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A common feature of fluorescent sensing materials for detecting chemical warfare agents (CWAs) and simulants is the presence of nitrogen-based groups designed to nucleophilically displace a phosphorus atom substituent, with the reaction causing a measurable fluorescence change. However, such groups are also basic and so sensitive to acid. In this study we show it is critical to disentangle the response of a candidate sensing material to acid and CWA simulant. We report that pyridyl-containing sensing materials designed to react with a CWA gave a strong and rapid increase in fluorescence when exposed to Sarin, which is known to contain hydrofluoric acid. However, when tested against acid-free diethylchlorophosphate and di-iso-propylfluorophosphate, simulants typically used for evaluating novel G-series CWA sensors, there was no change in the fluorescence. In contrast, simulants that had been stored or tested under a standard laboratory conditions all led to strong changes in fluorescence, due to acid impurities. Thus the results provide strong evidence that care needs to be taken when interpreting the results of fluorescence-based solid-state sensing studies of G-series CWAs and their simulants. There are also implications for the application of these pyridyl-based fluorescence and other nucleophilic/basic sensing systems to real-world CWA detection. Chemical warfare agents and simulants are commonly detected with fluorescent sensing materials containing nitrogen-based groups, however these groups’ basicity can cause false positives in the presence of acids. Here, the authors disentangle the response of pyridyl-containing sensing materials to acid-containing and acid-free Sarin and simulants.

A gold(I) complex with a 1,1′-binaphthyl-substituted diphosphene was synthesized and fully characterized. A phosphorus atom with a less-hindered binaphthyl group coordinates to a gold(I) moiety in ...

The structures and energetics of the binuclear phospholyl chromium carbonyl derivatives (C4H4P)2Cr2(CO)n (n = 6, 5, 4, 3) have been investigated by density functional theory. The lowest energy (C4H4P)2Cr2(CO)n (n = 6, 4, 3) structures are completely analogous to their Cp2Cr2(CO)n analogues with two terminal pentahapto phospholyl rings. However, for the pentacarbonyl (C4H4P)2Cr2(CO)5 the lowest energy structure has a bridging seven-electron donor η5,η1-C4H4P ligand using the phosphorus lone pair in addition to the π-system of the phospholyl ligand as well as a Cr-Cr single bond. Thus, except for the pentacarbonyl the phosphorus lone pair of the phospholyl ligand is seen to play a minor role in the energetically preferred structures of the binuclear phospholyl chromium carbonyl derivatives.

International audience; Proazaphosphatranes, also known as Verkade's superbases, have been investigated as ligands for gold(I). If the coordination to the gold center by the phosphorus atom suggests phosphine‐like behavior, gold(I)‐containing Verkade's superbase complexes could also be prepared from the weak conjugate acid azaphosphatrane by the formation of the corresponding silver complex and subsequent transmetalation to gold, similarly to the synthetic route used for complexes bearing N‐heterocyclic carbene ligands (NHCs). A competitive transmetalation experiment highlighted the higher lability of Verkade's superbases compared with NHCs. Furthermore, combined theoretical and experimental studies showed that they display strong σ‐donor ability, better than phosphines and similar to NHCs. Thus, some specific properties of both NHCs and phosphines are combined in Verkade's superbases, thereby providing a new approach to tuning the ligand properties of gold(I) complexes.

Preparation of diastereomericamidosulfites or phosphonic acid amidoesters derived from a diastereomerically or enantiomerically pure phenol residue containing a chiral auxiliary is presented. The a...

The chemistry of transition metal compounds that contain a phosphorus atom acting as ligand, sometimes called “naked” phosphorus, started at the end of the last century. However, it is still an area of permanent interest and expansion, in which new examples of complexes with novel structural features are appearing in the literature. In this review, the phosphide complexes are classified based on the different coordination modes found in structurally characterised complexes for coordination numbers from 1 to 4 at the phosphorous atom. Structural aspects are discussed and, in some cases, the bonding patterns rationalised. Additionally to the structural analysis, data from 31P NMR spectroscopy, as a potent characterization tool, are also revised and briefly analysed.

The interplay of NMR experiments and DFT calculations of NMR parameters is a reliable method for determining the relative configurations of pentacoordinate chiral spirophosphoranes bearing two six- or five-membered rings at the phosphorus atom in solution. The major product of the Betti based derivatives corresponds to the isomers with both substituents at chiral carbons being opposite to the P-H proton. The next populated product corresponds to the isomer with different chiralities at carbons. The least populated isomer is one with both substituents being at the same side of the heterocycle as the P-H bond.

