Suppression of superconductivity by non-magnetic disorder in the organic superconductor <InlineEquation ID="Equ1"> <EquationSource Format="TEX">$\mathsf{(TMTSF)_{2}(ClO_{4})_{(1-x)}(ReO_{4})_{x}}$</EquationSource> </InlineEquation>

We present a study of the superconducting properties (T <Subscript> c </Subscript> and H <Subscript> c2</Subscript>) in the solid solution <InlineEquation ID="Equ2"> <EquationSource Format="TEX">${\rm (TMTSF)_{2}(ClO}_{4})_{(1-x)}{\rm (ReO_{4})}_{x}$</EquationSource> </InlineEquation>, with a <InlineEquation ID="Equ3"> <EquationSource Format="TEX">$\rm ReO_{4}^{-}$</EquationSource> </InlineEquation> nominal concentration up to <InlineEquation ID="Equ4"> <EquationSource Format="TEX">$x=6\%$</EquationSource> </InlineEquation>. The dramatic suppression of T <Subscript> c </Subscript> when the residual resistivity is increased upon alloying with no modification of the Fermi surface is the signature of non-conventional superconductivity. This behaviour strongly supports p or d wave pairing in quasi one dimensional organic superconductors. The determination of the electron lifetime in the normal state at low temperature confirms that a single particle Drude model is unable to explain the temperature dependence of the conductivity and that a very narrow zero frequency mode must be taken into account for the interpretation of the transport properties. Copyright Springer-Verlag Berlin/Heidelberg 2004