The oxygen Kα x-ray emission spectra of fluorinated anisoles and pentafluorophenol

Oxygen and fluorine K_α X-ray emission spectra have been obtained for a number of oxygen-containing compounds: H₂O, CH₃OH, C₆H₅OH, C₆H₅OCH₃, C₆F₅OH and 4-XC₆F₄OCH₃ (X = F, OCH₃, CF₃) in the solid or gaseous states and interpreted on the basis of the UV photoelectron and ESCA data and the results of MINDO/3 calculations. The mixing of the oxygen 2pAO with the highest occupied π-orbitals of the benzene ring is concluded to be small. The main contribution of the 2p(O)AO is shown to be to the system of σ-levels and lower-lying π-levels. CH₃OH is assumed to have hyperconjugation. Comparison of the electronic structures of oxygen in phenol and anisole with those in their polyfluorinated analogues shows the reduced effectiveness of oxygen 2pAO conjugation with the π-system of the benzene ring in the latter cases.     

Beiträge zur chemie des iodpentafluorids teil II. Iod(V)-verbindungen mit α,ω-difunktionellen alkoholaten

Nucleophilic substitution reactions of iodine pentaflurode with a series of homologous bifunctional alcoholates ^?O(CH₂)_nO^? (n=2,3,4,5,6,12), a geminal dialcoholate CC?₃ CH(O^?)₂ and a trifunctional alcoholate CH₃C(CH₂O^?)₃ protected by (CH₃)₃Si - groups are reported. Systems with short CH₂ - chains (n<4) first form short lived species IF₄[O(CH₂)_nO]X (X = SiMe₃, IF₄) which rearrange to mononuclear chelates IF₃[O(CH₂)_nO] of high stability. Dialcoholates with long CH₂-chains (n>4) behave as bridging ligands forming stable multinuclear compounds IF₄[O(CH₂)_nO]IF₄ and {IF₃[O(CH₂)_nO]}_m (m≥2). 1,4-Butanediolate is on the border line of the two systems.Products with greater substitution IF[O(CH₂)_nO]₂ (n=2,3) and IF₂(OCH₂)₃CCH₃ are also characterized.The dependence of ¹⁹F-NMR-shifts on the nature and arrangement of ligands is discussed.     

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.     

Pentafluorophenylcompounds of polyvalent iodine

The oxidation of C₆F₅I by oxidizers containing positive chlorine was investigated with the intention to prepare pentafluorophenyliodine (III) compounds: C₆F₅IX₂, where X are halides or oxoderivatives. Using ClF, ClOCF₃, Cl₂/AlCl₃ or Cl₂O as oxidizers C₆F₅ IF₂, C₆F₅ I Cl₂ and C₆F₅I (OCl)₂ - all thermally unstable - could be prepared and characterized.In contrast to these compounds the perfluoroaromatic carboxylates: C₆F₅I [O(O)C R_F]₂ are crystalline solids thermally stable up to 200 °C. Single crystal investigations show T-coordinated iodine with significant secondary bonding between iodine and the keto oxygens. C₆F₅ IO-formed by hydrolysis of C₆F₅IX₂ - changes if stored at RT forming (C₆F₅)₂I IO₃.(C₆F₅)₂I⁺ - formation is also observed when C₆F₅ IO is heated in inert (C₆F₅I, C₆H₆, CCl₄ …), protic (H₂O, CH₃OH, …) and strong acidic (FSO₃H …) dilution medium.C₆F₅IO reacts with acids, acid anhydrides and acid halides as could be shown by the preparation of C₆F₅ ICl₂ and C₆F₅ ICl (NO₃).Starting with C₆F₅ IX₂ different preparative ways for (C₆F₅)₂ I⁺ - compounds were successful. Principly (C₆F₅)₂ IX - compounds decompose thermally forming C₆F₅I + C₆F₅X.C₆F₅ IX₄ - compounds can be obtained from C₆F₅ IF₄ which is the specific displacement product of IF₅ with Si (C₆F₅)₄. By nucleophilic displacement it is possible to prepare C₆F₅ IF₂O, C₆F₅ IO₂, C₆F₅ IO (OAc_F)₂ and C₆F₅ I [OC(CH₃)₂  C(CH₃)₂O]₂,wich are all white, thermally stable solids.For the fluorine-ligand-exchange we used silycompounds as reagents. If the ligand is oxidable by C₆F₅ I(V) a stepwise reduction via C₆F₅I(III) to C₆F₅I could be shown by NMR-measurements.     

