A list of spectroscopists typically includes notable scientists and researchers who have made significant contributions to the field of spectroscopy. Spectroscopy is the study of the interaction between matter and electromagnetic radiation, and it has applications in various fields such as chemistry, physics, astronomy, and materials science.

Linear dichroism (LD) is a spectroscopic technique used to study the orientation of molecules in a sample by measuring the difference in absorbance of light polarized in different directions. It is particularly useful for analyzing macromolecules like proteins, nucleic acids, and some types of polymers. In a typical LD experiment, a sample is illuminated with linearly polarized light, and the absorbance is measured for two orthogonal polarization directions (usually parallel and perpendicular to a particular molecular axis).

Laser diffraction analysis is a widely used technique for measuring the size distribution of particles in a sample. This method is based on the principle of diffraction, which occurs when a beam of light interacts with particles. Here’s how it works and its key aspects: ### Principles of Laser Diffraction 1. **Laser Beam**: A coherent light source, typically a laser, emits a beam of light that is directed towards a sample containing particles.

Laser-induced breakdown spectroscopy (LIBS) is an analytical technique used to identify the elemental composition of materials. It involves focusing a high-energy laser pulse onto the surface of a sample, creating a localized plasma. This process can be summarized in the following steps: 1. **Laser Interaction**: A focused laser pulse is directed at the sample material. The intense energy of the laser causes the material to ablate, creating a small volume of plasma.

A Kerr frequency comb is a type of optical frequency comb that is generated through the process of the Kerr effect in nonlinear optical media. The Kerr effect refers to a phenomenon where the refractive index of a material changes in response to the intensity of light passing through it. When high-intensity light waves are introduced into such a medium, they can generate multiple new frequency components, resulting in a comb-like spectrum of optical frequencies.

A Jablonski diagram is a graphical representation of the electronic states of a molecule and the transitions between these states, typically used in the field of photophysics and photochemistry. It depicts the energy levels of the singlet and triplet states of a molecule, along with the various types of electronic transitions and the associated processes.

JCAMP-DX is a data format used for the exchange and representation of spectroscopic data, particularly in the field of analytical chemistry. It is a standardized format designed to facilitate the sharing and storage of spectral data, such as that from infrared spectroscopy, nuclear magnetic resonance (NMR), and mass spectrometry. The JCAMP-DX format is characterized by its use of ASCII text files that include a set of standard headers and data points.

Isotopic labeling is a technique used in various scientific fields, including chemistry, biology, and medicine, to trace and study the behavior of molecules by incorporating isotopes into their structure. Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons, resulting in different atomic masses. In isotopic labeling, one or more atoms in a molecule are replaced with isotopes of the same element.

Isomeric shift (or isotopic shift) is a phenomenon observed in nuclear magnetic resonance (NMR), particularly in the context of Mössbauer spectroscopy. It refers to the change in energy of gamma rays emitted or absorbed by a nucleus when it is in a different chemical or physical environment compared to a reference state. In the case of Mössbauer spectroscopy, the isomeric shift is primarily influenced by the electronic environment surrounding the nucleus, particularly the s-electron density at the nucleus.

Intervalence charge transfer (IVCT) refers to a molecular electronic transition in which an electron is transferred between two metal centers that have different oxidation states within a complex, typically in mixed-valence compounds. This type of charge transfer occurs in systems where there are two or more closely spaced metal ions, and at least one is in a different oxidation state from the others.

The Molecular Hamiltonian is a mathematical operator used in quantum mechanics that describes the total energy of a molecular system. It is a fundamental part of quantum chemistry, as it helps in understanding the electronic structure of molecules. The Hamiltonian incorporates various contributions to the energy of a molecule, including kinetic and potential energy terms.

A microprobe is a scientific instrument used to analyze the composition of small samples of material at a microscale. It employs various techniques to determine the chemical and physical properties of materials, often down to the level of individual grains or particles. Microprobes can be used in a wide range of fields, including materials science, geology, biology, and electronics.

The term "magic angle" in the context of Electron Energy Loss Spectroscopy (EELS) relates to the angle at which a sample is tilted to optimize the resolution and signal quality in the measurement of energy losses in electrons transmitted through a thin material. In EELS, the "magic angle" typically refers to an angle of approximately 54.

IRsweep is a company that specializes in the development and production of advanced infrared (IR) spectroscopy systems. Their technology focuses on the high-resolution measurement of molecular gases and other substances using tunable laser technology. IRsweep's products are commonly used in fields such as environmental monitoring, industrial applications, and scientific research. One of their key innovations is the ability to provide fast and precise gas analysis by utilizing a range of tunable infrared lasers.

Sorption is a physical and chemical process by which one substance becomes attached to another. It encompasses both adsorption and absorption: 1. **Adsorption**: This is the process where particles adhere to the surface of a solid or liquid. In this case, the molecules do not penetrate the bulk of the substance but instead form a layer on its surface. Common examples include the adherence of gas molecules to a solid surface, such as activated carbon adsorbing pollutants from air or water.

Nucleic acid quantitation refers to the measurement of the concentration and purity of nucleic acids, such as DNA and RNA, in a sample. This process is essential in various fields including molecular biology, genetics, and biotechnology, as accurate quantitation is crucial for applications like PCR (polymerase chain reaction), cloning, sequencing, and gene expression studies.

Nuclear spectroscopy is a branch of spectroscopy that focuses on the study of the energy levels and transitions of atomic nuclei. It involves the analysis of the interactions between nuclear states and various radiation forms, particularly gamma rays, which are emitted during nuclear decays or transitions. The primary techniques used in nuclear spectroscopy include gamma-ray spectroscopy, neutron activation analysis, and various forms of nuclear magnetic resonance (NMR) spectroscopy tailored to nuclear states.

Hyperchromicity refers to an increase in the absorbance of light (usually in the ultraviolet-visible spectrum) by a substance, typically nucleic acids like DNA or RNA, when they undergo conformational changes. This phenomenon often occurs during processes such as DNA melting (denaturation), where double-stranded DNA unwinds into single strands.

Hydrogen–deuterium exchange (H/D exchange) is a chemical process that involves the replacement of hydrogen atoms (H) in a molecule with deuterium atoms (D), which are isotopes of hydrogen. Deuterium has one proton and one neutron in its nucleus, while ordinary hydrogen has only one proton. This exchange is a valuable technique in various fields such as chemistry, biochemistry, and analytical science, as it can provide insights into molecular structure, dynamics, and interactions.

The history of spectroscopy is a fascinating journey through science and technology that spans several centuries. Spectroscopy, the study of the interaction between matter and electromagnetic radiation, has roots in early optical experiments and has evolved into a key analytical technique across various scientific fields. ### Early Beginnings (17th - 19th Century) 1. **Isaac Newton (1671)**: The foundation of spectroscopy can be traced back to Newton's experiments with prisms.