Never a dull moment with praseodymium metal

Abstract

Unexpectedly, a mixture of bismuth N,N′-bis(2,6-diisopropylphenyl)formamidinates in three different oxidation states namely, [Bi^I₂(DippForm)₂] (1), [Bi^II₂(DippForm)₂(C₆F₅)₂] (2) and [Bi^III(DippForm)₂(C₆F₅)] (3), together with [Pr(DippForm)₂F(thf)]·PhMe (4), [p-HC₆F₄DippForm]·0.5thf (5), and a ring-opened tetrahydrofuran [o-HC₆F₄O(CH₂)₄DippForm] (6) was obtained by the reaction of an excess of praseodymium metal with tris(pentafluorophenyl)bismuth, [Bi(C₆F₅)₃]·0.5dioxane, and bulky N,N′-bis(2,6-diisopropylphenyl)formamidine (DippFormH) in tetrahydrofuran. Similar reactions between praseodymium metal, [Bi(C₆F₅)₃]·0.5dioxane and 3,5-diphenylpyrazole (Ph₂pzH), or 3,5-di-tert-butylpyrazole (tBu₂pzH), yielded the paddlewheel dibismuthanes [Bi^II₂(Ph₂pz)₄]·dioxane (7) and [Bi^II₂(tBu₂pz)₄] (8) respectively.