The preparation and structural characterization of two monomeric covalent species,Sn(
5-C
5Me
5)Cl(
1) andSn{
5-C
5Me
4(SiMe
2Bu
t)}Cl(
2), are reported,including solid- and solution-state multinuclear NMRspectroscopic data and, for
1, a molecularstructuredetermination.