Aluminium complexes with thio-phosphorus ligands: syntheses and characterisations of [Al2(CyPS3)2(CyPHS2)2] and [Al(S2PPh2)3]

Abstract

The novel aluminium complexes [Al(2)(CyPS(3))(2)(CyPHS(2))(2)] and [Al(S(2)PPh(2))(3)] have been prepared as potential models for alumino-thiophosphonate based materials; [Al(2)(CyPS(3))(2)(CyPHS(2))(2)] is the first example of a primary dithiophosphinate to be characterised in the solid state.

Preparations of Metal Trichalcogenophosphonates from Organophosphonate Esters

“…This complex is most likely formed through condensation of two PhCH 2 PS 3 Li 2 species (present in 1 ) with the elimination of lithium sulfide. A similar mechanism has been previously documented for the reaction of [Al 2 (S 2 P(H)C 6 H 11 ) 2 (S 3 PC 6 H 11 ) 2 ] with n BuLi to give [(C 6 H 11 P(S 2 )) 2 Li 2 (TMEDA) 2 ] …”

“…The P−P bond is rotated such that the benzyl groups are staggered with respect to one another. 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 ], 27 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 ].…”

“…A similar mechanism has been previously documented for the reaction of [Al 2 (S 2 P-(H)C 6 H 11 ) 2 (S 3 PC 6 H 11 ) 2 ] with n BuLi to give [(C 6 H 11 P-(S 2 )) 2 Li 2 (TMEDA) 2 ]. 27 The unit cell of 2 contains two independent complexes, 2-A and 2-B, both of which adopt the same structure with just minor variations in the bonding parameters (see Table 3). Within each complex, the [PhCH 2 P(S) 2 P(S) 2 CH 2 Ph] 2− ligand coordinates the two metal centers in a doubly bidentate manner, with each PS 2 moiety chelating a lithium center to create two four-membered PSLiS rings.…”

“…Transmetalation, ,, ion exchange, − and silyl ester cleavage ,,, protocols have also been used to introduce a metal center to an existing RPS 3 group. Moreover, and particularly salient to this work, we have previously reported on the reaction of primary phosphines with an organometal deprotonating agent and elemental chalcogen to give metal trithio- and triselenophosphonate complexes (Scheme c). − …”

Aluminium, gallium, indium and thallium

“…For comparison Ph 2 PH was treated with AlMe 3 and S 8 , leading to [(Ph 2 PS 2 ) 3 Al] whose molecular structure shows a distorted octahedral geometry around aluminium. 34 36 The synthesis of LAl{[C 3 (SiMe 3 ) 2 ]C(O)C(SiMe 3 )C(SiMe 3 )} is afforded by hydrolysis and alcoholysis of the cyclic aluminium acyl LAl[C(O)C(SiMe 3 )C(SiMe 3 )] (L = HC[(CMe)(NAr)] 2 , Ar = 2,6-i Pr 2 C 6 H 3 ) with concomitant elimination of aluminium hydroxides LAlOH(OR) (R = H, Et, t Bu). The complex was fully characterised and its structure shows an unusual spirocyclic species where a carbon atom is shared between a cyclopropene and an AlC 4 ring, this being the first cyclopropenyl aluminium species.…”