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Reaktionen von R 2 AlAlR 2 (R CH(SiMe 3 ) 2 ) mit Trimethylsilylazid — Insertion in die AlAl‐Bindung und Abbau zum trimeren Dialkylaluminiumazid
Author(s) -
Uhl Werner,
Gerding Rolf,
Pohl Siegfried,
Saak Wolfgang
Publication year - 1995
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19951280112
Subject(s) - chemistry , azide , trimethylsilyl azide , trimethylsilyl , bond length , crystallography , steric effects , crystal structure , medicinal chemistry , stereochemistry , organic chemistry
Reactions of R 2 AlAlR 2 (R CH(SiMe 3 ) 2 ) with Trimethylsilyl Azide — Insertion into the AlAl Bond and Formation of a Trimeric Dialkylaluminium Azide Tetrakis[bis(trimethylsilyl)methyl]dialuminium(4) ( 1 ) reacts with trimethylsilyl azide under insertion of one nitrogen atom into the AlAl bond. As shown by NMR spectra and crystal structure the product contains three and four coordinated Al atoms due to the coordination of the α‐nitrogen atom of the azide group to one of the Al atoms. An electronically delocalized N 3 ‐system is formed with a NN bond length of 132.0 pm and a bond order of 1.5 for both NN bonds. With an excess of trimethylsilyl azide further reaction is observed only under mild irradiation conditions with an exchange of the azide group between Si and Al and formation of Me 6 Si 2 and the dialkylaluminium azide 3 , which is better synthesized by the reaction of Me 3 SiN 3 with ClAl[CH(SiMe 3 ) 2 ] 2 . The sterically highly shielded aluminium azide 3 is a trimer in the solid state showing a non‐planar 12‐membered Al 3 N 9 heterocycle with short NN bonds (114 pm).