C.I. Pigment Red 266, or 4-{[4-(aminocarbonyl)phenyl]hydrazono}-N-(2-methoxyphenyl)-3-oxo-3,4-dihydronaphthalene-2-carboxamide, C25H20N4O4, adopts the keto-hydrazone tautomeric form with significant intramolecular hydrogen bonding. The molecules pack to form layers involving an extensive network of intermolecular hydrogen bonds, in which the primary amide group plays a prominent role. The good technical performance of this pigment in application may be attributed principally to the pattern of intra- and intermolecular hydrogen bonding.
Supporting information
CCDC reference: 224651
C·I. Pigment Red 266 was synthesized by diazotization of 4-aminobenzamide, using sodium nitrite in dilute hydrochloric acid, and reaction of the resulting diazonium salt with 3-hydroxy-N-(2-methoxyphenyl)-2-naphthalenecarboxamide (Naphthol AS—OL), using a simultaneous aqueous azo coupling procedure at pH 5–6 (Hoechst, 1974). Crystals suitable for X-ray analysis were obtained by slow cooling of a solution of the pigment in nitrobenzene, contained in a sealed tube, from 463 K.
Amide and amine H atoms were located from a difference Fourier map and their positions were refined freely. Other H-atom positions were calculated and were constrained to idealized positions with C—H distances of 0.98 (phenyl), 0.97 (methylene) and 0.96 Å (methyl). The Uiso parameters of the amino, phenyl, methylene and methyl H atoms were defined as 1.2, 1.2, 1.2 and 1.5 times Ueq of the parent atom, respectively.
Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1999); software used to prepare material for publication: SHELXTL.
4-{[4-(aminocarbonyl)phenyl]hydrazono}-
N-(2-methoxyphenyl)-3-oxo- 3,4-dihydronaphthalene-2-carboxamide
top
Crystal data top
C25H20N4O4 | F(000) = 920 |
Mr = 440.45 | Dx = 1.450 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 56 reflections |
a = 7.254 (1) Å | θ = 6.7–30.7° |
b = 24.115 (3) Å | µ = 0.10 mm−1 |
c = 11.565 (2) Å | T = 160 K |
β = 94.22 (1)° | Triangular plate, red |
V = 2017.6 (5) Å3 | 0.54 × 0.42 × 0.20 mm |
Z = 4 | |
Data collection top
Bruker P4 diffractometer | Rint = 0.026 |
Radiation source: fine-focus sealed tube | θmax = 25.0°, θmin = 2.0° |
Graphite monochromator | h = −1→8 |
ω scans | k = −1→28 |
4668 measured reflections | l = −13→13 |
3549 independent reflections | 3 standard reflections every 97 reflections |
2761 reflections with I > 2σ(I) | intensity decay: none |
Refinement top
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)] = 0.042 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.110 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | w = 1/[σ2(Fo2) + (0.0591P)2 + 0.3084P] where P = (Fo2 + 2Fc2)/3 |
3549 reflections | (Δ/σ)max < 0.001 |
