TABLE 1.
Table of example relative bond strengths, highlighting the intermediate nature of metal ligand dative covalent bonds.
| Bond type | Bond | Approx. bond energy/kJ mol−1 |
|---|---|---|
| Hydrogen | OH-:O (in water) | 23 a |
| Metal ligand (dative) | Zn-O | 180 b |
| Metal ligand (dative) | Cu-N | 90 b |
| Covalent | C-C | 376 c |
| Covalent | C-H | 438 c |
The hydrogen bond energy was obtained from the application of statistical mechanical principles and the known dielectric constant of water and matches closely with experimental data (Suresh and Naik, 2000).
The metal-ligand values are derived from work performed analysing the Cambridge Structural Database. Several different crystal structures were investigated to obtain estimates for metal ligand bond strengths (Anders et al., 2013).
The organic covalent bond strengths were derived experimentally by three different experimental techniques (radical kinetics, photoionization mass spectrometry, acidity/electron affinity cycle) (Blanksby and Ellison, 2003).