Irradiation of matrix-isolated dicyanodiazomethane (4) with 254 nm-light leads to the dicyanocarbene 5, which, upon further photoexcitation, undergoes successive isomerizations until a photoequilibrium between the five C3N2 isomers dicyanocarbene (T-5), cyanoisocyanocarbene (T-6), 3-cyano-2H-azirenylidene (S-7), 3-isocyano-2H-azirenylidene (S-8), and diisocyanocarbene (S-9) is reached. The preferential
用 254 nm 光照射基质分离的双
氰基
重氮甲烷 (4) 导致双
氰基卡宾 5,其在进一步光激发后经历连续异构化,直到五种
C3N2 异构体双
氰基卡宾 (T-5)、
氰基异
氰卡宾 (T-6) 之间达到光平衡、3-
氰基-2H-亚氮基(S-7)、3-异
氰基-2H-亚氮基(S-8)和二异
氰基卡宾(S-9)。可以通过改变照射光的波长来优先形成该组的特定成员。未知化合物 6-9 的结构解析基于其计算和实验红外光谱的比较。(© Wiley-
VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)