Reaction of solid TlCl with [(C
5Ph
5)CrCl(
-Cl)]
2 inCH
2Cl
2 solvent yields the dimeric com
plex [(C
5Ph
5)CrCl(
-Cl)
2Tl]
2 in 80% isolated yield. The C
5H
5 and C
5Me
5 analogues donot react with TlCl, suggesting a steric basis for the reactionof the C
5Ph
5 material.