Download citation
Download citation
link to html
Mol­ecules of the title compound, porphyrin-54,104,154,204-tetra­benzoic acid, C48H30N4O8, lie on sites of 2/m symmetry in the space group Cmca. The crystals consist of doubly inter­woven two-dimensional supra­molecular arrays sustained by multiple (COOH)2 cyclic dimeric hydrogen bonds, each mol­ecule of the porphyrintetra­benzoic acid coordinating to four neighbouring species. This structure, which encloses substantial spaces occupied by disordered dimethyl­formamide solvent mol­ecules, represents yet another supra­molecular isomer of this porphyrin.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270107020975/gd3109sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270107020975/gd3109Isup2.hkl
Contains datablock I

CCDC reference: 655498

Comment top

The supramolecular chemistry of the title compound, (I), has been widely studied in recent years in an effort to formulate network and framework solids (George & Goldberg, 2006; George et al., 2006; Goldberg, 2005 and references therein; Diskin-Posner & Goldberg, 1999; Dastidar et al., 1996). Compound (I) provides a classic example of an organic moiety with multiple complementary terminal functional groups directed in four diverging directions of the equatorial molecular plane that exhibit a high propensity for self-assembling into hydrogen-bonded two-dimensional nets. One of the possible interaction modes involves association of every porphyrin unit to four different neighbouring species via four head-to-head (COOH)2 cyclic dimeric associations. This leads to the formation of quadrangular grid arrays with large pores and varying shapes, to be filled during the crystallization process either by occlusion of another guest/solvent component to avoid interweaving and allow a stacked organization of these arrays, or by their self-interpenetration.

The different modes of the self-assembly of (I) (George & Goldberg, 2006; George et al., 2006; Diskin-Posner & Goldberg, 1999) represent a phenomenon known as supramolecular isomerism of the conformation and catenane types (Moulton & Zaworotko, 2001). Fig. 1 shows the molecular structure of (I) (as observed in this study), which resides on a special position of site symmetry 2/m. The supramolecular assembly of (I) into flat grid arrays sustained by cooperative (COOH)2-type four-point hydrogen bonding is illustrated in Fig. 2. Every molecule of the tetra-acid effectively connects to four neighbouring species, being involved in eight nearly linear O—H···O interactions at O···O = 2.626 (2) Å.

Within the two-dimensional supramolecular assembly, there are nearly square spaces with dimensions ca 18 × 18 Å2 between the van der Waals surfaces. The crystalline architecture involves double interpenetration of these networks partly to fill the empty space (Fig. 3). The remaining voids between these hydrogen-bonded networks are occupied by molecules of the dimethylformamide solvent, which could not, however, be modelled as discrete atoms.

This structure represents a catenane-type supramolecular isomer of other architectures of (I) observed earlier (George & Goldberg, 2006; Diskin-Posner & Goldberg, 1999). In the latter, the supramolecular networking of (I) exhibits the same interporphyrin connectivity via cyclic dimeric hydrogen-bond synthons, but the open networks form offset stacks one on top of the other. It also represents a conformation-type supramolecular isomer, with differently shaped grids within the individual layers. Thus, the networks in this study represent a regular nearly square grid with van der Waals width of about 18 Å. In another structure with similarly doubly interpenetrating networks of (I), a rhomboid grid with van der Waals width of about only 16 Å was observed (George et al., 2006). On the other hand, in yet another non-interpenetrating structure of network arrays of the porphyrin tetra-acid, the supramolecular networks were found to be characterized by a distorted grid with alternating spacing of about 15 and 20 Å (George & Goldberg, 2006). The previously observed conformational isomers of the grid networks are shown in Fig. 4.

The various distortions could be associated with the tendency to minimize the interporphyrin void space in such hydrogen-bonded networks. The supramolecular isomerism discussed above resembles to some extent the appearance of isomeric interwoven and non-interwoven supramolecular hexagonal networks in solids of 1,3,5-benzenetricarboxylic acid (Moulton & Zaworotko, 2001; Herbstein, 1987).

