Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270109034568/gg3214sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270109034568/gg3214Isup2.hkl |
CCDC reference: 756003
Compound (I) was prepared following the procedure of Lin & Lang (1977). A solution of 2-acetylpyrrole (20 g, 0.18 mol) in dimethylformamide dimethylacetal (100 g, 0.84 mol) was refluxed under N2 for 48 h. Evaporation of the solvent gave a dark-brown solid residue that was purified by dissolution in CH2Cl2 and filtration through a silica plug. Pure 3-(dimethylamino)-1-(1H-pyrrol-2-yl)-2-propen-1-one was obtained from the resultant solution as a yellow solid, by addition of ethyl acetate. A solution of this intermediate (12 g, 0.073 mol) and hydrazine monohydrate (25 g, 0.50 mol) in methanol (200 ml) was refluxed for 6 h. The reaction was quenched with water, and the solution extracted with CH2Cl2 (3 × 100 ml). Evaporation of the extracts to dryness yielded an orange oil which slowly solidified upon storage at 253 K. Two further recrystallizations from CH2Cl2–hexanes [Solvent ratio?] afforded analytically pure yellow crystals of (I) (yield 5.5 g, 57%). Analysis, found: C 62.9, H 5.3, N 31.5%; calculated for C7H7N3: C 63.1, H 5.3, N 31.6%. 1H NMR [(CD3)2SO, 298 K, δ, p.p.m.]: 6.09 (d, J = 2.6 Hz, 1H), 6.41 (s, 1H), 6.47 (d, J = 2.0 Hz, 1H), 6.79 (d, J = 1.3 Hz, 1H), 7.62 (s, 1H), 11.14 (br s, 1H), 12.72 (br s, 1H); EI mass spectrum m/z 133.0 ([M]+), 104.0 ([M—N2]+).
The pyrrole and pyrazole rings in molecules A and B were distinguished by the isotropic displacement parameters of their atoms N1 and C10, by the absence of an H atom on atom N2 in the Fourier map, and by the short hydrogen bonds accepted by both pyrazole N2 atoms. All H atoms were located in a difference Fourier map and allowed to refine freely. The refined C—H distances are in the range 0.952 (17)–1.001 (15) Å, and N—H distances are in the range 0.880 (16)–0.911 (16) Å.
Data collection: APEX2 (Bruker, 2004); cell refinement: APEX2 (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: local program.
C7H7N3 | F(000) = 560 |
Mr = 133.16 | Dx = 1.283 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 17932 reflections |
a = 10.442 (2) Å | θ = 2.3–28.9° |
b = 13.004 (2) Å | µ = 0.08 mm−1 |
c = 10.8849 (19) Å | T = 150 K |
β = 111.119 (9)° | Fragment, pale yellow |
V = 1378.7 (4) Å3 | 0.18 × 0.15 × 0.09 mm |
Z = 8 |
Bruker X8 APEX diffractometer | 3601 independent reflections |
Radiation source: rotating anode | 2789 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.040 |
Detector resolution: 120 microns pixels mm-1 | θmax = 28.9°, θmin = 2.3° |
rotation images scans | h = −14→14 |
Absorption correction: multi-scan (SADABS; Sheldrick, 2002) | k = −17→17 |
Tmin = 0.795, Tmax = 0.925 | l = −14→14 |
17932 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.039 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.111 | All H-atom parameters refined |
