Phosphonium Salts of 1,8‐Bis(diphenylphosphino)naphthalene: Molecular Structures and NMR‐spectroscopic Studies

A representative series of diphosphine monophosphonium salts [1‐Ph₂P(C₁₀H₆)‐8‐PRPh₂]⁺X^– ( 2 b : R = H, X = CF₃SO₃; 4 : R = Me, X = CF₃SO₃; 5 : R = C₆H₅CH₂ = Bn, X = Br) has been prepared by treatment of 1,8‐bis(diphenylphosphino)naphthalene (dppn, 1 ) with stoichiometric amounts of HSO₃CF₃ or CH₃SO₃CF₃ in CH₂Cl₂ at +20 °C and with C₆H₅CH₂Br in toluene at +80 °C. Their X‐ray crystal structures show that there is no evidence for dative P → P⁺ interactions. Instead, steric repulsion deflects the substituent groups to opposite faces of the naphthalene plane [splay angles: +11.4° ( 2 b ), +13.6° ( 4 ); +16.7° ( 5 )]. In solution 2 b , 4 , and 5 were dynamic according to ³¹P, ¹³C, and ¹H NMR spectroscopy. The fluxionality of 2 b involves rapid intramolecular proton exchange between the two phosphorus atoms, which slows down at low temperature, whereas the dynamic behaviour of 4 and 5 is interpreted in terms of hindered rotation of the bulky RPh₂P⁺ groups (R = Me or Bn) about the P–C(naphthyl) bond. Treatment of 1,8‐bis(diphenylphosphoryl)naphthalene (dppnO₂, 6 ) with HSO₃CF₃ gave the protonated bis(phosphine oxide), as the triflate salt, dppnO₂H⁺ CF₃SO₃^– ( 7 ). The X‐ray structure analysis of 7 revealed a highly strained molecule (P1…P2 365.5 pm) in which the P=O bonds point to the same face of the naphthalene plane to accommodate the proton. All isolated compounds were characterised by a combination of ³¹P, ¹H, and ¹³C NMR spectroscopy, IR spectroscopy ( 7 ), mass spectrometry and elemental analysis.     

Perfluormthyl-Element-Liganden. XVII. Adduktbildung von MenE(CF3)3−n-Liganden mit BX3-Verbindungen (Me = CH3; E = P,As, Sb; n = 0–3; X = H,CH3, Hal)

Perfluoromethyl-Element-Ligands. XVII. Formation of Adducts of Me_nE(CF₃)_3?n Ligands with BX₃ Compounds (Me = CH₃; E = P, As, Sb; n = 0–3; X = H, CH₃, Hal) The ligands Me_nE(CF₃)_3?n (Me = CH₃; E = P, As, Sb; n = 0–3) have been prepared (partly using new methods) and studied by n.m.r. spectroscopy (¹H, ¹⁹F, ³¹P, ¹³C). In order to deduce their relative donor strength their reactions with the Lewis acids “BH₃”, BMe₃, BMe₃, Me₂BBr, and BX₃ (X = F, Cl, Br) have been studied. Control of adduct formation occurs by n.m.r. spectroscopy (¹H, ¹⁹F). The following series of decreasing basicity or acidity are obtained:      

Hexa-, hepta- und octafluortrimethylamin

The electrofluorination of N(CH₃)₃ yields, along with fragmentation and recombination products and N(CF₃)₃ (I), minor quantities of the hitherto unknown compounds (CF₃)₂ NCF₂H (II), CF₃N(CF₂H)₂ (III) and N(CF₂H)₃ (IV). I –IV have been isolated and characterized by their ¹H, ¹³C and ¹⁹F nmr and their E I and C I mass spectra.     

Trimethylgermyl-methane and -trifluoromethane-sulfonates

Me₃GeOS(O₂)CH₃ and Me₃GeOS(O)₂CF₃ have been prepared and characterised by their ¹H, ¹³C, ¹⁹F NMR, IR, Raman and mass spectra.     