Related literature top

For related literature, see: Dastidar (1996); Diskin-Posner & Goldberg (1999); George & Goldberg (2006); George, Lipstman, Muniappan & Goldberg (2006); Goldberg (2005); Herbstein (1987); Moulton & Zaworotko (2001); Spek (2003).

Experimental top

Crystals of (I) were obtained accidentally, while trying to react the free base tetra-acid porphyrin with Gd3+ ions in the presence of dimethylformamide, in an effort to prepare the corresponding metal–organic framework material (all reactants are commercially available). Single crystals were obtained by recrystallization from dimethylformamide. [Please check added text]

Refinement top

H atoms bound to C and N were located in calculated positions and were constrained to ride on their parent atoms, with N—H = 0.88 and C—H = 0.95 Å, and with Uiso(H) = 1.2Ueq(C,N). The inner pyrrole H atoms are disordered between the four N sites. H atoms attached to O atoms were located in a difference Fourier map and their atomic parameters were allowed to refine freely; O—H = 0.94 (3) Å. The porphyrin molecules reside on special positions of 2/m symmetry at (0, 0, 1/2). The solvent moiety is disordered about a similar site at (0, 1/2, 1/2), but it could not be reliably modelled as discrete atoms. Correspondingly, the contribution of the solvent was subtracted from the diffraction data using the SQUEEZE procedure in PLATON (Spek, 2003). The solvent-accessible voids were estimated to be 487 Å3, 12% of the unit-cell volume. The residual electron-density count was assessed as 132 electrons per unit cell, which is consistent with nearly four molecules of the dimethylformamide solvent. The maximum residual electron density, 0.61 e Å-3, is located at the inversion centre in the porphyrin unit, 1.16 Å from atom H6 and 1.23 Å from atom H7.

Computing details top

Data collection: COLLECT (Nonius, 1999); cell refinement: DENZO (Otwinowski & Minor, 1997); data reduction: DENZO; program(s) used to solve structure: SIR97 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing the atom-labelling scheme. Displacement ellipsods are drawn at the 50% probability level at ca 110 K. The molecule resides on a special 2/m position and the asymmetric unit consists of only one quarter of it. H atoms have been omitted, except those of the carboxylic acid functions.
[Figure 2] Fig. 2. Space-filling illustration of the supramolecular assembly of (I) into two-dimensional networks by cooperative (COOH)2 hydrogen bonding in the four lateral directions of the porphyrin unit.
[Figure 3] Fig. 3. The crystalline architecture of (I), viewed approximately down the b axis, exhibiting the double interpenetration of the porphyrin networks (stick illustration, H atoms omitted for clarity). The cyclic dimeric (COOH)2 hydrogen bonds are indicated by dotted lines.
[Figure 4] Fig. 4. Two other conformational isomers of the network grid of the porphyrin tetra-acid, as observed in previous investigations (George & Goldberg, 2006; George et al., 2006).
meso-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin top
Crystal data top
C48H30N4O8F(000) = 1640
Mr = 790.76Dx = 1.297 Mg m3
Orthorhombic, CmcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2bc 2Cell parameters from 2650 reflections
a = 31.0164 (3) Åθ = 1.4–27.9°
b = 8.5897 (11) ŵ = 0.09 mm1
c = 15.1952 (6) ÅT = 110 K
V = 4048.3 (5) Å3Plate, red
Z = 40.50 × 0.25 × 0.02 mm
Data collection top
Nonius KappaCCD area-detector
diffractometer
1653 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.072
Graphite monochromatorθmax = 26.0°, θmin = 2.6°
Detector resolution: 12.8 pixels mm-1h = 038
1 ° ω scansk = 010
15184 measured reflectionsl = 180
2033 independent reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.059Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.138H atoms treated by a mixture of independent and constrained refinement
S = 1.13 w = 1/[σ2(Fo2) + (0.0482P)2 + 8.4601P]
where P = (Fo2 + 2Fc2)/3
2033 reflections(Δ/σ)max < 0.001
141 parametersΔρmax = 0.61 e Å3
0 restraintsΔρmin = 0.23 e Å3
Crystal data top
C48H30N4O8V = 4048.3 (5) Å3
Mr = 790.76Z = 4
Orthorhombic, CmcaMo Kα radiation
a = 31.0164 (3) ŵ = 0.09 mm1
b = 8.5897 (11) ÅT = 110 K
c = 15.1952 (6) Å0.50 × 0.25 × 0.02 mm
Data collection top
Nonius KappaCCD area-detector
diffractometer
1653 reflections with I > 2σ(I)
15184 measured reflectionsRint = 0.072
2033 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0590 restraints
wR(F2) = 0.138H atoms treated by a mixture of independent and constrained refinement
S = 1.13Δρmax = 0.61 e Å3
2033 reflectionsΔρmin = 0.23 e Å3
141 parameters
Special details top

