Use of a smaller counterion results in an 'inverse sandwich' diindium cation

Treatment of In(C5Me5) with [(toluene)H[[B(C6F5)(4)] affords the salt [In(eta(5)-C5Me5)In][B(C6F5)(4)]. X-ray analysis indicates that the cation possesses an inverse sandwich structure, one indium atom of which experiences a close contact with a meta-fluorine of a C6F5 group of a [B(C6F5)(4)](-) counterion. The other indium atom exhibits a weak eta(6)-interaction with a C6F5 group of a different [B(C6F5)(4)](-) anion. (C) 2002 Elsevier Science B.V. All rights reserved.