Unexpected One‐Electron Oxidation of a Secondary Phosphite Selenide Cp(CO) 2 FeP(Se)(O i Pr) 2 by GaCl 3 and InCl 3 – Rare Examples of Di‐ and Triselenide Formation

The reactions of the neutral phosphonoselenoate [Cp(CO) 2 FeP(Se)(O i Pr) 2 ] ( 1 ) with Lewis acids (GaCl 3 , InCl 3 ) produce dicationic complexes [{Cp(CO) 2 FeP(O i Pr) 2 } 2 Se n ][GaCl 4 ] 2 , [ n = 2 ( 2 ), 3 ( 3 )] and [{Cp(CO) 2 FeP(O i Pr) 2 } 2 Se n ][InCl 4 ] 2 [ n = 2 ( 4 ), 3 ( 5 )] in good yields; the complexes comprise an Se 3 (or Se 2 ) chain that bridges two FpP(O i Pr) 2 groups [Fp = Cp(CO) 2 Fe]. These compounds are the one‐electron oxidation products of secondary phosphite selenide 1 by group 13 (Ga, In) trichlorides. On the other hand, the reaction of GaCl 3 with ( i PrO) 2 PSe 2 – (dsep) yields only the Lewis adduct tris( O , O ‐diisopropyldiselenophosphate)gallium ( 6 ). The 31 P NMR spectrum of 6 at 183 K reveals that the gallium(III) center is surrounded by one chelating and two pendant dsep ligands, which is in line with the obtained X‐ray structure. In addition, the two‐electron oxidation of 1 leads to phosphite [Cp(CO) 2 FeP(O)(O i Pr) 2 ] formation.