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.

Disordered molecules of DMF solvent are included in the interporphyrin voids, which could not be modeled by discrete atoms. Correspondingly, their contribution to the diffraction pattern was subtracted by the Squeeze procedure (Spek, 2003).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
C10.02163 (7)0.2697 (3)0.26741 (14)0.0225 (5)
H10.03990.32550.22840.027*
C20.03508 (7)0.1680 (3)0.33848 (14)0.0206 (5)
C30.07880 (7)0.1349 (3)0.35778 (14)0.0199 (5)
C40.09344 (7)0.0586 (3)0.43355 (14)0.0197 (5)
C50.13718 (7)0.0334 (3)0.45934 (15)0.0205 (5)
H50.16200.05880.42560.025*
N60.00000.1109 (3)0.38255 (16)0.0200 (6)
H60.00000.05040.42930.024*0.50
N70.06792 (8)0.00000.50000.0202 (6)
H70.03950.00000.50000.024*0.50
C80.11154 (7)0.1762 (3)0.28923 (14)0.0201 (5)
C90.14847 (7)0.2645 (3)0.30741 (15)0.0224 (5)
H90.15260.30650.36460.027*
C100.17897 (7)0.2910 (3)0.24290 (15)0.0235 (5)
H100.20380.35130.25610.028*
C110.17356 (7)0.2299 (3)0.15842 (15)0.0230 (5)
C120.13630 (7)0.1451 (3)0.13907 (15)0.0246 (5)
H120.13200.10510.08150.029*
C130.10583 (7)0.1195 (3)0.20345 (15)0.0236 (5)
H130.08050.06240.18950.028*
C140.20637 (7)0.2467 (3)0.08862 (16)0.0245 (5)
O150.23890 (5)0.3403 (2)0.10779 (11)0.0329 (5)
H150.2592 (10)0.329 (4)0.062 (2)0.049*
O160.20328 (5)0.1781 (2)0.01805 (11)0.0310 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0201 (10)0.0306 (12)0.0168 (11)0.0005 (10)0.0001 (9)0.0061 (10)
C20.0191 (11)0.0258 (12)0.0169 (10)0.0013 (9)0.0011 (9)0.0026 (10)
C30.0178 (11)0.0251 (12)0.0168 (10)0.0007 (9)0.0013 (9)0.0004 (9)
C40.0169 (11)0.0243 (12)0.0178 (11)0.0010 (9)0.0029 (9)0.0007 (9)
C50.0173 (11)0.0253 (12)0.0189 (11)0.0001 (9)0.0023 (9)0.0004 (9)
N60.0163 (13)0.0300 (15)0.0138 (13)0.0000.0000.0032 (11)
N70.0179 (13)0.0280 (15)0.0147 (13)0.0000.0000.0023 (11)
C80.0181 (11)0.0261 (12)0.0161 (11)0.0031 (9)0.0025 (9)0.0038 (9)
C90.0178 (11)0.0309 (13)0.0185 (11)0.0021 (9)0.0008 (9)0.0028 (10)
C100.0201 (11)0.0297 (13)0.0207 (11)0.0012 (9)0.0017 (9)0.0033 (10)
C110.0218 (12)0.0264 (12)0.0207 (12)0.0030 (9)0.0034 (9)0.0063 (10)
C120.0239 (12)0.0317 (13)0.0181 (11)0.0003 (10)0.0031 (9)0.0022 (10)
C130.0193 (11)0.0321 (13)0.0193 (12)0.0026 (9)0.0001 (9)0.0021 (10)
C140.0200 (11)0.0294 (12)0.0239 (12)0.0039 (10)0.0033 (10)0.0052 (10)
O150.0255 (10)0.0491 (11)0.0241 (9)0.0062 (8)0.0090 (7)0.0017 (8)
O160.0279 (9)0.0415 (10)0.0236 (9)0.0026 (8)0.0103 (7)0.0031 (8)