311 parameters | Δρmax = 0.20 e Å−3 |
0 restraints | Δρmin = −0.26 e Å−3 |
Crystal data top
C25H20N4O4 | V = 2017.6 (5) Å3 |
Mr = 440.45 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.254 (1) Å | µ = 0.10 mm−1 |
b = 24.115 (3) Å | T = 160 K |
c = 11.565 (2) Å | 0.54 × 0.42 × 0.20 mm |
β = 94.22 (1)° | |
Data collection top
Bruker P4 diffractometer | Rint = 0.026 |
4668 measured reflections | 3 standard reflections every 97 reflections |
3549 independent reflections | intensity decay: none |
2761 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.042 | 0 restraints |
wR(F2) = 0.110 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | Δρmax = 0.20 e Å−3 |
3549 reflections | Δρmin = −0.26 e Å−3 |
311 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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
N1 | 0.7260 (2) | 0.21014 (5) | 0.81610 (12) | 0.0239 (3) | |
H1 | 0.826 (3) | 0.1985 (8) | 0.7912 (16) | 0.029* | |
N2 | 0.70924 (19) | 0.26380 (5) | 0.81015 (11) | 0.0242 (3) | |
C10 | 0.5895 (2) | 0.17576 (7) | 0.85697 (14) | 0.0228 (4) | |
C11 | 0.6343 (2) | 0.11985 (7) | 0.86939 (14) | 0.0256 (4) | |
H11 | 0.7535 | 0.1071 | 0.8528 | 0.031* | |
C12 | 0.5056 (2) | 0.08300 (6) | 0.90571 (15) | 0.0262 (4) | |
H12 | 0.5369 | 0.0449 | 0.9152 | 0.031* | |
C13 | 0.3295 (2) | 0.10119 (7) | 0.92866 (14) | 0.0234 (4) | |
C14 | 0.2873 (2) | 0.15742 (7) | 0.91831 (14) | 0.0257 (4) | |
H14 | 0.1686 | 0.1702 | 0.9358 | 0.031* | |
C15 | 0.4167 (2) | 0.19500 (7) | 0.88274 (15) | 0.0258 (4) | |
H15 | 0.3874 | 0.2333 | 0.8761 | 0.031* | |
C16 | 0.1912 (2) | 0.05846 (6) | 0.95898 (14) | 0.0249 (4) | |
O17 | 0.21751 (17) | 0.00909 (5) | 0.93557 (12) | 0.0358 (3) | |
N18 | 0.0402 (2) | 0.07550 (6) | 1.00793 (14) | 0.0297 (4) | |
H18A | −0.042 (3) | 0.0479 (8) | 1.0285 (16) | 0.036* | |
H18B | 0.026 (3) | 0.1111 (8) | 1.0283 (16) | 0.036* | |
C20 | 0.8457 (2) | 0.29263 (7) | 0.76501 (14) | 0.0233 (4) | |
C21 | 1.0063 (2) | 0.26650 (7) | 0.71928 (14) | 0.0236 (4) | |
O21 | 1.02365 (16) | 0.21421 (5) | 0.72299 (11) | 0.0305 (3) | |
C22 | 1.1446 (2) | 0.30173 (7) | 0.67047 (14) | 0.0245 (4) | |
C23 | 1.1245 (2) | 0.35767 (7) | 0.67620 (14) | 0.0250 (4) | |
H23 | 1.2189 | 0.3802 | 0.6481 | 0.030* | |
C24 | 0.9696 (2) | 0.38480 (7) | 0.72198 (14) | 0.0252 (4) | |
C25 | 0.9566 (3) | 0.44295 (7) | 0.72281 (15) | 0.0315 (4) | |
H25 | 1.0538 | 0.4647 | 0.6957 | 0.038* | |
C26 | 0.8045 (3) | 0.46865 (7) | 0.76242 (16) | 0.0346 (4) | |
H26 | 0.7971 | 0.5080 | 0.7634 | 0.042* | |
C27 | 0.6608 (3) | 0.43667 (7) | 0.80128 (16) | 0.0342 (4) | |
H27 | 0.5546 | 0.4545 | 0.8271 | 0.041* | |
C28 | 0.6707 (2) | 0.37968 (7) | 0.80278 (15) | 0.0296 (4) | |
H28 | 0.5722 | 0.3586 | 0.8303 | 0.035* | |
