Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807044868/kp2135sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807044868/kp2135Isup2.hkl |
CCDC reference: 663620
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.003 Å
- R factor = 0.036
- wR factor = 0.097
- Data-to-parameter ratio = 14.4
checkCIF/PLATON results
No syntax errors found
Alert level B PLAT094_ALERT_2_B Ratio of Maximum / Minimum Residual Density .... 4.96
Alert level C PLAT048_ALERT_1_C MoietyFormula Not Given ........................ ? PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given ....... ?
Alert level G PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K PLAT794_ALERT_5_G Check Predicted Bond Valency for Zn1 (2) 1.84
0 ALERT level A = In general: serious problem 1 ALERT level B = Potentially serious problem 2 ALERT level C = Check and explain 3 ALERT level G = General alerts; check 3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 1 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 1 ALERT type 5 Informative message, check
Quinoline-3-carbonitrile (1 mmol, 0.154 g), Zn(NO3)2.6H2O (0.5 mmol, 0.10 g) in water (10 ml). The mixture solution was stirred for 30 min at room temperature. The mixed solution were added to 15 ml sealed teflon-lined stainless steel vessels and the teflon-lined stainless steel vessels was left at 433 K vacuum case for 3 d under autogenous pressure. After cooled to room temperature, colourless crystals were obtained (yield: 80%, based on Zn).
All other H atoms were positioned geometrically and refined as riding, with C–H distances of 0.93 Å and Uiso(H) = 1.2 Ueq(C).
Organic nitriles ligands and their hydroxlyate derivatives (carboxylates) have been widely used for hydrothermal synthesis of coordination polymers (Lin, et al., 1998; Tong, et al., 2003). Notably, these kinds of ligand reactions, relatively straight forward in the context of reaction chemistry, have become an important approach in the crystal engineering of metal-organic frameworks exhibiting novel physical properties. In the title compound, (I), the quin-3 - c group evidently results from the hydrolysis of quinoline-3-carbonitrile. The quin-3 - c ligands used in this work exhibit bridging mode different from other quinoline derivatives (Odoko, et al., 2001; Okabe & Muranishi, 2003). To the best of our knowledge, this is the first isolated quin-3 - c coordination polymer.
There are one ZnII atom and two quin-3 - c ligands in the asymmetric unit. The ZnII atom has a tetrahedral environment formed by two N atoms [Co – N 2.097 (2) - 2.102 (2) Å] and two O atoms [Co – O 1.927 (2) - 1.963 (2) Å] belonging to for different quin-3 - c ligands. The quin-3 - c ion binds to zinc in a bridge mode, through the carboxylate O atom and the quinoline N atom. The carboxylato group is monodentate. Each ZnII atom is connected by four ditopic quin-3 - c ligands, which construct a two-dimensional layer parallel to the (100) plane (Fig. 2) and generate two-dimensional square grids based on the (4, 4) topology. The quinoline rings of quin-3 - c penetrating into the adjacent layers are parallel to each other, and face-to-face separations are about 3.59 (1) Å (the second quinoline rings symmetry code: x, y, 1 - z) indicating π···π interaction.
For related literature, see: Odoko et al. (2001); Okabe & Muranishi (2003); Lin et al. (1998); Tong et al. (2003).
Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL (Bruker, 1997).