We studied the reactions of manganese and rhenium phenylvinylidenes Cp(CO)2M═C═C(H)Ph (Mn1 M = Mn; Re1 M = Re) with HP(O)R2 (R = C6F5, Ph, and OEt) and HP(S)Ph2, which resulted in the selective formation of η2-E-phosphorylalkene complexes Cp(CO)2M{η2-E-H[R2(O)P]C═C(H)Ph} (Mn2, Re2 R = C6F5; Mn3, Re3 R = Ph; and Mn6, Re6 R = OEt) and Cp(CO)2M{η2-E-H[Ph2(S)P]C═C(H)Ph} (Mn5, Re5). The DFT/B3LYP(6-31G*) analysis showed the model reactions of Mn1 with HP(O)Me2 and HP(O) (OMe)2 to proceed via the initial transition state Cp(CO)2{Ph(H)C═C═}Mn···HO–PR2 (TS1) where the minor PA form HO–PR2 is hydrogen-bonded to the metal, followed by stereoselective (trans- to the phenyl group) addition of the PA phosphorus atom to the Cα-vinylidene atom, which defines both the rate of the process and the anti-Markovnikov structure of the reaction product. The reactions can proceed at a relatively low content of the reactive PA form.

The structures and thermodynamics of the binuclear phospholyl iron carbonyls (C 4 H 4 P) 2 Fe 2 (CO) n ( n = 6, 5, 4, 3, 2) have been investigated using density functional theory. The low-energy (C 4 H 4 P) 2 Fe 2 (CO) n ( n = 4, 3, 2) structures are found to have direct iron–iron bonds and terminal five-electron donor pentahapto η 5 -C 4 H 4 P rings with the phosphorus lone pairs not involved in the bonding to the iron atoms. They are thus analogous to the corresponding cyclopentadienyliron carbonyl derivatives. However, they differ from the binuclear phospholyl manganese carbonyls (C 4 H 4 P) 2 Mn 2 (CO) n ( n = 5, 4) for which structures with bridging seven-electron donor η 5 , η 1 -C 4 H 4 P phospholyl rings are the lowest energy structures by substantial margins. Partially bonded phospholyl rings, as well as direct Fe–Fe bonds, are found in the carbonyl-rich (C 4 H 4 P) 2 Fe 2 (CO) n ( n = 6, 5) species. The pentacarbonyl (C 4 H 4 P) 2 Fe 2 (CO) 5 does not appear to be a viable species since it is disfavored relative to CO loss and to disproportionation into (C 4 H 4 P) 2 Fe 2 (CO) 6 + (C 4 H 4 P) 2 Fe 2 (CO) 4 .

The synthesis of gold(I) complexes of 2,5-diferrocenyl-1-phenyl-1 H -phosphole ( 1 ) is presented. Chloro(2,5-diferrocenyl-1-phenyl-1 H -phosphole)gold ( 3 ) has successfully been prepared by the reaction of 1 with AuCl(SMe 2 ) ( 2 ). Treatment of 2 with arylethyne (aryl = ferrocenyl, phenyl) using catalytical amounts of [CuI] and 1 equiv. of 1 gave arylethynyl-(2,5-diferrocenyl-1-phenyl-1 H -phosphole)gold 4a and 4b (aryl: a = ferrocenyl; b = phenyl). Compound [ μ -(1,4-phenylenedi-2,1-ethynediyl)]bis(2,5-diferrocenyl-1-phenyl-1 H -phosphole)digold ( 5 ) could be synthesized by a similar procedure using 0.5 equiv. of 1,4-diethynylbenzene. The electrochemical properties of 3 , 4a,b and 5 were investigated by cyclic and square wave voltammetry. In 3 , 4a and 4b each ferrocenyl unit shows one reversible redox event with redox separations of the ferrocenyl moieties in 2,5 position of approximately 260 mV. In 5 two redox events for the four ferrocenyl groups were observed. Spectroelectrochemical measurements of 3 , 4a and 4b reveal IVCT absorptions with intensities of 1100–1300 L mol −1 cm −1 and a full-width-at-half-height of ≈3650 cm −1 . In 5 two mixed-valent units are present per molecule and therefore, the intensity of the IVCT band is increased to 2700 L mol −1 cm −1 . Compounds 3 , 4a,b and 5 can be classified as moderately coupled class II systems according to Robin and Day. The complexation of the gold(I) fragment by the phosphorus atom leads to a decreased metal–metal interaction when compared to 1 .

A new effective synthetic route to the racemic phosphine oxides and phosphonium salts with a P-asymmetric center was developed based on the stepwise reaction of phosphacoumarins with organomagnesium compounds. A selective P–C bond formation was achieved on each step owing to the differences in reactivity of the exocyclic P–Cl or P–O bonds and endocyclic P–O bond of phosphacoumarins. It was found that the P(O)OMgX fragment of the phosphocoumarin salt does not hinder in the substitution reaction at the phosphorus atom accompanied by ring-opening and P–C bond formation.

