NEW FAMILIES OF COORDINATED CARBON - OXIDATIVE COUPLING AND CROSS-COUPLING OF A TRANSITION-METAL BUTADIYNYL COMPLEX TO BIMETALLIC M-C-CC-CC-CC-C-M AND M-C-CC-CC-C-M ADDUCTS

[(eta(5)-C(5)Me(5))Re(NO)(PPh(3))(C=CC=CC=CC=C)(Ph(3)P)(ON)Re(eta(5)-C(5)Me(5))] and [(eta(5)-C(5)Me(5))Re(NO)(PPh(3))(C=CC=CC=C)-(Ph(3)P) (ON)Re(eta(5)-C(5)Me(5))], which contain the longest chains of elemental carbon tethered between two transition metals to date, are prepared by Cu(OAc)(2) coupling of [(eta(5)-C(5)Me(5))Re(NO)(PPh(3))(C=CC=CH)], or cross-coupling with the corresponding;ethynyl-complex; unusual spectroscopic and redox properties are described.