C29 | 0.8258 (2) | 0.35248 (7) | 0.76388 (14) | 0.0247 (4) | |
O30 | 1.42644 (16) | 0.31045 (5) | 0.57583 (11) | 0.0315 (3) | |
C31 | 1.3109 (2) | 0.27915 (7) | 0.61400 (14) | 0.0242 (4) | |
N32 | 1.3190 (2) | 0.22321 (6) | 0.60724 (12) | 0.0269 (3) | |
H32 | 1.228 (3) | 0.2058 (8) | 0.6389 (16) | 0.032* | |
C33 | 1.4588 (2) | 0.18879 (7) | 0.56802 (14) | 0.0265 (4) | |
C34 | 1.6272 (2) | 0.20672 (8) | 0.53259 (15) | 0.0305 (4) | |
H34 | 1.6537 | 0.2453 | 0.5299 | 0.037* | |
C35 | 1.7574 (3) | 0.16828 (8) | 0.50092 (16) | 0.0374 (5) | |
H35 | 1.8735 | 0.1807 | 0.4779 | 0.045* | |
C36 | 1.7193 (3) | 0.11237 (8) | 0.50274 (17) | 0.0416 (5) | |
H36 | 1.8086 | 0.0864 | 0.4803 | 0.050* | |
C37 | 1.5502 (3) | 0.09372 (8) | 0.53736 (16) | 0.0373 (5) | |
H37 | 1.5240 | 0.0551 | 0.5385 | 0.045* | |
C38 | 1.4208 (2) | 0.13150 (7) | 0.57008 (15) | 0.0304 (4) | |
O39 | 1.25075 (18) | 0.11823 (5) | 0.60622 (11) | 0.0383 (3) | |
C40 | 1.2120 (3) | 0.06142 (7) | 0.62649 (19) | 0.0444 (5) | |
H40A | 1.2100 | 0.0410 | 0.5532 | 0.067* | |
H40B | 1.0914 | 0.0582 | 0.6589 | 0.067* | |
H40C | 1.3080 | 0.0460 | 0.6813 | 0.067* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0201 (7) | 0.0196 (7) | 0.0333 (8) | −0.0004 (6) | 0.0111 (6) | 0.0035 (6) |
N2 | 0.0244 (7) | 0.0211 (7) | 0.0275 (7) | −0.0015 (6) | 0.0050 (6) | 0.0013 (5) |
C10 | 0.0207 (8) | 0.0236 (8) | 0.0246 (8) | −0.0022 (7) | 0.0051 (7) | 0.0018 (6) |
C11 | 0.0182 (8) | 0.0234 (8) | 0.0361 (9) | 0.0019 (7) | 0.0089 (7) | −0.0001 (7) |
C12 | 0.0248 (9) | 0.0171 (8) | 0.0378 (10) | 0.0017 (7) | 0.0100 (8) | 0.0008 (7) |
C13 | 0.0228 (8) | 0.0211 (8) | 0.0271 (8) | −0.0016 (7) | 0.0067 (7) | 0.0013 (6) |
C14 | 0.0193 (8) | 0.0237 (8) | 0.0354 (9) | 0.0025 (7) | 0.0111 (7) | 0.0017 (7) |
C15 | 0.0247 (9) | 0.0193 (8) | 0.0344 (9) | 0.0025 (7) | 0.0090 (7) | 0.0040 (7) |
C16 | 0.0224 (9) | 0.0181 (8) | 0.0350 (9) | −0.0002 (7) | 0.0081 (7) | 0.0018 (7) |
O17 | 0.0286 (7) | 0.0190 (6) | 0.0628 (9) | −0.0016 (5) | 0.0228 (6) | −0.0010 (6) |
N18 | 0.0241 (8) | 0.0179 (7) | 0.0490 (9) | −0.0022 (6) | 0.0159 (7) | 0.0006 (7) |
C20 | 0.0209 (8) | 0.0236 (8) | 0.0259 (8) | −0.0029 (7) | 0.0042 (7) | 0.0016 (7) |
C21 | 0.0210 (8) | 0.0227 (8) | 0.0272 (8) | −0.0015 (7) | 0.0027 (7) | 0.0022 (6) |
O21 | 0.0242 (6) | 0.0198 (6) | 0.0493 (8) | 0.0003 (5) | 0.0143 (5) | 0.0043 (5) |
C22 | 0.0230 (9) | 0.0236 (8) | 0.0275 (9) | −0.0020 (7) | 0.0052 (7) | 0.0016 (6) |
C23 | 0.0224 (8) | 0.0257 (9) | 0.0278 (9) | −0.0061 (7) | 0.0073 (7) | 0.0031 (7) |
C24 | 0.0272 (9) | 0.0225 (8) | 0.0267 (8) | −0.0031 (7) | 0.0068 (7) | 0.0005 (7) |
C25 | 0.0332 (10) | 0.0238 (9) | 0.0387 (10) | −0.0066 (8) | 0.0115 (8) | 0.0001 (7) |
C26 | 0.0418 (11) | 0.0204 (9) | 0.0432 (11) | −0.0006 (8) | 0.0141 (9) | 0.0010 (7) |
