An approach towards the synthesis of lithium and beryllium diphenylphosphinites

Abstract

The diphenylphosphinites [(THF)Li(OPPh2)]4 and [(THF)2Be(OPPh2)2] have been synthesized via direct deprotonation of diphenylphosphine oxide with n BuLi and BePh2, respectively, as well as via salt metathesis. These compounds were characterized by multinuclear NMR spectroscopy, and the side-products of the reactions obtained under various reaction conditions have been identified. The beryllium derivative could not be isolated and decomposed into diphosphine oxide Ph2PP(O)Ph2. The solid-state structure of this final product together with that of [(THF)Li(OPPh2)]4 have been determined by single-crystal X-ray diffraction.

Alkaline‐earth metal dimesitylphosphinites and their ether adducts – A structural study in solution and in the crystalline state

“…Contrary to this finding, for calcium ions the binding of thf molecules is highly favored in comparison to phosphane [28] . In contrast to 2‐Et 2 O the alkali metal phosphinites always aggregate solely via bridging oxygen atoms [7–9,11] as has also been observed for the heteroleptic magnesium derivatives 2‐Et and 2‐Br . Molecular structure and atom labeling scheme of centrosymmetric 2‐Et 2 O are depicted in Figure 5.…”

“…Contrary to this finding, for calcium ions the binding of thf molecules is highly favored in comparison to phosphane. [28] In contrast to 2-Et 2 O the alkali metal phosphinites always aggregate solely via bridging oxygen atoms [7][8][9]11] as has also been observed for the heteroleptic magnesium derivatives Selected structural parameters of 3-thf and 3-dme are listed in Table 2, whereas the low data quality for 3-diglyme and 3triglyme only allow elucidation of the connectivity but not a reliable analysis of bond lengths and angles. The phosphinite 18), Ca1À O2 242.17 (19) Ca1À O3 247.80 (19), P1À O1 156.73 (19); angles (deg.…”

“…[6] However, peculiar degradation reactions have been observed for the lightest congeners containing lithium or beryllium. The molecular structures of the tetranuclear thf adduct [(thf)LiÀ OPPh 2 ] 4 [7,8] and the dinuclear dme complex [(dme)LiÀ OPPh 2 ] 2 have been reported, [9] but slightly bulkier lithium dimesitylphosphinite disproportionates into the phosphinate LiÀ O 2 PMes 2 and the corresponding phosphanide LiPMes 2 . [10] Beryllium bis(diphenylphosphinite) can be synthesized in THF solution via deprotonation of Ph 2 P(O)H with BePh 2 [δ( 31 P) = 83.4 ppm], however, during preparation substantial amounts of Ph 2 PH form and during attempted isolation, this complex degrades yielding mainly 1,1,2,2-tetraphenyldiphosphane 1-oxide.…”

“…[10] Beryllium bis(diphenylphosphinite) can be synthesized in THF solution via deprotonation of Ph 2 P(O)H with BePh 2 [δ( 31 P) = 83.4 ppm], however, during preparation substantial amounts of Ph 2 PH form and during attempted isolation, this complex degrades yielding mainly 1,1,2,2-tetraphenyldiphosphane 1-oxide. [8] The thf and thp adducts of potassium dimesitylphosphinite crystallize as tetranuclear complexes with a central (KO) 4 heterocubane cage, [11] whereas the crown ether complexes [(18C6)KÀ OPAr 2 ] (Ar=Ph, Mes) are mononuclear. [12] The reaction of Ca[CH(SiMe 3 ) 2 ] 2 with diphenylphosphane oxide in the presence of phenylsilane leads to phosphinite species which decompose to 1,1,2,2-tetraphenyldiphosphane 1oxide according to an NMR study at room temperature.…”

Coordination chemistry of alkali metal dimesityl-thio- and dimesityl-selenophosphinites [(L)2A-EPMes2]2 (A = Li, Na, K; E = S, Se; L = THF, THP) and [(18C6)K-SPMes2]

“…5 Despite the reactivity, tetranuclear [(thf)Li-OPPh 2 ] 4 and dinuclear [(dme)Li-OPPh 2 ] 2 with tetra-coordinate lithium atoms have been isolated and structurally authenticated. 6,7…”