What is the molecular orbital theory?
Molecular orbital theory or theory of MO is a method of explanation of the bond between atoms in terms of electrons that spread around the molecule rather than located around atoms, unlike the theory of valence binding or VB theories. Electrons in atoms are arranged on orbitals inside Subshells inside shells. In general, they are electrons on orbitals within the farthest shell, which are involved in chemical binding, although there are exceptions. Orbital may contain a maximum of two electrons that must have the opposite rotation. In the theory of molecular orbital theory, when two atoms form a chemical bond, atomic orbitals of binding electrons combine and form molecular orbitals with similar rules on the number and rotation of electrons. Instead of occupying a certain point in space at a given time, electroron extends at all of its possible places around the atomic core and its transplant can only be expressed in terms of probability. To determine the "wave function" ATOThe moon orbital can be used by an equation developed by physicist Erwin Schrodinger, which gives the probability of finding electron at various places around the core in terms of electron density distribution. Molecular orbital theory explains atomic links by adding wave functions of atomic orbitals involved in binding to provide wave functions for molecular orbitals surrounding the entire molecule.
Since the equation of the wave function gives positive and negative values known as the phase, two molecular orbitals are formed. In the first, atomic orbitals are added in phase-positive to positive and negative to negative. The second type is a type where they are outside phase-negative to positive and positive to negative.
In addition,in -fase gives molecular -perbital with electrons density concentrated in the space between the cores, which closer to each other and results in configuration at a lower energy than two original atomicé orbitals. This is known as the gluing of the orbital. Adding off the phase leads to the electron density from the space between the cores, expanding them further apart and creating a configuration with a higher energy level than atomic orbitals. This is known as an anti-binding of the orbital. Electrons from atomic orbitals involved in the binding will prefer to fill in molecular orbitals with lower energy.
To determine the nature of the binding between two atoms, the "order order" is calculated as: (electrons-anti-rafted electrons)/2. The order of bonds zero suggests that there will be no connection. For comparison, the order of binding 1 indicates one binding, with 2 and 3 indicating double and triple bonds.
as a very simple example, the combination of two hydrogen atoms can be described in terms of molecular orbital theory. Each atom has only one electron, usually in the lowest energy orbital. The wave functions of these orbitals are added, giving gluing and anti-rarely orbital. Two electrons fill nMore energy gluing of the orbital, without electrons in an anti-bond orbital. The order of bonds is therefore (2 - 0)/2 = 1, which gives a single link. This is consistent with VB theory and observation.
Interacts two atoms of another element in the periodic table, helium, gives a different result, because in each helium atom there are two electrons in the orbital. When wool functions are added, the binding and anti-public orbit are produced, as in hydrogen. This time, however, four electrons are connected. Two electrons will fill the orbital gluing and two other two will have to fill orbital against binding higher energy. The order of bonds this time is (2 - 2)/2 = 0, so no WSE connection takes. Again, it agrees with the VB theory and observation: Helium does not form molecules.
Molecular orbital theory also correctly predicts double and triple bonds for oxygen and nitrogen molecules. In most cases, the theory of MO and valence link is in accordance; The first, howevermagnetic properties of molecules. The main disadvantage of molecular orbital theory is that, with the exception of very simple cases, such as the above, calculations are much more complicated.