Search results
Results from the WOW.Com Content Network
The following exergonic equilibrium gives rise to the triiodide ion: . I 2 + I − ⇌ I − 3. In this reaction, iodide is viewed as a Lewis base, and the iodine is a Lewis acid.The process is analogous to the reaction of S 8 with sodium sulfide (which forms polysulfides) except that the higher polyiodides have branched structures.
The polyiodides are a class of polyhalogen anions composed entirely of iodine atoms. [1] [2] The most common member is the triiodide ion, I −3.Other known larger polyiodides include [I 4] 2−, [I 5] −, [I 6] 2−, [I 7] −, [I 8] 2−, [I 9] −, [I 10] 2−, [I 10] 4−, [I 11] 3−, [I 12] 2−, [I 13] 3−, [I 14] 4-, [I 16] 2−, [I 22] 4−, [I 26] 3−, [I 26] 4−, [I 28] 4− and ...
[1] [2] [3] Introduced by Gilbert N. Lewis in his 1916 article The Atom and the Molecule, a Lewis structure can be drawn for any covalently bonded molecule, as well as coordination compounds. [4] Lewis structures extend the concept of the electron dot diagram by adding lines between atoms to represent shared pairs in a chemical bond.
The most common Lewis bases are anions. The strength of Lewis basicity correlates with the pK a of the parent acid: acids with high pK a 's give good Lewis bases. As usual, a weaker acid has a stronger conjugate base. Examples of Lewis bases based on the general definition of electron pair donor include: simple anions, such as H − and F −
In the natural bond orbital viewpoint of 3c–4e bonding, the triiodide anion is constructed from the combination of the diiodine (I 2) σ molecular orbitals and an iodide (I −) lone pair. The I − lone pair acts as a 2-electron donor, while the I 2 σ* antibonding orbital acts as a 2-electron acceptor. [ 12 ]
Finally, the triiodide ion (I − 3) is also based upon a trigonal bipyramid, but the actual molecular geometry is linear with terminal iodine atoms in the two axial positions only and the three equatorial positions occupied by lone pairs of electrons (AX 2 E 3); another example of this geometry is provided by xenon difluoride, XeF 2.
Arsenic triiodide Unit cell ball and stick model of arsenic triiodide ... Crystal structure. Rhombohedral, hR24, SpaceGroup = R-3, ... It is a pyramidal molecule that ...
In its pure state, boron triiodide forms colorless, otherwise reddish, shiny, air and hydrolysis-sensitive [3] crystals, which have a hexagonal crystal structure (a = 699.09 ± 0.02 pm, c = 736.42 ± 0.03 pm, space group P6 3 /m (space group no. 176)). [4] Boron triiodide is a strong Lewis acid and soluble in carbon disulfide. [2]