Synthesis and structural characterization of dialkyldithiocarbamato complexes of niobium

Abstract

The reaction of alkyne-containing niobium(III) complexes [NbCl₃(dme)(RCCR′)] (dme = 1,2-dimethoxyethane) with the appropriate Na(S₂CNR″₂) reagents, in a 1∶3 molar ratio, afforded the corresponding dialkyldithiocarbamato complexes [Nb(RCCR′)(S₂CNR″₂)₃] (R = R′ = Ph, R″ = Me 1; R = R′ = Ph, R″ = Et 2; R = R′ = R″ = Me 3; R = R′ = Me, R″ = Et 4; R = R′ = Et, R″ = Me 5; R = R′ = R″ = Et 6; R = R′ = SiMe₃, R″ = Me 7; R = R′ = SiMe₃, R″ = Et 8; R = Ph, R′ = Me, R″ = Me 9). The same complexes were also prepared from the reaction of the appropriate [NbCl₃(bpzm)(RCCR′)] [bpzm = bis(pyrazol-1-yl)methane] complexes with the corresponding sodium dialkyldithiocarbamates. All complexes were spectroscopically characterized and the dynamic behaviour of some of them was studied by variable-temperature NMR techniques. The molecular structure of complex 9 was also established.