	1.379 (2)
C3—H3B	0.96	C15—H15A	0.93
C3—H3C	0.96	C16—H16	0.93
S1—O13	1.4375 (11)	N21—C26	1.331 (2)
S1—O12	1.4381 (13)	N21—C22	1.3466 (19)
S1—O11	1.4471 (11)	C22—C23	1.382 (2)
S1—C4	1.818 (2)	C22—H22	0.93
F1—C4	1.3280 (19)	C23—C24	1.394 (2)
F2—C4	1.3252 (19)	C23—H23	0.93
F3—C4	1.315 (2)	C24—C25	1.395 (2)
O1—C1	1.2160 (18)	C25—C26	1.382 (2)
N1—C1	1.3834 (18)	C25—H25	0.93
N1—C14	1.3913 (19)	C26—H26	0.93
N1—H1	0.86
O3—Ca1—O2	89.42 (4)	C1—N2—H2A	116.9
O3—Ca1—O11	83.08 (4)	C24—N2—H2A	116.9
O2—Ca1—O11	88.24 (4)	O1—C1—N2	124.02 (14)
O3^i—Ca1—O11	96.92 (4)	O1—C1—N1	123.58 (15)
O2^i—Ca1—O11	91.76 (4)	N2—C1—N1	112.40 (14)
O11^i—Ca1—O11	180	C12—N11—C16	115.60 (16)
C2—O2—H2	109.5	N11—C12—C13	124.31 (17)
O2—C2—H2B	109.5	N11—C12—H12	117.8
O2—C2—H2C	109.5	C13—C12—H12	117.8
H2B—C2—H2C	109.5	C12—C13—C14	119.08 (18)
O2—C2—H2D	109.5	C12—C13—H13	120.5
H2B—C2—H2D	109.5	C14—C13—H13	120.5
H2C—C2—H2D	109.5	C15—C14—N1	125.20 (14)
C3—O3—H3	109.5	C15—C14—C13	117.27 (16)
O3—C3—H3A	109.5	N1—C14—C13	117.53 (15)
O3—C3—H3B	109.5	C16—C15—C14	118.72 (17)
H3A—C3—H3B	109.5	C16—C15—H15A	120.6
O3—C3—H3C	109.5	C14—C15—H15A	120.6
H3A—C3—H3C	109.5	N11—C16—C15	124.99 (18)
H3B—C3—H3C	109.5	N11—C16—H16	117.5
O13—S1—O12	114.92 (8)	C15—C16—H16	117.5
O13—S1—O11	114.99 (7)	C26—N21—C22	115.56 (13)
O12—S1—O11	114.24 (7)	N21—C22—C23	123.95 (15)
O13—S1—C4	104.20 (8)	N21—C22—H22	118.0
O12—S1—C4	103.04 (9)	C23—C22—H22	118.0
O11—S1—C4	103.28 (8)	C22—C23—C24	119.40 (15)
S1—O11—Ca1	153.75 (8)	C22—C23—H23	120.3
F3—C4—F2	107.80 (16)	C24—C23—H23	120.3
F3—C4—F1	108.07 (15)	C23—C24—C25	117.36 (14)
F2—C4—F1	108.13 (15)	C23—C24—N2	117.99 (13)
F3—C4—S1	111.69 (13)	C25—C24—N2	124.64 (14)
F2—C4—S1	111.16 (13)	C26—C25—C24	118.38 (15)
F1—C4—S1	109.87 (13)	C26—C25—H25	120.8
C1—N1—C14	126.53 (14)	C24—C25—H25	120.8
C1—N1—H1	116.7	N21—C26—C25	125.36 (15)
C14—N1—H1	116.7	N21—C26—H26	117.3
C1—N2—C24	126.11 (13)	C25—C26—H26	117.3
O13—S1—O11—Ca1	156.19 (15)	N11—C12—C13—C14	−0.8 (3)
O12—S1—O11—Ca1	20.2 (2)	C1—N1—C14—C15	−5.8 (3)
C4—S1—O11—Ca1	−90.98 (18)	C1—N1—C14—C13	175.15 (16)
O3^i—Ca1—O11—S1	−0.18 (18)	C12—C13—C14—C15	2.0 (3)
O2^i—Ca1—O11—S1	89.45 (17)	C12—C13—C14—N1	−178.86 (16)
O13—S1—C4—F3	59.24 (14)	N1—C14—C15—C16	179.02 (16)
O12—S1—C4—F3	179.56 (12)	C13—C14—C15—C16	−1.9 (3)
O11—S1—C4—F3	−61.25 (14)	C12—N11—C16—C15	0.6 (3)
O13—S1—C4—F2	179.69 (13)	C14—C15—C16—N11	0.6 (3)
O12—S1—C4—F2	−60.00 (14)	C26—N21—C22—C23	0.4 (2)
O11—S1—C4—F2	59.19 (15)	N21—C22—C23—C24	−0.2 (3)
O13—S1—C4—F1	−60.66 (14)	C22—C23—C24—C25	−0.3 (2)
O12—S1—C4—F1	59.65 (14)	C22—C23—C24—N2	179.86 (14)
O11—S1—C4—F1	178.84 (12)	C1—N2—C24—C23	178.92 (15)
C24—N2—C1—O1	1.3 (3)	C1—N2—C24—C25	−0.9 (3)
C24—N2—C1—N1	−178.88 (14)	C23—C24—C25—C26	0.4 (2)
C14—N1—C1—O1	1.9 (3)	N2—C24—C25—C26	−179.70 (15)
C14—N1—C1—N2	−177.95 (14)	C22—N21—C26—C25	−0.3 (3)
C16—N11—C12—C13	−0.6 (3)	C24—C25—C26—N21	−0.2 (3)

Symmetry code: (i) −x+2, −y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O12	0.86	2.01	2.8608 (18)	170
N2—H2A···O13	0.86	2.27	3.1025 (17)	163
C3—H3A···O12^i	0.96	2.52	3.316 (2)	140
O2—H2···N11^ii	0.82	1.87	2.6891 (18)	179
O3—H3···N21^iii	0.82	1.92	2.7250 (16)	167

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