The preparation of perfluorinated carboxylic esters and perfluoro carbonates

Aliphatic perfluorinated carboxylic esters have been prepared by two methods; (i) the reaction of the potassium salt of perfluoro 3-ethyl pent-3-ol, KOC(C₂F₅)₃, with perfluoro acid chlorides R_fCOCl, to yield perfluorinated esters of composition R_fCOOC(C₂F₅)₃, and (ii) the reaction of carbonyl chloride or thionyl chloride with a mixture of the potassium salt KOC(C₂F₅)₃ and perfluoro acid salts of the general formula KOCOR_f in a polar solvent. The product ester has the composition R_fCOOC(C₂F₅)₃, and in this instance carbon dioxide or sulphur dioxide is liberated during the reaction. A qualitative study of the thermal decomposition of a perfluoro ester has been made.A tertiary perfluoro carbonate of composition [(C₂F₅)₂CF₃CO]₂CO has been prepared by the reaction of phosgene with the potassium salt KOC(C₂F₅)₂CF₃ in a polar solvent. The intermediate acid chloride (C₂F₅)₂CF₃COCOCl can be isolated.     

Explored routes to unknown polyfluoroorganyliodine hexafluorides, RFIF6

Two routes to R_FIF₆ compounds were investigated: (a) the substitution of F by R_F in IF₇ and (b) the fluorine addition to iodine in R_FIF₄ precursors. For route (a) the reagents C₆F₅SiMe₃, C₆F₅SiF₃, [NMe₄][C₆F₅SiF₄], C₆F₅BF₂, and 1,4-C₆F₄(BF₂)₂ were tested. C₆F₅IF₄ and CF₃CH₂IF₄ were used in route (b) and treated with the fluoro-oxidizers IF₇, [O₂][SbF₆]/KF, and K₂[NiF₆]/KF. The observed sidestep reactions in case of routes (a) and (b) are discussed. Interaction of C₆F₅SiX₃ (X = Me, F), C₆F₅BF₂, 1,4-C₆F₄(BF₂)₂ with IF₇ gave exclusively the corresponding ring fluorination products, perfluorinated cyclohexadiene and cyclohexene derivatives, whereas [NMe₄][C₆F₅SiF₄] and IF₇ formed mixtures of C₆F_nIF₄ and C₆F_nH compounds (n = 7 and 9). CF₃CH₂IF₄ was not reactive towards the fluoro-oxidizer IF₇, whereas C₆F₅IF₄ formed C₆F_nIF₄ compounds (n = 7 and 9). C₆F₅IF₄ and CF₃CH₂IF₄ were inert towards [O₂][SbF₆] in anhydrous HF. CF₃CH₂IF₄ underwent C-H fluorination and C-I bond cleavage when treated with K₂[NiF₆]/KF in HF. The fluorine addition property of IF₇ was independently demonstrated in case of perfluorohexenes. C₄F₉CFCF₂ and IF₇ underwent oxidative fluorine addition at −30 °C, and the isomers (CF₃)₂CFCFCFCF₃ (cis and trans) formed very slowly perfluoroisohexanes even at 25 °C. The compatibility of IF₇ and selected organic solvents was investigated. The polyfluoroalkanes CF₃CH₂CHF₂ (PFP), CF₃CH₂CF₂CH₃ (PFB), and C₄F₉Br are inert towards iodine heptafluoride at 25 °C while CF₃CH₂Br was slowly converted to CF₃CH₂F. Especially PFP and PFB are new suitable organic solvents for IF₇.     

On the reactions of dimethylsulfoxide with acyl fluorides - pummerer rearrangements and formation of monofluoromethyl esters

In stoichiometry-dependent reactions, dimethylsulfoxide (DMSO) reacts with acyl fluorides, R_fC(O)F (R_f = F, CF₃), to yield CH₃SCH₂F and R_fC(O)OCH₂F, while CH₃SCH₂Cl and FC(O)OCH₂Cl are obtained with COClF. Oxalyl difluoride, C₂O₂F₂, reacts with DMSO to give CH₃SCH₂F and FCH₂OCH₂F.     

