Ligand non-innocence allows isolation of a neutral and terminal niobium nitride
Ligand non-innocence allows isolation of a neutral and terminal niobium nitride
复制标题
配体非纯真允许分离中性和末端氮化铌
DOI：
10.1039/d2cc04696b
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发表时间：
2022
影响因子：
4.9
通讯作者：
Mindiola, Daniel J.
中科院分区：
文献类型：
--
作者：
Senthil, Shuruthi;Kwon, Seongyeon;Im, Hoyoung;Gau, Michael R.;Baik, Mu-Hyun;Mindiola, Daniel J.
络合物（PNP）NbCl 2（N[tBu]Ar）（1）（PNP− = N[2-PiPr 2 -4-methylphenyl]2; Ar = 3，5-Me 2C 6 H3）与1当量的的NaN 3形成（PNPN）NbCl 2（N[tBu]Ar）（2）和（PNP）NbN（N[tBu]Ar）（3）的混合物，这两者都已被光谱学和晶体学表征，包括15 N同位素标记研究。配合物3代表中性和单核Nb氮化物的第一个结构表征的实例。独立的研究证实3是通过2的双电子还原形成的，而3被双电子氧化则相反。计算研究表明，生成中间体[（PNP）NbCl（N3）（N[tBu]Ar）]（A）的金属交换步骤将N2挤出以形成膦酰亚胺[（PNPN）NbCl（N[tBu]Ar）]（B），然后还原为2和低价[（PNPN）Nb（N[tBu]Ar）]（C）。后者然后经历分子内N原子转移以形成3中的氮化物部分。
Complex (PNP)NbCl2(N[tBu]Ar) (1) (PNP− = N[2-PiPr2-4-methylphenyl]2; Ar = 3,5-Me2C6H3) reacts with one equiv. of NaN3 to form a mixture of (PNPN)NbCl2(N[tBu]Ar) (2) and (PNP)NbN(N[tBu]Ar) (3), both of which have been spectroscopically and crystallographically characterized, including 15N isotopic labelling studies. Complex 3 represents the first structurally characterized example of a neutral and mononuclear Nb nitride. Independent studies established 3 to form via two-electron reduction of 2, whereas oxidation of 3 by two-electrons reversed the process. Computational studies suggest the transmetallation step to produce the intermediate [(PNP)NbCl(N3)(N[tBu]Ar)] (A) which extrudes N2 to form the phosphinimide [(PNPN)NbCl(N[tBu]Ar)] (B) followed by disproportionation to 2 and low-valent [(PNPN)Nb(N[tBu]Ar)] (C). The latter then undergoes intramolecular N-atom transfer to form the nitride moiety in 3.