[Zn(C10H6NO2)2] | F(000) = 1664 |
Mr = 409.69 | Dx = 1.685 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
a = 28.7995 (17) Å | Cell parameters from 3505 reflections |
b = 8.0475 (5) Å | θ = 1.6–27.0° |
c = 15.2845 (9) Å | µ = 1.55 mm−1 |
β = 114.262 (1)° | T = 293 K |
V = 3229.5 (3) Å3 | Block, yellow |
Z = 8 | 0.15 × 0.10 × 0.04 mm |
Bruker SMART CCD area-detector diffractometer | 3505 independent reflections |
Radiation source: fine-focus sealed tube | 3139 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.030 |
phi and ω scans | θmax = 27.0°, θmin = 1.6° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −35→36 |
Tmin = 0.801, Tmax = 0.941 | k = −10→10 |
12965 measured reflections | l = −19→19 |
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)] = 0.036 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.097 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0609P)2 + 2.5142P] where P = (Fo2 + 2Fc2)/3 |
3505 reflections | (Δ/σ)max = 0.001 |
244 parameters | Δρmax = 1.47 e Å−3 |
0 restraints | Δρmin = −0.30 e Å−3 |
[Zn(C10H6NO2)2] | V = 3229.5 (3) Å3 |
Mr = 409.69 | Z = 8 |
Monoclinic, C2/c | Mo Kα radiation |
a = 28.7995 (17) Å | µ = 1.55 mm−1 |
b = 8.0475 (5) Å | T = 293 K |
c = 15.2845 (9) Å | 0.15 × 0.10 × 0.04 mm |
β = 114.262 (1)° |
Bruker SMART CCD area-detector diffractometer | 3505 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 3139 reflections with I > 2σ(I) |
Tmin = 0.801, Tmax = 0.941 | Rint = 0.030 |
12965 measured reflections |
R[F2 > 2σ(F2)] = 0.036 | 0 restraints |
wR(F2) = 0.097 | H-atom parameters constrained |
S = 1.07 | Δρmax = 1.47 e Å−3 |
3505 reflections | Δρmin = −0.30 e Å−3 |
244 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Zn1 | 0.126630 (9) | 0.87864 (3) | 0.431899 (16) | 0.02379 (11) | |
N2 | 0.08079 (7) | 0.8761 (2) | 0.50917 (13) | 0.0245 (4) | |
O4 | 0.07901 (6) | 1.0274 (2) | 0.80930 (11) | 0.0339 (4) | |
O3 | 0.14500 (7) | 1.0907 (2) | 0.77747 (13) | 0.0414 (4) | |
C19 | 0.10001 (8) | 0.9447 (3) | 0.59501 (15) | 0.0271 (4) | |
H19A | 0.1312 | 0.9988 | 0.6141 | 0.033* | |
C17 | 0.03160 (9) | 0.8594 (3) | 0.63348 (16) | 0.0297 (5) | |
H17A | 0.0155 | 0.8544 | 0.6752 | 0.036* | |
C16 | 0.00951 (8) | 0.7822 (3) | 0.54283 (15) | 0.0276 (4) | |
C18 | 0.07678 (8) | 0.9417 (3) | 0.65969 (15) | 0.0265 (4) | |
C20 | 0.10280 (9) | 1.0280 (3) | 0.75489 (15) | 0.0300 (5) | |
C12 | 0.01183 (9) | 0.7247 (3) | 0.38800 (15) | 0.0305 (5) | |
H12A | 0.0278 | 0.7340 | 0.3462 | 0.037* | |
C14 | −0.05816 (10) | 0.6271 (3) | 0.4220 (2) | 0.0411 (6) | |
H14A | −0.0889 | 0.5703 | 0.4019 | 0.049* | |
C11 | 0.03451 (8) | 0.7944 (2) | 0.48051 (14) | 0.0242 (4) | |
C13 | −0.03377 (10) | 0.6432 (3) | 0.35961 (18) | 0.0374 (5) | |
H13A | −0.0488 | 0.5979 | 0.2983 | 0.045* | |
C15 | −0.03718 (9) | 0.6940 (3) | 0.51180 (18) | 0.0362 (5) | |
H15A | −0.0535 | 0.6819 | 0.5528 | 0.043* | |
N1 | 0.17247 (7) | 0.0863 (2) | 0.49329 (13) | 0.0232 (3) | |
O1 | 0.16472 (6) | 0.67676 (19) | 0.47914 (12) | 0.0349 (4) | |
