Tungsten and Iodine

PR Reaction of concentrated hydroiodic acid with WClg at 100 °C. 

Will be decomposed by air to WI2 and I2, is soluble in water, but hydrolyzes insoluble in ether and CHCI3, slowly soluble in cold alcohol chlorine replaces iodine at 18 °C, and bromine replaces it at 100 °C. Dissolution and iodine release occurs with KOH solutions, molten alkali carbonates, molten potassium bisulfide, and liquid potassium. 

Is also one of the products of the reaction of W6I12 with iodine gas. PP Gray needles. 

PP Brownish crystalline substance hexamer structure [W6l8]l2l4/2- 

PR By reaction of iodine gas and VeIi2 at 350 °C in vacuum (coexists with WI3). 

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