INCORPORATION OF -DICYANO-2H-PYRROL-2-YLIDE)-1,1,2-TRICYANOETHANIDE IN CROSS-LINKED POLYVINYLFORMAL - FORMATION AND PROPERTIES OF THE COPPER(II) COMPLEX IN THE MATRIX

The metal(II) coordinating anion icyano-2H-pyrrol-2-ylidene)-1,1,2-tri cyanoethanide (C11N7H2-, L', lambda(max) = 570 nm) has been incorporat ed by impregnation as the sodium salt in a membrane (0.1 mm thick) of crosslinked polyvinylformal (PVF) at a concentration 1.5 x 10(-3) M. T he L'-doped PVF membrane, soaked in a concentrated aqueous solution of Cu2+ (0.1 M), changes colour from violet to blue on formation of the corresponding pure bis-pyrrolizinato complex CuL(2) (lambda(max) = 660 nm). The CuL(2)-doped PVF membrane reacts in the gas phase on exposur e to species (X) that are copper-coordinating ligands stronger than L, generating the reverse colour change to violet. The remarkable stabil ity towards water of CuL(2)/PVF is a promising indication for prospect ive use of ML(2) complexes, incorporated in polymeric membranes, for t he detection of (X) species in the atmosphere even in the presence of moisture, or directly in aqueous solutions.