Polycarbon ligands: synthesis and characterization of the phosphinodiynes Ph\\r sub/2sub\\r PC≡C-C≡CR (R = Bu\\r supiti\\r sup\\r , Ph, SiMe\\r sub/3sub\\r ), the μ-η\\r sup1sup\\r ,η\\r sup2supsub/α,βsub\\r -butadiynyl complexes Ru\\r sub/2sub\\r (CO)\\r sub/6sub\\r -(μ-PPh\\r sub/2sub\\r )(μ-η\\r sup1sup\\r ,η\\r sup2supsub/α,βsub\\r -C≡C-C≡CR), and the molecular structure of a cobalt carbonyl derivative Ru\\r sub/2sub\\r (CO)\\r sub/6sub\\r (μ-PPh\\r sub/2sub\\r )(μ-η\\r sup1sup\\r ,η\\r sup2supsub/α,βsub\\r :-μ-η\\r sup2sup\\r ,η\\r sup2supsub/γ,δsub\\r -C≡C-C≡CBu\\r supiti\\r sup\\r )Co\\r sub/2sub\\r (CO)\\r sub/6sub