Reaction of Cp(2)LnCl with 1 equiv of KTp(Me2) in toluene gives the mixed Tp(Me2)/Cp lanthanide complexes Cp(2)Ln(Tp(Me2)) (Ln = Yb (1a), Er (1b), Dy (1c)), while unexpected complexes CpLn(Tp(Me2))Cl(THF) (Ln = Yb (2a), Er (2b . THF), Dy (2c), Y (2d)) are obtained when the reactions are carried out in THF. Complex 2b can also be formed by the reaction of CpErCl2(THF)(3) with 1 equiv of KTp(Me2) in THF. Moreover, complex 1a can also be obtained from the reaction Of Cp3Yb and KTp(Me2). The results not only represent an efficient and versatile method for the synthesis of mixed Cp/Tp(Me2) lanthanide complexes but also provide new insight into the reactivity of Cp(2)LnCl. Furthermore, the reactivities of complexes la-c toward proton-donating reagents are examined. It has been found that 1b reacts with benzotriazole (C6H4NHN2) in THF to yield a lanthanide metallomacrodyclic complex [(Tp(Me2))CpEr(mu-N3C6H4)](3) (3), while the reaction of la with 1 equiv of 2-aminopyridine in THF gives an unexpected oxide complex [(Tp(Me2))Yb(2-HNC5H4N)](2)(mu-O) (4). Presumably, the oxide ligand of compound 4 results from adventitious water. In addition, treatment of 1c with 2 equiv of 3,5-dimethylpyrazole yields a completely Cp-abstracted product (Tp(Me2))Dy(Pz(Me2))(2)(THF) (5), which can also be directly obtained from a three-component reaction Of Cp2DyCl, KTp(Me2), and 3,5-dimethyl pyrazole in THF. These results further indicate that the new mixed Tp(Me2)/Cp lanthanide complexes are practical and versatile precursors for the synthesis of poly(pyrazolyl)borate lanthanide derivatives. All new compounds have been characterized by elemental analysis and spectroscopic methods. The structures of complexes 1a,b and 2-5 have also been determined through single-crystal X-ray diffraction analysis.