[PdCl{P(OC6H4NMe)2}{P(OC6H4NMe)OC6H4NHMe}] was prepared by the reaction of LiP(OC6H4N(CH3))2 with [PdCl2{P(OC6H4N(CH3))(OC6H4NH(CH3))}]. The expected four diastereomers of the complex are observed in the 31P{1H} and 1H NMR at −20 °C, however at room temperature there is fast exchange between pairs of diastereomers. The energetics of three possible mechanisms by which the diastereomers may be interconverting, are considered by DFT studies: displacement of the coordinated amine, followed by inversion at the nitrogen atom; displacement of the coordinated phosphoramidite, followed by inversion at the phosphorus atom; Berry pseudorotation at the coordinated phosphoranide. The inversion of a dissociated amine appears to be the most likely mechanism.

Complexes [Ph3PCH2CH=CHCH2PPh3]2+[AuCl4]2− (I) and [Ph3PCH2CH2COOH]+[AuCl4]− (II) have been synthesized by the reaction of hydrotetrachloroauric acid with 2-butene-1,4-bis(triphenylphosphonium) dichloride (2: 1 mol/mol) and 2-carboxyethyltriphenylphosphonium chloride (1: 1 mol/mol). The phosphorus atoms in the cations of complexes I and II have a slightly distorted tetrahedral coordination (CPC, 106.5(7)°–112.5(8)°), and P-C bond lengths are 1.768(14)–1.819(17) A. The square coordination of the gold atom in the anions of complexes I and II is almost undistorted: ClAuCl angles are 88.53(6)°–91.3(3)°, Au-Cl bond lengths are 2.254(5)–2.289(6) A. The cations in crystals are bonded by H⋯Cl hydrogen bonds of 2.72–2.79 A I) and 2.77–2.85 A II). The cations of complex II form dimers due to strong H⋯O bonds (1.85 A) between carboxyl groups.

The interest of organophosphorus compounds bearing chirality on the phosphorus atom has greatly expanded in last decade, due to the development of efficient stereoselective synthetic methods, using...

The positive electrostatic potentials (ESP) outside the σ-hole along the extension of OP bond in OPH3 and the negative ESP outside the nitrogen atom along the extension of the CN bond in NCX could form the Group V σ-hole interaction OPH3⋯NCX. In this work, the complexes NCY⋯OPH3⋯NCX and OPH3⋯NCX⋯NCY (X, YF, Cl, Br) were designed to investigate the enhancing effects of Y⋯O and X⋯N halogen bonds on the P⋯N Group V σ-hole interaction. With the addition of Y⋯O halogen bond, the VS, max values outside the σ-hole region of OPH3 becomes increasingly positive resulting in a stronger and more polarizable P⋯N interaction. With the addition of X⋯N halogen bond, the VS, min values outside the nitrogen atom of NCX becomes increasingly negative, also resulting in a stronger and more polarizable P⋯N interaction. The Y⋯O halogen bonds affect the σ-hole region (decreased density region) outside the phosphorus atom more than the P⋯N internuclear region (increased density region outside the nitrogen atom), while it is contrary for the X⋯N halogen bonds. © 2015 Wiley Periodicals, Inc.

The NHC PH adduct IMes: PH was used to form one- and two-centered coordination compounds with tungsten and boron atoms using one or two lone pairs of phosphorus atom.

The reactivity of bis(organoamino)phosphanes PhP(NHR)(NHR′) (1a–1c, in which R, R′ = tBu for 1a; tBu, Dip for 1b; and Ph for 1c; Dip = C6H3–2,6-iPr2) and tBuP(NHDip)2 (1d) with Me3Al was investigated. The reaction of 1a or 1b gave in the first step compounds [PhP(NHR)(NR′)]AlMe2 (in which R, R′ = tBu for 2a; tBu, Dip for 2b) as a result of methane elimination that upon heating underwent nitrogen-to-phosphorus hydrogen-atom migration under the formation of diiminophosphinates [Ph(H)P(NR)(NR′)]AlMe2 (in which R, R′ = tBu for 3a; tBu, Dip for 3b). In contrast, phosphane 1c showed a reversed reaction sequence that yielded an intermediate [Ph(H)P(NHPh)(=NPh)]AlMe3 (2c) first as a consequence of hydrogen-atom migration followed by the methane elimination and formation of diiminophosphinate [Ph(H)P(NPh)2]AlMe2 (3c). The partial deprotonation of 1a,b,d using one molar equivalent of nBuLi followed by the treatment with AlCl3 smoothly produced compounds [Ph(H)P(NR)(NR′)]AlCl2 (in which R, R′ = tBu for 4a; tBu, Dip for 4b) and [tBu(H)P(NDip)2]AlCl2 (4d), in which the hydrogen atom was again shifted from the nitrogen to the phosphorus atom. All studied compounds were characterized with the help of elemental analysis; 1H, 13C{1H}, 31P, and 31P{1H} NMR spectra; and in the case of 3c, 4a, 4b, and 4d by using single-crystal X-ray diffraction analysis. The phenomenon of the hydrogen-atom migration was subjected also to a theoretical survey with particular emphasis on the influence of the phosphane used.