Bis(fluorbenzoyloxy)methylphosphanoxide

Bis(fluorbenzoyloxy)methyl phosphane oxides CH₃P(O)[OC(O)R]₂ [R = C₆H₄2F (1), C₆H₄3F (2), C₆H₄4F (3), C₆H₃2,6F₂ (4), C₆H2,3,5,6F₄ (5)] were prepared by treating silver salts of carboxylic acids AgOC(O)R with CH₃P(O)C?₂ (IR-, ¹H-, ¹⁹?F-and ³¹P{¹H}-NMR-data). The mixed anhydrides 1–5 show unusual thermal stability at room temperature. Stability against hydrolysis decreases with increasing number of fluorine-atoms. The reaction of R′P(O)C?₂ [R′ = CH₃, C₆H₅, (CH₃)₃C] with M^IOC(O)R_F [R_F = CF₃, C₂F₅, C₆F₅; M^I = Ag^I, Na^I T?^I] was investigated.     

Reactive EC(p‐p)π‐systems 53 [1]: Reactivity studies on perfluoro‐2‐arsapropene: [2+2]‐cycloaddition reactions and quantum chemical calculations

The extremely labile perfluoro‐2‐arsapropene F₃CAsCF₂ ( 1 ) has been generated by an improved pyrolysis process of Me₃SnAs(CF₃)₂ and found to be stabilized by the presence of hexamethyldisiloxane and tert‐butylphosphaethyne, thus allowing (i) reactivity studies with alkyne derivatives like tBuCP, (iPr)₂NCP, MeCCN(iPr)₂, HCCOEt and (ii) a full NMR investigation of 1 (¹⁹F, ¹³C). Due to the instability of 1 and some of the products, the [2+2]‐cycloaddition reactions gave the expected arsaphospha‐ and arsa‐cyclobutene derivatives, respectively, in moderate to good yields, but in some cases contaminated with side and/or decomposition products. Unequivocal characterization of the novel compounds was accomplished by spectroscopic in‐ vestigations (¹H, ¹³C, ¹⁹F, ³¹P NMR, IR, MS) supported by comparison with the data of the more stable phosphorus analogues. An interesting isomerization was observed for the 2‐dialkylamino‐4,4‐difluoro‐ 1‐trifluoromethyl‐1‐arsa‐3‐phospha‐2‐cyclobutenes yielding the more stable 3‐dialkylamino‐2,4‐difluoro‐ 1‐trifluoromethyl‐1‐arsa‐2‐phospha‐3‐cyclobutenes. Quantum chemical calculations [B3LYP/6‐311+ G(d,p)] of HAsCH₂, F₃CAsCF₂, and F₃CPCF₂ were carried out to compare the length of the AsC double bond with the literature data and to elucidate substituent effects on its electronic structure. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:406–419, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20118     

Carbon-fluorine two-dimensional NMR correlation spectra

Direct detection heteronuclear correlation (HETCOR) ¹³C{¹⁹F} and indirect detection gHMQC and gHSQC ¹⁹F{¹³C} two-dimensional correlation spectra have been compared for 1,3-perfluoro dimethylcyclohexane. Correlations to the geminally non-equivalent fluorine atoms in the CF₂ groups are more difficult to unambiguously observe using gHMQC or HETCOR in this typical cyclic fluorochemical in which ²J_FF ∼ > ¹J_CF, but they are readily observed and assigned in the gHSQC experiment. Excellent 2D gHSQC ¹⁹F{¹³C} correlation spectra have also been obtained on H(CF₂)₄CH₂OH without proton decoupling, although half of the correlations within the several FH multiplets have zero intensity.     

Low Temperature 1H‐, 19F‐, and 31P‐PGSE Diffusion Measurements. Applications to Cationic Alcohol Complexes

The problems associated with low‐temperature pulsed‐gradient spin‐echo (PGSE) NMR diffusion measurements are discussed. The influence of convection is overcome by employing a coaxial insert inside a normal 5 mm NMR tube. By means of this configuration, correct diffusion constants and temperature‐independent hydrodynamic radii can be obtained. Low‐temperature ¹H‐, ¹⁹F‐, and ³¹P‐PGSE measurements on unstable cationic alcohol complexes of palladium and tungsten (in MeOH and CH₂Cl₂) are reported. For [W(Cp)(adamant‐1‐ol)(CO)₃](CF₃SO₃), a strong hydrogen bond between the alcohol OH group and the trifluoromethanesulfonate anion is demonstrated.     

