Facile Synthesis of Bis(dichalcogenophosphinate)s and a Remarkable [Li₈(OH)₆]²⁺ Polyhedron

Abstract

The synthesis and characterization of three lithium complexes of novel bis(dichalcogenophosphinate) ligands are reported: (PhP(S) 2 CH 2 CH 2 P(S) 2 Ph)Li 2 (THF) 4 (2), (PhP(Se) 2 CH 2 CH 2 P(Se) 2 Ph)Li 2 (THF) 4 .(PhP(Se) 2 CH 2 CH 2 P(Se) 2 Ph)Li 2 (THF) 6 (3) and [PhP(Te) 2 CH 2 CH 2 P(Te) 2 Ph][Li 8 (OH) 6 (THF) 8 ] (4). The synthetic route to these complexes proceeds via the insertion reaction of elemental chalcogens into the phosphorus-lithium bonds of 1,2-dilithio-1,2-di(phenylphosphine)ethylene (1). X-ray analysis of 2 revealed anisobidentate coordination of the lithiums by the dithiophosphinate groups. In contrast, the diselenophosphinate groups in 3 coordinate the lithium centers in both isobidentate and mono-dentate modes, and the ditellurophosphinate groups in 4 form non-coordinate separate ion pairs. The counter-cation in 4 is shown to be a unique [Li 8 (OH)

Organophosphorus–Tellurium Chemistry: From Fundamentals to Applications

“…151 The structure of the related dianion [PhP(Te) 2 CH 2 CH 2 P(Te) 2 Ph] 2− has been determined in a salt with the octanuclear cluster counterion [Li 8 (OH) 6 (THF) 8 ] 2+ . 152 In their early work, Bildstein and Sladky showed that the reaction of tellurium with diorganylphosphides takes place even when the phosphide is coordinated to a Lewis acid to give the adducts (L)PR 2 Te − (R = Ph, L = BH 3 ; R = t Bu, Cr(CO) 5 ). 150 More recently, Wagner and co-workers obtained the potassium salts of [(H 3 B)PR 2 Te] − [H 3 B•40, R = Ph, t Bu] in almost quantitative yields and structurally characterized the [K(18crown-6)] + adducts; the anionic ligand in the R = Ph derivative binds to K + through the B atom as well as the Te center.…”

Secondary diphosphine and diphosphido ligands: synthesis, characterisation and group 1 coordination compounds

“…Preparation of 1,3-( t BuPLiCH 2 ) 2 C 6 H 4 •TMEDA (8). An aliquot of n BuLi (1.86 mL, 1.73 M in hexanes, 3.22 mmol) was added dropwise via syringe to a solution of 2 (455 mg, 1.61 mmol) in toluene (40 mL) at 0 °C.…”

“…The compound 1,2-(PhPLi) 2 C 6 H 4 has also been used to synthesize dichalcogenophosphinate derivatives by reaction with selenium or tellurium. 8 The coordination chemistry of phosphido ligands is vastly different from that of neutral phosphines, which only have one lone pair and are typically π-accepting. Phosphido centres feature two lone pairs, and hence have a propensity for π-donation, making them suitable for coordination to electron-deficient early transition metals and prone to bridging bonding motifs.…”

Alkaline and alkaline earth metals

“…62 The synthesis and characterisation of three lithium complexes of novel bis(dichalcogenophosphinate) ligands have been reported through insertion reactions of elemental chalcogens into the phosphorus-lithium bonds of 1,2-dilithio-1,2-di(phenylphosphine)ethylene. 63 The structural characterisation of two monomeric lithium uranyl-peroxide salts, Li 26 have been obtained from aqueous-alcohol solutions rather than the analogous aqueous solutions from which lithium uranyl-peroxide clusters were isolated. 64…”