Chiral ferrocene-based phosphines with a wide variety of substituents at the phosphorus atom(s) have been simply and modularly synthesized by ortho lithiation of Ugi’s amine and then reaction with PCl3 and finally treatment with Grignard or organolithium reagents.

The addition of Re(CO)5+ [as Re(CO)5FBF3] to P(CN)3 and to P(CN)2– affords the complexes [Re(CO)5]3P(CN)3(BF4)3 and Re(CO)5P(CN)2, respectively. The spectroscopic data indicate that Re(CO)5+ is coordinated to each of the three cyano groups of P(CN)3 to give {P[C≡N-Re(CO)5]3}[BF4]3, whereas the pseudohalide P(CN)2– is bonded to the rhenium cation through the phosphorus atom.

The salt [(C6H5)3PC4H9]3[PW12O40] has been synthesized by a reaction between triphenylbutyl phosphonium bromide and dodecatungstophosphoric heteropoly acid in water and structurally characterized. The phosphorus atoms in the two types of crystallographically independent [(C6H5)3PC4H9]+ cations each have a distorted tetragonal coordination (P-C distances, 1.745(16)–1.823(15) A; CPC angles, 107.2(8)°–112.1(9)°). In centrosymmetric [PW12O40]3− anions (with a phosphorus atom at the inversion center) the W-Oend, W-O(μ2), and W-O(μ4) bonds are 1.61(1)–1.71(2), 1.87(2)–1.94(2), and 2.44(2)–2.50(2) A, respectively.

The first examples of butadiyne derived cyclic fluorophosphazenes have been synthesized and structurally characterized. A reaction of PhC C C CLi with P3N3F6 yielded the phenylbutadiyne monosubstituted fluorophosphazene, [PhC C C C(F)PN](PNF2)2 (1) along with the geminally disubstituted fluorophosphazene [(PhC C C C)2PN](PNF2)2 (2), while an analogous reaction of FcC C C C Li (Fc = ferrocenyl) with N3P3F6 gave the ferrocenylbutiadiyne monosubstituted fluorophosphazene, [FcC C C C(F)PN](PNF2)2 (3) and the geminally disubstituted fluorophosphazene [(FcC C C C)2PN](PNF2)2 (4). Compound 1 on reaction with FcC CLi yielded the unsymmetrical geminally disubstituted compound [(FcC C)(PhC C C C)PN](F2PN)2 (5). Reactions of compound 3 with PhC CLi and FcC CLi, also resulted in unsymmetrically disubstituted fluorophosphazenes [(PhC C)(FcC C C C)PN](F2PN)2 (6) and [(FcC C)(FcC C C C)PN](F2PN)2 (7), having both butadiyne and alkyne units on the same phosphorus atom of the heterocycle. All new compounds were characterized by IR, NMR [1H, 13C{1H}, 31P{1H}, and 19F{1H}] and HRMS studies. Compounds 1, 2, 4 and 5 have also been structurally characterized.

A synthetic strategy has been developed to prepare liquid crystalline cyclotriphosphazenes that have two different types of mesogenic units linked to the same phosphorus atom. Hexachlorocyclotriphosphazene, N3P3Cl6, was reacted with 3 mol of the calamitic unit 4-cyano-4'-hydroxybiphenyl to give a mixture of compounds in which the nongem-trans-trisubstituted derivative N3P3Cl3(OC6H4C6H4{CN}-p)3 was the major product. The substitution of all three chlorine atoms in this nongeminal compound gave rise to the hydroxyl-functional phosphazenes, nongem-trans-N3P3(OC6H4C6H4{CN}-p)3(OC6H4{OH}-p)3 or nongem-trans-N3P3(OC6H4C6H4{CH3}-p)3(OC6H4{OH}-p)3, from which the second mesogenic unit, a polycatenar one, was introduced. The chemical structure of the resulting materials, deduced from spectroscopic and MALDI-TOF techniques, was in accordance with monodisperse, fully functionalized cyclotriphosphazenes. Mesomorphism is highly dependent on the terminal group of the calamitic units, and liquid crystal phases were only detected on the cyano-derivatives. The calamitic or columnar nature of the mesophase depends on the number of alkyl chains of the polycatenar moieties., This work was supported by the MICINN, Spain, under the projects CTQ2015-70174-P, MAT2014-55205-P, and CTQ2011-22589, FEDER, Gobierno de Aragon-Fondo Social Europeo (Spain, Dpto. de Innovación, Investigación y Universidad, groups E-97 and E-09).

