Synthesis, characterization and studies on the third-order optical non-linearities of novel charge-transfer heteropoly complexes (C8H12N2)5H7PMo12O40 and (C8H12N2)3H3PMo12O40·5H2O

Abstract

Two novel charge-transfer (CT) heteropoly complexes, (C8H12N2)5H7PMo12O40 (1) and (C8H12N2)3H3-PMo12O40·5H2O (2), prepared by reacting p-Me2NC6H4NH2 with the four-electron heteropoly blue H7PMo12O40·12H2O and heteropoly acid H3PMo12O40· xH2O, respectively, were characterized by elemental analysis, and u.v., i.r., XPS and e.s.r. spectroscopies. A sizable electron-transfer interaction occurs within the product molecules and the heteropoly anions retain their Keggin structure. Their third-order optical non-linearity coefficients were measured using the Z-scan technique at a concentration of 4.68 × 10−6 mol dm−3 for (1) and 2.79 × 10−6 mol dm−3 for (2), with I 0 = 2.38 × 1013 w m−2 and λ = 532nm. The ¦χ(3)¦ for (1) is 2.61 × 10−10 esu and ¦χ(3)¦ for (2) is 1.05 × 10−10 esu.