Alkali Metal Tetraselenohypodiphosphonates: Synthesis, NMR Spectroscopy and Crystal Structures

Abstract

The one-pot reaction of alkyl or aryl dichlorophosphanes RPCl 2 with alkali metal selenides M 2 Se and M 2 Se 2 in a 2:2:1 molar ratio provides a simple and general route to alkali metal tetraselenohypodiphosphonates (RP) 2 Se 4 M 2 (M = Li, Na; R = alkyl, aryl). The new compounds were characterized by multinuclear ( 31 P, 77 Se, 1 H, 13 C) NMR spectroscopy and

New Salts of the Waterstable P2Se64− Anion

“…As expected, the 77 Se satellites in the 31 P NMR spectrum display the eight line pattern for the A part . From this, the 1 J PP coupling constant is directly evaluated and agrees well with the −210 Hz found in tetraselenohypodiphosphonate anions . The 1 J SeP coupling constant (−532 Hz) is in between the values found for two coordinated selenium atoms (P−Se−) and the values observed in phosphorus selenides (R 3 PSe) .…”

“…24 From this, the 1 J PP coupling constant is directly evaluated and agrees well with the -210 Hz found in tetraselenohypodiphosphonate anions. 25 The 1 J SeP coupling constant (-532 Hz) is in between the values found for two coordinated selenium atoms (P-Se-) and the values observed in phosphorus selenides (R 3 PdSe). 26 The 2 J SeP coupling constant is 9 Hz.…”

Preparations of Metal Trichalcogenophosphonates from Organophosphonate Esters

“…The “end-on” coordination mode observed in 2 is very different from the “side-on” coordination observed in tetrathiohypodiphosphonate [(C 6 H 11 P(S 2 )) 2 Li 2 (TMEDA) 2 ], in which two five-membered PPSLiS chelate rings are present, both of which include the P–P bond. To our knowledge, the only other example of similar “end-on” coordination as featured in 2 is in the tetraselenohypodiphosphonate complex [(PhP(Se 2 )) 2 Li 2 (TMEDA) 2 ] …”

“…The P−P bond is rotated such that the benzyl groups are staggered with respect . 36 Attempts to prepare the trithiophosphonate 1 in higher purity and yield by lowering the reaction temperature to −78 °C in order to minimize the occurrence of the condensation reaction proved unsuccessful, with 31 P NMR showing tetrathiohypodiphosphonate 2 to still be present in the product mixture in appreciable quantity. However, substitution of PhCH 2 PO 3 Et 2 with n PrPO 3 Et 2 did lead to an improvement in yield and purity with the trithiophosphonate 3 obtained in 20% yield as colorless crystals (Scheme 3).…”

Oxygen, sulfur, selenium, tellurium and polonium

“…80 A number of studies have reported the oxidation of P(III) to P(V) by a range of chalcogen sources; reaction of RPCl 2 (R = Me, Et, i Pr, t Bu, Ph, Ad, 2-thiophenyl) with M 2 Se and M 2 Se 2 (2 : 2 : 1) afforded [(RP) 2 Se 4 ]M 2 (M = Li, Na). 81 82 Hydrophosphination of appropriate alkenes followed by oxidation by elemental chalcogen (S, Se) produced extremely bulky secondary phosphine chalocogenides in excellent yield. 83 A new series of arylselenium(II) derivatives of dithiophosphorus ligands ArSeSP(S)R 2 [R = Ph, or OR] have been prepared from Ar 2 Se 2 and [R 2 P(S)S] 2 .…”