The reaction of tetraphenylphosphonium chloride with an equimolar amount of potassium tetrachloroplatinate or hexachloroplatinic acid in dimethyl sulfoxide gave the complexes [Ph4P]+[PtCl3(DMSO)] - (I) and [Ph4P]+[PtCl5(DMSO)] - (II), respectively. The phosphorus atoms in the cations have tetrahedral environment, the CPC angles and P-C distances 105.63(13) -112.13(14), 1.795(3)-1.797(3) Å I) and 105.7(3) -112.9(3), 1.783(7)-1.791(6) Å II). The platinum coordination polyhedra in the anions [PtCl3(DMSO)]- and [PtCl5(DMSO)]- are distorted square (Pt-S, 2.1937(8); Pt-Cl, 2.2894(10)-2.3024(10) Å; trans-angles: SPtCl, 177.38(4); ClPtCl, 175.40(4)) and octahedron (Pt-S 2.291(2) Å; Pt-Cl, 2.312(2)-2.334(2) Å, trans-angles: SPtCl, 178.28(9); ClPtCl, 178.80(9) and 178.88(8)). © 2013 Pleiades Publishing, Ltd.

The diastereoselective synthesis of Pro-Phe phosphinyl dipeptide isosteres in protected form was achieved by starting from optically active 1,1-diethoxyethyl(aminomethyl)phosphinate. Our methodology involves diastereoselective α-alkylation and β′-alkylation of phosphinate derivatives with an asymmetric center at the phosphorus atom.

Go for the gold! Incorporating a borate anion into the backbone of a triphosphenium cation produces a unique zwitterionic phosphanide that can coordinate to one or two {AuCl} fragments depending on the steric bulk of the ligand (see picture; Au yellow, P purple, Cl green). Computational investigations show that in this μ-type ligand, the phosphorus atom behaves only as a σ,π donor.

A spiro to ansa rearrangement has been investigated by the reactions of cyclotriphosphazene derivatives having five-membered spiro rings, N3P3Cl4[O(CH2)2NH], (1) and N3P3Cl4[O(CH2)2O], (2) with disodium salts of 1,3-propanediol and 2,2,3,3-tetrafluoro-1,4-butanediol. Compounds 1 and 2 with the strong nucleophile, 1,3-propapanediol, give rearrangement reactions to form stable ansa–ansa compounds, whereas reaction of compounds 1 and 2 with the fluorinated alkoxide results in normal nucleophilic substitution at the PCl2 groups and no rearrangement takes place with the weaker nucleophile. The synthesised compounds (3a, 3b, 4b, 5a–d, 6c and 6d), have been fully characterised by elemental and mass (MS) analysis, and by 1H and 31P NMR spectroscopy. Crystal structures of 3b, 4b, 5b–d and 6c have been characterised by X-ray crystallography. It is found that 1,3-propapanediol is a sufficiently strong nucleophile to cause a spiro to ansa rearrangement in the mono-spiro cyclotriphosphazenes compounds 1 and 2, even though crystallographic evidence shows that formation of the seven- and eight-membered ansa–ansa rings in compound 3b results in distortion and compression of the cyclophosphazene ring. A possible mechanism, which depends on attack of the anionic oxygen nucleophile at spiro-bearing phosphorus atom, was used to help understand the spiro-to-ansa rearrangement reaction.

The reaction of (Z)-4-aminopent-3-en-2-one with different chlorodiorganylphosphanes established three new ligands composed of a hard and soft coordination site. The soft phosphane site is easily coordinated to palladium(II) as a first step in the potential formation of heterodinuclear complexes. Surprisingly, the formed square-planar dichloridopalladium(II) complexes exhibit exclusively trans configuration. A cis configurated palladium(II) complex can be formed, when the linker between the phosphane and the enaminoketone unit is enlarged and allows more flexibility. The reaction between (Z)-4-(2′-hydroxyethylamino)pent-3-en-2-one and chlorodiorganylphosphanes revealed two new ligands that coordinate to palladium(II). With phenyl substituents at the phosphorus atom a cis palladium complex was obtained, whereas for isopropyl substituents a trans complex was formed. Molecular structures of all complexes were analyzed by single-crystal X-ray diffraction.

A simple and practical method for modifications of tertiary arylphosphine oxides based on their reaction with sodium in liquid ammonia is presented. Depending on the structure of the starting compounds, either dearomatisation of the phenyl substituent or cleavage of a P-aryl bond from phosphorus atom can be selectively performed and the corresponding (1,4-cyclohexadien-3-yl)phosphine oxides or secondary phosphine oxides were obtained in good to excellent yields.

In a notable extension of previous work, we have shown that several diphosphanes will form larger (7- or 8-membered ring) cyclic triphosphenium ions (CTIs) in solution by reaction with PX 3 (X = Cl, Br or I), sometimes in the presence of SnCl 2 or SnBr 2 . We have also formed new CTIs from two ferrocene derivatives. The ions are readily identifiable by 31 P NMR solution-state spectroscopy, having large 1 J P–P values between the middle ‘bare’ phosphorus atom P A and the outer phosphorus atoms P B (and P C where the outer groups are inequivalent). In addition, some data for known CTIs, but with different counter-ions, are presented. Three of the new CTIs have been successfully protonated, two by both AlCl 3 / t BuCl and triflic acid, and one via the triflic acid route only.

