While pinning down a single oxygen atom sounds difficult, trying to then manipulate electrons associated with that single atom to alter its charge sounds downright impossible. However, for the first time, this achievement has been reported by an international research team led by Osaka University.
Along with collaborators from Slovakia and the United Kingdom, graduate student Yuuki Adachi from Osaka University's Department of Applied Physics has recently published this research in ACS Nano.
Oxygen is one of the most abundant elements on Earth. Usually found in its diatomic form, O2, oxygen is highly reactive and doesn't hang around long in a gaseous state. The ground state, or least reactive form of oxygen, is referred to as triplet oxygen because it has three possible arrangements of electron spins. However, singlet oxygen, with its one possible spin arrangement, is more reactive and plays a major role in a diverse range of chemical reactions, ranging from green fuel production to photodynamic cancer treatments.
Unsurprisingly then, there is significant interest in controlling the formation and activation of molecular oxygen.
"We used Kelvin probe force spectroscopy to examine the charge states of oxygen atoms attached to a titanium dioxide rutile surface, and to then manipulate the charge through the transfer of individual electrons to and from pairs of oxygen atoms," explains Adachi. "We identified three different charge states amongst the pairs: O-/O-, O2-/O2-, and O-/O2-. Depending on the applied voltage and where we positioned the tip of the probe relative to the atoms, we could then reversibly switch the charge between the O- and O2- states."
The team then showed that they could use the same method to induce controlled, reversible bond formation between two adjacent oxygen atoms, forming molecular oxygen (O2).
Interestingly, they also found that the charge state could be controlled remotely by locating the tip elsewhere on the rutile surface. Electrons were transferred to the oxygen atoms via surface polarons, a phenomenon where electrons can travel through a crystal lattice.
"This level of control over the charge state of oxygen atoms has not previously been possible," says corresponding author of the study Associate Professor Yan Jun Li. "Our work provides a novel method to examine transition-metal-oxide-based catalytic reactions, and can likely be applied to other atoms, and perhaps other surfaces, where controlled chemical reactions initiated by charge manipulation are performed."
FAQs
The valence orbitals of molecular oxygen (middle); in the ground state, the electrons in the π* orbitals have their spins parallel. The s = 1⁄2 spins of the two electrons in degenerate orbitals gives rise to 2 × 2 = 4 independent spin states in total.
What is the spin value of oxygen? ›
The oxygen atom in its quantum mechanical ground state has the electronic configuration 1s22s22p4. The ground state atom is in a 3P state, i.e., it is an electron-spin triplet (S = 1) and has orbital angular momentum quantum number L = 1.
What is the spin of the oxygen atom? ›
Hence, The spin multiplicity valve of the Oxygen(O₂)element is "3".
What is the spin multiplicity of oxygen atom? ›
Atomic oxygen
According to Hund's first rule, the ground state configuration corresponds to an orbital occupancy that gives the highest multiplicity1. The first configuration has a multiplicity of 3 (hence termed triplet), and the other configurations have a multiplicity of 1 (hence termed singlet).
What is the nuclear spin state of oxygen-17? ›
As a spin 5/2 nucleus, oxygen-17 exhibits a quadrupole moment.
Is oxygen spin active? ›
Oxygen has one naturally occurring NMR active nucleus, 17O. It has a spin of 5/2 and is therefore quadrupolar, yielding broad signals even for the smallest of molecules that become too broad to observe in a high resolution spectrometer even for medium sized molecules.
What is the spin quantum number of oxygen? ›
Accordingly, the principal quantum number (n) will be 3 (M orbit), azimuthal quantum number (l) will be 1, magnetic quantum number (m) will be 0, and spin quantum number (s) will be -1/2.
What is the total spin of a molecule? ›
The total spin momentum has magnitude Square root of√S(S + 1) (ℏ), in which S is an integer or half an odd integer, depending on whether the number of electrons is even or odd. The possible value of the total spin angular momentum can be found from all the possible orientations of electrons within the atom.
What is the nuclear spin quantum number of oxygen? ›
The nuclear spin of Oxygen-17 is calculated by considering the number of protons and neutrons in its nucleus. Oxygen-17 has 8 protons and 9 neutrons, resulting in a total spin of 5/2. This can also be represented as a quantum number, I, which in this case is 5/2.
What is the nuclear spin of molecules? ›
Nuclear spin–lattice relaxation of gas-phase molecules occurs primarily via the spin–rotation (SR) mechanism. The magnitude of the magnetic field generated by the rotational motion of the molecule changes at a rate that is dependent on the rotationally inelastic collision frequency.
Consider the diatomic oxygen molecule , which is rotating in the xy plane about the z-axis passing through its center, perpendicular to its length. The mass of each oxygen atom is 2.66 × 10 − 26 kg , and at room temperature, the average separation between the two oxygen atoms is d = 1.21 × 10 − 26 m .
What is the nuclear symbol of oxygen? ›
Oxygen is a chemical element with symbol O and atomic number 8. Classified as a nonmetal, Oxygen is a gas at room temperature.
What is the difference between molecular oxygen and atomic oxygen? ›
An atom of oxygen is just a single atom, represented by the corresponding symbol of the element, . A molecule is a group of two or more atoms that are connected to each other by chemical bonds. A molecule of oxygen is composed of two oxygen atoms connected to each other by covalent bonds.
What is the multiplicity of molecular oxygen? ›
The level of ab initio theory used was double zeta valence (DZV). Oxygen is a triplet since it has two unpaired electrons in the molecular orbital, thus a multiplicity of three was used on the calculations of this molecule.
What is the spin of oxygen 16? ›
Oxygen isotopes
These are oxygen-16 and oxygen-18, which both have zero nuclear spin, and oxygen-17, which has a nuclear spin of 5/2.
What are the two states of oxygen? ›
Layers of gases, which surrounds a planet, and are held in place due to gravity are known as an atmosphere. The two forms of oxygen present in the atmosphere are: Ozone (O3) Molecular oxygen (O2)
What type of state of matter is oxygen? ›
Fact box
| Group | 16 | Melting point |
|---|
| Period | 2 | Boiling point |
| Block | p | Density (g cm−3) |
| Atomic number | 8 | Relative atomic mass |
| State at 20°C | Gas | Key isotopes |
2 more rowsSpin states when describing transition metal coordination complexes refers to the potential spin configurations of the central metal's d electrons. For several oxidation states, metals can adopt high-spin and low-spin configurations.
What is the pure state of oxygen? ›
Non-combined gaseous oxygen normally exists in form of diatomic molecules, O2, but it also exists in triatomic form, O3, named ozone. In normal conditions oxygen is a colourless, odourless and insipid gas; it condensates in a light blue liquid.
