Group Contributions to ΔH
f0(g) and S0(g) at 298 K*
| Group | ΔHf° (kJ/mol) | S° (J/mol K) |
|---|---|---|
| CO-(CO)(C) | -122.1 | |
| CO-(O)(Cd) | -140.0 | |
| CO-(O)(CB) | -192.3 | |
| CO-(O)(C) | -139.6 | 61.8 |
| [CO-(O)(H)] | -123.3 | 146.0 |
| CO-(CB)2 | -163.4 | |
| CO-(CB)(C) | -157.2 | |
| [CO-(CB)(H)] | -132.5 | |
| CO-(C)2 | -131.7 | 62.7 |
| CO-(C)(H) | -123.7 | 146.0 |
| CO-(H)2 | -115.8 | 224.3 |
| O-(CO)2 | -212.8 | |
| O-(CO)(O) | -79.4 | |
| [O-(CO)(Cd)] | -172.6 | |
| O(CO)(C) | -172.6 | 35.1 |
| O-(CO)(H) | -252.0 | 102.5 |
| Group | ΔHf° (kJ/mol) | S° (J/mol K) |
|---|---|---|
| O-(O)(O) | 79.4 | 39.3 |
| O-(O)(C) | -18.8 | 39.3 |
| O-(O)(H) | -68.0 | 116.4 |
| O-(Cd)2 | -137.1 | |
| O-(Cd)(C) | -130.8 | |
| O-(CB)2 | -80.7 | |
| O-(CB)(C) | -94.5 | |
| [O-(CB)(H)] | -158.4 | 121.6 |
| [C-(O)(H)3] | -42.1 | 127.1 |
| O-(C)2 | -99.1 | 36.3 |
| O-(C)(H) | -158.3 | 121.5 |
| Cd(CO)(O) | 26.3 | |
| CO-(Cd)(H) | -132.5 | |
| Cd-(CO)(C) | 39.3 | |
| [Cd-(CO)(H)] | 32.2 | |
| [Cd-(O)(Cd)] | 37.2 |
| Group | ΔHf° (kJ/mol) | S° (J/mol K) |
|---|---|---|
| [Cd-(O)(C)] | 43.0 | |
| [Cd-(O)(H)] | 36.0 | |
| CB-(CO) | 40.5 | |
| CB-(O) | -7.5 | -42.6 |
| C-(CO)2(H)2 | -30.1 | |
| C-(CO)(C)3 | 6.6 | |
| C-(CO)(C)2(H) | -7.6 | -50.2 |
| C-(CO)(C)(H)2 | -20.9 | 40.1 |
| [C-(CO)(H)3] | -42.1 | 127.1 |
| C-(O)2(C)2 | -70.2 | |
| C-(O)2(C)(H) | -71.9 | |
| C-(O)2(H)2 | -74.0 | |
| C-(O)(CB)(H)2 | -27.6 | 40.6 |
| C-(O)(Cd)(H)2 | -28.8 | |
| C-(O)(C)3 | -27.6 | -140.3 |
| C-(O)(C)2(H) | -29.3 | -46.0 |
| C-(O)(C)(H)2 | -35.5 | 43.0 |
*The subscripts "d" and "t" designate carbon atoms in carbon-carbon double and triple bonds; "a", an allenic carbon; "B", an aromatic carbon; "A", a nitrogen atom in a nitrogen-nitrogen double bond; and "I", a nitrogen atom in a nitrogen-carbon double bond. Bracketed values are estimated.
Reference: S.W. Benson, F.R. Cruickshank, D.M. Golden, G.R. Haugen, H.E. O'Neal, A.S. Rodgers, R. Shaw, and R. Walsh, Chem. Rev., 69, 279 (1969).