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

Abstract

The reactions of cis-Re 2(O 2CCH 3) 2Cl 4(py) 2 or ( n-Bu 4N) 2Re 2Cl 8, with PR, (R = Cy or Ph) in refluxing 1,2-dichloroethane afford the bis-phosphonium salts (R 3PCH 2CH 2PR 3)Re 2Cl 8; the crystal structure of the derivative where R = Ph shows that this is only the second example of a salt of the [Re 2Cl 8] 2 anion in which a 3-fold orientational disorder of the ReRe units is encountered. Å cation exchange reaction between (Ph 3PCH 2CH 2PPh 3)CI 2 and ( n-Bu 4N) 2Os 4Cl 8 affords (Ph 3PCH 2CH 2PPh 3)Os 2Cl 8,, which possesses an OsOs bond distance of 2.1896(3) Å and is the second example of a crystal structure of a [Os 2Cl 8] 2− salt in which a fully staggered rotational geometry is present.