Trialkyl phosphate complexes

Curious products isolated by Bailey and Evans from the reaction of benzotrisfuroxan with triphenyl phosphine have been examined by X-ray crystallography by Cameron and Prout. The structures (44-46) were determined.A molecular complex of trialkyl phosphate with benzotrisfurazan is formed using a trialkyl phosphite as reducing agent. 

Trialkyl phosphates form volatile 1 1 adducts with acids such as nitric and chloroacetic, from which the esters are recovered by base treatment. I.r. and n.m.r. spectral data suggest that these are hydrogen-bonded complexes. At low temperatures, in FSOaH-SbFj, trialkyl phosphates were shown (by n.m.r.) to give protonated species in which there appears to be considerable pir-d-rr back-donation from oxygen to phosphorus. These species are not stable the tri-n-butyl ester decomposing over the course of two days to MeaC+ and (HOiP. ... 

The reduction of nickel(II) dichloride with trialkyl phosphite is another synthetic route to Ni(0) complexes (eq (2)) [8]. This reaction involves the oxidation of trialkyl phosphite to trialkyl phosphate. 

Many complexes of trialkyl phosphates and the phosphonates OP(OR)2R have been isolated, especially with shorter alkyl chains. The dependence of the type of complex formed on the steric demands of the ligand is illustrated by the formulations proposed for complexes of 0(0104)2 [Co(OC103)(OH2) OP(OBu")3 4][C104], [Co(OH2)2 OPMe(OPr )2 4][C104]2, [Co OP(OMe)3 s]-[C104]2 and [Co(OCI03) OPMe(OPr )2 4][C104]. 

Electron-diffraction measurements on trimethyl phosphate are best interpreted by assuming the presence of two rotational isomers the molecular parameters reported are cf(P=0) 1.477 cf(P—O) 1.580 d 0—C) 1.432 A, Z.OPO 105.2°, and Z.POC 118.4°. Thermal condensation reactions between trialkyl phosphates and dialkyl phosphorochloridates give monophosphorus side-products in addition to alkyl pyrophosphates. Detailed examinations of such systems suggest that oxonium-type intermediates such as (111) are involved rather than quasi-phosphonium complexes. 

Organophosphate Ester Hydraulic Fluids. Organophosphate esters are made by condensing an alcohol (aryl or alkyl) with phosphorus oxychloride in the presence of a metal catalyst (Muir 1984) to produce trialkyl, tri(alkyl/aryl), or triaryl phosphates. For the aryl phosphates, phenol or mixtures of alkylated phenols (e.g., isobutylated phenol, a mixture of several /-butylphenols) are used as the starting alcohols to produce potentially very complex mixtures of organophosphate esters. Some phosphate esters (e.g., tricresyl and trixylyl phosphates) are made from phenolic mixtures such as cresylic acid, which is a complex mixture of many phenolic compounds. The composition of these phenols varies with the source of the cresylic acid, as does the resultant phosphate ester. The phosphate esters manufactured from alkylated phenylated phenols are expected to have less batch-to-batch variations than the cresylic acid derived phosphate esters. The differences in physical properties between different manufacturers of the same phosphate ester are expected to be larger than batch-to-batch variations within one manufacturer. 

Den Auwer et al have studied the complexation of the uranyl ion by a series of trialkyl and triaryl phosphates tri- -butylphosphate(T BP), tri- -butylphosphate(TBP), trimethylphospha-te(TMP), and triphenylphosphate(TPhP) by EXAFS. EXAFS was used to help better understand the coordination environment of the extracted complexes, as well as the extractive ability of the organophosphorus compounds. 

Trialkyl and triaryl phosphates, in common with their phosphonate, phosphinate and phosphine oxide analogues, will complex heavy metals in solution and some of these complexes can be isolated as crystalline solids. Complexing affinity increases with increasing basicity of the donor phosphoryl compound (R being constant) ... 

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