Synthesis and structural characterization of a diruthenium pentalene complex, [Cp∗Ru{(Cp∗Ru)2B6H14}(Cp∗Ru)]

Treatment of nido -[1,2-(Cp*Ru) 2 ( μ -H) 2 B 3 H 7 ], 1 with five equivalents of Te powder led to the isolation of diruthenium pentalene analogue [ ( Cp*Ru ) { ( Cp*Ru ) 2 B 6 H 14 } ( RuCp* ) ] , 2 and a metal indenyl complex [ ( Cp*Ru ) 2 B 2 H 6 C 6 H 3 ( CH 3 ) ], 3 . The [ ( Cp*Ru ) 2 B 6 H 14 ] fragment in 2 may be considered as a true metal–boron analogue of η 5 - η 5 -pentalene ligand ( C 8 H 6 ) and [ ( Cp*Ru ) B 2 H 6 C 6 H 3 ( CH 3 ) ] fragment in 3 is an analogue of η 5 -indenyl ligand. The solid-state X-ray structures were unambiguously determined by crystallographic analysis of compounds 2 and 3 . Further, the density functional theory (DFT) calculations were performed to investigate the bonding and the electronic properties of 2a (Cp analogue of 2 ). The frontier molecular orbital analysis of both 2a and 2b (Cp analogue of [ ( Cp*Ru ) B 8 H 14 ( RuCp* ) ] ) reveals a lower HOMO–LUMO gap indicating less thermodynamic stability. Graphical Abstract SYNOPSIS Treatment of nido-[1,2-(Cp ∗ Ru) 2 ( μ -H) 2 B 3 H 7 ] with Te powder led to the isolation of diruthenium pentalene analogue [ ( Cp*Ru ) { ( Cp*Ru ) 2 B 6 H 14 } ( RuCp* ) ] and a metal indenyl complex [ ( Cp*Ru ) 2 B 2 H 6 C 6 H 3 ( CH 3 ) ].