Synthese und Kristallstruktur von [Ru₂(CO)₄(μ‐H)(μ‐NO)(μ‐PtBu₂)(μ‐PPh₂CH₂PPh₂)]BF₄

Abstract

Abstract The reaction of the coordinatively unsaturated complex [Ru 2 (CO) 4 (μ‐H)(μ‐P t Bu 2 )(μ‐dppm)] ( 1 , dppm = Ph 2 PCH 2 PPh 2 )] with the nitrosonium ion was revisited. Even by variation of the reaction conditions, the reaction afforded in each case not the sole addition product [Ru 2 (CO) 4 (μ‐NO)(μ‐H)(μ‐P t Bu 2 )(μ‐dppm)] + ( 2 ) as reported by us in an earlier paper. Instead always a mixture of three compounds containing the complexes [Ru 2 (CO) 4 (μ‐H) 2 (μ‐P t Bu 2 )(μ‐dppm)] + ( 3 ), [Ru 2 (CO) 4 (μ‐NO)(μ‐P t Bu 2 )(μ‐dppm)] ( 4 ), beside the originally described complex 2 was obtained. A new synthetic procedure affording compound 4 as the sole product by reaction of 1 with the nitrosylating reagent diazald ( N ‐methyl‐ N ‐nitroso‐ p ‐toluenesulfonamide) is described. It was found that complex 2 can act as an acid strong enough to protonate the starting complex 1 . Thus, the formation of the mixture of components in the title reaction could be explained. A mixing experiment of equimolar amounts of 1 and 2 showed unambiguously the formation of complexes 3 and 4 . A clean preparation of complex 2 as the sole product in form of its tetrafluoridoborate salt is only possible by reaction of 4 with tetrafluoridoboric acid in diethyl ether solution. The X‐ray crystal structure of [ 2 ]BF 4 is reported confirming the molecular structure of the complex 2 . Using the originally described preparation route for 2 afforded in each attempt of crystallization the complexes 2 and 3 as 1:1 mixture in the solid.