Iron-bismuth halido compounds: molecules, clusters, and polymers.

The pentamethylcyclopentadienyl substituted iron-bismuth halides [Bi{FeCp*(CO)2}X2] [X = Cl (1), Br (2), I (3); Cp* = η(5)-C5Me5] were synthesized starting from [FeCp*(CO)2]2 and BiX3 (X = Cl, Br), followed by halogen exchange reaction with KI in case of 3. From a reaction mixture of [FeCp*(CO)2]2 with BiCl3 in CH2Cl2 to which CH3CN had been added, a novel coordination polymer of the formula [FeCp*(CO)2(CH3CN)]2n[Bi4Cl14]n (4) was isolated. The change of the molar ratio from 1:1 to 1:2 in the reaction of [FeCp*(CO)2]2 with BiBr3 afforded the novel ionic complex [{FeCp*(CO)2Br]2[Bi6Br22{FeCp*(CO)2}]·CH2Cl2 (5·CH2Cl2). It is demonstrated that treatment of [FeCp*(CO)2X] (X = Cl, Br) with BiCl3 and BiBr3, respectively, is a more convenient route to synthesize the new halido bismuthates 4 and 5.