Acylthio- and Thioacylthiophosphines [(RCES)nPPh3-n, E = O, S; n = 1—3]: Synthesis and Structural Analysis

Stoichiometric reactions of alkali metal thio- and dithiocarboxylates with Ph2PCl, PhPCl2, and PBr3 gave the corresponding acylthio- and thioacylthiophosphines [(RCES)nPPh3-n, E = O, S; n = 1—3] 3—8 in moderate to good yields. The structures of (4-CH3C6H4COS)nPPh3-n (3d: n = 1, 4d: n = 2, 5d: n = 3) and (4-CH3C6H4CS2)2PPh (7b) were analyzed by X-rays. In the thiocarboxylate derivatives 3d, 4d, and 5d, the intramolecular interactions between the carbonyl oxygen and the central phosphorus atoms are weak and the thiocarboxylato ligands act as monodentates through the sulfur atoms. Similarly, in the dithiocarboxylate derivative 7b, the intramolecular interactions between the thiocarbonyl sulfur and the central phosphorus atoms are weak and the dithiocarboxylato ligands act as monodentates. The covalent phosphorus-sulfur and/or phosphorus-phenyl ipso-carbon bonds are nearly at right angles to one another, forming a distorted tetrahedron with the unshared electron pair orbital at the apex. The 31P NMR spectra o...