Reactivity of 2,3-bis(2-pyridyl)pyrazine with [Re2(CO)8(CH3CN)2]: Molecular structures of [Re2(CO)8(C14H10N4)] and [Re2(CO)8(C14H10N4)Re2(CO)8]

摘要: Abstract The reaction of the labile compound [Re2(CO)8(CH3CN)2] with 2,3-bis(2-pyridyl)pyrazine in dichloromethane solution at reflux temperature afforded structural dirhenium isomers [Re2(CO)8(C14H10N4)] (1 and 2), complex [Re2(CO)8(C14H10N4)Re2(CO)8] (3). In 1, ligand is σ,σ′-N,N′-coordinated to a Re(CO)3 fragment through pyridine pyrazine form five-membered chelate ring. A seven-membered ring obtained for isomer 2 by N-coordination 2-pyridyl groups while remains uncoordinated. For 2, 2a 2b are found dynamic equilibrium ratio [2a]/[2b]  =  7 solution, detected 1H NMR (−50 °C, CD3COCD3), coalescence being observed above room temperature. 3 behaves as an 8e-donor bridge bonding two fragments (σ,σ′-N,N′) interactions. When was carried out refluxing tetrahydrofuran, [Re2(CO)6(C14H10N4)2] (4) addition compounds 1–3. dinuclear rhenium derivative 4 contains units organic each core. X-ray crystal structures 1 reported.