Synthetic and Structural Studies of Lithium Complexes of Selenophosphorus Ligands

Davies, Robert P.; Martinelli, Márcia

doi:10.1021/ic010835q

Cited by 59 publications

(58 citation statements)

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“…Using a synthetic route analogous to that employed to prepare the seleno-phosphorus compounds 1 and 2, [8] and also in accordance with literature procedures, [9] reaction of one equivalent of elemental tellurium with lithium diphenylphosphide in THF gave insertion of the tellurium into the phosphorus-lithium bond to yield the tellurophosphinite, [ phenylphosphide with elemental selenium and tellurium in a one-pot reaction, although we were also able to prepare 6 from reaction of 1 or 4 with one equivalent of tellurium or selenium respectively (Scheme 1). All of these telluriumcontaining compounds (4Ϫ6) are much more reactive than their selenium analogues (1, 2), being highly air, moisture, and light sensitive, and readily decompose to deposit amorphous tellurium.…”

Section: Resultsmentioning

confidence: 99%

“…Given the weakness of phosphorusϪtellurium double bonds [1c] it is perhaps not unexpected that the equilibrium lies well on the side of the Ph 2 PϪTe Ϫ tautomer and this is also in agreement with our observations with the selenium analogue 1, which also exists in a similar tautomeric form. [8] The 31 P NMR spectrum of 4 consists of a single peak with 125 Te satellites ( 1 J P,Te ϭ 747 Hz). As expected the coupling constant is approximately two to three times larger than the corresponding PϪSe coupling constants in 1, and is also at the top end of the range of values expected for PϪTe single bonds (reflecting the slightly shorter PϪTe distance), for example 451 Hz in (tBu 2 P) 2 Te.…”

Section: Resultsmentioning

confidence: 99%

“…( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) synthesis and characterisation of new selenolate and tellurolate complexes utilising the insertion reaction of elemental chalcogens into carbonϪlithium [7] or heteroatomϪlithium bonds [8] and have recently reported the synthesis and structural characterisation of a lithium selenophosphinite, [Ph 2 Figure 1). [8] In these systems the ligands were shown to exhibit a variety of novel coordination modes to the lithium centres which differed from those exhibited by their thio-phosphorus counterparts.…”

Section: Introductionmentioning

confidence: 99%

“…[8] In these systems the ligands were shown to exhibit a variety of novel coordination modes to the lithium centres which differed from those exhibited by their thio-phosphorus counterparts. This observation has now led us to turn our attention to the corresponding tellurium and mixed selenium/tellurium analogues.…”

Section: Introductionmentioning

confidence: 99%

“…[9] In contrast, reaction of RPLi 2 with three equivalents of selenium leads to formation of the dilithio triselenophosphonate 3. [8] We now report how reaction of (c-C 6 H 11 )PLi 2 with an excess (Ͼ3.2 equivalents) of selenium results in a single phosphorus-phosphorus coupling reaction to yield the novel tetraselenohypodiphosphonate complex [{(c-C 6 H 11 )P(Se)(SeLi)} 2 ·2TMEDA] (7).…”

Section: Introductionmentioning

confidence: 99%

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Structural Studies of Lithium Telluro‐ and Seleno‐Phosphorus Compounds

et al. 2003

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Lithium tellurophosphinite [Ph2PTe][Li(TMEDA)1.33(THF)1.33] (4), ditellurophosphinate, [Ph2PTe2][Li(THF)3.5(TMEDA)0.25] (5), and selenotellurophosphinate [Ph2P(Se)Te][Li(THF)2(TMEDA)] (6) complexes have been prepared from the insertion/oxidation reactions of lithiated secondary phosphanes with elemental chalcogens and characterised by X‐ray crystallography. Compounds 4−6 contain no tellurium−lithium bonding interactions in the solid state, instead existing as ion‐separated species with THF/TMEDA‐solvated lithium cations. Reaction of dilithiated primary phosphanes with more than three equivalents of elemental selenium gives [{(c‐C6H11)P(Se)(SeLi)}2·2TMEDA] (7) via a phosphorus‐phosphorus coupling reaction. Solid state characterisation of 7 reveals the organo groups in the tetradentate tetraselenohypodisphosphinate ligand to be in an anti conformation to one another and each lithium atom to be coordinated by two selenium atoms, one from each of the diselenophosphinate groups. Multinuclear NMR spectroscopic data are consistent with retention of the solid‐state structures of 4−7 in solution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Structural Studies of Lithium Telluro‐ and Seleno‐Phosphorus Compounds

et al. 2003

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Organic Compounds Containing Bonds between Se or Te with P, As, Sb and Bi

Murai

2014

Patai's Chemistry of Functional Groups

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This chapter describes syntheses, structures, and reactions of the compounds with phosphorus‐selenium double bonds and with at least one carbon‐phosphorus single bond and of their heavier congeners. Among them, phosphane selenides have been the most deeply studied and used as Lewis base catalysts, metal ligands, molecular sensors, and stating materials leading to selenium‐containing nanoparticles. The coupling constants between the phosphorus and selenium atoms are informative on the basicity of the phosphanes. Phosphinoselenoic acid chlorides and secondary phosphanes are frequently used precursors to give a range of phosphinoselenoic acid derivatives, whereas selenation of dichlorophosphanes leads to phosphonoselenoic acid dichlorides, which are converted to a variety of acid derivatives. The selenation of phosphinites also gives phosphinoselenoic acid O ‐esters. Stereochemical course of the substitution reaction at P ‐chiral phosphorus center in the substitution reaction has been elucidated. Some reactions of dimers of diselenoxophosphanes such as Woollin's reagent are also shown. The chapter finally describes examples of phosphane tellurides, arsenic, antimony, and bismuth isologues of phosphane selenides, although these are fewer.

