Preparation and characterization of a series of bromodiphenyl(N,N-dialkyldithiocarbamato)tellurium(IV) compounds where R=Me, Et, i-Pr, Bu, and of chlorodiphenyl(N,N-dibutyldithiocarbamato)tellurium(IV) and diphenylbis(N,N-dibutyldithiocarbamato)tellurium(IV). Crystal structure of Ph2TeBr[S2CNEt2] and Ph2Te[S2CNBu2]2

Abstract

The series Ph2TeBr[S2CNR2], where R = Bu, Pr, i-Pr, Et, and Me, as well as Ph2TeCl[S2CNR2] and Ph2Te[S2CNR2]2, where R=Bu, Pr, have been synthesized and characterized by elemental analysis and vibrational spectroscopy. Comparisons of the effect of changing R groups and halogen atoms can be made based on the two crystal structures determined herein along with earlier work. The geometry about tellurium is consistent with that of a distorted sawhorse structure where the dithiocarbamate groups are monodentate (or anisobidentate). The crystal structures of Ph2TeBr[S2CNEt2], 4, and Ph2Te[S2CNBu2]2, 7, were completed. The cell parameters for 4 are a = 11.204(3) Å, b = 14.106(11) Å, c = 13.867(10) Å, α = 99.62(6)°, β = 102.76(5)°, γ = 87.73(4)°, V = 2107 Å3, Z = 4, R = 0.0448, and Rw = 0.0489 and for 7 are a = 19.392(6) Å, b = 9.622(2) Å, c = 19.089(6) Å, β = 104.70(2)°, V = 3445(2) Å3, Z = 4, R = 0.0397, and Rw = 0.0439. Nuclear magnetic resonance spectra are not simple and indicate that several species are present in solution, as rearrangements and reductive elimination take place. Key words: structure, tellurium, bromo, diphenyl, dialkyldithiocarbamato.