  New intercalation superconductors of Li$_x$(C$_2$H$_8$N$_2$)$_y$TiSe$_2$ and
Li$_x$(C$_6$H$_{16}$N$_2$)$_y$TiSe$_2$ with $T_{\rm c}$ = 4.2 K have
successfully been synthesized via the co-intercalation of lithium and
ethylenediamine or hexamethylenediamine into 1T-TiSe$_2$. Moreover, it has been
found that both intercalation compounds of Li$_x$TiSe$_2$ and
(C$_2$H$_8$N$_2$)$_y$TiSe$_2$ also show superconductivity with $T_{\rm c}$ =
2.4 K and 2.8 K, respectively. These results indicate that both the electron
doping due to the intercalation of lithium and the expansion of the interlayer
spacing between TiSe2 layers due to the intercalation of diamines suppress the
charge density wave in 1T-TiSe$_2$, leading to the appearance of
superconductivity.