O2 | 0.10349 (7) | 0.5261 (2) | 0.36969 (13) | 0.0435 (4) | |
C8 | 0.17215 (8) | 0.3862 (2) | 0.49059 (16) | 0.0242 (4) | |
C9 | 0.15142 (8) | 0.2295 (2) | 0.45446 (15) | 0.0244 (4) | |
H9A | 0.1210 | 0.2263 | 0.3998 | 0.029* | |
C10 | 0.14361 (9) | 0.5398 (3) | 0.44045 (16) | 0.0274 (4) | |
C6 | 0.24106 (8) | 0.2430 (3) | 0.61467 (15) | 0.0256 (4) | |
C7 | 0.21666 (8) | 0.3917 (2) | 0.57096 (16) | 0.0270 (5) | |
H7A | 0.2309 | 0.4937 | 0.5969 | 0.032* | |
C2 | 0.24291 (9) | −0.0598 (3) | 0.61506 (17) | 0.0326 (5) | |
H2A | 0.2283 | −0.1611 | 0.5886 | 0.039* | |
C1 | 0.21828 (8) | 0.0899 (2) | 0.57371 (15) | 0.0233 (4) | |
C3 | 0.28822 (9) | −0.0562 (3) | 0.69407 (18) | 0.0394 (6) | |
H3A | 0.3045 | −0.1554 | 0.7204 | 0.047* | |
C4 | 0.31046 (10) | 0.0950 (3) | 0.7359 (2) | 0.0415 (6) | |
H4A | 0.3410 | 0.0951 | 0.7903 | 0.050* | |
C5 | 0.28758 (8) | 0.2421 (3) | 0.69749 (17) | 0.0345 (5) | |
H5A | 0.3026 | 0.3420 | 0.7257 | 0.041* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Zn1 | 0.02945 (17) | 0.01509 (15) | 0.02426 (16) | 0.00046 (8) | 0.00844 (11) | 0.00107 (8) |
N2 | 0.0269 (9) | 0.0225 (9) | 0.0220 (9) | −0.0012 (6) | 0.0080 (7) | 0.0001 (6) |
O4 | 0.0402 (9) | 0.0345 (9) | 0.0235 (7) | 0.0045 (7) | 0.0095 (7) | −0.0047 (6) |
O3 | 0.0431 (10) | 0.0376 (9) | 0.0365 (9) | −0.0101 (8) | 0.0094 (8) | −0.0105 (7) |
C19 | 0.0285 (11) | 0.0237 (11) | 0.0262 (10) | −0.0040 (8) | 0.0084 (9) | −0.0016 (8) |
C17 | 0.0337 (12) | 0.0296 (11) | 0.0277 (11) | 0.0002 (9) | 0.0147 (9) | −0.0003 (8) |
C16 | 0.0282 (11) | 0.0231 (10) | 0.0285 (10) | −0.0003 (8) | 0.0087 (9) | −0.0007 (8) |
C18 | 0.0318 (11) | 0.0222 (10) | 0.0223 (10) | 0.0010 (8) | 0.0079 (8) | −0.0006 (8) |
C20 | 0.0392 (12) | 0.0195 (10) | 0.0237 (10) | 0.0059 (9) | 0.0052 (9) | −0.0010 (8) |
C12 | 0.0350 (12) | 0.0253 (11) | 0.0264 (11) | 0.0001 (9) | 0.0078 (9) | −0.0014 (8) |
C14 | 0.0285 (12) | 0.0366 (14) | 0.0487 (15) | −0.0099 (10) | 0.0061 (11) | −0.0057 (10) |
C11 | 0.0268 (10) | 0.0165 (9) | 0.0252 (10) | 0.0012 (7) | 0.0066 (8) | 0.0004 (7) |
C13 | 0.0383 (13) | 0.0297 (12) | 0.0308 (12) | −0.0034 (10) | 0.0008 (10) | −0.0054 (9) |
C15 | 0.0296 (12) | 0.0355 (13) | 0.0436 (13) | −0.0054 (9) | 0.0150 (10) | −0.0026 (10) |
N1 | 0.0254 (9) | 0.0157 (8) | 0.0264 (9) | −0.0003 (6) | 0.0085 (7) | 0.0011 (6) |
O1 | 0.0412 (9) | 0.0132 (7) | 0.0431 (9) | 0.0018 (6) | 0.0102 (8) | 0.0008 (6) |
O2 | 0.0402 (10) | 0.0279 (9) | 0.0456 (10) | 0.0076 (7) | 0.0006 (8) | 0.0077 (7) |
C8 | 0.0283 (11) | 0.0140 (9) | 0.0306 (11) | 0.0028 (7) | 0.0124 (9) | 0.0025 (7) |
C9 | 0.0242 (10) | 0.0187 (10) | 0.0273 (10) | −0.0007 (8) | 0.0074 (8) | 0.0003 (8) |
C10 | 0.0321 (11) | 0.0174 (10) | 0.0327 (11) | 0.0050 (8) | 0.0134 (9) | 0.0039 (8) |
C6 | 0.0255 (10) | 0.0204 (10) | 0.0291 (11) | −0.0001 (8) | 0.0094 (9) | 0.0004 (8) |
C7 | 0.0304 (11) | 0.0170 (10) | 0.0313 (11) | −0.0025 (8) | 0.0102 (9) | −0.0021 (7) |
