Bond forming reactions of carbyne and nitrene complexes. Final technical report for DE-FG02-96ER14608

Templeton, J.L.

University of North Carolina at Chapel Hill

关键词: Carbynes;    37 Inorganic, Organic, Physical And Analytical Chemistry;    Carbenes;    Carbides;    Mesons;   

DOI  :  10.2172/803353
RP-ID  :  DOE/ER/14608-1
RP-ID  :  FG02-96ER14608
RP-ID  :  803353

美国|英语

来源: UNT Digital Library

【 摘 要 】

An isolobal relationship among terminal carbyne, nitrene and oxo ligands provided the basis for our efforts to explore new synthetic routes to such complexes and to probe bond forming reactions of these ligands. The specific goals of this project were to explore reactions of carbyne and nitrene ligands, and a summary of our results follows. Manipulation of metal-ligand pi bonds to control reactivity patterns provided the conceptual basis for this work. New transformations and coupling reactions of the CR and NR moieties bound to metal centers have been explored and transformations of carbyne or nitrene ligands have been achieved. Perhaps the most exciting results have come in the area of the simplest ligand: the CH carbyne unit. Treatment of [Tp'(CO){sub 2}W{triple_bond}C-PPh{sub 3}] [PF{sub 6}] Tp' = hydridotris(3,5-dimethylpyrazolylborate) with Na[HBEt{sub 3}] forms the methylidyne complex Tp' (CO){sub 2}W{triple_bond}C-H via formyl and carbene intermediates. Protonation of the Tp'(CO){sub 2}W{triple_bond}C-H methylidyne complex yields the cationic agostic methylidene complex, [Tp'(CO){sub 2}W=CH{sub 2}][BF{sub 4}]. The methylidyne complex with a pK{sub a} of 28.7 can be deprotonated to provide the anionic terminal carbide Tp' (CO){sub 2}W{triple_bond}C-Li; a resonance at 556 ppm in the {sup 13}C NMR spectrum has been assigned to the carbide carbon. Addition of excess Na[HBEt{sub 3}] to Tp'(CO){sub 2}W{triple_bond}C-H generates the anionic methylidene complex [Na] [Tp'(CO){sub 2}W{triple_bond}CH{sub 2}].