2J(P,C) and 3J(P,C) Coupling Constants in Some New Phosphoramidates. Crystal Structures of CF3C(O)N(H)P(O)[N(CH3)(CH2C6H5)]2 and 4‐NO2‐C6H4N(H)P(O)[4‐CH3‐NC5H9]2

Some new phosphoramidates were synthesized and characterized by ¹H, ¹³C, ³¹P NMR, IR spectroscopy and elemental analysis. The structures of CF₃C(O)N(H)P(O)[N(CH₃)(CH₂C₆H₅)]₂ ( 1 ) and 4‐NO₂‐C₆H₄N(H)P(O)[4‐CH₃‐NC₅H₉]₂ ( 6 ) were confirmed by X‐ray single crystal determination. Compound 1 forms a centrosymmetric dimer and compound 6 forms a polymeric zigzag chain, both via ‐N‐H…O=P‐ intermolecular hydrogen bonds. Also, weak C‐H…F and C‐H…O hydrogen bonds were observed in compounds 1 and 6 , respectively. ¹³C NMR spectra were used for study of ²J(P,C) and ³J(P,C) coupling constants that were showed in the molecules containing N(C₂H₅)₂ and N(C₂H₅)(CH₂C₆H₅) moieties, ²J(P,C)>³J(P,C). A contrast result was obtained for the compounds involving a five‐membered ring aliphatic amine group, NC₄H₈. ²J(P,C) for N(C₂H₅)₂ moiety and in NC₄H₈ are nearly the same, but ³J(P, C) values are larger than those in molecules with a pyrrolidinyl ring. This comparison was done for compounds with six and seven‐membered ring amine groups. In compounds with formula XP(O)[N(CH₂R)(CH₂C₆H₅)]₂, ²J(P,CH₂)_benzylic>²J(P,CH₂)_aliphatic, in an agreement with our previous study.     

Fluorierte Elementorganica: Oxidative Flüssigphasen-Direktfluorierung. X. Organyloxyfluorphosphorane: Direktsynthese durch F2-Addition an Phosphinic-, Phosphonic- sowie Phosphoricsäureester(fluoride) und Thermolyseverhalten

Fluorinated Organoelements: Oxidative Liquid-Phase Direct Fluorination. X. Organyloxyfluorophosphoranes: Direct Synthesis by F₂-Addition to Phosphinic-, Phosphonic-, and Phosphoric-Acid Ester(fluorides) and Thermal Behaviour The phenoxyfluorophosphoranes (PhO)₂PF₂R ( 2a: R = CH₃, 2b: R = Ph) and (PhO)_3?nPF_n+2 ( 4a: n = 0, 4b: n = 1, 4c: n = 2) were obtained in reasonable yield by direct fluorination of the corresponding organyloxy(fluoro)phosphanes for the first time. Contrary to 4c the intramolecular ligand exchange can be frozen up in 4b. The up to now unknown thermally unstable alkoxy-substituted difluorides (AlkO)_3?PF₂R_n ( 6a: Alk = CH₃, R = Ph), n = 2; 6b: Alk = CH₂CF₃, R = Ph, n = 2; 6c: Alk = CH₃, R = Ph, n = 1; 6d: Alk = CH₃, n = 0) were isolated by low temperature F₂-addition in pure substance, too. Their thermal decomposition (scrambling, CH₃F-elimination) was cleared up for 6a as model substance and transferred to (CH₃O)₃PF₂ 6d Here the splitting of (CH₃)₂O under “Arbusov-conditions” is very surprising. The trigonal bipyramidal covalent structure of all organyloxyphosphoranes was confirmed by multinuclear ¹⁹F, ³¹P{¹H}, ¹³C{¹H}) NMR experiments.     