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The Selenium‐Based Hexameric Macrocycle [(Se)P(μ‐NtBu)₂P(μ‐Se)]₆

et al. 2008

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Recently, we have developed logical approaches to a family of phosphorus-nitrogen-based macrocycles of the type [{P(m-NR)} 2 (m-Y)] n . [1,2] The tetrameric, nitrogen-bridged macrocycle [{P(m-NtBu)} 2 (m-NH)] 4 (Scheme 1 a) is obtained by the condensation of the dimers [ClP(m-NtBu)] 2 and [(NH 2 )P-(m-NtBu)] 2 in the presence of Et 3 N.[3] However, the pentameric homologue is produced exclusively if this reaction is undertaken in the presence of I À ions, resulting in the hostguest complex [{P(m-NtBu)} 2 (m-NH)] 5 I À (Scheme 1 b).[4] The toroidal structures of the tetramer and pentamer and the presence of endo NÀH functionalities combine the appearance and host-guest characteristics of organic macrocycles such as calixarenes and porphyrins.Less progress has been made in attempts to extend this class of new ligands to macrocycles containing other bridging elements, owing largely to the inability to generalize the synthetic methods used for N-bridged species. Indeed, the only representative of this type reported to date is the oxygenbridged dimer [{P(m-N(2-py)} 2 (m-O)] 2 (2-py = 2-pyridyl), obtained by hydrolysis of [ClP{m-N(2-py)}] 2 in the presence of CuCl and pyridine.[5] However, we reported a key synthetic step in the potential extension of this methodology to a broader range of macrocycles by showing that oligomerization can be effected between P 2 N 2 units by the reaction of a deprotonated P(H) = O group with a P À Cl bond (Scheme 2). [6] This reaction can be rationalized by a change from a Pcentered to an O-centered nucleophile. In this sense, the reaction can be seen to involve an intermediate possessing "masked" functionality. However, it should be noted in this regard that the ambiguous nature of species containing [R 2 P = E] À anions (E = O, S, Se, NR, etc.) is well established by previous structural and theoretical studies, as is the fact that the negative charge normally lies primarily over to the side of E. [7] We report herein the success of this approach by showing that the reaction of the dimer [(Cl)(Se=)P(m-NtBu)] 2 (1) with excess sodium metal in toluene at reflux gives the macrocyclic, selenium-bridged hexamer [(Se = )P(m-NtBu) 2 P(m-Se)] 6 (2) as a crystalline product in good yield (45 %) by formal head-to-tail cyclization of the intermediate anion. The formation of the P-Se-P bridge again stems from the ambidentate nature of the intermediate anion (Scheme 3). Evidence of the resulting presence of alternate P III and P V centers within the backbone of 2 is seen in the roomtemperature 31 P{ 1 H} NMR spectrum in toluene, which shows P III (d, d = 206.8 ppm) and P V centers (d, d = 54.4 ppm) that are coupled to each other with a coupling constant that is typical of a P-(m-NR)-P bridge ( 2 J31 P-31 P = 44 Hz). [8] This spectrum can be compared to that of the precursor 1, which shows two singlet resonances in the P V region only, for the cis (d = 22.1 ppm, major) and trans (d = 22.7 ppm, minor) isomers (together with 77 Se satellites attributed to the AA'X isotopomer containing one 77 Se atom...

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Synthetic and Structural Studies of Lithium Complexes of Selenophosphorus Ligands

Cited by 59 publications

References 22 publications

Structural Studies of Lithium Telluro‐ and Seleno‐Phosphorus Compounds

Structural Studies of Lithium Telluro‐ and Seleno‐Phosphorus Compounds

Organic Compounds Containing Bonds between Se or Te with P, As, Sb and Bi

The Selenium‐Based Hexameric Macrocycle [(Se)P(μ‐NtBu)₂P(μ‐Se)]₆

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Synthetic and Structural Studies of Lithium Complexes of Selenophosphorus Ligands

Cited by 59 publications

References 22 publications

Structural Studies of Lithium Telluro‐ and Seleno‐Phosphorus Compounds

Structural Studies of Lithium Telluro‐ and Seleno‐Phosphorus Compounds

Organic Compounds Containing Bonds between Se or Te with P, As, Sb and Bi

The Selenium‐Based Hexameric Macrocycle [(Se)P(μ‐NtBu)2P(μ‐Se)]6

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The Selenium‐Based Hexameric Macrocycle [(Se)P(μ‐NtBu)₂P(μ‐Se)]₆