The preparation and substitution chemistry of the cationic bis(hydrazido(2−))rhenium(VII) complex [ReCl2(NNMePh)2(PPh3)][BPh4]. The crystal and molecular structures of [Re(NNMePh)2(S2CNMe2)2][BPh4] and [ReOCl(NNMePh)(PPh3)2][PF6]2

Abstract Reaction of [ReOCl 3 (PPh 3 ) 2 ] with MePhNNH 2 in boiling methanol gives the orange five-coordinate bis(hydrazido) cation [ReCl 2 (NNMePh) 2 (PPh 3 )][BPh 4 ] ( 1 ). Attempted recrystallization of 1 as its [PF 6 ] − salt led unexpectedly to the brown crystalline oxo-hydrazido dication [ReOCl(NNMePh)(PPh 3 ) 2 ][PF 6 ] 2 ( 2 ). The structure of 2 was determined as five-coordinate with the oxo- and hydrazido-moieties in the equatorial plane of a trigonal bipyramid, and with the mutually trans -phosphine ligands occupying the axial sites. Complex 1 is a versatile starting material and reacts with the sodium dithiocarbamates (NaS 2 CNR 2 , R = Me and Et) to give the red-crystalline bis(hydrazido)-bis-(dithio-carbamato) cations [Re(NNMePh) 2 (S 2 CNR 2 ) 2 ][BPh 4 ] [R = Me ( 3 ) and R = Et ( 4 )]. The structure of 3 was determined as pseudo-octahedral with linear, mutually cis -NNMePh groups and cis -chelating dithiocarbamato ligands. Reaction of 1 with the sterically hindered thiol 2,6-dichlorobenzene thiol (DCTH) gives the orange cationic bis(hydrazido)-bis(thiolato) complex [Re(NNMePh) 2 (DCT) 2 (PPh 3 )][BPh 4 ] ( 5 ). Reaction of the imido precursor [ReCl 3 (NPh)(PPh 3 ) 2 ] with excess MePhNNH 2 gives the yellow imido-hydrazido cation [ReCl 2 (NPh)(NNMePh)(PPh 3 )][BPh 4 ] ( 6 ). Complexes 1 , 2 and 6 contain the formally isoelectronic cores [Re(NNR 2 ) 2 ] 3+ , [ReO(NNR 2 )] 3+ and [Re(NPh)(NNR 2 )] 3+ .