C2 | 0.0342 (12) | 0.0216 (11) | 0.0381 (12) | 0.0029 (9) | 0.0109 (10) | 0.0038 (9) |
C1 | 0.0234 (10) | 0.0201 (9) | 0.0256 (10) | 0.0020 (7) | 0.0093 (8) | 0.0027 (7) |
C3 | 0.0368 (13) | 0.0324 (13) | 0.0423 (13) | 0.0124 (10) | 0.0093 (11) | 0.0135 (10) |
C4 | 0.0288 (12) | 0.0443 (14) | 0.0386 (14) | 0.0045 (10) | 0.0010 (11) | 0.0052 (11) |
C5 | 0.0299 (11) | 0.0299 (12) | 0.0355 (12) | −0.0029 (9) | 0.0052 (10) | −0.0024 (9) |
Zn1—O1 | 1.927 (2) | C13—H13A | 0.9300 |
Zn1—O4i | 1.963 (2) | C15—H15A | 0.9300 |
Zn1—N1ii | 2.097 (2) | N1—C9 | 1.323 (3) |
Zn1—N2 | 2.102 (2) | N1—C1 | 1.385 (3) |
N2—C19 | 1.317 (3) | N1—Zn1iv | 2.0974 (17) |
N2—C11 | 1.386 (3) | O1—C10 | 1.280 (3) |
O4—C20 | 1.277 (3) | O2—C10 | 1.221 (3) |
O4—Zn1iii | 1.9626 (15) | C8—C7 | 1.364 (3) |
O3—C20 | 1.227 (3) | C8—C9 | 1.407 (3) |
C19—C18 | 1.403 (3) | C8—C10 | 1.508 (3) |
C19—H19A | 0.9300 | C9—H9A | 0.9300 |
C17—C18 | 1.365 (3) | C6—C7 | 1.410 (3) |
C17—C16 | 1.410 (3) | C6—C1 | 1.415 (3) |
C17—H17A | 0.9300 | C6—C5 | 1.415 (3) |
C16—C11 | 1.414 (3) | C7—H7A | 0.9300 |
C16—C15 | 1.419 (3) | C2—C3 | 1.366 (3) |
C18—C20 | 1.505 (3) | C2—C1 | 1.409 (3) |
C12—C13 | 1.370 (3) | C2—H2A | 0.9300 |
C12—C11 | 1.408 (3) | C3—C4 | 1.401 (4) |
C12—H12A | 0.9300 | C3—H3A | 0.9300 |
C14—C15 | 1.362 (4) | C4—C5 | 1.365 (3) |
C14—C13 | 1.404 (4) | C4—H4A | 0.9300 |
C14—H14A | 0.9300 | C5—H5A | 0.9300 |
O1—Zn1—O4i | 138.54 (7) | C14—C15—C16 | 120.1 (2) |
O1—Zn1—N1ii | 110.34 (7) | C14—C15—H15A | 119.9 |
O4i—Zn1—N1ii | 100.64 (7) | C16—C15—H15A | 119.9 |
O1—Zn1—N2 | 100.00 (7) | C9—N1—C1 | 118.26 (18) |
O4i—Zn1—N2 | 100.73 (7) | C9—N1—Zn1iv | 113.89 (14) |
N1ii—Zn1—N2 | 100.45 (7) | C1—N1—Zn1iv | 127.47 (14) |
C19—N2—C11 | 118.00 (18) | C10—O1—Zn1 | 117.62 (14) |
C19—N2—Zn1 | 116.85 (14) | C7—C8—C9 | 118.22 (18) |
C11—N2—Zn1 | 124.84 (14) | C7—C8—C10 | 123.04 (18) |
C20—O4—Zn1iii | 105.61 (14) | C9—C8—C10 | 118.7 (2) |
N2—C19—C18 | 124.6 (2) | N1—C9—C8 | 124.18 (19) |
N2—C19—H19A | 117.7 | N1—C9—H9A | 117.9 |
C18—C19—H19A | 117.7 | C8—C9—H9A | 117.9 |
C18—C17—C16 | 119.6 (2) | O2—C10—O1 | 125.8 (2) |
C18—C17—H17A | 120.2 | O2—C10—C8 | 119.73 (19) |
C16—C17—H17A | 120.2 | O1—C10—C8 | 114.51 (19) |
C17—C16—C11 | 118.84 (19) | C7—C6—C1 | 118.64 (18) |
C17—C16—C15 | 122.2 (2) | C7—C6—C5 | 122.1 (2) |
C11—C16—C15 | 119.0 (2) | C1—C6—C5 | 119.22 (19) |
C17—C18—C19 | 118.3 (2) | C8—C7—C6 | 120.00 (18) |
C17—C18—C20 | 122.9 (2) | C8—C7—H7A | 120.0 |
C19—C18—C20 | 118.8 (2) | C6—C7—H7A | 120.0 |
O3—C20—O4 | 123.6 (2) | C3—C2—C1 | 120.0 (2) |
O3—C20—C18 | 120.3 (2) | C3—C2—H2A | 120.0 |
O4—C20—C18 | 116.2 (2) | C1—C2—H2A | 120.0 |
C13—C12—C11 | 119.9 (2) | N1—C1—C2 | 120.02 (19) |
C13—C12—H12A | 120.1 | N1—C1—C6 | 120.68 (18) |
C11—C12—H12A | 120.1 | C2—C1—C6 | 119.30 (19) |
C15—C14—C13 | 120.6 (2) | C2—C3—C4 | 120.9 (2) |
C15—C14—H14A | 119.7 | C2—C3—H3A | 119.5 |
C13—C14—H14A | 119.7 | C4—C3—H3A | 119.5 |
N2—C11—C12 | 119.71 (19) | C5—C4—C3 | 120.5 (2) |
N2—C11—C16 | 120.66 (18) | C5—C4—H4A | 119.8 |
