Neptunium(III) chloride or neptunium trichloride is an inorganic compound with a chemical formula NpCl3.

This salt is strongly radioactive.

Neptunium(III) chloride can be produced by reducing neptunium(IV) chloride by ammonia or hydrogen at 350~400 °C:[1] Neptunium(III) chloride hydrolyzes at 450 °C and forms an oxychloride NpOCl.

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