Pseudohalogeno-metallverbindungen LXXII. Addition des azid-ions und anderer N-nucleophile an koordinierte kohlenmonoxid- und CO-ähnliche liganden und verwandte reaktionen. Azido- und isocyanato-carbonyl-metallkomplexe

Synthesis and Characterization of Terminal [Re(XCO)(CO)2(triphos)] (X=N, P): Isocyanate versus Phosphaethynolate Complexes

“…Cyanate complexes are often pre-pared by reaction of carbonyl complexes with an azide salt, according to [M] À CO + N 3 À ! [M] À NCO À + N 2 (M = W, Cr, Mo), [7] or inversely by reaction of azide complexes with CO. [8] We observed that Fe(CO) 5 reacts with NaPH 2 to form phosphaethynolate, however, in noncoordinated form as Na-A C H T U N G T R E N N U N G (OCP), while the iron-containing product is Na 2 [Fe(CO) 4 ]. [3] Further attempts to prepare [M] À PCO or [M] À OCP complexes by reaction of carbonyl complexes with NaPH 2 failed so far, and transition-metal complexes of terminal PCO À anions remain unknown.…”

Reactions of Metal Carbonyls with the Azide Ion and – vice versa – Reactions of Azido Complexes with Carbon Monoxide: Isocyanato Complexes. Analogous Reactions in NO+/N3– Transition Metal Chemistry [1]

“…Kinetic measurements were carried out for the reactions of the azide ion with the hexacarbonyl complexes [ M (CO) 6 ] ( M = Cr, Mo, W) to give [ M (CO) 5 NCO] – [2, 13]; with [Ru 3 (CO) 12 ] 17 (which has been shown to yield [Ru 3 (CO) 11 NCO] – 14), with [CpFe(CO) 2 L] + 18, and with [Mo(CO) 4 (bipy)] 19. The rate law and the activation parameters of these reactions are in agreement with a primary, rate determining, attack of the azide ion (as of other nucleophiles OH – , OR – , NHR – , R – , H – , 5) on the positively charged 20 carbon atom of a carbonyl ligand followed by a rapid elimination of N 2 and a Curtius type rearrangement [Scheme , Equation (7)].…”

“…In case of coordinatively saturated azido complexes, e.g. [(L)(DH) 2 CoN 3 ], CO pressure is necessary 5; the hexacoordinated complex [Co(NH 3 ) 5 N 3 ] 2+ shows no reaction with CO 40.…”

“…Without irradiation, Cp 2 Ti(N 3 ) 2 and CO react in an autoclave at 50 bar to give Cp 2 Ti(NCO) 2 41. Generally, it appears that reactions of CO with (coordinatively saturated) azido complexes, which require drastic conditions or irradiation to give isocyanate, proceed via nitrene species as intermediates 5 [Scheme , Equation (13)]. Nitrene complexes, e.g.…”

“…In the following, we summarize the literature on these reactions, which appeared since 1990 and also include some publications not cited in 5.…”