Synthesis, spectroscopic, and structural studies of dimethyltellurium(IV) alkylene and diphenyl dithiophosphates. Crystal structures of and

Abstract

and -CH2CEt2CH2-, have been synthesized in 80-90% yields by reaction of the corresponding sodium or ammonium salts of the appropriate dithiophosphoric acids with dimethyltellurium dichloride in toluene. Me,Te[S,P(OPh),], was also prepared in a similar fashion. The compounds have been characterised by elemental analyses -and 'H, l3C, 3 '~, and ' 2 5~e NMR, infrared and Raman spectroscopy. = 0.0295. The immediate environment about tellurium in both molecules is that of the saw-horse structure typical of tellurium(1V) compounds with the two methyl groups equatorial and one sulfur atom from each dithiophosphate group occupying the axial positions. The consideration of the second sulfur atom as part of the coordinating sphere is discussed in terms of a modification of Pauling's approach to partial bond orders. The 'H NMR spectra suggest that these dithiophosphates may be fluxional in solution andlor that there is rapid exchange of the sulfur atoms.

A study of a variety of O,O-alkylene dithiophosphate derivatives of triphenyl-and diphenylgermane. Crystal structures of and

“…In other words, the shifts are consistent with the structures in solution apparently remaining the same as the solid state structures of 1-3, where the ligand is monodentate or weakly anisobidentate because the second sulfur atom is oriented toward rather than away from germanium but at a sufficiently large distance to imply, at best, a weak interaction. The shifts are smaller than those-observed for the methyl germanium analogues and considerably smaller than those observed for analogous dimethyltellurium derivatives where AP ranged from 11 to 16 ppm downfield (17). Although the dithiophosphate groups had trast, in the tin and tellurium analogues, the dithiophosphate groups undergo exchange in solution to bring about equivalence for all atoms in the groups, presumably by interchanging the bonded and aniso-bonded sulfur positions, which is consistent with the general tendency for dithio ligands to be bidentate when attached to tin and tellurium (34,35).…”

“…This structure is also typical of xanthate derivatives of germanium (3)(4)(5). Recently, we reported the synthesis and characterization of a number of cyclic dithiophosphate derivatives of methylgermanes (6) whose NMR spectra showed unusual features that suggested that the solid state structures were maintained in solution, in contrast to what had been observed in general (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) and for tin and tellurium analogues in particular (14,17). Unfortunately, we were only successful in obtaining a crystal structure for one derivative, ~OCH,CE~,CH,$]-C~H~, 3, but have not been able to get data of sufficient quality to fully solve the structures of any of the diphenylgermanium analogues, 6 6 .…”

“…environments, as is the fact that these couplings are not observed in a consistent manner (8,9,12,14,17). The 3 1~( H ) NMR spectra, which are presented in Table 9 along with the 'H NMR data, show a single peak in all compounds 1-6, consistent with both dithiophosphate groups in 4-6 being in identical environments.…”

“…H(l), H(4)) and H, (i.e., H(2), H(3)) in Figs. 4 and 5 occupy The 'H NMR spectra of compounds 2,3,5, and 6 all display axial and equatorial positions, respectively, in a chair, rather the same complex Pattern arising from the nonequivalence than boat (6), configuration that is maintained in solution. The of the hydrogen atoms of the CH2 groups in the six-memvalues for J(PH) differ because the distance from P to the Ha bered ring, which is apparent from the X-ray strutpositions is much larger than that to the H, positions.…”

Synthesis, spectroscopic and structural studies of O-methyl and O-isopropyl monothiocarbonate (monoxanthate) derivatives of dimethyl-and diphenyltellurium(IV). Crystal structures of Me2Te[SCO2(i-Pr)]2, Ph2Te[SCO2(i-Pr)]2, Me2TeCl[SCO2Me], and Me2TeBr[SCO2(i-Pr)]

“…There have been a number of reports on the reactions of organotellurium(1V) compounds with a variety of 1,l -dithio ligands, such as O-alkyl dithiocarbonates (1)(2)(3)(4)(5)(6), N,N-dialkyl dithiocarbamates (5)(6)(7)(8)(9)(10)(11)(12)(13)(14), and 0,O-dialkyl(alky1ene) dithiophosphates (4-6, [14][15][16][17][18][19][20][21], as well as a recent extensive review of supramolecular associations in tellurium complexes with sulfur ligands (22). In general, the chemistry of monothio ligands has received much less attention but a few reports have appeared relating to main group element derivatives including those on monothiocarbamate compounds of thallium (23), tin (24,25), and, most recently, tellurium (26) as well as on monothiophosphate compounds of tin (27,28).…”