摘要:
We developed a salt-free reduction of WCl6 using 1-methyl-3,6-bis(trimethylsilyl)-1,4-cyclohexadiene (MBTCD) in toluene to give a low-valent trinulcear tungsten complex involving W(II) and W(III) centers, while in the presence of redox active ligands such as alpha-diketone and alpha-diimine the same reduction produced W(IV) complexes with the corresponding redox-active ligands, (alpha-diketone)WCl4 and (alpha-diimine)WCl4. A W(VI) complex with two alpha-diketone ligands, (alpha-diketone)(2)WCl2, was found to be synthetically equivalent to low-valent W(IV) species that trapped azopyridine to give (alpha-diketone)WCl2(azopyridine).