(η5-C5Ph5)Rh(CO)2 has been prepared in 62% yield by treatment of [Rh(CO)2Cl]2 with NaC5Ph5 in THF. The title com pound crystallizes in the rhombic space group Pcab with the lattice parameters a = 2064.7(7) pm , b = 2065.2(8) pm, c = 1407.6(6) pm and Z = 8 . The crystal structure consists of discrete (η5-C5Ph5)Rh(CO)2 molecules and the Rh(CO)2 fragment adopts an eclipsed conformation relative to the cyclopentadienyl ring.
The reaction of phenylpentazole, C6H5-cyclo-N5, with n-butyl lithium in tetrahydrofuran or in diethylether does not yield a lithium pentazolide such as Li(THF)4+N5−. Instead, a mixture of several primary products is obtained, which probably include lithium 1-n-butyl-5-phenyl-pentaazadienide, Li+[n-C4H9− N=N−N−N=N−C6H5]− and di-n-butyl-phenylhydrazide, Li+[(n-C4H9)2N−N−C6H5]−. After hydrolysis 1,1-di-n- butyl-2-phenylhydrazine, (n- C4H9)2N−NH−C6H5, is ob- tained with good yield. This compound is an oil that was characterized by NMR, mass and IR spectroscopy