41. In addition, the lone pairs of electrons on the O are in the direction opposite to the hydrogen atoms. 42. For example, bases donating a lone pair from an oxygen atom are harder than bases donating through a nitrogen atom. 43. This is potentially due to a lead lone pair of electrons, also found in lead complexes with an imidazole ligand. 44. They can form a chemical bond between two atoms, or they can occur as a lone pair of valence electrons. 45. Significant delocalisation of the lone pair of electrons on the nitrogen atom gives the group a cis or trans isomers. 46. However, the presence of two lone pairs of electrons on the oxygen atoms makes hydrogen bonding with water molecules possible. 47. In the + 3 oxidation state, arsenic is typically pyramidal owing to the influence of the lone pair of electrons. 48. In molecular systems the lone pair can also result in a distortion in the coordination of ligands around the metal ion. 49. If this dimer existed as a dicarbene, the electron lone pairs on the carbenic carbon would be forced into close proximity. 50. The deprotonation of the carboxyl group causes the lone pair of electrons to move down making carbon dioxide and separating from oxalosuccinate.