A first methodical approach to salts with unsymmetrical fluorophenyl(pentafluorophenyl)difluoroiodonium(V) cations [Rf(RF)IF2] (Rf=x-FC6H4, x=2, 3, 4; RF=C6F5)

A promising approach to the unknown type of [Ar′(Ar)IF₂]X salts is offered. x-FC₆H₄IF₄ (x=2, 3, 4) reacts with C₆F₅BF₂ in CH₂Cl₂ and forms [x-FC₆H₄(C₆F₅)IF₂][BF₄] salts in good yields. For [4-FC₆H₄(C₆F₅)IF₂][BF₄] the fluoro-oxidizer property is shown in reactions with weakly reducing agents like E(C₆F₅)₃ (E=P, As, Sb, Bi) and ArI (Ar=4-FC₆H₄, C₆F₅). The fluorine/aryl substitution method is also applied to the synthesis of [(4-FC₆H₄)₂IF₂][BF₄], an example with two identical aryl groups in the difluoroiodonium(V) moiety.     

Perfluoralkyljod-verbindungen: Darstellungen und eigenschaften von CF3JO,CF3JOF2 und CF3JO2

Perfluoroalkyl iodine compounds: preparations and properties of CF₃IO, CF₃IOF₂, and CF₃IO₂. The trifluoromethyl iodine compounds CF₃IO, CF₃IOF₂, and CF₃IO₂ are formed from the reactions of CF₃I, CF₃IF₂ or CF₃IF₄ with ozone or silicon dioxide respectively. Their preparartions, properties, ¹⁹F-nmr spectra, and ir spectra are described.     

Pentafluorphenyliod(III)-Verbindungen. 2. Fluor-Aryl Substitution an Iodtrifluorid: Synthese von Pentafluorphenylioddifluorid C6F5IF2 und Bis(pentafluorphenyl)iodonium Pentafluorphenylfluoroboraten [(C6F5)2I]+[(C6F5)nBF4−n]−

Pentafluorophenyliodine(III) Compounds. 2. Fluorine-Aryl Substitution Reactions on Iodinetrifluoride: Synthesis of Pentafluorophenyliodinedifluoride C₆F₅IF₂ and Bis(pentafluorophenyl)iodonium Pentafluorophenylfluoroborates[(C₆F₅)₂I]⁺[(C₆F₅)_nBF_4?n]^? Mono- and disubstitution can be achieved in the fluorine-aryl substitution reaction on the low-temperature phase IF₃ in CH₂Cl₂ at ?78°C depending on the aryl transfer reagent. With B(C₆F₅)₃ [(C₆F₅)₂I]⁺ [(C₆F₅)_nBF_4?n]^? (68% yield) and with Cd(C₆F₅)₂ C₆F₅IF₂ (97% yield) is obtained whereas with C₆F₅SiMe₃ no fluorine-aryl substitution takes place on IF₃ even under basic conditions (EtCN or F^? addition). At ?78°C in EtCN solution IF₃ does not disproportionate but attacks the solvent under formation of HF.     

Fluorine Kα x-ray emission studies of fluorinated organic compounds

Fluorine K_α X-ray emission spectra have been measured and interpreted using UV photoelectron and X-ray photoelectron spectral data and the results of quantum-chemical calculations, for a series of fluorine-containing organic molecules: CH₃F, n-C₅F₁₂, polytetrafluoroethylene, tetrafluoroethylene, 4-XC₆H₄F (X = H, F, NH₂, NO₂), 1,3-difluorobenzene, 1,2,4,5-tetrafluorobenzene, 1,4-difluorobenzene, C₆F₅X (X = H, F, SCH₃, OCH₃, CN, NO₂, C₆F₅, P(OCH₃)₂), pentafluoropyridine, octafluoronaphthalene and 2,4-dinitrofluorobenzene, all in solid or gaseous states. It has been concluded that the fluorine 2pAO contribution to the highest occupied π-orbitals of the benzene ring and π-orbital of the ethylene bond is small: it is somewhat higher for a system of lower-lying π-orbitals and the highest for σ-orbitals. CH₃F is assumed to have hyperconjugation.     