S = 1.02 | w = 1/[σ2(Fo2) + (0.0551P)2 + 0.2494P] where P = (Fo2 + 2Fc2)/3 |
3601 reflections | (Δ/σ)max = 0.001 |
237 parameters | Δρmax = 0.22 e Å−3 |
0 restraints | Δρmin = −0.18 e Å−3 |
C7H7N3 | V = 1378.7 (4) Å3 |
Mr = 133.16 | Z = 8 |
Monoclinic, P21/n | Mo Kα radiation |
a = 10.442 (2) Å | µ = 0.08 mm−1 |
b = 13.004 (2) Å | T = 150 K |
c = 10.8849 (19) Å | 0.18 × 0.15 × 0.09 mm |
β = 111.119 (9)° |
Bruker X8 APEX diffractometer | 3601 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2002) | 2789 reflections with I > 2σ(I) |
Tmin = 0.795, Tmax = 0.925 | Rint = 0.040 |
17932 measured reflections |
R[F2 > 2σ(F2)] = 0.039 | 0 restraints |
wR(F2) = 0.111 | All H-atom parameters refined |
S = 1.02 | Δρmax = 0.22 e Å−3 |
3601 reflections | Δρmin = −0.18 e Å−3 |
237 parameters |
Experimental. Rotating anode power 3 kW. |
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. There are two unique molecules in the asymmetric unit, which are labelled 'A' and 'B'. No disorder was detected during refinement, and no restraints were applied. All non-H atoms were refined anisotropically. All H atoms were located in the Fourier map, and allowed to refine freely. The refined C—H distances range from 0.952 (17)–1.001 (15) Å, and N—H distances are between 0.880 (16)–0.911 (16) Å. |
x | y | z | Uiso*/Ueq | ||
N1A | 0.33632 (12) | 0.19259 (9) | 0.56261 (11) | 0.0434 (3) | |
H1A | 0.3511 (19) | 0.1458 (15) | 0.6271 (19) | 0.069 (6)* | |
N2A | 0.22010 (11) | 0.25217 (8) | 0.52432 (10) | 0.0362 (2) | |
C3A | 0.22918 (12) | 0.30883 (9) | 0.42394 (11) | 0.0314 (2) | |
C4A | 0.35031 (14) | 0.28413 (11) | 0.39908 (13) | 0.0412 (3) | |
H4A | 0.3769 (16) | 0.3152 (12) | 0.3328 (16) | 0.052 (4)* | |
C5A | 0.41629 (15) | 0.21050 (12) | 0.49051 (14) | 0.0466 (3) | |
H5A | 0.5024 (18) | 0.1729 (13) | 0.5072 (17) | 0.059 (5)* | |
N6A | 0.00975 (10) | 0.40392 (8) | 0.38763 (10) | 0.0334 (2) | |
H6A | −0.0179 (16) | 0.3669 (12) | 0.4447 (15) | 0.048 (4)* | |
C7A | 0.12521 (12) | 0.38570 (9) | 0.35650 (11) | 0.0315 (2) | |
C8A | 0.12154 (14) | 0.45528 (10) | 0.25846 (13) | 0.0416 (3) | |
H8A | 0.1909 (17) | 0.4605 (11) | 0.2179 (15) | 0.050 (4)* | |
C9A | 0.00137 (15) | 0.51698 (11) | 0.23154 (14) | 0.0461 (3) | |
H9A | −0.0288 (17) | 0.5726 (13) | 0.1674 (16) | 0.060 (5)* | |
C10A | −0.06594 (14) | 0.48382 (10) | 0.31227 (13) | 0.0393 (3) | |
H10A | −0.1529 (17) | 0.5075 (12) | 0.3198 (15) | 0.053 (4)* | |
N1B | −0.03790 (10) | −0.04424 (7) | 0.62179 (10) | 0.0319 (2) | |
H1B | −0.0668 (16) | −0.0668 (11) | 0.5389 (15) | 0.044 (4)* | |
N2B | 0.04056 (10) | 0.04353 (7) | 0.65025 (9) | 0.0284 (2) | |
C3B | 0.08013 (10) | 0.05347 (8) | 0.78201 (10) | 0.0249 (2) | |
C4B | 0.02943 (13) | −0.02912 (9) | 0.83664 (12) | 0.0339 (3) | |
H4B | 0.0438 (15) | −0.0422 (11) | 0.9313 (15) | 0.042 (4)* | |
C5B | −0.04538 (13) | −0.08947 (9) | 0.73075 (13) | 0.0363 (3) | |
H5B | −0.0974 (16) | −0.1541 (12) | 0.7257 (15) | 0.049 (4)* | |
