A New Contribution Confirming the Analogy Between NO⁺ and Related Aryldiazo Ligands

Abstract The reaction of the cyclometalated five‐coordinate 16 electron iridium(III) complex [IrCl(H){P( t Bu) 2 C 6 H 4 –κ 2 P,C}{P( t Bu) 2 Ph}] ( 1 ) with the diazonium salt [ p ‐BrC 6 H 4 N 2 ]BF 4 in dichloromethane at room temperature was investigated. By spontaneous reductive elimination the iridium(I) complex salt trans ‐[IrCl(N 2 C 6 H 4 Br‐ p ){(P( t Bu) 2 )Ph} 2 ]BF 4 ( 2 ) was obtained in good yield. Therefore, this observed reaction behavior exhibits the diazonium unit as a strong π‐acceptor group and confirms furthermore the analogy between nitrosyl and aryldiazonium ligands. The new compound 2 has been characterized by standard spectroscopic methods and the molecular structure of 2 was determined by a single‐crystal X‐ray diffraction analysis (monoclinic, space group Cc , Z =4).