This page provides supplementary chemical data on aniline.
Material Safety Data Sheet
The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet (MSDS) for this chemical from a reliable source and follow its directions. Mallinckrodt Baker Science Stuff
Structure and properties
Structure and properties Dielectric constant,Lange's Handbook of Chemistry, 10th ed. pp. 1234–1237 εr 6.89 ε0 at 20 °C Surface tensionLange's Handbook of Chemistry, 10th ed. pp. 1661–1663 44.0 dyn/cm at 10 °C42.9 dyn/cm at 20 °C24.4 dyn/cm at 180 °C
Thermodynamic properties
Phase behavior Triple point 267.13 K (–6.02 °C), ? Pa Std entropy changeof fusion, ΔfusSo 39.57 J/(mol·K) at –6.3 °C Solid properties Std enthalpy changeof formation, ΔfHosolid ? kJ/mol Standard molar entropy,Sosolid ? J/(mol K) Heat capacity, cp ? J/(mol K) Liquid properties Gas properties Std enthalpy changeof formation, ΔfHogas 87 kJ/mol Standard molar entropy,Sogas ? J/(mol K) Heat capacity, cp 148.7 J/(mol K) at 25 °C van der Waals' constantsLange's Handbook of Chemistry, 10th ed, pp. 1522–1524 a = 2685 L2 kPa/mol2 b = 0.1369 liter per mole
Vapor pressure of liquid P in mm Hg 1 10 40 100 400 760 1520 3800 7600 15200 30400 45600 T in °C 34.8 69.4 96.7 119.9 161.9 184.4 212.8 254.8 292.7 342.0 400.0 — Table data obtained from CRC Handbook of Chemistry and Physics 44th ed.
Distillation data See also: m-xylene (data page) p-xylene (data page)
Vapor-liquid Equilibriumfor Aniline/WaterP = 745 mm Hg BPTemp.°C % by mole water liquid vapor 98.5 96.5 101 24.7 94.8 105 20.0 94.3 109.8 15.3 92.4 115.8 11.7 89.3 121 9.3 86.2 126 7.6 81.6 131 5.9 75.9 140 4.25 70.8 152 2.50 60.5 160 1.70 48.7 168 1.05 34.1 Vapor-liquid Equilibriumfor Aniline/n-hexaneP = 101.325 kPa BPTemp.°C % by mole hexane liquid vapor 150.2 1.50 62.50 136.4 2.50 76.00 116.0 5.30 88.70 90.0 11.00 96.00 79.5 16.85 97.66 75.7 20.99 98.07 74.1 27.35 98.31 73.25 37.90 98.42 73.20 52.00 98.62 73.15 71.46 98.78 72.15 81.26 98.93 71.50 86.50 99.06 70.70 90.93 99.16 69.80 95.32 99.36 69.10 97.86 99.61
Spectral data
UV-Vis Ionization potential 7.72(62281) eV(cm−1) λmax 230 nm (E2-band)Kaur, H. Spectroscopy. Global Media: Meerut, India, 2009; p. 304 280 nm (B-band) Extinction coefficient, ε 8 600 (E2-band) 1 430 (B-band) IR Major absorption bands (liquid film) Wave number transmittance 3663 cm−1 77% 3429 cm−1 32% 3354 cm−1 20% 3214 cm−1 44% 3088 cm−1 62% 3072 cm−1 55% 3037 cm−1 38% 3010 cm−1 67% 2930 cm−1 81% 2904 cm−1 79% 2640 cm−1 79% 2627 cm−1 81% 1929 cm−1 77% 1839 cm−1 79% 1705 cm−1 77% 1621 cm−1 7% 1601 cm−1 5% 1557 cm−1 70% 1525 cm−1 66% 1496 cm−1 4% 1467 cm−1 34% 1332 cm−1 74% 1312 cm−1 57% 1277 cm−1 25% 1176 cm−1 32% 1154 cm−1 68% 1053 cm−1 77% 1028 cm−1 64% 996 cm−1 60% 881 cm−1 53% 754 cm−1 8% 693 cm−1 10% 620 cm−1 47% 529 cm−1 50% 504 cm−1 18% NMR Proton NMR Carbon-13 NMR Other NMR data MS Masses of main fragments
UV Absorbance Spectroscopy of Aniline Aniline is a benzenoid compound. The NH2 group attached to the benzene ring means that there is a lone pair of electrons that can enter into conjugation with the benzene ring resulting in delocalization in the aniline.
Aniline absorbs in the K (220 - 250 nm) and the B (250 - 290 nm) bands exhibited by benzenoid compounds. The K and B bands arise from π to π* transitions as a result of the a group containing multiple bond being attached to the benzene ring. When dissolved in ethanol, λmax for aniline is 230 nm, but in dilute aqueous acid λmax is 203 nm. In the latter case the anilinium cation is formed and the lone pair is no longer available for conjugation with the benzene ring. Consequently, the absorption of the molecule shifts to the lower λmax value and behaves like benzene.
Regulatory data Regulatory data Flash point 70 °C RTECS ? Autoignition temperature 615 °C
References
Finar, I.L. (1974); Organic Chemistry Vol.2 – Stereochemistry and the chemistry of natural products 5th. Ed. Longman