Bildung und reaktivität kationischer rhodiummethyl- trimethylphosphit-komplexes;eine weitere metall- organische variante der Michaelis—Arbuzov-reaktion

C₅H₅Rh(P(OCH₃)₃]₂ (I) reacts CH₃I and (CH₃)₃OBF₄ at low temperatures to give [C₅H₅RhCH₃{P(OCH₃)₃}₂]X (II: X = I; III: X = BF₄). Elimination of CH₃I from II yields the phosphonate complex C₅H₅RhCH₃[P(OCH₃)₃]- [P(O)(OCH₃)₂] (IV) which reacts with (CH₃)₃OBF₄ to give III.     

Phenyliodine(V) fluorides

The known compound phenyltetrafluoroiodine(V) is shown by X-ray diffraction to have a tetragonal pyramidal structure with an apical phenyl group. This structure is compared to that of IF(OTeF₅)₄, where the apical position is occupied by the fluorine atom. C₆H₅IF₄ adds F⁻, forming C₆H₅IF₅⁻, which has a pentagonal pyramidal structure with an apical phenyl group. Fluoride abstraction from C₆H₅IF₄ by SbF₅ results in the formation of the cation C₆H₅IF₃⁺, which has a pseudotrigonal bipyramidal structure with the phenyl group occupying an equatorial position. Isoelectronic C₆H₅IOF₂ has a similar structure, with the phenyl group and oxygen atom both occupying equatorial positions.     

Rhenium-Komplexe von Sauerstoffchelatliganden: Ein Weg zu neuen Radiopharmaka?

Rhenium Complexes Stabilized by Tris-chelating Oxygen Ligands: Potential New Radiopharmaca? Ris-chelating oxygen ligands of the general formula L^? = [(C₅H₄R)Co{P(O)R′R″}₃]^? (R = COOCH₃, COOH and R′ = OCH₃; R = H and R′ = O(CH₂)₅COOCH₃, O(CH₂)₅COOH; R″ = OCH₃) have been synthesized. These ligands L^? and others of the same type have been used to prepare the rhenium oxo complexes [LReO₃] and [LReOX₂] (X = Cl, Br, I). In order to judge their use in radioimmunotherapy the corresponding complexes containing radioactive rhenium isotopes have also been synthesized. The rhenium(VII) as well as the diamagnetic rhenium(V) complexes are stable in air in the solid state as well as in organic solvents. They hydrolyze slowly in water to yield perrhenic acid. The X-ray structures of the sodium salt Na[(C₅H₄COOCH₃)Co{P(O)(OCH₃)₂}₃] and of the rhenium complex [LReOBr₂] (R = H, R′ = R″ = OCH₃) have been determined. The sodium salt crystallizes in trimeric units with the composition [(NaL)₃ · 3 H₂O]. Each sodium has a distorted octahedral oxygen coordination. In [LReOBr₂] the ReO₄Br₂ octahedron is only slightly distorted.     

Beiträge zur chemie des iodpentafluorids teil III. Chelatisierung und strukturisomerie bei α,β-methylierten IOD(V)-α,β-ethandiolat-fluoriden

We report metathetical reactions of IF₅ with series of α,β-trimethylsilylated ethanediolates with increasing numbers of CH₃-groups in α- and β-positions. Short lived intermediates IF₄[OC₂H_4?n(CH₃)_nO]X with X = Si(CH₃)₃ or IF₄ and stable chelates IF₃[OC₂H_4?n(CH₃)_nO] and IF[OC₂H_4?n(CH₃)_nO]₂ (n = 0–4) are observed and characterized. Time and temperature dependence of ¹⁹F-NMR-spectra in relation to degree of methylation, arrangement and stereo-chemistry are discussed referring to previously published mono- and polynuclear I(V)-compounds containing a series of monodentate alcoholates CH_3?n(CH₃)_nO^? and (CH₃)₃CCH₂O^? (n = 0,2,3) [1,2] and of bidentate alcoholates ^?O(CH₂)_nO^? (n = 2,3,4,5,6,12) [1]. In contrast to aliphatic α,β-diolates the aromatic diolates 1,2-C₆H₄(O^?)₂, 1,2-C₆Cl₄(O^?)₂ rapidly undergo redox reactions even at low temperatures.     

