thermal decompn.;

C6H6 in solid matrix V atoms deposited with benzene matrix at 12 K; not isolated, detected by UV, ESR;

aluminium trichloride; sodium dithionite; aluminium in benzene mixt. of VCl3, Al powder, AlCl3, and C6H6 is boiled, dild. with C6H6, and slowly poured in a well cooled 30percent KOH soln. containing Na2S2O4; recryst. from diethyl ether;

AlCl3; THF; benzene in tetrahydrofuran; benzene a mixt. of VCl3, Al and AlCl3 in benzene is refluxed for 15 h under Ar, filtration, slow addn. of the lower layer to THF at room temp. during 2 h, the soln. is stirred 15 h at room temp.; cooled to -30°C overnight, filtration, washed (THF), briefly dried (vac.), the V(0)-compd. is isolated from the concd. soln. at -78°C;

sodium hydroxide; aluminium trichloride; aluminium in benzene reaction in abs. benzene at boiling temp.; removal of C6H6, layering with petroleum ether, hydrolysis with 1N NaOH; (C6H6)2V obtained from the petroleum ether layer is sublimated in high vacuum;

phenyl-magnesium bromide in tetrahydrofuran addn. of the V complex to PhMgBr in THF at -15°C; addn. of oxygen-free H2O; filtration; evapn.; (C6H5)2 sublimated off; extn. of the residue with hexane/ether (3:1); from the mixt. of (C6H6)2V and (C6H5C6H5)2V, (C6H6)2V is isolated by recrystn. from ether at -20°C;

C6H6 in neat (no solvent, gas phase) low-temp. cocondensation of atomic metal and ligand-vapor; recondensation under vacuum;

dysprosium(II) diiodide in benzene under conditions precluding exposure to atm.; soln. of vanadocene in benzene added to powder DyI2 at about 20°C; mixt. heated with stirring to 85°C for 10 h; soln. sepd. from ppt.; benzene removed (vac.); residue extd. (hexane); solvent removed at room temp.; residue heated in vac. by gradually raising the temp. to 110°C; mixt. of crystals sepd. by repeated sublimation (vanadocene sublimed at 50-60...;

phenyl-magnesium bromide in tetrahydrofuran addn. of the V complex to PhMgBr in THF at -15°C; addn. of oxygen-free H2O; filtration; evapn.; (C6H5)2 sublimated off; extn. of the residue with hexane/ether (3:1); from the mixt. of (C6H6)2V and (C6H5C6H5)2V, (C6H6)2V is isolated by recrystn. from ether at -20°C;

in gaseous matrix V vapour produced via laser vaporization carried by He into a flow tube reactor where C6H6 vapour injected; not isolated, detected by MS;