We give examples of non-amenable ICC groups Ξ with the Haagerup
property, weakly amenable with constant \Lambda_{\cb}(\Gamma) = 1, for which
we show that the associated II1β factors L(Ξ) are strongly
solid, i.e. the normalizer of any diffuse amenable subalgebra PβL(Ξ) generates an amenable von Neumann algebra. Nevertheless, for these
examples of groups Ξ, L(Ξ) is not isomorphic to any interpolated
free group factor L(\F_t), for 1<tβ€β.Comment: 20 page