- Hexaphenyl-hexa-phosphinane benzene solvate
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In the mol-ecular crystal of hexa-phenyl-hexa-phosphinane benzene solvate, C36H30P6·C6H6, representing the trigonal form of phospho-benzene as a solvate, the six-membered ring of P atoms adopts a chair conformation wherein the six phenyl groups are located in equatorial positions. The mol-ecules [mol-ecular symmetry (C 3i )] are stacked infinitely along the c-axial direction.
- Weigand, Jan J.,Decken, Andreas,Burford, Neil
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- Indium(III) promoted oxidative P-P coupling of silylphosphines
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The reaction of indium(III) salts with Ph2PSiMe3 and PhP(SiMe3)2 gives rise to a one- and two-electron reductive P-P coupling respectively, with the formation of new P-P bonds resulting in the preparation of (Ph2P)2 and the cyclicoligophosphane compounds (PhP)4 and (PhP)6.
- Cartlidge, Ashleigh J.,Matthews, Peter D.
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supporting information
(2022/01/28)
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- Exploring the Reactivity of Donor-Stabilized Phosphenium Cations: Lewis Acid-Catalyzed Reduction of Chlorophosphanes by Silanes
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Phosphane-stabilized phosphenium cations react with silanes to effect either reduction to primary or secondary phosphanes, or formation of P-P bonded species depending upon counteranion. This operates for in situ generated phosphenium cations, allowing catalytic reduction of P(III)-Cl bonds in the absence of strong reducing agents. Anion and substituent dependence studies have allowed insight into the competing mechanisms involved.
- Pearce, Kyle G.,Borys, Andryj M.,Clark, Ewan R.,Shepherd, Helena J.
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p. 11530 - 11536
(2018/09/21)
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- Facile Phenylphosphinidene Transfer Reactions from Carbene–Phosphinidene Zinc Complexes
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Phosphinidenes [R-P] are convenient P1 building blocks for the synthesis of a plethora of organophosphorus compounds. Thus far, transition-metal-complexed phosphinidenes have been used for their singlet ground-state reactivity to promote selective addition and insertion reactions. One disadvantage of this approach is that after transfer of the P1 moiety to the substrate, a challenging demetallation step is required to provide the free phosphine. We report a simple method that enables the Lewis acid promoted transfer of phenylphosphinidene, [PhP], from NHC=PPh adducts (NHC=N-heterocyclic carbene) to various substrates to produce directly uncoordinated phosphorus heterocycles that are difficult to obtain otherwise.
- Krachko, Tetiana,Bispinghoff, Mark,Tondreau, Aaron M.,Stein, Daniel,Baker, Matthew,Ehlers, Andreas W.,Slootweg, J. Chris,Grützmacher, Hansj?rg
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supporting information
p. 7948 - 7951
(2017/06/27)
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- Non-Metal-Catalyzed Heterodehydrocoupling of Phosphines and Hydrosilanes: Mechanistic Studies of B(C6F5)3-Mediated Formation of P-Si Bonds
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Non-metal-catalyzed heterodehydrocoupling of primary and secondary phosphines (R1R2PH, R2 = H or R1) with hydrosilanes (R3R4R5SiH, R4, R5 = H or R3) to produce synthetically useful silylphosphines (R1R2P-SiR3R4R5) has been achieved using B(C6F5)3 as the catalyst (10 mol %, 100 °C). Kinetic studies demonstrated that the reaction is first-order in hydrosilane and B(C6F5)3 but zero-order in phosphine. Control experiments, DFT calculations, and DOSY NMR studies suggest that a R1R2HP·B(C6F5)3 adduct is initially formed and undergoes partial dissociation to form an "encounter complex". The latter mediates frustrated Lewis pair type Si-H bond activation of the silane substrates. We also found that B(C6F5)3 catalyzes the homodehydrocoupling of primary phosphines to form cyclic phosphine rings and the first example of a non-metal-catalyzed hydrosilylation of P-P bonds to produce silylphosphines (R1R2P-SiR3R4R5). Moreover, the introduction of PhCN to the reactions involving secondary phosphines with hydrosilanes allowed the heterodehydrocoupling reaction to proceed efficiently under much milder conditions (1.0 mol % B(C6F5)3 at 25 °C). Mechanistic studies, as well as DFT calculations, revealed that PhCN plays a key mechanistic role in facilitating the dehydrocoupling reactions rather than simply functioning as H2-acceptor.