C27 | 0.0358 (10) | 0.0264 (9) | 0.0424 (11) | 0.0040 (8) | 0.0155 (9) | −0.0001 (8) |
C28 | 0.0277 (9) | 0.0276 (9) | 0.0348 (9) | −0.0031 (7) | 0.0125 (8) | 0.0027 (7) |
C29 | 0.0256 (9) | 0.0236 (8) | 0.0254 (8) | −0.0019 (7) | 0.0058 (7) | 0.0012 (6) |
O30 | 0.0253 (7) | 0.0248 (6) | 0.0463 (8) | −0.0032 (5) | 0.0150 (6) | 0.0037 (5) |
C31 | 0.0205 (8) | 0.0256 (9) | 0.0270 (8) | −0.0020 (7) | 0.0041 (7) | 0.0028 (7) |
N32 | 0.0237 (8) | 0.0237 (8) | 0.0346 (8) | −0.0009 (6) | 0.0122 (6) | 0.0028 (6) |
C33 | 0.0255 (9) | 0.0294 (9) | 0.0252 (9) | 0.0033 (7) | 0.0056 (7) | 0.0007 (7) |
C34 | 0.0287 (9) | 0.0310 (9) | 0.0328 (9) | 0.0012 (8) | 0.0087 (8) | −0.0001 (7) |
C35 | 0.0296 (10) | 0.0445 (12) | 0.0394 (10) | 0.0050 (9) | 0.0116 (8) | −0.0021 (9) |
C36 | 0.0390 (11) | 0.0425 (11) | 0.0443 (11) | 0.0132 (9) | 0.0107 (9) | −0.0053 (9) |
C37 | 0.0446 (12) | 0.0267 (9) | 0.0413 (11) | 0.0062 (8) | 0.0083 (9) | −0.0022 (8) |
C38 | 0.0315 (10) | 0.0289 (9) | 0.0315 (9) | 0.0002 (8) | 0.0073 (8) | 0.0012 (7) |
O39 | 0.0388 (8) | 0.0232 (6) | 0.0551 (8) | −0.0031 (6) | 0.0179 (6) | −0.0002 (6) |
C40 | 0.0532 (13) | 0.0257 (10) | 0.0554 (13) | −0.0072 (9) | 0.0114 (11) | 0.0032 (9) |
Geometric parameters (Å, º) top
N1—N2 | 1.3012 (19) | C24—C29 | 1.416 (2) |
N1—C10 | 1.400 (2) | C25—C26 | 1.373 (3) |
N1—H1 | 0.85 (2) | C25—H25 | 0.9500 |
N2—C20 | 1.346 (2) | C26—C27 | 1.397 (3) |
C10—C15 | 1.390 (2) | C26—H26 | 0.9500 |
C10—C11 | 1.392 (2) | C27—C28 | 1.376 (2) |
C11—C12 | 1.377 (2) | C27—H27 | 0.9500 |
C11—H11 | 0.9500 | C28—C29 | 1.404 (2) |
C12—C13 | 1.394 (2) | C28—H28 | 0.9500 |
C12—H12 | 0.9500 | O30—C31 | 1.2332 (19) |
C13—C14 | 1.393 (2) | C31—N32 | 1.353 (2) |
C13—C16 | 1.497 (2) | N32—C33 | 1.411 (2) |
C14—C15 | 1.389 (2) | N32—H32 | 0.89 (2) |
C14—H14 | 0.9500 | C33—C34 | 1.385 (2) |
C15—H15 | 0.9500 | C33—C38 | 1.409 (2) |
C16—O17 | 1.2388 (19) | C34—C35 | 1.392 (3) |
C16—N18 | 1.334 (2) | C34—H34 | 0.9500 |
N18—H18A | 0.94 (2) | C35—C36 | 1.377 (3) |
N18—H18B | 0.90 (2) | C35—H35 | 0.9500 |
C20—C29 | 1.450 (2) | C36—C37 | 1.392 (3) |
C20—C21 | 1.458 (2) | C36—H36 | 0.9500 |
C21—O21 | 1.268 (2) | C37—C38 | 1.381 (3) |
C21—C22 | 1.460 (2) | C37—H37 | 0.9500 |
C22—C23 | 1.359 (2) | C38—O39 | 1.369 (2) |
C22—C31 | 1.515 (2) | O39—C40 | 1.421 (2) |
C23—C24 | 1.434 (2) | C40—H40A | 0.9800 |
C23—H23 | 0.9500 | C40—H40B | 0.9800 |
C24—C25 | 1.406 (2) | C40—H40C | 0.9800 |
| | | |
N2—N1—C10 | 122.76 (14) | C24—C25—H25 | 119.7 |
N2—N1—H1 | 112.9 (13) | C25—C26—C27 | 119.65 (16) |
C10—N1—H1 | 124.3 (13) | C25—C26—H26 | 120.2 |
N1—N2—C20 | 117.75 (14) | C27—C26—H26 | 120.2 |
C15—C10—C11 | 120.57 (15) | C28—C27—C26 | 121.05 (17) |