N6B | 0.19094 (10) | 0.22454 (7) | 0.78617 (10) | 0.0303 (2) | |
H6B | 0.1651 (15) | 0.2314 (11) | 0.7002 (16) | 0.041 (4)* | |
C7B | 0.16455 (11) | 0.14056 (8) | 0.85149 (10) | 0.0258 (2) | |
C8B | 0.23231 (12) | 0.15669 (10) | 0.98512 (12) | 0.0348 (3) | |
H8B | 0.2346 (15) | 0.1082 (11) | 1.0560 (15) | 0.046 (4)* | |
C9B | 0.30167 (13) | 0.25384 (10) | 0.99986 (13) | 0.0392 (3) | |
H9B | 0.3597 (17) | 0.2878 (12) | 1.0816 (16) | 0.052 (4)* | |
C10B | 0.27445 (13) | 0.29310 (9) | 0.87627 (14) | 0.0373 (3) | |
H10B | 0.3049 (16) | 0.3565 (12) | 0.8458 (15) | 0.048 (4)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1A | 0.0435 (6) | 0.0471 (6) | 0.0378 (6) | 0.0061 (5) | 0.0124 (5) | 0.0013 (5) |
N2A | 0.0344 (5) | 0.0428 (5) | 0.0306 (5) | −0.0019 (4) | 0.0109 (4) | 0.0015 (4) |
C3A | 0.0329 (6) | 0.0353 (6) | 0.0267 (5) | −0.0110 (4) | 0.0114 (4) | −0.0075 (4) |
C4A | 0.0408 (7) | 0.0508 (7) | 0.0374 (7) | −0.0064 (6) | 0.0207 (6) | −0.0084 (6) |
C5A | 0.0425 (7) | 0.0545 (8) | 0.0443 (7) | 0.0049 (6) | 0.0173 (6) | −0.0106 (6) |
N6A | 0.0339 (5) | 0.0365 (5) | 0.0313 (5) | −0.0070 (4) | 0.0135 (4) | 0.0027 (4) |
C7A | 0.0319 (6) | 0.0348 (5) | 0.0285 (5) | −0.0120 (4) | 0.0117 (4) | −0.0039 (4) |
C8A | 0.0406 (7) | 0.0473 (7) | 0.0391 (7) | −0.0138 (6) | 0.0168 (6) | 0.0053 (5) |
C9A | 0.0443 (7) | 0.0451 (7) | 0.0454 (7) | −0.0090 (6) | 0.0120 (6) | 0.0131 (6) |
C10A | 0.0351 (6) | 0.0391 (6) | 0.0409 (7) | −0.0053 (5) | 0.0105 (5) | 0.0037 (5) |
N1B | 0.0339 (5) | 0.0289 (5) | 0.0300 (5) | −0.0029 (4) | 0.0078 (4) | −0.0065 (4) |
N2B | 0.0303 (5) | 0.0265 (4) | 0.0250 (4) | −0.0007 (3) | 0.0056 (4) | −0.0012 (3) |
C3B | 0.0236 (5) | 0.0265 (5) | 0.0242 (5) | 0.0034 (4) | 0.0081 (4) | −0.0011 (4) |
C4B | 0.0438 (7) | 0.0308 (5) | 0.0313 (6) | −0.0028 (5) | 0.0185 (5) | −0.0019 (4) |
C5B | 0.0422 (7) | 0.0287 (5) | 0.0422 (7) | −0.0060 (5) | 0.0202 (5) | −0.0059 (5) |
N6B | 0.0304 (5) | 0.0284 (5) | 0.0309 (5) | −0.0011 (4) | 0.0097 (4) | −0.0003 (4) |
C7B | 0.0244 (5) | 0.0282 (5) | 0.0256 (5) | 0.0010 (4) | 0.0102 (4) | −0.0023 (4) |
C8B | 0.0340 (6) | 0.0437 (6) | 0.0270 (6) | −0.0046 (5) | 0.0114 (5) | −0.0056 (5) |
C9B | 0.0327 (6) | 0.0464 (7) | 0.0375 (7) | −0.0070 (5) | 0.0113 (5) | −0.0171 (5) |
C10B | 0.0324 (6) | 0.0310 (6) | 0.0484 (7) | −0.0052 (5) | 0.0146 (5) | −0.0077 (5) |
N1A—C5A | 1.3563 (19) | N1B—C5B | 1.3511 (16) |
N1A—N2A | 1.3719 (16) | N1B—N2B | 1.3736 (13) |
N1A—H1A | 0.90 (2) | N1B—H1B | 0.892 (15) |
N2A—C3A | 1.3491 (15) | N2B—C3B | 1.3481 (14) |
C3A—C4A | 1.4222 (18) | C3B—C4B | 1.4193 (15) |
C3A—C7A | 1.4637 (17) | C3B—C7B | 1.4666 (14) |
C4A—C5A | 1.374 (2) | C4B—C5B | 1.3805 (17) |
C4A—H4A | 0.952 (17) | C4B—H4B | 1.001 (15) |
C5A—H5A | 0.981 (17) | C5B—H5B | 0.992 (16) |
N6A—C10A | 1.3820 (17) | N6B—C10B | 1.3787 (15) |
N6A—C7A | 1.3852 (16) | N6B—C7B | 1.3840 (14) |
N6A—H6A | 0.911 (16) | N6B—H6B | 0.880 (16) |
C7A—C8A | 1.3890 (17) | C7B—C8B | 1.3851 (16) |
