The mononuclear Pd(ii) complex cis-[PdCl(2)([9]aneS(3))]([9]aneS(3)= 1,4,7-trithiacyclononane) converts at 44 kbar pressure into an intensely coloured chain polymer, which exhibits distorted octahedral co-ordination at the metal centre and an unprecedented [1233] conformation for the thioether crown.