C15—C10—N1 | 123.12 (15) | C28—C27—H27 | 119.5 |
C11—C10—N1 | 116.30 (15) | C26—C27—H27 | 119.5 |
C12—C11—C10 | 119.89 (15) | C27—C28—C29 | 120.30 (16) |
C12—C11—H11 | 120.1 | C27—C28—H28 | 119.8 |
C10—C11—H11 | 120.1 | C29—C28—H28 | 119.8 |
C11—C12—C13 | 120.43 (15) | C28—C29—C24 | 118.71 (15) |
C11—C12—H12 | 119.8 | C28—C29—C20 | 122.91 (15) |
C13—C12—H12 | 119.8 | C24—C29—C20 | 118.38 (15) |
C14—C13—C12 | 119.22 (15) | O30—C31—N32 | 123.78 (15) |
C14—C13—C16 | 122.91 (15) | O30—C31—C22 | 121.20 (14) |
C12—C13—C16 | 117.83 (14) | N32—C31—C22 | 115.01 (14) |
C15—C14—C13 | 120.78 (15) | C31—N32—C33 | 129.84 (15) |
C15—C14—H14 | 119.6 | C31—N32—H32 | 114.3 (12) |
C13—C14—H14 | 119.6 | C33—N32—H32 | 115.6 (12) |
C14—C15—C10 | 119.07 (15) | C34—C33—C38 | 119.27 (16) |
C14—C15—H15 | 120.5 | C34—C33—N32 | 125.55 (16) |
C10—C15—H15 | 120.5 | C38—C33—N32 | 115.15 (15) |
O17—C16—N18 | 122.20 (15) | C33—C34—C35 | 120.01 (17) |
O17—C16—C13 | 119.58 (15) | C33—C34—H34 | 120.0 |
N18—C16—C13 | 118.19 (14) | C35—C34—H34 | 120.0 |
C16—N18—H18A | 116.5 (12) | C36—C35—C34 | 120.48 (19) |
C16—N18—H18B | 121.4 (13) | C36—C35—H35 | 119.8 |
H18A—N18—H18B | 121.6 (17) | C34—C35—H35 | 119.8 |
N2—C20—C29 | 116.23 (14) | C35—C36—C37 | 120.19 (18) |
N2—C20—C21 | 123.19 (15) | C35—C36—H36 | 119.9 |
C29—C20—C21 | 120.58 (14) | C37—C36—H36 | 119.9 |
O21—C21—C20 | 119.87 (14) | C38—C37—C36 | 119.78 (18) |
O21—C21—C22 | 121.50 (15) | C38—C37—H37 | 120.1 |
C20—C21—C22 | 118.62 (14) | C36—C37—H37 | 120.1 |
C23—C22—C21 | 118.66 (15) | O39—C38—C37 | 125.13 (16) |
C23—C22—C31 | 118.01 (14) | O39—C38—C33 | 114.60 (15) |
C21—C22—C31 | 123.33 (14) | C37—C38—C33 | 120.27 (17) |
C22—C23—C24 | 124.09 (15) | C38—O39—C40 | 117.98 (15) |
C22—C23—H23 | 118.0 | O39—C40—H40A | 109.5 |
C24—C23—H23 | 118.0 | O39—C40—H40B | 109.5 |
C25—C24—C29 | 119.66 (16) | H40A—C40—H40B | 109.5 |
C25—C24—C23 | 120.83 (15) | O39—C40—H40C | 109.5 |
C29—C24—C23 | 119.48 (15) | H40A—C40—H40C | 109.5 |
C26—C25—C24 | 120.60 (16) | H40B—C40—H40C | 109.5 |
C26—C25—H25 | 119.7 | | |
| | | |
C10—N1—N2—C20 | −177.33 (14) | C25—C26—C27—C28 | 1.4 (3) |
N2—N1—C10—C15 | 7.2 (2) | C26—C27—C28—C29 | −0.7 (3) |
N2—N1—C10—C11 | −173.73 (15) | C27—C28—C29—C24 | −0.8 (3) |
C15—C10—C11—C12 | 1.1 (3) | C27—C28—C29—C20 | 178.99 (16) |
N1—C10—C11—C12 | −178.00 (15) | C25—C24—C29—C28 | 1.5 (2) |
C10—C11—C12—C13 | 0.9 (3) | C23—C24—C29—C28 | −176.72 (15) |
C11—C12—C13—C14 | −2.2 (3) | C25—C24—C29—C20 | −178.26 (15) |
C11—C12—C13—C16 | 175.38 (15) | C23—C24—C29—C20 | 3.5 (2) |
C12—C13—C14—C15 | 1.6 (3) | N2—C20—C29—C28 | −2.5 (2) |
C16—C13—C14—C15 | −175.83 (15) | C21—C20—C29—C28 | 177.54 (15) |
C13—C14—C15—C10 | 0.3 (3) | N2—C20—C29—C24 | 177.26 (14) |