Syntheses and Spectroscopic Study of Some New N‐4‐Fluorobenzoyl Phosphoric Triamides; Crystal Structures of 4‐F‐C6H4C(O)N(H)P(O)R2, R = NH‐C(CH3)3, NH‐CH2C6H5, N(CH3)(CH2C6H5)

Some new N‐4‐Fluorobenzoyl phosphoric triamides with formula 4‐F‐C₆H₄C(O)N(H)P(O)X₂, X = NH‐C(CH₃)₃ ( 1 ), NH‐CH₂‐CH=CH₂ ( 2 ), NH‐CH₂C₆H₅ ( 3 ), N(CH₃)(C₆H₅) ( 4 ), NH‐CH(CH₃)(C₆H₅) ( 5 ) were synthesized and characterized by ¹H, ¹³C, ³¹P NMR, IR and Mass spectroscopy and elemental analysis. The structures of compounds 1 , 3 and 4 were investigated by X‐ray crystallography. The P=O and C=O bonds in these compounds are anti. Compounds 1 and 3 form one dimensional polymeric chain produced by intra‐ and intermolecular ‐P=O···H‐N‐ hydrogen bonds. Compound 4 forms only a centrosymmetric dimer in the crystalline lattice via two equal ‐P=O···H‐N‐ hydrogen bonds. ¹H and ¹³C NMR spectra show two series of signals for the two amine groups in compound 1 . This is also observed for the two α‐methylbenzylamine groups in 5 due to the presence of chiral carbon atom in molecule. ¹³C NMR spectrum of compound 4 shows that ²J(P,C_aliphatic) coupling constant for CH₂ group is greater than for CH₃ in agreement with our previous study. Mass spectra of compounds 1 ‐ 3 (containing 4‐F‐C₆H₄C(O)N(H)P(O) moiety) indicate the fragments of amidophosphoric acid and 4‐F‐C₆H₄CN⁺ that formed in a pseudo McLafferty rearrangement pathway. Also, the fragments of aliphatic amines have high intensity in mass spectra.     

Addition of Benzodioxahalogenophosphoranes to the Carbonyl Group: New Phosphoranes and their Reactivity

Abstract

Halogenophosphoranes catPX₃ (X = C1, Br) (3), catPBr₂Y [Y = CHF₂CF₂CH₂(4), F(5), OCH=CBr₂ (6), CN (7), cat = C₆H₄O₂-o] react with aldehydes containing electron-withdrawing groups (CZ₃CHO, Z = C1, Br) in solvent to form the products of insertion in P-X bond. The structure of compounds (12–15) and their diastereomeric composition were determined by the NMR ¹H, ¹³C, and ³¹P spectroscopy. Phosphoranes (8–11) disproportionate to PX₃ and cat₂POCHXCZ₃ (X, 2 = Br, Br; C1, Br) (16, 17). Dibromophosphoranes (4–7) and monobromophosphorane (3) are also added to the carbonyl group of CZ₃CHO to form unsymmetric P(V) derivatives catPBr(OCHBrCZ₃)Y (18, 19) and (16, 17, 20–25). The thermal behaviour of compounds (18, 19) was investigated.     

19F and 31P NMR characterisation of the phosphaalkene,CF3 P=CF2, intermediate in the alkaline hydrolysis of bis(trifluoromethyl)phospine

The previously postulated phosphaalkene intermediate CF₃ P=CF₂ in the alkaline hydrolyses of (CF₃)₂ PH has been trapped and characterised by its ¹⁹F and ³¹P NMR spectra.     

Darstellung von Trifluormethylhalogen-Iodaten(I) des Typs (CH3)4N+CF3IX− (X = F,Cl, Br) und Trifluormethyltrifluormethoxyiodat(I) (CH3)4N+CF3IOCF3−

Preparation of Trifluormethylhalogen Iodate(I) Salts (CH₃)₄N⁺CF₃IX^? (X = F, Cl, Br) and Trifluormethyltrifluormethoxy Iodate(I) (CH₃)₄N⁺CF₃IOCF₃^? We describe the preparation of new trifluormethyliodate(I) salts CF₃IX^? (X = F, Cl, Br, OCF₃). (CH₃)₄N⁺CF₃ICl^? and (CH₃)₄N⁺CF₃IBr^? are obtained via addition of CF₃I with the corresponded tetramethylammonium halogenide. (CH₃)₄N⁺CF₃IOCF₃^? is synthesized by comproportionation of (CH₃)₄N⁺CF₃ICl^? with CF₃OCl under formation of Cl₂ at ?78°C. (CH₃)₄N⁺CF₃IF^? is formed either, through thermolysis of (CH₃)₄N⁺ CF₃IOCF₃^? under separation of COF₂, or reaction of CF₃I with (CH₃)₄N⁺ OCF₃^?. The thermolabile compounds have been characterized by i.r., Raman, ¹⁹F-, ¹³C NMR spectroscopy.     