- Wu, Lipeng,Chitnis, Saurabh S.,Jiao, Haijun,Annibale, Vincent T.,Manners, Ian
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supporting information
p. 16780 - 16790
(2017/11/28)
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- Cationic 5-phosphonio-substituted N-heterocyclic carbenes
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2-Phosphanyl-substituted imidazolium salts 2-PR2(4,5-Cl-Im)[OTf] (9a,b[OTf]) (4,5-Cl-Im = 4,5-dichloro-1,3-bis(2,6-di-isopropylphenyl)-imidazolium) (a: R = Cy, b: R = Ph) are prepared from the reaction of R2PCl (R = Cy, Ph) with NHC 8 (4,5-dichloro-1,3-bis(2,6-di-isopropylphenyl)-imidazolin-2-ylidene) in the presence of Me3SiOTf. 5-Phospanyl-substituted imidazolium salts 5-PR2(2,4-Cl-Im)[OTf] (10a,b[OTf]) are obtained in quantitative yield when a slight excess of the NHC 8 is used. 5-Phosphonio-substituted imidazolium salts 5-PR2Me(2,4-Cl-Im)[OTf]2 (14a,b[OTf]2) and 5-PR2F(2,4-Cl-Im)[OTf]2 (16a,b[OTf]2) result from methylation reaction or oxidation of 10a,b[OTf] with XeF2 and subsequent fluoride abstraction. According to our quantum chemical studies the Cl1 atom at the 2-position at the imidazolium ring of dication 14b2+ carries a slightly positive charge and is therefore accessible for nucleophilic attack. Accordingly, the reaction of 14a,b[OTf]2 and 16a,b[OTf]2 with R3P (R = Cy, Ph) affords cationic 5-phosphonio-substituted NHCs 5-PR2Me(4-Cl-NHC)[OTf] (17a,b[OTf]) and 5-PR2F(4-Cl-NHC)[OTf] (18a,b[OTf]) via a SN2(Cl)-type reaction. A series of transition metal complexes such as [AuCl(5-PPh2Me(4-Cl-NHC))][OTf] (19[OTf]), [CuBr(5-PPh2Me(4-Cl-NHC))][OTf] (20[OTf]), [AuCl(5-PPh2F(4-Cl-NHC))[OTf] (21[OTf]) and [RhCl(cod)(5-PPh2Me(4-Cl-NHC))][OTf] (23[OTf]) are prepared to prove the coordination abilities of carbenes 17b[OTf] and 18b[OTf]. The isolation of a rare example of a tricationic bis-carbene silver complex [Ag(5-PPh2Me(4-Cl-NHC))2][OTf]3 (22[OTf]3) is achieved by reacting 14b[OTf] with Cy3P in the presence of AgOTf. NHC 17b[OTf] represents a very effective dehydrocoupling reagent for secondary (R2PH, R = Ph, Cy, iBu) and primary (RPH2, R = Ph, Cy) phosphanes to give diphosphanes of type R4P2 (R = Ph, Cy, iBu) and oligophosphanes R4P4, R5P5 (R = Ph, Cy), respectively. Methylation of 17b+ and subsequent deprotonation reaction with LDA affords the cationic NHO (N-heterocyclic olefin) 35+ of which the gold complex 36+ is readily accessible via the reaction with AuCl(tht).
- Schwedtmann, Kai,Schoemaker, Robin,Hennersdorf, Felix,Bauzá, Antonio,Frontera, Antonio,Weiss, Robert,Weigand, Jan J.
