Names | |
---|---|
Other names Californium diiodide | |
Identifiers | |
3D model (JSmol) | |
| |
| |
Properties | |
CfI2 | |
Molar mass | 505 g·mol−1 |
Appearance | dark purple solid |
Density | g/cm3 |
insoluble | |
Structure | |
cubic | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Californium(II) iodide is a binary inorganic compound of californium and iodine with the formula CfI
2. [1]
It can be produced by reducing californium triiodide with hydrogen in a quartz thin tube at 570 °C: [2]
The compound forms a dark purple solid. At slightly higher temperatures, it melts and reacts with the silica in the thin tube, producing CfOI.[ citation needed ]
Californium diiodide has two crystal structures, one is CdCl
2-type crystal structure, stable at room temperature, with lattice parameters a = 743.4 ± 1.1 pm and α = 35.83 ± 0.07°; the other is metastable, of CdI
2-type with lattice parameters a = 455.7 ± 0.4 pm and c = 699.2 ± 0.6 pm. [3] Californium diiodide has an absorption band in the wavelength range from 300 to 1100 nm, which proves the existence of Cf(II). [4]
Berkelium is a synthetic chemical element; it has symbol Bk and atomic number 97. It is a member of the actinide and transuranium element series. It is named after the city of Berkeley, California, the location of the Lawrence Berkeley National Laboratory where it was discovered in December 1949. Berkelium was the fifth transuranium element discovered after neptunium, plutonium, curium and americium.
Few compounds of californium have been made and studied. The only californium ion that is stable in aqueous solutions is the californium(III) cation. The other two oxidation states are IV (strong oxidizing agents) and II (strong reducing agents). The element forms a water-soluble chloride, nitrate, perchlorate, and sulfate and is precipitated as a fluoride, oxalate or hydroxide. If problems of availability of the element could be overcome, then CfBr2 and CfI2 would likely be stable.
Berkelium forms a number of chemical compounds, where it normally exists in an oxidation state of +3 or +4, and behaves similarly to its lanthanide analogue, terbium. Like all actinides, berkelium easily dissolves in various aqueous inorganic acids, liberating gaseous hydrogen and converting into the trivalent oxidation state. This trivalent state is the most stable, especially in aqueous solutions, but tetravalent berkelium compounds are also known. The existence of divalent berkelium salts is uncertain and has only been reported in mixed lanthanum chloride-strontium chloride melts. Aqueous solutions of Bk3+ ions are green in most acids. The color of the Bk4+ ions is yellow in hydrochloric acid and orange-yellow in sulfuric acid. Berkelium does not react rapidly with oxygen at room temperature, possibly due to the formation of a protective oxide surface layer; however, it reacts with molten metals, hydrogen, halogens, chalcogens and pnictogens to form various binary compounds. Berkelium can also form several organometallic compounds.
Iron(II) iodide is an inorganic compound with the chemical formula FeI2. It is used as a catalyst in organic reactions.
Californium(III) bromide is an inorganic compound, a salt with a chemical formula CfBr3. Like in californium(III) oxide (Cf2O3) and other californium halides, including californium(III) fluoride (CfF3), californium(III) chloride, and californium(III) iodide (CfI3), the californium atom has an oxidation state of +3.
Berkelium(IV) oxide, also known as berkelium dioxide, is a chemical compound with the formula BkO2. This compound slowly decays to californium(IV) oxide. It can be converted to berkelium(III) oxide by hydrogen reduction at 600 °C.
Curium (Cm) usually forms compounds in the +3 oxidation state, although compounds with curium in the +4, +5 and +6 oxidation states are also known.
Curium(III) chloride is the chemical compound with the formula CmCl3.
Einsteinium compounds are compounds that contain the element einsteinium (Es). These compounds largely have einsteinium in the +3 oxidation state, or in some cases in the +2 and +4 oxidation states. Although einsteinium is relatively stable, with half-lives ranging from 20 days upwards, these compounds have not been studied in great detail.
Berkelium(III) chloride also known as berkelium trichloride, is a chemical compound with the formula BkCl3. It is a water-soluble green salt with a melting point of 603 °C. This compound forms the hexahydrate, BkCl3·6H2O.
Praseodymium(III) iodide is an inorganic salt, consisting of the rare-earth metal praseodymium and iodine, with the chemical formula PrI3. It forms green crystals. It is soluble in water.
Praseodymium diiodide is a chemical compound with the empirical formula of PrI2, consisting of praseodymium and iodine. It is an electride, with the ionic formula of Pr3+(I−)2e−, and therefore not a true praseodymium(II) compound.
Americium compounds are compounds containing the element americium (Am). These compounds can form in the +2, +3, and +4, although the +3 oxidation state is the most common. The +5, +6 and +7 oxidation states have also been reported.
Californium(III) fluoride is a binary inorganic compound of californium and fluorine with the formula CfF
3
Californium(III) oxide is a binary inorganic compound of californium and oxygen with the formula Cf
2O
3. It is one of the first obtained solid compounds of californium, synthesized in 1958.
Californium(IV) oxide is a binary inorganic compound of californium and oxygen with the formula CfO
2.
Californium(III) iodide is a binary inorganic compound of californium and iodine with the formula CfI
3.
Berkelium(III) fluoride is a binary inorganic compound of berkelium and fluorine with the chemical formula BkF
3.
Berkelium(III) oxide is a binary inorganic compound of berkelium and oxygen with the chemical formula Bk
2O
3.
Berkelium bromide is a bromide of berkelium, with the chemical formula BkBr3.