Hafniumtetrachlorid Chemische Eigenschaften,Einsatz,Produktion Methoden
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Chemische Eigenschaften
Hafnium(IV) chloride is the inorganic compound with the formula HfCl4. This colourless solid is the precursor to most hafnium organometallic compounds. It has a variety of highly specialized applications, mainly in materials science and as a catalyst.
Physikalische Eigenschaften
White monoclinic crystal; sublimes at 317°C; melts at 432°C at 33 atm (triple point); critical temperature 452.5°C; critical pressure 53.49 atm; critical volume 314 cm3/mol.
Verwenden
Hafnium chloride tetrahydrofuran complex is an efficient catalyst for the Diels-Alder cycloadditions, Ziegler-Natta polymerization of alkenes. It is used as control rods in nuclear reactors and in manufacture of light bulb filaments.
synthetische
Hafnium(IV) chloride can be prepared
(i) by chlorination of hafnium dioxide in the presence of carbon:
HfO
2 + 2Cl
2 + C → HfCl
4 + 2CO
It also may be prepared by several other methods, such as
(ii) reaction of carbon tetrachloride with hafnium dioxide above 450°C;
(iii) heating a mixture of hafnium dioxide and carbon above 700°C;
and (iv) reaction of chlorine with hafnium at elevated temperatures.
Reaktionen
Hafnium(IV) chloride hydrolyzes, evolving hydrogen chloride:
HfCl4 + H2O→ HfOCl2+ 2 HCl
Aged samples thus often are contaminated with oxychlorides, which are also colourless.
THF forms a monomeric 2:1 complex:
HfCl4+ 2 OC4H8→HfCl4(OC4H8)2
Hafniumtetrachlorid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte