Synthesis Of Heteroaromatic 3,3 '-Bridged Biscarbenes Of The 1,2,4-Triazole Series And Their Properties

The stable 3,3'-bridged biscarbenes, 1,4- and 1,3-bis[1-alkyl-4-phenyl-1,2,4-triazol-5-yliden-3yl] benzenes (5a,b,d) and 1,3-bis[1-(1-adamantyl)-4-phenyl-1,2,4-triazol-5-yliden-3-yl] butane (5c) have been prepared. Treatment of 5b with copper (I) chloride in tetrahydrofuran/acetonitrile solution and cobalt (II) chloride in acetonitrile or acetonitrile/toluene solution afforded the biscarbene copper (I) complex 8. The reactions of 5d with diphenyldiazomethane and sulfur resulted in the novel bisthione 6 and bisazine (7) derivatives, respectively. The X-ray crystal structures of 5d, 8 were determined.