symmetry involving two degenerate Sc—N2—Sc bonding orbitals. Upon brief exposure of the orange Sc3+ bridging dinitrogen complex to UV-light, photolysis to form the monomeric Sc2+ complex, [K(crypt)][Sc(NR2)3], was observed. Conversion of the Sc2+ complex to the Sc3+ dinitrogen complex was not observed with this crypt system, but it did occur with the 18-crown-6 (crown) analog which formed K(crown)}2
第一(N = N)2-配合物与最终上桥二氮,K(隐窝)}的稀土类
金属的2 - [(R 2 N)3
钪] 2 [μ-η 1:η 1 -N 2 ]}(crypt = 2.2.2-cryptand,R = SiMe 3),已在-35°C下于氮气中从Sc(NR 2)3的还原中分离出,并通过X射线晶体学表征。该结构不同于先前观察到的40多个具有晶体学特征的式[A 2 Ln(THF)x ] 2的稀土
金属(N═N)2–配合物的侧面结构。[μ-η 2:η 2 -N 2(Ln为SC,Y,和
镧系元素; X = 0,1; A =阴离子配位体,如酰胺,
环戊二烯,和芳基氧化物)。1.221(3)ÅN–N距离和1644 cm –1拉曼拉伸与(N═N)2–桥的存在是一致的。通过Evans方法测量所观察到的复合物的顺磁性与DFT计算结果一致,该DFT计算结果表明D 3对称性中的三重态(3 A 2)基态涉及两个简并的Sc-N