Bis(trimethylsilyl)diazene revisited. Density functional theory (DFT) calculations of nitrogen NMR parameters of some azo-compounds

✍ Scribed by Bernd Wrackmeyer; Christian Köhler

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 120 KB
• Volume: 16
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/hc.20075

✦ Synopsis

Calculations of nitrogen NMR parameters [chemical shifts δN and indirect nuclear spin-spin coupling constants

and N N(SiH 2 CH 2 SiH 2 )] by density functional theory (DFT) methods [B3LYP/6-311+G(d,p) level of theory] provide data in reasonable agreement

with experimental values. The influence of cis-and trans-geometry is reflected by the calculations, and amino-nitrenes are also included for comparison. The spin-spin coupling constants are analyzed with respect to contact (Fermi contact term, FC) and noncontact contributions (paramagnetic and diamagnetic spin-orbital terms, PSO and DSO, and spindipole term, SD). Bis(trimethylsilyl)diazene 6a can be generated by an alternative method, using the reaction of bis(trimethylsilyl)sulfur diimide with bis-(trimethylsilyl)amino-trimethylsilylimino-phosphane.