Experimental Evidence for Linear Metal–Azido Coordination: The Binary Group 5 Azides [Nb(N3)5], [Ta(N3)5], [Nb(N3)6]−, and [Ta(N3)6]−, and 1:1 Acetonitrile Adducts [Nb(N3)5(CH3CN)] and [Ta(N3)5(CH3CN)]

✍ Scribed by Ralf Haiges; Jerry A. Boatz; Thorsten Schroer; Muhammed Yousufuddin; Karl O. Christe

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 166 KB
• Volume: 45
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.200601060

✦ Synopsis

Dedicated to Professor Reint Eujen on the occasion of his 60th birthday

Whereas the existence of numerous binary transition-metalazido complexes has been reported, [1][2][3] no binary Group 5 azides are known. Only a limited number of partially azidosubstituted compounds of vanadium, niobium, and tantalum have previously been reported. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Herein, we communicate the synthesis and characterization of [Nb(N 3 ) 5 ], [Ta(N 3 ) 5 ], and their 1:1 adducts with CH 3 CN, as well as the anions [Nb(N 3 ) 6 ] À and [Ta(N 3 ) 6 ] À . The crystal structures of [Nb(N 3 ) 5 (CH 3 CN)] and [PPh 4 ][Nb(N 3 ) 6 ] and the first experimental evidence for the existence of azido compounds with linear M-N-N coordination are also reported.

The reactions of NbF 5 or TaF 5 with excess (CH 3 ) 3 SiN 3 in SO 2 solution at À20 8C resulted in complete fluorido-azido exchange and yielded clear solutions of [Nb(N 3 ) 5 ] or