Search results
Results from the WOW.Com Content Network
Carbon disulfide (also spelled as carbon disulphide) is an inorganic compound with the chemical formula CS 2 and structure S=C=S. It is also considered as the anhydride of thiocarbonic acid . [ 8 ] It is a colorless, flammable, neurotoxic liquid that is used as a building block in organic synthesis.
The structure of a disulfide bond can be described by its χ ss dihedral angle between the C β −S γ −S γ −C β atoms, which is usually close to ±90°. The disulfide bond stabilizes the folded form of a protein in several ways: It holds two portions of the protein together, biasing the protein towards the folded topology.
Structure and properties Index of refraction, n D: 1.6276 at 20 °C Abbe number? Dielectric constant, ε r: 2.641 ε 0 at 20 °C Bond strength? Bond length? Bond angle? Magnetic susceptibility? Surface tension [1] 35.3 dyn/cm at 0 °C 32.3 dyn/cm at 20 °C Viscosity [2] 0.495 mPa·s at –10 °C 0.436 mPa·s at 0 °C 0.380 mPa·s at 5 °C 0.363 ...
The bond angle for a symmetric tetrahedral molecule such as CH 4 may be calculated using the dot product of two vectors. As shown in the diagram at left, the molecule can be inscribed in a cube with the tetravalent atom (e.g. carbon) at the cube centre which is the origin of coordinates, O. The four monovalent atoms (e.g. hydrogens) are at four ...
When the thiol groups of two cysteine residues (as in monomers or constituent units) are brought near each other in the course of protein folding, an oxidation reaction can generate a cystine unit with a disulfide bond (−S−S−). Disulfide bonds can contribute to a protein's tertiary structure if the cysteines are part of the same peptide ...
A site adjacent to the unsaturated carbon atom is called the allylic position or allylic site. A group attached at this site is sometimes described as allylic. Thus, CH 2 =CHCH 2 OH "has an allylic hydroxyl group". Allylic C−H bonds are about 15% weaker than the C−H bonds in ordinary sp 3 carbon centers and are thus more reactive.
Iron disulfide (pyrite, FeS 2) on the other hand consists of S 2− 2, or − S–S − dianion, in association with divalent iron in the formal +2 oxidation state (ferrous ion: Fe 2+). Dimethyldisulfide has the chemical binding CH 3 –S–S–CH 3, whereas carbon disulfide has no S–S bond, being S=C=S (linear molecule analog to CO 2).
Stereochemistry demands special attention because three-dimensionality is the most difficult part of a structure to visualize. Techniques for presenting 3-dimensional structures reflect the tastes of the artist. Three dimensionality is best highlighted by the depictions of bonds, using wedges, bolding, and hashed formats.