Aniline (data page)
# Aniline (data page)

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 :

| Index of refraction, $n_D$ | 1.5863 at 20 °C |
| - | - |
| Abbe number | ? |
| Dielectric constant, $ε_r$ | 6.89 $ε_0$ at 20 °C |
| Bond strength | ? |
| Bond length | ? |
| Bond angle | ? |
| Magnetic susceptibility | ? |
| Surface tension | 44.0 dyn/cm at 10 °C 42.9 dyn/cm at 20 °C 24.4 dyn/cm at 180 °C |
| Viscosity | 6.023 mPa·s at 12 °C 4.467 mPa·s at 20 °C 2.92 mPa·s at 22 °C 1.555 mPa·s at 60 °C |

## Thermodynamic properties

Phase behavior :

| Triple point | 267.13 K (–6.02 °C), ? Pa |
| - | - |
| Critical point | 698.8 K (425.7 °C), 4890 kPa |
| Std enthalpy change of fusion, $Δ_{fus}H^o$ | 10.54 kJ/mol |
| Std entropy change of fusion, $Δ_{fus}S^o$ | 39.57 J/(mol·K) at –6.3 °C |
| Std enthalpy change of vaporization, $Δ_{vap}H^o$ | 55.83 kJ/mol at 25 °C 42.44 kJ/mol at 184.1 °C |
| Std entropy change of vaporization, $Δ_{vap}S^o$ | ? J/(mol·K) |
| Solid properties ||
| Std enthalpy change of formation, $Δ_fH^o_{solid}$ | ? kJ/mol |
| Standard molar entropy, $S^o_{solid}$ | ? J/(mol K) |
| Heat capacity, $c_p$ | ? J/(mol K) |
| Liquid properties ||
| Std enthalpy change of formation, $Δ_fH^o_{liquid}$ | 31 kJ/mol |
| Standard molar entropy, $S^o_{liquid}$ | 191. J/(mol K) |
| Enthalpy of combustion, $Δ_cH^o_{liquid}$ | –3393 kJ/mol |
| Heat capacity, $c_p$ | 193.7 J/(mol K) at 25 °C |
| Gas properties ||
| Std enthalpy change of formation, $Δ_fH^o_{gas}$ | 87 kJ/mol |
| Standard molar entropy, $S^o_{gas}$ | ? J/(mol K) |
| Heat capacity, $c_p$ | 148.7 J/(mol K) at 25 °C |
| van der Waals' constants | a = 2685 $L^2$ $kPa/mol^2$ b = 0.1369 liter per mole |

## Vapor pressure of liquid

| P in mm Hg | P in mm Hg | 1 | 10 | 40 | 100 | 400 | 760 | 1520 | 3800 | 7600 | 15200 | 30400 | 45600 |
| - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| T in °C | 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 Equilibrium for Aniline/Water P = 745 mm Hg :

| BP Temp. °C | % by mole water | % by mole water |
| - | - | - |
| BP Temp. °C | 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 Equilibrium for Aniline/n-hexane P = 101.325 kPa :

| BP Temp. °C | % by mole hexane | % by mole hexane |
| - | - | - |
| BP Temp. °C | 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) $eV(cm^{−1})$ |
| - | - |
| $λ_{max}$ | 230 nm $(E_2-band)$ 280 nm (B-band) |
| Extinction coefficient, ε | 8 600 $(E_2-band)$ 1 430 (B-band) |
| IR ||
| Major absorption bands | (liquid film) Wave numbertransmittance 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 $NH_2$ 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, $λ_{max}$ for aniline is 230 nm, but in dilute aqueous acid $λ_{max}$ 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 $λ_{max}$ value and behaves like benzene.

## Regulatory data

Regulatory data :

| Flash point | 70 °C |
| - | - |
| RTECS | ? |
| Autoignition temperature | 615 °C |
