âSorry for the paucity of posts over the past few days but I'm in a state of upheaval known as âjob changeâ.â âThere is no scheme in all these projects to solve the paucity of clean, safe drinking water.â âThe paucity of these qualities in the present Republic would stagger them.â
Benzene is the archetypical aromatic compound. It is planar, bond angles=120Âº, all carbon atoms in the ring are sp2 hybridized, and the pi-orbitals are occupied by 6 electrons. The aromatic heterocycle pyridine is similar to benzene, and is often used as a weak base for scavenging protons.
In benzene all bonds have the same length: 139 pm. Carbonâcarbon single bonds increased s-character is also notable in the central bond of diacetylene (137 pm) and that of a certain tetrahedrane dimer (144 pm). In propionitrile the cyano group withdraws electrons, also resulting in a reduced bond length (144 pm).