Search results
Results from the WOW.Com Content Network
Vanadium(IV) oxide or vanadium dioxide is an inorganic compound with the formula VO 2.It is a dark blue solid. Vanadium(IV) dioxide is amphoteric, dissolving in non-oxidising acids to give the blue vanadyl ion, [VO] 2+ and in alkali to give the brown [V 4 O 9] 2− ion, or at high pH [VO 4] 4−. [4]
Many template reactions are only stoichiometric, and the decomplexation of the "templating ion" can be difficult. The alkali metal-templated syntheses of crown ether syntheses are notable exceptions. Metal Phthalocyanines are generated by metal-templated condensations of phthalonitriles, but the liberation of metal-free phthalocyanine is difficult.
Ionic radius, r ion, is the radius of a monatomic ion in an ionic crystal structure. Although neither atoms nor ions have sharp boundaries, they are treated as if they were hard spheres with radii such that the sum of ionic radii of the cation and anion gives the distance between the ions in a crystal lattice.
Metal aqua ions are always accompanied in solution by solvated anions, but much less is known about anion solvation than about cation solvation. [ 6 ] Understanding of the nature of aqua ions is helped by having information on the nature of solvated cations in mixed solvents [ 7 ] and non-aqueous solvents , such as liquid ammonia , methanol ...
For example, in an aqueous solution of sodium chloride, less than half of the current is carried by the positively charged sodium ions (cations) and more than half is carried by the negatively charged chloride ions (anions) because the chloride ions are able to move faster, i.e., chloride ions have higher mobility than sodium ions. The sum of ...
Positively charged ions are called cations and negatively charged ions are called anions. The cation is always named first. Ions can be metals, non-metals or polyatomic ions. Therefore, the name of the metal or positive polyatomic ion is followed by the name of the non-metal or negative polyatomic ion.
The association is strongest as a covalent bond and weakest when the pair exists as free ions. [6] In cationic polymerization, the ions tend to be in equilibrium between an ion pair (either tight or solvent-separated) and free ions. [2] The more polar the solvent used in the reaction, the better the solvation and separation of the ions.
In organic chemistry, neighbouring group participation (NGP, also known as anchimeric assistance) has been defined by the International Union of Pure and Applied Chemistry (IUPAC) as the interaction of a reaction centre with a lone pair of electrons in an atom or the electrons present in a sigma or pi bond contained within the parent molecule but not conjugated with the reaction centre.