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  2. Methyl group - Wikipedia

    en.wikipedia.org/wiki/Methyl_group

    This is a free rotation only in the simplest cases like gaseous methyl chloride CH 3 Cl. In most molecules, the remainder R breaks the C ∞ symmetry of the R−C axis and creates a potential V(φ) that restricts the free motion of the three protons. For the model case of ethane CH 3 CH 3, this is discussed under the name ethane barrier. In ...

  3. Proton nuclear magnetic resonance - Wikipedia

    en.wikipedia.org/wiki/Proton_nuclear_magnetic...

    When the CH 2 −CH group is changed to CH 3 −CH 2, keeping the chemical shift and coupling constants identical, the following changes are observed: The relative areas between the CH 3 and CH 2 subunits will be 3:2. The CH 3 is coupled to two protons into a 1:2:1 triplet around 1 ppm. The CH 2 is coupled to three protons.

  4. Eclipsed conformation - Wikipedia

    en.wikipedia.org/wiki/Eclipsed_conformation

    The example below is looking down the C2 and C3 bond. Below is the sawhorse and Newman representation of butane in an eclipsed conformation with the two CH 3 groups (C1 and C4) at a 0-degree angle from one another (left). If the front is rotated 60° clockwise, the butane molecule is now in a staggered conformation (right).

  5. Methyl radical - Wikipedia

    en.wikipedia.org/wiki/Methyl_radical

    Methyl radical is an organic compound with the chemical formula CH • 3 (also written as [CH 3] •). It is a metastable colourless gas, which is mainly produced in situ as a precursor to other hydrocarbons in the petroleum cracking industry. It can act as either a strong oxidant or a strong reductant, and is quite corrosive to metals.

  6. Methine group - Wikipedia

    en.wikipedia.org/wiki/Methine_group

    Methine or methylylidene (IUPAC) In organic chemistry, a methine group or methine bridge is a trivalent functional group =CH−, derived formally from methane.It consists of a carbon atom bound by two single bonds and one double bond, where one of the single bonds is to a hydrogen.

  7. Isovalent hybridization - Wikipedia

    en.wikipedia.org/wiki/Isovalent_hybridization

    The value of 1 J 13 C-1 H for cyclopropane, cyclobutane and cyclopentane are 161, 134, and 128 Hz, respectively. This is a consequence of the fact that the C-C bonds in small, strained rings (cyclopropane and cyclobutane) employ excess p character to accommodate their molecular geometries (these bonds are famously known as ' banana bonds ').

  8. Grignard reagent - Wikipedia

    en.wikipedia.org/wiki/Grignard_reagent

    For the coupling of aryl halides with aryl Grignard reagents, nickel chloride in tetrahydrofuran (THF) is also a good catalyst. Additionally, an effective catalyst for the couplings of alkyl halides is the Gilman catalyst lithium tetrachlorocuprate (Li 2 CuCl 4), prepared by mixing lithium chloride (LiCl) and copper(II) chloride (CuCl 2) in THF.

  9. J-coupling - Wikipedia

    en.wikipedia.org/wiki/J-coupling

    Example 1 H NMR spectrum (1-dimensional) of ethanol plotted as signal intensity vs. chemical shift.There are three different types of H atoms in ethanol regarding NMR. The hydrogen (H) on the −OH group is not coupling with the other H atoms and appears as a singlet, but the CH 3 − and the −CH 2 − hydrogens are coupling with each other, resulting in a triplet and quartet respectively.