C11—C10—C15—C14 | −1.6 (2) | C21—C20—C29—C24 | −2.7 (2) |
N1—C10—C15—C14 | 177.37 (15) | C23—C22—C31—O30 | 1.1 (2) |
C14—C13—C16—O17 | 159.68 (16) | C21—C22—C31—O30 | −178.60 (15) |
C12—C13—C16—O17 | −17.8 (2) | C23—C22—C31—N32 | −177.64 (15) |
C14—C13—C16—N18 | −18.5 (2) | C21—C22—C31—N32 | 2.7 (2) |
C12—C13—C16—N18 | 163.99 (16) | O30—C31—N32—C33 | 6.2 (3) |
N1—N2—C20—C29 | −177.69 (14) | C22—C31—N32—C33 | −175.08 (15) |
N1—N2—C20—C21 | 2.2 (2) | C31—N32—C33—C34 | 3.6 (3) |
N2—C20—C21—O21 | −1.4 (2) | C31—N32—C33—C38 | −178.57 (16) |
C29—C20—C21—O21 | 178.57 (15) | C38—C33—C34—C35 | −0.8 (3) |
N2—C20—C21—C22 | 178.96 (15) | N32—C33—C34—C35 | 176.93 (16) |
C29—C20—C21—C22 | −1.1 (2) | C33—C34—C35—C36 | 1.0 (3) |
O21—C21—C22—C23 | −175.55 (15) | C34—C35—C36—C37 | −0.6 (3) |
C20—C21—C22—C23 | 4.1 (2) | C35—C36—C37—C38 | −0.1 (3) |
O21—C21—C22—C31 | 4.1 (2) | C36—C37—C38—O39 | −179.64 (17) |
C20—C21—C22—C31 | −176.20 (14) | C36—C37—C38—C33 | 0.3 (3) |
C21—C22—C23—C24 | −3.5 (2) | C34—C33—C38—O39 | −179.91 (15) |
C31—C22—C23—C24 | 176.84 (15) | N32—C33—C38—O39 | 2.1 (2) |
C22—C23—C24—C25 | −178.65 (17) | C34—C33—C38—C37 | 0.1 (3) |
C22—C23—C24—C29 | −0.4 (2) | N32—C33—C38—C37 | −177.81 (16) |
C29—C24—C25—C26 | −0.9 (3) | C37—C38—O39—C40 | 8.7 (3) |
C23—C24—C25—C26 | 177.37 (17) | C33—C38—O39—C40 | −171.23 (16) |
C24—C25—C26—C27 | −0.6 (3) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O21 | 0.85 (2) | 1.73 (2) | 2.4845 (18) | 147.4 (18) |
N18—H18A···O17i | 0.94 (2) | 1.94 (2) | 2.8747 (19) | 177.4 (17) |
N18—H18B···O30ii | 0.90 (2) | 2.11 (2) | 2.9929 (19) | 166.7 (18) |
N32—H32···O21 | 0.89 (2) | 1.84 (2) | 2.6178 (18) | 145.2 (17) |
N32—H32···O39 | 0.89 (2) | 2.155 (19) | 2.5796 (18) | 108.8 (15) |
C11—H11···N18iii | 0.95 | 2.75 | 3.419 (2) | 128 |
C12—H12···O17iv | 0.95 | 2.72 | 3.434 (2) | 133 |
C14—H14···O30ii | 0.95 | 2.52 | 3.387 (2) | 152 |
Symmetry codes: (i) −x, −y, −z+2; (ii) x−3/2, −y+1/2, z+1/2; (iii) x+1, y, z; (iv) −x+1, −y, −z+2. |
Experimental details
Crystal data |
Chemical formula | C25H20N4O4 |
Mr | 440.45 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 160 |
a, b, c (Å) | 7.254 (1), 24.115 (3), 11.565 (2) |
β (°) | 94.22 (1) |
V (Å3) | 2017.6 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.54 × 0.42 × 0.20 |
|
Data collection |
Diffractometer | Bruker P4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4668, 3549, 2761 |
Rint | 0.026 |
(sin θ/λ)max (Å−1) | 0.595 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.042, 0.110, 1.01 |
No. of reflections | 3549 |
No. of parameters | 311 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.20, −0.26 |
Selected geometric parameters (Å, º) topN1—N2 | 1.3012 (19) | O30—C31 | 1.2332 (19) |
N1—C10 | 1.400 (2) | C31—N32 | 1.353 (2) |