The stepwise protonation constants of a series of thiomonophosphate anions, i.e., monothiomonophosphate, dithiomonophosphate, trithiomonophosphate, and tetrathiomonophosphate anions, were determined by (31)P NMR chemical shift measurements in aqueous solution. Despite the remarkably fast hydrolysis rates of these anions, the protonation processes of all thiomonophosphate anions may be evaluated accurately without any previous purification, because the NMR signals corresponding to thiomonophosphate anions and hydrolyzed residues are well resolved. The stepwise protonation constants decrease with an increase in the number of sulfur atoms bound to the central phosphorus atom. It was revealed that the logarithms of the stabilities of the proton complexes of the series of thiomonophosphate anions decrease "linearly" with an increase in the number of sulfur atoms in the anions. The intrinsic (31)P NMR chemical shifts due to orthophosphate and tetrathiomonophosphate anions show upfield shifts upon successive protonations of the anions, whereas the shifts of mono-, di-, and trithiomonophosphate anions move downfield relative to the anions upon protonation. Furthermore, more asymmetric molecular structures experience greater changes in their X-P-Y bond angles upon protonation or complex formation, leading to drastic changes in the nuclear screening. The symmetry of the molecular structure is related to the direction of the (31)P NMR chemical shift change upon successive protonation of thiomonophosphate anions.

Two stereoisomers, the trans form 1a and the cis form 1b, of 2,3,7,8-tetramethyl-5,10-diphenyl-5,10-dihydrophosphanthrene dioxide (1) were formed by spontaneous oxidation in air of the corresponding 5,10-dihydrophosphanthrenes 2 and were separated by recrystallization. Both 1a and 1b were characterized by X-ray crystallographic analysis, which revealed configurations at the phosphorus and conformations of the central tricyclic system. The 31P NMR of the reaction mixture showed at first two signals at −15.3 and −15.1 ppm, which shifted to 9.11 and 10.3 ppm after purification of the reaction mixture under aerobic conditions by oxidation of phosphorus atoms. The reaction of 1b with HSiCl3 in toluene-d8 at 100 °C gave no change, whereas 1a reacted with HSiCl3 to give reduced compounds 2a and 2b under the same conditions. The trans–cis isomerization of 2 occurred via vertex inversion at phosphorus atom. VT-NMR, X-ray analysis, and density functional theory (DFT) calculation showed that the conformatio...

We synthesized new phosphorus-containing linear and macrocyclic polyphenols using organic compounds containing phosphorus-carbon bonds and the phosphorus atom of various coordination, and also with reactive acetal, aldehyde, vinylethoxy, and methylene quinone fragments as starting materials. These achievements are briefly summarized.

Five secondary phosphine oxides (SPOs) differing in the steric and electronic properties of the P-substituents were reacted with [Rh(acac)(cod)]. Due to the tautomeric equilibrium, SPOs are able to coordinate to metal atoms via their trivalent tautomers. Their complexation behavior is strongly dependent on the substituents at the phosphorus atom. Electron-rich tertiary alkyl groups do not favor the reaction, whereas electron-poor phosphinous acids immediately coordinate, resulting in “quasi-chelate” complexes with a hydrogen bond in the backbone. The latter remains intact even in alcohols. Additionally, the SPOs were reacted with [Rh(cod)2]BF4, resulting in the corresponding BF2-capped complexes.

The tautomeric behaviour of five secondary phosphane oxides (SPOs) with different electronic properties has been investigated by NMR and IR spectroscopy, density functional theory calculations and X-ray structural analysis. Proof is given that only with strong electron-withdrawing groups on the phosphorus atom can the relevant trivalent phosphinous acid be observed in the equilibrium, whereas in the case of electron-rich phosphane oxides the pentavalent species dominates. For a detailed analysis of the IR spectra, the deconvolution programme BTEM has been successfully applied.

Treatment of Ru(═CHPh)Cl2(PCy3)2 (Cy = cyclohexyl) with K[N(i-Pr2PS)2] afforded a mixture of Ru(═CHPh)[N(i-Pr2PS)2](PCy3)Cl (1) and Ru(═CHPh)[N(i-Pr2PS)2]2 (2). Reaction of 1 with TlOPh gave Ru(═CHPh)[N(i-Pr2PS)2](PCy3)(OPh) (3), whereas that with NaOMe yielded the Ru(II) hydride compound Ru(H)[N(i-Pr2PS)2][PCy2(η2-C6H9)] (4), in which the dicyclohexyl(cyclohex-3-enyl)phosphine ligand binds to Ru via the phosphorus atom and the C═C bond of the cyclohex-3-enyl ring. The structures of complexes 3 and 4 have been established by X-ray crystallography.

The phosphinocarbyne complex [Mo(≡CPPh2)(CO)2{HB(pzMe2)3}] is obtained by successive treatment of [Mo(≡CBr)(CO)2{HB(pzMe2)3}] with nBuLi and ClPPh2. An alternative approach to phosphorus-functional...