C8A—C9A | 1.428 (2) | C8B—C9B | 1.4361 (18) |
C8A—H8A | 0.977 (16) | C8B—H8B | 0.990 (15) |
C9A—C10A | 1.3773 (19) | C9B—C10B | 1.369 (2) |
C9A—H9A | 0.975 (17) | C9B—H9B | 0.982 (16) |
C10A—H10A | 0.990 (16) | C10B—H10B | 0.983 (16) |
C5A—N1A—N2A | 112.88 (12) | C5B—N1B—N2B | 112.46 (10) |
C5A—N1A—H1A | 126.8 (12) | C5B—N1B—H1B | 129.7 (10) |
N2A—N1A—H1A | 120.2 (12) | N2B—N1B—H1B | 117.3 (10) |
C3A—N2A—N1A | 104.00 (10) | C3B—N2B—N1B | 104.41 (9) |
N2A—C3A—C4A | 110.95 (11) | N2B—C3B—C4B | 110.83 (9) |
N2A—C3A—C7A | 121.55 (10) | N2B—C3B—C7B | 121.31 (9) |
C4A—C3A—C7A | 127.48 (11) | C4B—C3B—C7B | 127.87 (10) |
C5A—C4A—C3A | 105.53 (12) | C5B—C4B—C3B | 105.34 (10) |
C5A—C4A—H4A | 129.6 (10) | C5B—C4B—H4B | 126.3 (8) |
C3A—C4A—H4A | 124.8 (10) | C3B—C4B—H4B | 128.3 (8) |
N1A—C5A—C4A | 106.63 (12) | N1B—C5B—C4B | 106.93 (10) |
N1A—C5A—H5A | 121.4 (10) | N1B—C5B—H5B | 121.6 (9) |
C4A—C5A—H5A | 131.9 (10) | C4B—C5B—H5B | 131.4 (9) |
C10A—N6A—C7A | 110.21 (10) | C10B—N6B—C7B | 109.68 (10) |
C10A—N6A—H6A | 123.3 (10) | C10B—N6B—H6B | 124.3 (10) |
C7A—N6A—H6A | 126.4 (10) | C7B—N6B—H6B | 125.8 (9) |
N6A—C7A—C8A | 106.92 (11) | N6B—C7B—C8B | 107.40 (10) |
N6A—C7A—C3A | 123.21 (10) | N6B—C7B—C3B | 122.56 (9) |
C8A—C7A—C3A | 129.82 (11) | C8B—C7B—C3B | 130.03 (10) |
C7A—C8A—C9A | 107.62 (12) | C7B—C8B—C9B | 107.27 (11) |
C7A—C8A—H8A | 124.9 (9) | C7B—C8B—H8B | 125.5 (9) |
C9A—C8A—H8A | 127.4 (9) | C9B—C8B—H8B | 127.2 (9) |
C10A—C9A—C8A | 107.81 (12) | C10B—C9B—C8B | 107.48 (10) |
C10A—C9A—H9A | 125.6 (10) | C10B—C9B—H9B | 124.4 (9) |
C8A—C9A—H9A | 126.6 (10) | C8B—C9B—H9B | 128.2 (9) |
C9A—C10A—N6A | 107.45 (12) | C9B—C10B—N6B | 108.18 (11) |
C9A—C10A—H10A | 130.5 (9) | C9B—C10B—H10B | 131.8 (9) |
N6A—C10A—H10A | 122.0 (9) | N6B—C10B—H10B | 120.0 (9) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H1A···XAi | 0.90 (2) | 2.55 | 3.31 | 143.5 |
N6A—H6A···XBii | 0.911 (16) | 2.68 | 3.32 | 127.4 |
N1B—H1B···N2Biii | 0.892 (15) | 2.193 (15) | 2.9512 (15) | 142.5 (13) |
N6B—H6B···N2A | 0.880 (16) | 2.204 (16) | 2.9952 (16) | 149.3 (13) |
Symmetry codes: (i) x+1/2, −y+1/2, z+1/2; (ii) x−1/2, −y+1/2, z−1/2; (iii) −x, −y, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C7H7N3 |
Mr | 133.16 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 150 |
a, b, c (Å) | 10.442 (2), 13.004 (2), 10.8849 (19) |
β (°) | 111.119 (9) |
V (Å3) | 1378.7 (4) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.18 × 0.15 × 0.09 |
Data collection | |
Diffractometer | Bruker X8 APEX diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2002) |
Tmin, Tmax | 0.795, 0.925 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 17932, 3601, 2789 |
Rint | 0.040 |
(sin θ/λ)max (Å−1) | 0.680 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.039, 0.111, 1.02 |
No. of reflections | 3601 |
No. of parameters | 237 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.22, −0.18 |
Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), local program.
