were, in all cases, borazine, [HNBH]3, and polyborazylene, [NBHx] (x < 1), whereas other minor products were derived from B–N bond-cleavage processes. Over the course of these reactions, complexes 1a–c were transformed into the corresponding mononuclear hydrides [MCpH(CO)3] [M = Cr (2a), Mo (2b), W (2c)], which are supposed to be the catalytically active species in these processes, as also supported by
用催化量 (5 mol-%) 的单键二聚体 [M2Cp2(CO)6] [M = Cr (1a), Mo (1b), W ( 1c);Cp =
环戊二烯基] 在温和的热活化 (333 K) 下导致加合物逐步脱氢,并分别在 12、24 和 >34 小时后实现定量转化。在这些反应的初始阶段(低转化率),主要产物是
氨基
硼烷(NH2=
BH2)的环状和支链低聚物。然而,在更长的反应时间(高转化率)下,在所有情况下,主要产物是环
硼氮烷 [HNBH]3 和聚
硼氮烷 [NBHx] (x < 1),而其他次要产物来自 B-N 键- 裂解过程。在这些反应过程中,配合物 1a-c 被转化为相应的单核氢化物 [MCpH(CO)3] [M = Cr (2a), Mo (2b), W (2c)],它们被认为是这些过程中的催化活性物质,也得到了二
氢化物纯样品 [Mo2Cp2(H)2(μ-Ph2PCH2PPh2)(CO)2]