The reaction of dialkylphosphonites with N-(bromomethyl)phthalimide furnishes alkyl phenyl hydrogenphosphinates, dialkyl phenylphosphonates, and N-[(bromomethyl)phthalimido)]-phosphinates. The stereoselectivity of the primary product of the reaction appears to increase with the increasing size of the groups attached to the phosphorus atom.

A direct, Grignard reagent-based route for the syntheses of [2-(CF3)C6H4]2P(O)H (1) and [3,5-(CF3)2C6H3]2P(O)H (2) has been developed and the isolation and characterization of these crystalline reagents is described. The crystal structures for 1 and 2 were determined and the structure of 1 reveals unexpected close non-bonded interaction between F-atoms of one CF3 group and the back-side of the central phosphorus atom.

The use of quinine as a chiral solvating agent allows us to determine a tentative absolute configuration at the phosphorus atom of hydroxyphosphinates with two stereogenic centres (at the phosphorus and α-carbon atoms). Two ethyl butyryloxyalkane( P -phenyl)phosphinates were hydrolysed using various lipases. In all cases isomers possessing α-carbon atom with an ( S )-configuration were hydrolysed preferentially. The absolute configuration of both chiral centres of obtained α-hydroxyphosphinates was determined by using ( S )-(+)-MTPA-Cl and quinine. The mode of chiral discrimination of α-hydroxyphosphinates by quinine was studied by means of computational chemistry, which confirmed the experimental findings that the signals in 31 P NMR spectra of compounds with an ( R P )-configuration are situated upfield when compared with the respective ( S P ) isomers.

The reaction of [Cp*Mo(H)(CO) 2 {P(NMeCH 2 ) 2 (OMe)}] with TMSOTf (Me 3 SiOSO 2 CF 3 ) afforded [Cp*Mo(CO) 2 (OTf){P(NMeCH 2 ) 2 (OMe)}] ( 2 ), showing preferential hydrido abstraction rather than OMe abstraction at the phosphorus atom. [Cp*Mo(OTf)(CO) 3 ] reacted with P(NMeCH 2 ) 2 (OMe) to afford cationic phosphite complexes [Cp*Mo(CO) 4−n {P(NMeCH 2 ) 2 (OMe)} n ][OTf] [n = 1, 2 ( 6 )] but not to give 2. Structures of 2 and 6 were determined by single crystal X-ray diffraction studies.

2,3-Oxaphosphabicyclo[2.2.2]octene 1 reacts with alcohols simultaneously according to two competitive mechanisms: bimolecular addition-elimination and unimolecular elimination-addition with the intermediacy of metaphosphonate Ph-PO 2 ( 2 ). In 1,2-dichloroethane at 60°C, cyclic phosphinate 1 reacts with methanol in the bimolecular reaction five times faster than with tert-butanol. The reaction of metaphosphonate 2 with alcohols is unselective.

The reaction of the bis(amino)cyclodiphosph(III)azane cis-{(tBuNH)2(PNtBu)2} with AlEt3, AlBrEt2, AlBr2Et, and AlBr3 was investigated. The less Lewis acidic compound AlEt3 forms the adduct cis-[(tBuNH)2(PNtBu){P(·AlEt3)NtBu}], in which the aluminum atom is exclusively coordinated to one phosphorus atom. No ethane elimination was observed. By using the more Lewis acidic compounds AlBr2Et and AlBr3 the N-coordinated complexes cis-[(tBuNH)(PNtBu)(tBuN·AlBr2Et){P(H)NtBu}] and cis-[(tBuNH)(PNtBu)(tBuN·AlBr3){P(H)NtBu}] were obtained, in which the aluminum atoms are N-coordinated by a tBuN=PH unit. Upon coordination of the aluminum compounds, a concomitant 1,2-H shift from the nitrogen atom onto the phosphorus atom within the cis-{(tBuNH)2(PNtBu)2} ligand was observed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

The oxidative addition of C–H bonds to a dinuclear complex of divalent iridium, [Cp*Ir(μ-H)]2 (1), has been investigated. Reactions of 1 with phosphorus compounds containing a phenyl ring (PR1R2Ph) at ambient temperature gave novel five-membered diiridacyclic [(Cp*IrH)2(μ-H)(μ-R1R2PC6H4)] [R1 = R2 = Me (2a); R1 = Me, R2 = Ph (2b); R1 = R2 = Ph (2c); R1 = R2 = OEt (2d); and R1 = OEt, R2 = Ph (2e)] complexes through ortho-C–H activation of the phenyl ring bound to the phosphorus atom. The reaction of 1 with tripropylphosphane gave a new four-membered diiridacyclic [(Cp*IrH)2(μ-H)(μ-Pr2PCHCH2CH3)] (3) complex in a similar manner. On the other hand, the reaction of 1 with triethyl phosphite gave a Cp*-metalated product, [Ir(H)(P(OEt)3)(μ,η5,η1-C5Me4CH2)(μ-H)Ir(H)(Cp*)] (4), through C–H activation of a methyl group on one of the Cp* ligands. Furthermore, similar mild C–H activation reactions of 1 with sulfoxides have also been revealed. Thus, reactions of 1 with dimethyl sulfoxide and a couple of sulfoxides containing phenyl groups brought about the activation of the C–H bonds of a methyl group and a phenyl group to give [(Cp*IrH)2(μ-H)(μ-MeS(=O)CH2)] (5) and [(Cp*IrH)2(μ-H)(μ-RS(=O)C6H4)] [R = Me (6a) and R = Ph (6b)], respectively. The structures of 2a, 4, 5, and 6a have been confirmed by X-ray analysis. A plausible reaction pathway for these C–H activation reactions has been proposed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