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supporting information
p. 11384 - 11396
(2016/07/26)
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- PROCESS FOR PREPARING ACYLPHOSPHANES AND THEIR OXIDES AND SULPHIDES
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A process for the preparation of bis-acylphosphanes of formula R1P(COR2)2 wherein R1 is unsubstituted phenyl or phenyl substituted by one to five halogen, C1-C8-alkyl, C1-C8-alkylthio and/or C1-C8-alkoxy; R2 is C1-C18-alkyl or C2-C18-alkenyl ; C1C18-alkyl or C2-C18-alkenyl substituted once or more than once by halogen -OR10, -OCO-R10, -OCO-Hal, -COO-R10, -N(R11)-CO-R10, -N(R11)-CO-Hal, -CO-NR11R10, -CH=CH-CO-OR10 or -CH=CH-phenyl; -C(C1-C4alkyl)=C(C1-C4alkyl)-CO-OR10 or -C(C1-C4alkyl)=C(C1-C4alkyl)-phenyl; C5-C12cycloalkyl, C2-C18alkenyl, phenyl-C1-C4alkyl, phenyl, naphthyl, biphenyl or a 5- or 6-membered -0-, S- or N-containing heterocyclic ring, the radicals phenyl, naphthyl, biphenyl or the 5- or 6-membered -0-, S- or N-containing heterocyclic ring being unsubstituted or substituted by one to five halogen, C1-C8alkyl, C1-C8alkoxy and/or C1-C8alkylthio; the process comprises the steps in a) selective reduction of dichlorophenylphosphanes of the formula R1P(CI)2 by means of hydrogen at a temperature in the range from 20 to 200°C and under hydrogen pressure of atmospheric pressure to 20bar in the presence of a hydrogenation catalyst, a tert. aliphatic amine or an aromatic amine and in the presence of a non protic solvent which is unreactive under the hydrogenation conditions to obtain cyclic phenylphosphanes (R1P)n (n = 4 to 6); or b) selective reduction of R1P(CI)2 by means of hydrogen at a temperature in the range from 80 to 25O°C and under hydrogen pressure of 25 to 250bar in the presence of a hydrogenation catalyst, a tert. aliphatic amine or an aromatic amine and in the presence of a non protic solvent which is unreactive under the hydrogenation conditions to obtain R1PH2; c) subsequent reaction with an acid halide of formula in the presence of an apropriate base R2COHal wherein R2 is as defined above.
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Page/Page column 9
(2008/06/13)
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- Catalytic P-H activation by Ti and Zr catalysts
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Catalytic dehydrocoupling of phosphines was investigated using the anionic zirconocene trihydride salts [Cp*2Zr(μ-H) 3Li]3 (1a) or [Cp*2Zr(μ H) 3K(thf)4] (1b), and the metallocycles [CpTi(NPtBu 3)(CH2)4] (6) and [Cp*M(NPtBu 3)(CH2)4] (M = Ti 20, Zr 21) as catalyst precursors. Dehydrocoupling of primary phosphines RPH2 (R = Ph, C6H2Me3, Cy, C10H7) gave both dehydrocoupled dimers RP(H)P(H)R or cyclic oligophosphines (RP)n (n = 4, 5) while reaction of tBu3C6H2PH 2 gave the phosphaindoline fBu2(Me2C-CH 2)C6H2PH (9). Stoichiometric reactions of these catalyst precursors withprimary phosphines afforded [Cp* 2Zr((PR)2)H][K(thf)4] (R = Ph 2, Cy 3, C 6H2Me3 4), [Cp*2Zr((PPh) 3)H] [K(thf)4] (5), [CpTi(NPtBu3)(PPh) 3] (7) and [CpTi(NPfBu3)(nrPHPh)]2 (8), while reaction of 6 with (C6H2tBu3)PH2 in the presence of PMe3 afforded [CpTi(NPtBu3)(PMe 3)(P(C6H2tBu3)] (10). The secondary phosphines Ph2PH and (PhHPCH2)2CH2 also undergo dehydrocoupling affording (Ph2P)2 and (PhPCH2)2CH2. The bisphosphines (CH 2PH2)2 and C6H4(PH 2)2 are dehydrocoupled to give (PCH2CH 2PH)v (12) and (C6H4P(PH)) 2 (13) while prolonged reaction of 13 gave (C6H 4P2)8 (14). The analogous bisphosphine Me 2C6H4(PH)2 (17) was prepared and dehydrocoupling catalysis afforded (Me2C6H 2P(PH))2 (18) and subsequently [(Me2C 6H2P2)2(μ-Me2C 6H2P2)]2 (19). Stoichiometric reactions with these bi-sphosphines gave [Cp*2Zr(H)(PH)2C 6H4][Li(thf)4] (22), [CpTi(NPtBu 3)(PH)2C6H4]2 (23) and [Cp*Ti(NPfBu3)(PH)2C6H4] (24). Mechanistic implications are discussed.
