SYNTHESIS AND CHARACTERIZATION OF NEW CYC LOPENTADIENYLARSENIC COMPOUNDS

The new cyclopentadienylarsanes (CpAsR2)-As-x (Cp-x = Me5C5, R = H1, E t2, (i)Pr3, (t)Bu4; Cp-x = Me3H2C5, R = Cl5, Et6, (i)Pr7) were synthes ized via metathesis reactions in satisfactory to good yields. 2-7 were characterized by H-1- and C-13-NMR-spectroscopy, mass spectrometry an d CH-analysis. The dihydrido compound 1 is stable at room temperature for a short time only, it decomposes already at -70 degrees C under fo rmation of an As-film. The solid-state structure of 4 as well as tempe rature dependent H-1- and C-13 NMR-spectra indicate steric overcrowdin g. 4 crystallises in space group P2(1)/c, a = 12.021(2) Angstrom, b = 9.488(2) Angstrom, c = 16.972(2) Angstrom, beta = 110.830(10)degrees, V = 1809.2(5) Angstrom(3), Z = 4, RF = 0.0483. Pyrolysis-studies on th e cyclopentadienyl(dialkyl)arsanes 2-4, 6 and 7 show their potential s uitability as precursors in the MOCVD-and the MOMBE-process.