Search results
Results from the WOW.Com Content Network
The bonding electron pair shared in a sigma bond with an adjacent atom lies further from the central atom than a nonbonding (lone) pair of that atom, which is held close to its positively charged nucleus. VSEPR theory therefore views repulsion by the lone pair to be greater than the repulsion by a bonding pair.
Moreover, the multiple bonds of the elements with n=2 are much stronger than usual, because lone pair repulsion weakens their sigma bonding but not their pi bonding. [2] An example is the rapid polymerization that occurs upon condensation of disulfur, the heavy analogue of O 2. Numerous exceptions to the rule exist. [3]
Lone pairs in ammonia (A), water (B), and hydrogen chloride (C) A single lone pair can be found with atoms in the nitrogen group, such as nitrogen in ammonia. Two lone pairs can be found with atoms in the chalcogen group, such as oxygen in water. The halogens can carry three lone pairs, such as in hydrogen chloride.
The oxygen atom’s two lone pairs interact with a hydrogen each, forming two additional hydrogen bonds, and the second hydrogen atom also interacts with a neighbouring oxygen. Intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C) compared to the other group 16 hydrides , which have little capability to ...
In this case, however, the fluorine atoms and the lone pair could be arranged in two different ways with two different resultant molecular structures. The lone pair can either go on the axis of the trigonal bipyramid (i.e. “above” the sulfur) or on the equator of the bipyramid (i.e. “beside” the sulfur).
The +M effect, also known as the positive mesomeric effect, occurs when the substituent is an electron donating group. The group must have one of two things: a lone pair of electrons, or a negative charge. In the +M effect, the pi electrons are transferred from the group towards the conjugate system, increasing the density of the system.
However, when the hydrogen is replaced with a much more bulky phenyl ring the steric repulsion increases dramatically and the ligand "bows" which causes a change in the orientation of the lone pairs of electrons on the nitrogen atoms. These lone pairs are what is responsible for forming bonds with the metal centers so forcing them to move ...
Further, the lone pairs of electrons associated with the central chlorine atom reside in two kidney-shaped lobes which lie in the equatorial plane along with one of the fluorine atoms. This structure, consistent with the LDQ structure of the molecule, is also consistent with the VSEPR structure as the more diffuse chlorine lone pairs distort ...