Synthesis and reactions of fluorinated iminium salts

Different methods for the preparation of fluorinated iminium salts RR¹CNR²R³⁺MF₆^? (R=R¹=F ; R²=R³=CH₃, C₂H₅ M=As, Sb 4a ? c R=H, R¹=F; R²=R³=CH₃ M=As, Sb 5a, b R=R¹=CF₃; R²=H, R³=CH₃ M=Sb 12 R=R¹=CF₃; R²=R³=CH₃ M=As 14) are reported, the spectroscopic properties (IR, NMR) of the cations of these salts are briefly discussed. By F^?-addition to these salts, $\text{e.g.}$ to 16, perfluoroalkyl-bis(alkyl)-amines ($\text{e.g.}$ (CF₃)₂CFN(CH₃)₂ 15) can be prepared; from the methylation of CF₃NCF₂ bis(trifluoromethyl) methylamine (CF₃)₂NCH₃ (11) was obtained.     

Quantum-Chemical Study of the Electronic and Steric Structure of Vinyltetrazoles: II. 2-Vinyltetrazoles

The total Mulliken charges on the C and N atoms, populations of the S-trans-(N¹) conformers, and rotation barriers in the molecules of 2-vinyl-5-R-tetrazoles (R = H, CH₃, CH = CH₂, C₆H₅, CH₂Cl, CF₃) were calculated ab initio (HF/6-31G**, MP2/6-31G**). The results were compared with the ¹H and ¹³C NMR data for these compounds.     

Darstellung und spektroskopische Charakterisierung der Persulfoniumsalze (CH3)(CF3)SF3+SbF6− und (CH3)(CF3)2SF2+SbF6− und Kristallstruktur von CF3SF2+SbF6−

Preparation and Spectroscopic Characterization of the Persulfonium Salts (CH₃)(CF₃)SF₃⁺SbF₆^? and (CH₃)(CF₃)₂SF₂⁺SbF₆^? and Crystal Structure of CF₃SF₂⁺SbF₆^? [1] . The preparation of the persulfonium salts (CH₃)(CF₃)SF₃⁺SbF₆^? and (CH₃)(CF₃)₂SF₂⁺SbF₆^? by methylation of the sulfuranes CF₃SF₃ and (CF₃)₂SF₂ with CH₃OSO⁺SbF₆^? in liquid SO₂ is reported. The thermolabile compounds are characterized by IR, Raman, ¹H, ¹³C, and ¹⁹F NMR spectroscopy. CF₃SF₂⁺SbF₆^? crystallizes in the space group C2/c with a=16.889(8) Å, b=7.261(4) Å, c=13.416(7) Å, β=91.08° with 8 formula units per unit cell at 167 K. Cations and anions are connected via short SF contacts forming a Ψ-octahedral surrounding of the central S atom which is in close analogy to the already known CF₃SF₂⁺AsF₆^?.     

Trioxaphosphocanes-1,3,6,2, etude par R.M.N. (13C, 1H, 31P et stereochimie

The stereochemistry of several 2-R-1,3,6,2-trioxaphosphocanes (R = Cl, OCH₃, CH₃, N(CH₃)₃ has been investigated by ¹H, ¹³C and ³¹P n m r spectroscopy.     

(CF3)2PAsH2 und (CF3)2AsAsH2

(CF₃)₂PAsH₂ and (CF₃)₂AsAsH₂ (CF₃)₂PAsH₂ is obtained in yields between 30 and 60% according to eq. (1) (CF₃)₂AsAsH₂ is formed by the analogous reaction with (CF₃)₂AsI, but is not sufficiently stable to be isolated. Both compounds are decomposed according to eq. (2) (CF₃)₂PAsH₂ can be studied in solution below ?40°C; it is characterized by molar mass determination and by its n.m.r. spectra (¹H, ¹⁹F, ³¹P). Reactions with polar [HBr, (CH₃)₂AsH, (CH₃)₂PN(CH₃)₂] and nonpolar [Br₂, As₂(CH₃)₄] reagents proceed by cleavage of the P? As bond.