Reactivity of the reduced anthracene complex of scandium [Li(thf) 3 ][Sc{N( t Bu)Xy} 2 (anth)] ( 2-anth-Li ) (Xy = 3,5-Me 2 C 6 H 3 ; anth = C 14 H 10 2- , thf = tetrahydrofuran) toward Brönsted acid [NEt 3 H][BPh 4 ] and azobenzene is reported. While a stepwise protonation of 2-anth-Li with two equivalents of [NEt 3 H][BPh 4 ] afforded the scandium cation [Sc{N( t Bu)Xy} 2 (thf) 2 ][BPh 4 ] ( 3 ), reduction of azobenzene gave a thermolabile, anionic scandium azobenzene complex [Li(thf)][Sc{N( t Bu)Xy} 2 ( η 2 -PhNNPh)] ( 4 ), which slowly lost one of the anilide ligands to form the neutral scandium azobenzene complex dimer [Sc{N( t Bu)Xy}( μ – η 2 : η 2 -Ph 2 N 2 )] 2 ( 5 ). Exposure of 3 to CO 2 produced the scandium carbamate complex [Sc{η 2 -O 2 CN( t Bu)(Xy)} 2 ][BPh 4 ] ( 6 ) as result of CO 2 insertion into the Sc-N bonds. In an attempt to prepare scandium hydrides, the reaction of 3 with the hydride sources LiAlH 4 and Na[BEt 3 H] led to the terminal aluminum hydride [AlH{N( t Bu)Xy} 2 (thf)] ( 7 ) and the scandium n -butoxide [Sc{N( t Bu)(Xy)} 2 ( μ -O n Bu)] ( 8 ) after Sc/Al transmetalation and nucleophilic ring-opening of THF, respectively. All reported compounds isolated in moderate to good yields were fully characterized.
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