Reactivity and Structure of Complexes of Small Molecules: Dinitrogen

Abstract

In this contribution, a comprehensive review of the coordination chemistry of dinitrogen since 2003 is presented. Tremendous advances have been achieved during this time frame on the activation and functionalization of dinitrogen, i.e. fixation, by metal centers. An emphasis is made on these cases. Mechanistic aspects pertaining to functionalization of N 2 are presented.

Ammonia Synthesis at Room Temperature and Atmospheric Pressure from N2: A Boron‐Radical Approach

“…[10][11][12][13][14] Despite impressive results obtained recently, only a few complexes have been demonstrated to efficiently reduce N2 to NH3 using carefully optimized sources of protons and electrons. [15][16][17] Notably, this strategy was successfully applied most recently to main group boron species (borylene derivatives). [18][19][20] On the other hand, theoretical calculations show that the incorporation of N2 can take place in some organic molecules.…”

Catalytic Reduction of N2 to Borylamine at a Molybdenum Complex

“…The reactivity of 2 towards Cy 2 BCl was first revealed by marked color changes, observed upon simple mixing of stoichiometric amounts of both compounds in THF at room temperature (l max going from 415 to 394 nm; Supporting Information, Figures S14 and S15). Formation the imido complex 3 was further demonstrated by 31 P NMR, through the downfield shift of both singlets up to 102.3 (Dd = + 20 ppm) and 61.9 ppm ((Dd =+ 6 ppm).…”

Catalytic Reduction of N2 to Borylamine at a Molybdenum Complex

“…The reactivity of 2 towards Cy 2 BCl was first revealed by marked color changes, observed upon simple mixing of stoichiometric amounts of both compounds in THF at room temperature (l max going from 415 to 394 nm; Supporting Information, Figures S14 and S15). Formation of the imido complex 3 was further demonstrated by 31 P NMR, through the downfield shift of both singlets up to 102.3 (Dd = + 20 ppm) and 61.9 ppm ((Dd =+ 6 ppm).…”

“…[1][2][3][4][5][6][7][8][9][10][11] These intense efforts have culminated in the discovery of only two catalytic processes, N 2 -to-NH 3 , [12][13][14][15][16][17][18] and N 2 -to-NTMS 3 (TMS = trimethylsilyl), [19][20][21][22][23][24][25] using carefully designed metal complexes. [26][27][28][29][30][31] In these processes, N 2 is coordinated to the metal center and subsequently functionalized using external sources of electrons and electrophiles (H + and R 3 SiCl, respectively). Mechanistically speaking, NH bonds can be obtained via stepwise and/or coupled H + /e À transfers, [12,32] while it is proposed that the NSi bond formation occurs via Si radicals.…”