- Masuda, Jason D.,Hoskin, Aaron J.,Graham, Todd W.,Beddie, Chad,Fermin, Maria C.,Etkin, Nola,Stephan, Douglas W.
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p. 8696 - 8707
(2007/10/03)
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- PROCESS FOR THE SYNTHESIS OF CYCLOORGANYLPHOSPHANES AND DI(ALKALI METAL/ALKALINE EARTH METAL) OLIGOPHOSPHANEDIIDES
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The invention relates to a process for the preparation of cycloorganylphosphanes of formula 1(R1P)n by reaction of dihalo(organyl)phosphanes of formula R1PHal2 with: a) activated zinc in an organic solvent, or w
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- TRANSFORMATIONS OF DIFLUOROPHOSPHINES: THE INFLUENCE OF SOLVENT ON THE REACTION PATHWAY AND RING SIZE IN CYCLOPOLYPHOSPHINES
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The spontaneous transformation reactions of some difluorophosphines in chloroform as solvent are described.First, the redox disproportionation of 2,5-dimethylphenyldifluorophosphine, 1, unexpectedly led to the formation of the cyclopolyphosphine, hexakis-(2,5-dimethylphenyl)cyclohexaphosphine, 2a and 2,5-dimethylphenyltetrafluorophosphorane, 3.Secondly, CF3PF2, 4, was found to undergo a scrambling reaction with formation of (CF3)2PF, 5 and PF3, 6, rather than a redox disproportionation.In contrast, the difluorophosphines, RPF2 with R = 2,4,6-trimethylphenyl,9-anthracenyl, and 9-phenanthryl were found to be stable with regard to such transformations.A single crystal X-ray diffraction study of 2 (as a 1:1 solvate with CDCl3, 2a) was conducted. 2 was found to exist in a chair conformation with a PP bond length of 222.9 pm.The previously known hexamer, (PhP)6, 2b, was formed in the redox disproportionation of a neat sample of PhPF2, held at -20 deg C for several months.Its X-ray crystal structure, first reported in 1965, was redetermined, and served to establish the nature of the product. 2b was found to display a conformation very similar to that of 2/2a.Key words: Difluorophosphines; redox disproportionation; cyclopolyphosphines; X-ray crystal structure.