Geometric parameters (Å, º) top
C1—C1i1.342 (4)C8—C91.401 (3)
C1—C21.450 (3)C8—C131.403 (3)
C1—H10.9500C9—C101.381 (3)
C2—N61.369 (3)C9—H90.9500
C2—C31.416 (3)C10—C111.397 (3)
C3—C41.400 (3)C10—H100.9500
C3—C81.497 (3)C11—C121.397 (3)
C4—N71.378 (3)C11—C141.477 (3)
C4—C51.429 (3)C12—C131.378 (3)
C5—C5ii1.362 (4)C12—H120.9500
C5—H50.9500C13—H130.9500
N6—C2i1.369 (3)C14—O161.228 (3)
N6—H60.8800C14—O151.323 (3)
N7—C4ii1.378 (3)O15—H150.94 (3)
N7—H70.8800
C1i—C1—C2106.72 (12)C9—C8—C3123.1 (2)
C1i—C1—H1126.6C13—C8—C3118.6 (2)
C2—C1—H1126.6C10—C9—C8120.6 (2)
N6—C2—C3126.0 (2)C10—C9—H9119.7
N6—C2—C1110.58 (19)C8—C9—H9119.7
C3—C2—C1123.4 (2)C9—C10—C11120.5 (2)
C4—C3—C2125.1 (2)C9—C10—H10119.7
C4—C3—C8117.58 (19)C11—C10—H10119.7
C2—C3—C8117.23 (19)C10—C11—C12119.3 (2)
N7—C4—C3125.9 (2)C10—C11—C14122.7 (2)
N7—C4—C5106.79 (19)C12—C11—C14118.0 (2)
C3—C4—C5127.2 (2)C13—C12—C11120.1 (2)
C5ii—C5—C4108.23 (12)C13—C12—H12120.0
C5ii—C5—H5125.9C11—C12—H12120.0
C4—C5—H5125.9C12—C13—C8121.2 (2)
C2i—N6—C2105.3 (3)C12—C13—H13119.4
C2i—N6—H6127.3C8—C13—H13119.4
C2—N6—H6127.3O16—C14—O15122.9 (2)
C4ii—N7—C4109.9 (3)O16—C14—C11121.8 (2)
C4ii—N7—H7125.0O15—C14—C11115.3 (2)
C4—N7—H7125.0C14—O15—H15106.6 (19)
C9—C8—C13118.3 (2)
Symmetry codes: (i) x, y, z; (ii) x, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O15—H15···O16iii0.94 (3)1.69 (3)2.626 (2)176 (3)
Symmetry code: (iii) x+1/2, y+1/2, z.

Experimental details

Crystal data
Chemical formulaC48H30N4O8
Mr790.76
Crystal system, space groupOrthorhombic, Cmca
Temperature (K)110
a, b, c (Å)31.0164 (3), 8.5897 (11), 15.1952 (6)
V3)4048.3 (5)
Z4
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.50 × 0.25 × 0.02
Data collection
DiffractometerNonius KappaCCD area-detector
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
15184, 2033, 1653
Rint0.072
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.059, 0.138, 1.13
No. of reflections2033
No. of parameters141
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.61, 0.23

Computer programs: COLLECT (Nonius, 1999), DENZO (Otwinowski & Minor, 1997), DENZO, SIR97 (Altomare et al., 1994), SHELXL97 (Sheldrick, 1997), ORTEPIII (Burnett & Johnson, 1996) and Mercury (Macrae et al., 2006), SHELXL97.

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O15—H15···O16i0.94 (3)1.69 (3)2.626 (2)176 (3)
Symmetry code: (i) x+1/2, y+1/2, z.
 

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds