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 η 2 ‐π‐side‐on coordinated alkyne complexes R‐Se[(η 2 ‐C≡C–R′)Co 2 (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, 1 H‐, 77 Se‐, and 13 C‐NMR) data as well as by X‐ray analysis of C 6 H 5 )Co 2 ‐(CO) 6 ] ( 8a ).