Tributyltin(IV) penta(methoxycarbonyl)cyclopentadienides [SnBu3L2]+-[C5(CO2Me)5]–. X-Ray crystal structure of the diaquatributyltin(IV) salt, [SnBu3(OH2)2][C5(CO2Me)5], and electron spin resonance spectrum of the radical C5(CO2Me)5

Abstract

The ionic penta(methoxycarbonyl)cyclopentadienide salts of the diligated tributyltin(IV) cation, [SnBu₃L₂][C₅(CO₂Me)₅][L = H₂O, OP(NMe₂)₃, or HCONMe₂], have been isolated, and the crystal structure of the diaqua compound has been determined. The cation and anion have approximate C_3v and D_5h symmetry respectively, and, in the anion, the methoxycarbonyl groups are twisted out of the plane of the ring by between 29.2 and 53.2°. If 1,2,3,4,5-penta-(methoxycarbonyl)cyclopentadiene, or its dehydrodimer, (MeO₂C)₅C₅C₅(CO₂Me)₅, is photolysed, the e.s.r, spectrum of the persistent radical C₅(CO₂Me)₅˙ is observed, a(H)= 0.61 G.