- Schmutzler, Reinhard,Heuer, Lutz,Schomburg, Dietmar
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p. 149 - 156
(2007/10/02)
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- Organosubstituted 2,5-Dihydro-1,2,5-phosphasilaboroles - Preparation, Characterization, and Transformations
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The dimeric 4,5-diethyl-2,5-dihydro-2,2-dimethyl-3-organo-1-phenyl-1,2,5-phosphasilaboroles are prepared in yields of 70-80percent from the acylic (Z)-2-boryl-1-silylethene derivatives ClB(C2H5)C(C2H5)=CRSi(CH3)2Cl with Li2PC6H5.The solid (1a)2 is the trans isomer with a (PB)2 ring (X-ray analysis). (1a)2 forms the solid γ-Pic-1a with γ-picoline (γ-Pic), with trimethylphosphane (TMP) the easily dissociating TMP-1a. trans-Bis(4,5-diethyl-1,2,5,6-tetrahydro-2,2,3-trimethyl-1-phenyl-1,2,5-phosphasilaborin) (2a)2 (X-ray analysis) is obtained by methylene migration from (1a)2 and methylenetriphenylphosphorane (MTPP). (1a)2 reacts with trimethylamine N-oxide (TMANO) by C6H5P/O-exchange to form (3a) and (3'a), whereas (1a)2 and γ-picoline N-oxide (PNO) give γ-Pic-3a and (C6H5P)n (4; 4', 4'': n = 4-6). (1a)2 and electrophiles react to 1:1 addition compounds (1a-AlCl3; 1a-MeI).The crystalline (5a)2 is prepared by B/Al exchange from (1a)2 and 2. (1a)2 reacts with methanol by ring opening to give the (Z)-2-boryl-1-silylethene derivative CH3OB(C2H5)C(C2H5)=C(CH3)Si(CH3)2OCH3 (6a) and phenylphosphane (7) in high yield. (1a)2 and acetylacetone undergo C6H5P/O exchange giving a mixture of 3a and (Z/E)-4-(phenylphosphino)-3-penten-2-one (8). - The 11B-, 13C-, 29Si-, 31P-NMR data of the dimeric C2SiPB and C2SiPCB rings are compared and discussed together with the data of the unsaturated C2SiElB rings .
- Koester, Roland,Seidel, Guenter,Mueller, Gerhard,Boese, Roland,Wrackmeyer, Bernd
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p. 1381 - 1392
(2007/10/02)
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- ZUR DISPROPORTIONIERUNG DER PHENYLFLUOROPHOSPHANE (C6H5)2PF UND (C6H5)PF2
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Ph2P-PF2Ph2 has been identified by means of 19F- and 31P-NMR spectroscopy as an intermediate product of the disproportionation of Ph2PF.The disproportionation is catalyzed by acids.The reaction mechanism is discussed.PhPF2 disproportionates faster in solution inacetonitrile that neat, forming (PhP)6, instead of (PhP)5.
- Riesel, L.,Haenel, J.,Ohms, G.
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p. 335 - 340
(2007/10/02)
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- Organosubstituted 2,5-Dihydro-1,2,5-selenasilaboroles - Preparation, Characterization, and ?-Complexation
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The dichloro compounds ClB(C2H5)CC2H5=C(R)Si(CH3)2Cl : R = CH3; B: R = C(CH3)=CH2> react with Na2Se to form the five-membered cyclic compounds .A and Na2Se2 yield 1a and 3 (2). 1a is also formed from and Se in addition to (C6H5P)n and (C6H5P)4Se (5). - (3a)2 reacts with S8 to give the compounds (7a), (4)n (n = 4,5), and (C6H5P)4S (6). - 1a reacts with CH3OH under elimination of H2Se to form the intramolecularly associated (8).From 1a and acetylacetone (9) and C5H7O2B(C2H5)SeSi(CH3)2C(CH3)=CH(C2H5) (10) are obtained. 1 : 1 Adducts are synthesised from 1a or b with Lewis acids (1a-AlCl3, 1b-AlCl3) and with Lewis bases (Py-1a, Py-1b, TMP-1a). - 1a and b react thermally or photochemically with (ligand)transition metal(0) compounds or with (ligand)transition metal(I) compounds to form η4-?-complexes 4-1a, (OC)3Ru-η4-1a, Ni(η4-1a)2 (X-ray structure analysis), C5H5Co-η4-1a, (OC)3Fe-η4-1b, (OC)3Ru-η4-1b, Ni(η4-1b)2, C5H5Co-η4-1b>.The MS and NMR data (1H, 11B, 13C, 29Si, 77Se) of the new compounds are compared with those of other C2SiElB ring compounds (El = O, S, N, P).