N2—C20 | 1.346 (2) | N32—C33 | 1.411 (2) |
C16—O17 | 1.2388 (19) | C38—O39 | 1.369 (2) |
C16—N18 | 1.334 (2) | O39—C40 | 1.421 (2) |
C21—O21 | 1.268 (2) | | |
| | | |
N2—N1—C10 | 122.76 (14) | O17—C16—C13 | 119.58 (15) |
N2—N1—H1 | 112.9 (13) | C16—N18—H18A | 116.5 (12) |
C10—N1—H1 | 124.3 (13) | C16—N18—H18B | 121.4 (13) |
N1—N2—C20 | 117.75 (14) | H18A—N18—H18B | 121.6 (17) |
O17—C16—N18 | 122.20 (15) | C38—O39—C40 | 117.98 (15) |
| | | |
C10—N1—N2—C20 | −177.33 (14) | O21—C21—C22—C31 | 4.1 (2) |
N1—N2—C20—C21 | 2.2 (2) | C21—C22—C31—N32 | 2.7 (2) |
N2—C20—C21—O21 | −1.4 (2) | N32—C33—C38—O39 | 2.1 (2) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O21 | 0.85 (2) | 1.73 (2) | 2.4845 (18) | 147.4 (18) |
N18—H18A···O17i | 0.94 (2) | 1.94 (2) | 2.8747 (19) | 177.4 (17) |
N18—H18B···O30ii | 0.90 (2) | 2.11 (2) | 2.9929 (19) | 166.7 (18) |
N32—H32···O21 | 0.89 (2) | 1.84 (2) | 2.6178 (18) | 145.2 (17) |
N32—H32···O39 | 0.89 (2) | 2.155 (19) | 2.5796 (18) | 108.8 (15) |
C11—H11···N18iii | 0.95 | 2.75 | 3.419 (2) | 128 |
C12—H12···O17iv | 0.95 | 2.72 | 3.434 (2) | 133 |
C14—H14···O30ii | 0.95 | 2.52 | 3.387 (2) | 152 |
Symmetry codes: (i) −x, −y, −z+2; (ii) x−3/2, −y+1/2, z+1/2; (iii) x+1, y, z; (iv) −x+1, −y, −z+2. |
Organic pigments are insoluble colouring materials, which are manufactured in a finely-divided crystalline form (Christie, 2002). Their application properties are dependent on chemical structure and molecular packing in the solid state in addition to particle size and shape distribution. Single-crystal X-ray crystallographic information is vital in understanding the technical performance of pigments, including colour and fastness properties, and is an essential first step in the crystal engineering of new products for improved performance.
Naphthol azo red (or Naphthol AS) pigments constitute a group of products of industrial importance for application principally in coatings and printing inks. These products can be conveniently classified into two groups. Group 1 pigments contain a single amide group and generally provide only moderate technical performance. A number of single-crystal X-ray structures of these pigments have been reported previously (Kobelt et al., 1972, 1974; Whitaker, 1977). Group 2 pigments, with additional amide or sulphonamide substituents, provide improved technical performance yet have been less extensively investigated. In the only previous study, the X-ray crystal structure of C·I. Pigment Red 208, which contains a benzimidazolone group, has shown that the molecules are linked by a network of hydrogen bonds (Paulus & Hunger, 1980), a feature that is primarily responsible for the superior technical performance of this pigment.