C12—C11—C16 | 119.63 (19) | C3—C4—H4A | 119.8 |
C12—C13—C14 | 120.7 (2) | C4—C5—C6 | 120.1 (2) |
C12—C13—H13A | 119.6 | C4—C5—H5A | 120.0 |
C14—C13—H13A | 119.6 | C6—C5—H5A | 120.0 |
Symmetry codes: (i) x, −y+2, z−1/2; (ii) x, y+1, z; (iii) x, −y+2, z+1/2; (iv) x, y−1, z. |
Experimental details
Crystal data | |
Chemical formula | [Zn(C10H6NO2)2] |
Mr | 409.69 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 293 |
a, b, c (Å) | 28.7995 (17), 8.0475 (5), 15.2845 (9) |
β (°) | 114.262 (1) |
V (Å3) | 3229.5 (3) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 1.55 |
Crystal size (mm) | 0.15 × 0.10 × 0.04 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.801, 0.941 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12965, 3505, 3139 |
Rint | 0.030 |
(sin θ/λ)max (Å−1) | 0.639 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.036, 0.097, 1.07 |
No. of reflections | 3505 |
No. of parameters | 244 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.47, −0.30 |
Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1997).
Zn1—O1 | 1.927 (2) | Zn1—N1ii | 2.097 (2) |
Zn1—O4i | 1.963 (2) | Zn1—N2 | 2.102 (2) |
O1—Zn1—O4i | 138.54 (7) | O1—Zn1—N2 | 100.00 (7) |
O1—Zn1—N1ii | 110.34 (7) | O4i—Zn1—N2 | 100.73 (7) |
O4i—Zn1—N1ii | 100.64 (7) | N1ii—Zn1—N2 | 100.45 (7) |
Symmetry codes: (i) x, −y+2, z−1/2; (ii) x, y+1, z. |
Organic nitriles ligands and their hydroxlyate derivatives (carboxylates) have been widely used for hydrothermal synthesis of coordination polymers (Lin, et al., 1998; Tong, et al., 2003). Notably, these kinds of ligand reactions, relatively straight forward in the context of reaction chemistry, have become an important approach in the crystal engineering of metal-organic frameworks exhibiting novel physical properties. In the title compound, (I), the quin-3 - c group evidently results from the hydrolysis of quinoline-3-carbonitrile. The quin-3 - c ligands used in this work exhibit bridging mode different from other quinoline derivatives (Odoko, et al., 2001; Okabe & Muranishi, 2003). To the best of our knowledge, this is the first isolated quin-3 - c coordination polymer.
There are one ZnII atom and two quin-3 - c ligands in the asymmetric unit. The ZnII atom has a tetrahedral environment formed by two N atoms [Co – N 2.097 (2) - 2.102 (2) Å] and two O atoms [Co – O 1.927 (2) - 1.963 (2) Å] belonging to for different quin-3 - c ligands. The quin-3 - c ion binds to zinc in a bridge mode, through the carboxylate O atom and the quinoline N atom. The carboxylato group is monodentate. Each ZnII atom is connected by four ditopic quin-3 - c ligands, which construct a two-dimensional layer parallel to the (100) plane (Fig. 2) and generate two-dimensional square grids based on the (4, 4) topology. The quinoline rings of quin-3 - c penetrating into the adjacent layers are parallel to each other, and face-to-face separations are about 3.59 (1) Å (the second quinoline rings symmetry code: x, y, 1 - z) indicating π···π interaction.