The syntheses and structures of salts of the octachlorodirhenate(III) and octachlorodiosmate(III) anions with the 1,2-bis(triphenylphosphonium)ethane cation

Article abstract of DOI:10.1016/S0277-5387(97)00106-X

The reactions of cis-Re₂(O₂CCH₃)₂Cl ₄(py)₂ or (n-Bu₄N)₂Re₂Cl₈ with PR₃ (R = Cy or Ph) in refluxing 1,2-dichloroethane afford the bis-phosphonium salts (R₃PCH₂CH₂PR₃)Re₂Cl ₈; the crystal structure of the derivative where R = Ph shows that this is only the second example of a salt of the [Re₂Cl₈]^2- anion in which a 3-fold orientational disorder of the Re - Re units is encountered. A cation exchange reaction between (Ph₃PCH₂CH₂PPh₃)Cl₂ and (n-Bu₄N)₂Os₂Cl₈ affords (Ph₃PCH₂CH₂PPh₃)Os ₂Cl₈, which possesses an Os - Os bond distance of 2.1896(3) A and is the second example of a crystal structure of a [Os₂Cl₈]^2- salt in which a fully staggered rotational geometry is present.