Re(v) and Re(iii) complexes with sal2phen and triphenylphosphine: rearrangement, oxidation and reductionCCDC reference numbers 780134-780137. For crystallographic data in CIF or other electronic format see DOI: 10.1039/c0dt00993h

Reactions of Re V , tetradentate Schiff base complexes with tertiary phosphines have previously yielded both rearranged Re V and reduced Re III complexes. To further understand this chemistry, the rigid diiminediphenol (N 2 O 2 ) Schiff base ligand sal 2 phen ( N , N ′- o -phenylenebis(salicylaldimine)) was reacted with ( n -Bu 4 N)[ReOCl 4 ] to yield trans -[ReOCl(sal 2 phen)] ( 1 ). On reaction with triphenylphosphine (PPh 3 ), a rearranged Re V product cis -[ReO(PPh 3 )(sal 2 phen*)]PF 6 ( 2 ), in which one of the imines was reduced to an amine during the reaction, and the reduced Re III products trans -[ReCl(PPh 3 )(sal 2 phen)] ( 4 ) and trans -[Re(PPh 3 ) 2 (sal 2 phen)] + ( 5 ) were isolated. Reaction of sal 2 phen with [ReCl 3 (PPh 3 ) 2 (CH 3 CN)] resulted in the isolation of [ReCl 2 (PPh 3 ) 2 (salphen)] ( 3 ). The compounds were characterized using standard spectroscopic methods, elemental analyses and single crystal X-ray crystallography. Reaction of 1 with excess PPh 3 results in metal or imine reduction, substitution and rearrangement; Re( v ) is not an innocent bystander.