Reactions of the unsaturated anions [H3Re3(CO)10]2- and [H4Re3(CO)10]- with iodine in various solvents. X-ray characterization of the derivative H3Re3(CO)10(py)2

Treatment of [H3Re3(CO)10](NEt4)2 (I) with acids gives [H4Re3(CO)10](NEt4) (II) which is unsaturated, like the parent compound I. Both I and II react with iodine in ethanol; I gives a mixture of two saturated species [H3Re3(CO)10I](NEt4) (III) and [H2Re3(CO)10I](NEt4)2 (IV), while II gives only compound III. If the same reactions are carried out with iodine in pyridine, crystals of the saturated non-electrolyte compound H3Re3(CO)10(py)2 (V) are obtained. The results of an X-ray analysis show that the latter species contains an equilateral metal atom triangle with long hydrogen-bridged ReRe bonds of mean length 3.292\uc5. \ua9 1980