- Koester, Roland,Seidel, Guenter,Boese, Roland,Wrackmeyer, Bernd
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p. 1955 - 1966
(2007/10/02)
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- Contributions to the Chemistry of Phosphorus, 188. - Halogen-Substituted Cyclohexaphosphanes: Formation and Properties of (PCl)6 and (PBr)6
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Hexachlorocyclohexaphosphane (1) and hexabromocyclohexaphosphane (2) are formed in the partial dehalogenation of phosphorus trichloride and phosphorus tribromide, respectively, by magnesium or lithium hydride in polar solvents.As the first perhalogenated cyclophosphanes they are only stable in diluted solutions at low temperature and could be characterized by means of mass spectrometry and 31P nuclear magnetic resonance.Like the known hexaphenylcyclohexaphosphane, but in contrast to the parent compound P6H6, 1 and 2 have a six-membered phosphorus ring skeleton, which is obviously stabilized by electronegative substituents.
- Baudler, Marianne,Grenz, Detlef,Arndt, Uwe,Budzikiewicz, Herbert,Feher, Magda
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p. 1707 - 1710
(2007/10/02)
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- Contributions to the Chemistry of Phosphorus, 139. Triethylcyclotriphosphane, Trimethylcyclotriphosphane; Equilibria between Cyclophosphanes (PR)n at Elevated Temperatures
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Triethylcyclotriphosphane, (PEt)3 (1), has been generated by thermolysis of tetraethylcyclotetraphosphane, (PEt)4. 1 can be obtained as a 43percent solution in 1,2,3-triethyl-1,2,3-triphosphole, (PEt)3C2H2 (3), by fractional distillation of the product mixture formed in the reaction of K2(PEt)4 with ClHC=CHCl. 3 has been isolated and fully characterized.Furthermore 1 as well as (PMe)3 (2) and (PPh)3 exist besides (PR)4 (R = Et, Me, Ph) in thermodynamic equilibrium with (PR)5 at elevated temperatures; for R = Ph(PPh)6 is also formed.The thermodynamic data of the reactions 3/5 (PMe)5 (PMe)3 and 4/5 (PMe)5 (PMe)4 have been calculated from the equilibrium constants between 60 and 160 deg C.The ring strain of 2 is much smaller than that of cyclopropane but increases with increasing size and bulk of the substituents R at the phosphorus three-membered ring. - Key words: Triethylcyclotriphosphane, Trimethylcyclotriphosphane, Tetramethylcyclotetraphosphane, Equilibria between Cyclophosphanes, Strain Energies of Cyclophosphanes
- Baudler, Marianne,Hahn, Josef,Clef, Erwin
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p. 438 - 444
(2007/10/02)
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- Degradation of (PhP)5 by Cyanide: Formation, Structure, and Reactions of the Phenyl Cyanophosphide Ion
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Phenyl cyanophosphide PhPCN- is formed in the ractions of P(CN)2- with phenyllithium and of PhP(CN)2 with CN-, and it may be prepared by nucleophilic degradation of (PhP)5 with ammonium or phosphonium cyanides.With sulfur it yields phenyl cyanodithiophosphinates 4, by alkylation alkyl(phenyl)cyanophosphanes 6 and by hydrolysis of the latter alkyl(phenyl)phosphine oxides 7. - The molecular structure of PhPCN (3c) as determined by X-ray analysis shows an almost planar anion with 102 deg CPC angle.A long PC and short CN bond in the PCN group make PhPCN- appear as "cyanide complex of phenylphosphinidene".
- Schmidpeter, Alfred,Zirzow, Karl-Heinz,Burget, Guenther,Huttner, Gottfried,Jibril, Ibrahim
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p. 1695 - 1706
(2007/10/02)
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