Search results
Results From The WOW.Com Content Network
The Laporte rule is a rule that explains the intensities of absorption spectra for chemical species. It is a selection rule that rigorously applies to atoms, and to molecules that are centrosymmetric, i.e. with an inversion centre. It states that electronic transitions that conserve parity are forbidden. Thus transitions between two states that ...
The Laporte rule is a selection rule formally stated as follows: In a centrosymmetric environment, transitions between like atomic orbitals such as s-s, p-p, d-d, or f-f, transitions are forbidden. The Laporte rule (law) applies to electric dipole transitions , so the operator has u symmetry (meaning ungerade , odd).
The lattice must also be stable under chemical and photochemical conditions, as these are the environments the conversion will take place within. Finally, this host lattice ought to have low symmetry, allowing for a slight relaxation of the Laporte selection rules. The normally forbidden transitions lead to an increase in the f-f intermixing ...
Scientific method – body of techniques for investigating phenomena and acquiring new knowledge, as well as for correcting and integrating previous knowledge. It is based on observable , empirical , reproducible , measurable evidence , and subject to the laws of reasoning .
In spectroscopy, a forbidden mechanism (forbidden transition or forbidden line) is a spectral line associated with absorption or emission of photons by atomic nuclei, atoms, or molecules which undergo a transition that is not allowed by a particular selection rule but is allowed if the approximation associated with that rule is not made. [1]
Otto Laporte (July 23, 1902 – March 28, 1971) was a German-born American physicist who made contributions to quantum mechanics, electromagnetic wave propagation theory, spectroscopy, and fluid dynamics. His name is lent to the Laporte rule in spectroscopy and to the Otto Laporte Award of the American Physical Society. [1]
In mathematics, a selection principle is a rule asserting the possibility of obtaining mathematically significant objects by selecting elements from given sequences of sets. The theory of selection principles studies these principles and their relations to other mathematical properties.
Lipinski's rule of five, also known as Pfizer's rule of five or simply the rule of five (RO5), is a rule of thumb to evaluate druglikeness or determine if a chemical compound with a certain pharmacological or biological activity has chemical properties and physical properties that would likely make it an orally active drug in humans.