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H1A···XAi | 0.90 (2) | 2.55 | 3.31 | 143.5 |
N6A—H6A···XBii | 0.911 (16) | 2.68 | 3.32 | 127.4 |
N1B—H1B···N2Biii | 0.892 (15) | 2.193 (15) | 2.9512 (15) | 142.5 (13) |
N6B—H6B···N2A | 0.880 (16) | 2.204 (16) | 2.9952 (16) | 149.3 (13) |
Symmetry codes: (i) x+1/2, −y+1/2, z+1/2; (ii) x−1/2, −y+1/2, z−1/2; (iii) −x, −y, −z+1. |
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The 1H-pyrazole ring is an attractive synthon in inorganic supramolecular chemistry, since it possesses a metal-binding Lewis basic N-donor, and a Lewis acidic pyrrolic N—H group, in adjacent sites. A pyrazole ring can therefore bind a metal cation and anion simultaneously, and several 1H-pyrazole complexes have proved to be useful hosts for inorganic anions (Pérez & Riera, 2008). As part of our own investigations of the supramolecular chemistry of N—H pyrazole derivatives (Renard et al., 2002, 2006; Liu et al., 2004; Pask et al., 2006; Jones et al., 2006), we have achieved the first synthesis of the title compound, (I). Given the well known ability of pyrrole derivatives to act as anion hosts in their own right (Sessler, Camiolo & Gale, 2003), the combination of pyrrole and pyrazole groups in (I) makes it a potentially useful reagent for supramolecular chemistry. The Cambridge Structural Database (CSD, Version?; Allen, 2002) contains no other 1H-pyrrolyl-1H-pyrazole derivatives, although protonated and N-methylated derivatives of 3,5-bis(pyrrol-2-yl)pyrazole have been crystallographically characterized (Maeda et al., 2007).
The asymmetric unit of (I) contains two unique molecules, labelled A and B (Fig. 1). The molecules adopt essentially the same conformation, with the 3-substituted tautomer at the pyrazole ring and syn-pyrrole and pyrazole groups that are almost coplanar. The dihedral angle between the least-squares planes of the two heterocyclic rings is 4.57 (11)° for molecule A and 10.15 (7)° for molecule B. Molecules A and B associate through the N6B—H6B···N2A hydrogen bond, between the pyrrole group of molecule A and the pyrazole ring of molecule B (Fig. 1). Molecule B then forms a hydrogen-bonded dimer with its symmetry equivalent related by the inversion centre at (0, 0, 1/2), their pyrazole rings forming a cyclic dimer through the N1B—H1B···N2Bi interaction [symmetry code: (i) -x, -y, 1 - z] and its symmetry equivalent (Fig. 1). This cyclic dimer motif is common in crystalline pyrazoles substituted at the C3 and/or C5 positions (Claramunt et al., 2006). It is noteworthy that (I) does not adopt the alternative supramolecular dimer motif that is often exhibited by crystalline (1H-pyrrol-2-yl)aldimines (Fig. 2; see e.g. Franceschi et al., 2001; Sessler, Berthon-Gelloz et al., 2003; Matsui et al., 2004; Munro et al., 2006; Carabineiro et al., 2007; Wang et al., 2007).
The two N—H groups in molecule A form intermolecular N—H···C contacts to the π-systems of the two unique pyrrole rings. These are N1A—H1A···C10Aii and N6A—H6A···C9Biii [symmetry codes: (ii) x + 1/2, -y + 1/2, z + 1/2; (iii) x - 1/2, -y + 1/2, z - 1/2] (Fig. 3), (Table 1). The H···C distances are longer than the N—H···N hydrogen bonds in the structure, but still 0.2–0.4 Å shorter than the sum of the van der Waals radii of an aromatic group and an H atom (Pauling, 1960). In total, molecule A forms N—H···N or N—H···C contacts to four other adjacent molecules, while molecule B is connected to three neighbours. These interactions combine to give a puckered two-dimensional (3,4)-connected network, running parallel to the crystallographic (101) plane. The topology of the network is (3.82)2(32.82)2 in the short Schläfli notation (Fig. 4). While several different two-dimensional (3,4)-connected nets have been reported before, this example is new to our knowledge. The most common topology of this type in molecular crystals is (4.62)(42.62.82), which has been observed on at least five previous occasions (Zhong et al., 2001; Zheng et al., 2004; Xu et al., 2006; Xue et al., 2008; Li et al., 2008). Other known (3,4)-connected two-dimensional networks in metal–organic stuctures include (3.82)(42.82) (Zhong et al., 2008), (42.6)(42.64) (Qi et al., 2008) and the V2O5 net (42.6)(42.63.8) (Li et al., 2009).