Neptunium tetrachloride
Chemical compound
From Wikipedia, the free encyclopedia
Neptunium tetrachloride is a binary inorganic compound of neptunium metal and chlorine with the chemical formula NpCl4.[1][2]
-chlorid.png)
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| Identifiers | |
|---|---|
3D model (JSmol) |
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| Properties | |
| Cl4Np | |
| Molar mass | 379 g·mol−1 |
| Appearance | orange-brown crystals |
| Density | 4.95 g/cm3 |
| Melting point | 538 °C (1,000 °F; 811 K) |
| Related compounds | |
Related compounds |
Uranium tetrachloride, Thorium tetrachloride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis
The compound can be prepared by:
- the reaction of neptunium nitride with HCl:[3]
- 2 NpN + 8 HCl → N2 + 4 H2 + 2 NpCl4
- the reaction of neptunium sesquisulfide with HCl:
- Np2S3 + 8 HCl → 2 NpCl4 + 3 H2S + H2
- the reaction of carbon tetrachloride with neptunium(IV) oxide (NpO2). Neptunium tetrachloride is formed as a yellow sublimate.[4]
Other reactions are also used.[5]
Physical properties
NpCl4 crystallizes in tetragonal crystal system of space group I4/amd.[6]
Chemical properties
The compound reacts with ammonia to produce neptunium trichloride:[3]
- 6 NpCl4 + 2 NH3 → 6 NpCl3 + 6 HCl + N2
Neptunium tetrachloride can be reduced to neptunium trichloride by hydrogen at 450 °C.
- 2 NpCl4 + H2 → 2 NpCl3 + 2HCl
NpCl4 can form Lewis base adducts with non-protic solvents such as 1,2-dimethoxyethane (DME), pyridine and acetonitrile. These compounds are more accessible in practice than the binary NpCl4 salt. Solvates of the general formula NpCl4Lx may thus be isolated.[7] One starting material for metal-organic neptunium chemistry is NpCl4(DME)2, which can be isolated as a pink powder.[8]
₂_in_1,2-dimethoxyethane..jpg)