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  2. Methylidynephosphane - Wikipedia

    en.wikipedia.org/wiki/Methylidynephosphane

    Methylidynephosphane (phosphaethyne) is a chemical compound which was the first phosphaalkyne compound discovered, containing the unusual C≡P carbon-phosphorus triple bond. Although isolated samples of methylidynephosphane are impractical, other derivatives have been well studied such as tert-butylphosphaacetylene.

  3. Atmospheric-pressure chemical ionization - Wikipedia

    en.wikipedia.org/wiki/Atmospheric-pressure...

    Atmospheric pressure chemical ionization chamber cross section. Atmospheric pressure chemical ionization (APCI) is an ionization method used in mass spectrometry which utilizes gas-phase ion-molecule reactions at atmospheric pressure (10 5 Pa), [1] [2] commonly coupled with high-performance liquid chromatography (HPLC). [3]

  4. Mass spectral interpretation - Wikipedia

    en.wikipedia.org/wiki/Mass_spectral_interpretation

    Even when compounds only contain elements with less intense isotope peaks (carbon or oxygen), the distribution of these peaks can be used to assign the spectrum to the correct compound. For example, two compounds with identical mass of 150 Da, C 8 H 12 N 3 + and C 9 H 10 O 2 + , will have two different M+2 intensities which makes it possible to ...

  5. Mass spectrometry - Wikipedia

    en.wikipedia.org/wiki/Mass_spectrometry

    A mass spectrum is a type of plot of the ion signal as a function of the mass-to-charge ratio. These spectra are used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules, and to elucidate the chemical identity or structure of molecules and other chemical compounds. Discovery of Neon Isotopes

  6. Crystal structure - Wikipedia

    en.wikipedia.org/wiki/Crystal_structure

    This arrangement of atoms in a crystal structure is known as hexagonal close packing (hcp). If, however, all three planes are staggered relative to each other and it is not until the fourth layer is positioned directly over plane A that the sequence is repeated, then the following sequence arises:

  7. List of interstellar and circumstellar molecules - Wikipedia

    en.wikipedia.org/wiki/List_of_interstellar_and...

    The spectrum of a particular molecule is governed by the selection rules of quantum chemistry and by its molecular symmetry. Some molecules have simple spectra which are easy to identify, whilst others (even some small molecules) have extremely complex spectra with flux spread among many different lines, making them far harder to detect. [ 3 ]

  8. Methylaluminoxane - Wikipedia

    en.wikipedia.org/wiki/Methylaluminoxane

    Methylaluminoxane, commonly called MAO, is a mixture of organoaluminium compounds with the approximate formula (Al(CH 3)O) n. It is usually encountered as a solution in ( aromatic ) solvents , commonly toluene but also xylene , cumene , or mesitylene , [ 1 ] Used in large excess, it activates precatalysts for alkene polymerization.

  9. Hexamethylphosphoramide - Wikipedia

    en.wikipedia.org/wiki/Hexamethylphosphoramide

    Like other phosphine oxides (such as triphenylphosphine oxide), the molecule has a tetrahedral core and a P=O bond that is highly polarized, with significant negative charge residing on the oxygen atom. Compounds containing a nitrogen–phosphorus bond typically are degraded by hydrochloric acid to form a protonated amine and phosphate.