Search results
Results from the WOW.Com Content Network
Triplet oxygen, 3 O 2, refers to the S = 1 electronic ground state of molecular oxygen (dioxygen). Molecules of triplet oxygen contain two unpaired electrons, making triplet oxygen an unusual example of a stable and commonly encountered diradical : [ 2 ] it is more stable as a triplet than a singlet .
Aerobic organisms use atmospheric dioxygen as the terminal oxidant in cellular respiration in order to obtain chemical energy. The ground state of dioxygen is known as triplet oxygen, 3 [O 2], because it has two unpaired electrons. The first excited state, singlet oxygen, 1 [O 2], has no unpaired electrons and is metastable.
In the ground state of dioxygen, this energy level is occupied by two electrons of the same spin, as shown in the molecular orbital diagram. The molecule, therefore, has two unpaired electrons and is in a triplet state. In contrast, the first and second excited states of dioxygen are both states of singlet oxygen. Each has two electrons of ...
As in diboron, these two unpaired electrons have the same spin in the ground state, which is a paramagnetic diradical triplet oxygen. The first excited state has both HOMO electrons paired in one orbital with opposite spins, and is known as singlet oxygen. MO diagram of dioxygen triplet ground state
An electron configuration with two unpaired electrons, as is found in dioxygen orbitals (see the filled π* orbitals in the diagram) that are of equal energy—i.e., degenerate—is a configuration termed a spin triplet state. Hence, the ground state of the O 2 molecule is referred to as triplet oxygen.
[6] [7] This paper predicted a triplet ground state for the dioxygen molecule which explained its paramagnetism [8] (see Molecular orbital diagram § Dioxygen) before valence bond theory, which came up with its own explanation in 1931. [9] The word orbital was introduced by Mulliken in 1932. [5]
Examples of atoms in singlet, doublet, and triplet states. In quantum mechanics, a triplet state, or spin triplet, is the quantum state of an object such as an electron, atom, or molecule, having a quantum spin S = 1. It has three allowed values of the spin's projection along a given axis m S = −1, 0, or +1, giving the name "triplet".
As a result, when filling up atomic orbitals, the maximum number of unpaired electrons (and hence maximum total spin state) is assured. The valence orbitals of the oxygen atom (sides of diagram) and the dioxygen molecule (middle) in the ground state. In both atom and molecule, the electrons in singly occupied orbitals have their spins parallel.