New ligands with enhanced hemilabile character compared to iminophosphoranes known in the literature are presented. When diphenyl-2-picolylphosphane was oxidized with elemental sulfur or gray selenium, the new ligands Ph2P(S)(CH2Py) (1) and Ph2P(Se)(CH2Py) (2) were obtained. In addition, the calcium complex [(thf)2Ca{(PyCH)(Se)PPh2}2] (3), based on 2, is presented. This is only the second example of a molecular structure displaying a direct calcium−selenium contact. A structural comparison of the parent ligands and the related motifs in the organometallic complex reveals the bonding to the central phosphorus atom to be mostly strengthened by electrostatic means rather than by any double bonding. The spectroscopic data of 3 show features similar to those of iminophosphoranes, despite small differences in electronegativity. All of the compounds presented are accessible in good yields and high purity. The DTA analysis of 3 points to possible CVD applications to form CaSe from the gas phase.

The platinum(I) dinuclear carbonyl [Pt2(μ-PtBu2)2(PtBu2H)-(CO)] (4) reacts with carbon monoxide (80 atm) to give the dicarbonyl complex [Pt(μ-PtBu 2 )(CO)] 2 (9), which is thermally and air stable if protected from moisture. Wet solvents convert 9 into the known trinuclear hydride Pt 3 (μ-PtBu 2 ) 3 (CO) 2 -(H) (10), which is also formed by treating 9 with molecular hydrogen (180 atm). The reaction of 4 or 9 with phosphanes [PR 3 = PMe 3 , PPh 3 , PCy 3 , PCy 2 H] results in the formation of the corresponding derivatives [Pt2(μ-PtBu 2 )2(PtBu 2 H)(PR3)] [11, R = Me; 12, R = Ph; 13, R = Cy; 14, R 3 = Cy 2 H], [Pt 2 (μ-PtBu 2 ) 2 (CO)(PR 3 )] [15, R = Me; 16, R = Ph; 17, R = Cy] or [Pt(μ-PtBu 2 )(PR 3 )] 2 [18, R = Me; 19, R = Ph; 20, R = Cy] in good yields. Complex 19 is protonated at platinum by CF 3 SO 3 H yielding the hydride [Pt 2 (μ-PtBu 2 ) 2 (H)(PPh 3 ) 2 ]-CF 3 SO 3 (21). The protonation of asymmetrically substituted 12 forms rapidly the kinetic hydride [(tBu2HP)Pt(μ-PtBu 2 ) 2 -Pt(H)(PPh 3 )]CF 3 SO 3 (22a), which then isomerises slowly to the more stable isomer [(Ph3P)Pt(μ-PtBu2)2Pt(H)(PtBu 2 H)]-CF 3 SΟ 3 (22b). Dicarbonyl 9 is instead protonated at the phosphorus atom of a bridging phosphide; the unstable product of this reaction can be intercepted by adding CO to give the monophosphido-bridged [Pt 2 (μ-PtBu 2 )(PtBu 2 H)(CO)3]CF3-SO 3 (24) as a mixture of two isomers. The X-ray crystal and molecular structures of 9, of a 2:1 mixture of 9 and 10, and of complexes 18, 19 and 21 are also reported.

Complex formation in a K2PdCl4-HEDP system (HEDP is 1-hydroxyethylidene-1,1-diphosphonic acid) at the metal-to-ligand ratios 1 : 1 and 1 : 2 is studied by 31P and 1H NMR spectroscopy. The formation of equimolar complexes, in which HEDP is coordinated to palladium(II) in a bidentate mode through two oxygen atoms of the phosphonic groups, is found in these systems. The structure and charge characteristics of conformers of the complexes are simulated by the quantum-chemical methods.

Membrane transport of alkali and alkaline-earth metal ions by polyether podands containing terminal α-(phosphinoylalkylamino) fragments is studied. Some features of the relationship between the structure of the polyether bridge and substituents at the phosphorus atom, on the one hand, and transport properties of the carrier, on the other, are revealed. Transport efficiency is found to tend to correlate with transported ion size and distance between carrier donor centers.