Synthese und Koordinationsverhalten von Selenoalkinylen R―Se―C≡C―R'

Synthesis and Coordination Ability of Selenoalkynes R - Se - C ≡ C - R′ Several synthetic methods for the preparation of selenoalkynes R–Se–C≡C–R′ (1) are discussed. 1 reacts with octacarbonyl dicobalt to yield the η2-π-side-on coordinated alkyne complexes R-Se[(η2-C≡C–R′)Co2(CO)6 (8) which contain a sterically hindered carbon–cobalt tetrahedrane cluster unit. The identity of compounds 1 and 8 is documented by analytical and spectroscopic [IR, MS, 1H-, 77Se-, and 13C-NMR) data as well as by X-ray analysis of C6H5)Co2-(CO)6] (8a).