Bis tetrabutylammonium Octachlorodirhenate III

A Schlenk flask is flushed with a slow stream of nitrogen and into the flask is put [Bu4N][Re04] (1.5g, 3.0mmol). Benzoyl chloride (bp 198°C) (15mL, 

The blue salt is soluble in polar organic solvents such as acetonitrile, dichloro-methane, and methanol. The solid is stable in air and can be stored indefinitely without special precautions. It is readily converted into other compounds with Re Re quadmple bonds. The synthesis of one such derivative, Re2(02CCH3)4Cl2, is described below.  

Record the UV-vis spectrum of [Bu4N]2[Re2Cl8] in acetonitrile and calculate the extinction coefficient of the lowest-lying absorption band, the 6 — 8 transition, at about 680 mn. If possible, record the Raman spectrum of the recry staUi2ed material and identily the Re Re stretching frequency. 

Hie authors have not had [nxiblems with the hot benzoyl chloride leaching the grease out of the joint between the reaction fla and the condenser. If this does occur, the reaction can be set up again with the joint sealed either with a Teflon deeve or wilh Apiezon H grease. 

Orange Re2(02CCH3)4Cl2 is stable in air and virtually insoluble in common organic solvents. It reacts with boiling concentrated aqueous hydrochloric acid to regenerate the octachlorodrrhenate anion, which can be recovered as the tetrabutylammonium, 

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