The reaction of zinc (Zn) and sulfur (S) or selenium (Se) with hydrazine hydrate (N2H4 (.) H2O) at 80 degreesC leads to the formation of N2H4 intercalated lamellar zinc chalcogenides which are characterized by classical methods and shown to be self-assembled into I-D morphologies; decomposition of these molecular precursors in ethanol at 180 degreesC results in high temperature stable wurtzite ZnS or ZnSe nanofibers. (C) 2003 Published by Elsevier B.V.