C·I. Pigment Red 266, (I), is in this latter group and investigation of the crystallographic features, notably hydrogen bonding, that contribute to its superior technical performance, such as lightfastness, solvent resistance and thermal stability, is of industrial interest. Compound (I) possesses both primary and secondary amide groups. The latter is a commonly-encountered structural feature in azo pigments, yet the presence of the primary amide group is unusual in commercial organic pigments.
In common with all azo pigments whose crystal structures have been previously reported (Hunger, 1999), (I) exists in the ketohydrazone tautomeric form shown. Important bond lengths that can be highlighted in this respect are N1—N2, N2—C20 and C21—O21 (Table 1), which are similar to those reported for Group 1 naphthol azo pigments (Kobelt et al., 1972, 1974) with the following ranges in bond lengths: N—N = 1.32 (1)–1.336 (8) Å, C—N = 1.322 (9)–1.33 (1) Å and C—O = 1.255 (9)–1.26 (1) Å.
The shortest of the hydrogen bonds found in (I) are intramolecular hydrogen bonds bifurcated at the acceptor end, a type of bonding that is commonly encountered in commercial azo pigments. Interatomic distances indicate strong hydrogen-bonding interactions between hydrazone atom H1 and keto atom O21, and between atom O21 and secondary amide atom H32 (Table 2). The strong hydrogen bonds involving atom O21 probably contribute to the lengthening of the C═O bond. There is also a weaker interaction between atom H32 and methoxy atom O39. Intramolecular hydrogen bonding of this type is considered vital in determining lightfastness properties by providing electronic protection of the chromophore towards photochemical degradation.
Extensive intermolecular hydrogen bonding is also observed, with the primary amide group playing a prominent role. This functional group forms a dimeric R22(8) hydrogen- bonded arrangement (Etter, 1990; Etter & MacDonald, 1990), with the equivalent group in another molecule related by a centre of inversion (Table 2 and Fig. 2). The hydrogen-bonded network extends beyond the eight-membered ring via an N—H···O interaction involving the primary amide atoms N18/H18B and the secondary amide atom O30i [symmetry code: (i) x − 1.5, 0.5 − y, 0.5 + z]. A longer, C—H···O interaction links atom O17 to atom H25ii [symmetry code: (ii) 1.5 − x, y − 0.5, 1.5 − z] in the naphthol ring system, while another intralayer C—H···O interaction involves the secondary amide atom O30 and atom H14 in a different adjacent molecule (Table 2).
The pigment molecules are associated in layers as a result of the extensive two-dimensional network of intermolecular hydrogen bonds. These sheets are not parallel to any crystallographic axis but are inclined to the c axis at an angle of 22.95 (2)°. Weaker C—H···O and C—H···N contacts between layers can also be identified. The primary amide atoms O17 and N18 have very weak intermolecular interactions with atom H11 of a phenylhydrazone ring and with atom H12 of a phenylazo ring, respectively, of molecules in the next layer (Table 2). The C16—N18···H11iii and C16—O17···H12iv angles at the acceptor atoms are 114 and 115°, respectively [symmmetry codes: (iii) x − 1, y, z; (iv) 1 − x, −y, 2 − z]. Enhanced technical performance, especially solvent resistance, can be attributed primarily to the extensive intermolecular association present in (I), in contrast to the situation for Group 1 products, in which the intermolecular interactions are predominantly van der Waals forces (Whitaker, 1978).
In the solid state, (I) deviates slightly from planarity, with the phenylhydrazone and anilide rings both twisted slightly with respect to the naphthol plane. The r.m.s. deviation from the least-squares molecular plane defined by all the non-H atoms is 0.0970 Å. The angle between the two fused rings of the naphthol system is 2.63 (8)°. The phenylhydrazone (C10–C15) and anilide (C33–C38) rings are angled at 10.91 (7) and 6.67 (6)°, respectively, to the mean plane of the naphthol system (C20–C29). The primary amide group is twisted by 18.57 (14)° with respect to the phenyl ring to which it is attached, possibly in order to accommodate the dimeric hydrogen bonding arrangement with its neighbour.