Basische Metalle. XIII. Ein neuer Syntheseweg für Cyclopentadienyl-Rhodium-Phosphonat- aus Cyclopentadienyl-Rhodium-Phosphit-Komplexen

Basic Metals. XIII. A New Synthesis of Cyclopentadienylrhodium Phosphonate from Cyclopentadienylrhodium Phosphite Complexes C₅H₅Rh[P(OCH₃)₃]₂ reacts with alkali metal iodides MI (M = Li, Na, K) in two stages via the intermediate C₅H₅RhCH₃[P(O)(OCH₃) ₂]P(OCH₃)₃ to the corresponding bisphosphonate complexes C₅H₅RhCH₃[P(O)(OCH₃) ₂]₂M. Their properties suggest that they exist as contact ionpairs rather than dissociated ions. The reaction of C₅H₅RhCH₃[P(O)(OCH₃)₂]₂ Na with HCl in benzene yields the complex C₅H₅RhCH₃[P(O)(OCH₃) ₂]₂H, in which a chelate ligand with a P? O? H? O? P bridge is probably present. The acidic character of the bridging H atom is shown in the reaction with (CH₃)₃PCH₂ which leads to [C₅H₅RhCH₃{P(O)(OCH₃) ₂}₂][P(CH₃)₄]. C₅H₅RhCH₃[P(O)(OCH₃) ₂]₂Tl was formed in the reaction of C₅H₅RhCH₃[P(O)(OCH₃)₂]₂ H and thallium acetylacetonate. The n.m.r. spectra of the new phosphonate complexes are discussed.     

Etude RMN du 13C de composes fluoroaliphatiques et de tensioactifs non ioniques perfluoroalkyles

Carbon-13 chemical shifts, spin-lattice relaxation times and nuclear Overhauser enhancement factors at 28°C are reported for a series of polyfluoroaliphatic compounds :

, and perfluoroalkyl nonionic surfactants C_mF_2m+1CH₂(OC₂H₄)_nOH with m = 6, 7 and n = 3, 4, 5, 6 and C₆F₁₃CH₂CH₂CONH(C₂H₄O)_nH with n = 3, 4. The influence of the perfluoroalkyl group on the ¹³C chemtcal shifts of the neighbouring hydrogenated carbons is discussed in terms of hyperconjugative type interactions between lone electron pairs on fluorine and the neighbouring CC or CO bond. Relaxation data show similar flexibilities of the fluorinated chains in the different molecules investigated. Nonionic surfactants exhibit segmental motions in both the hydrophobic perfluoroalkyl and the hydrophilic polyoxyethylene chains ; these motions appear to be similar to those of the analogous hydrogenated surfactants.     

Studies on novel unsymmetrical azomethines—III : Copper(II) complexes of unsymmetrical tetradentate azomethines

Copper(II) complexes of unsymmetrical bifunctional tetradentate azomethines having the general formulae, (OC₁₀H₆CH:NXN:C(R)C₆H₄O)Cu, (OC₁₀H₆CH:NXN:C(CH₃)CHC(CH₃)OCu, (OC₆H₄CH:NXN:C(CH₃)C₆H₄O)Cu, (OC₆H₄C(R);NXN:C(CH₃)CHC(CH₃)O)Cu (where R = H or CH₃, X = (CH₂)₃, (CH₂)₄, (CH₂)₆ or -oC₆H₄) have been synthesized by the reactions of preformed mixed imine complexes of the type, CuLL′ (where L and L′ are two different imines such as 2-hydroxy-1-naphthaldimine, salicylaldimine, o-hydroxyacetophenonimine or acetylacetonimine) with diamines such as 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane or o-phenylenediamine. These complexes have been characterized by elemental analyses, TLC, conductance, magnetic measurements, IR and electronic spectra.     

[(C6F5)2IF2][BF4], the First Salt with the Electrophilic Cation [(C6F5)2IF2]+: Synthesis,Reactivity, and Structure

The substitution of hypervalently bonded fluorine atoms in C₆F₅IF₄ was performed with C₆F₅BF₂ and resulted in the new salt [(C₆F₅)₂IF₂][BF₄]. The iodonium(V) salt was characterized by multi‐NMR and Raman spectroscopy and X‐ray crystal structure analysis. The fluorinating ability of the new electrophilic cation [(C₆F₅)₂IF₂]⁺ was exemplified in reactions with monovalent iodine compounds (C₆F₅I, p‐FC₆H₄I, and I₂) and with electron‐poor tri(organyl)pnictanes ER₃ (E = P, As, Sb, Bi; R = C₆F₅). In a heterogeneous reaction with CsF in MeCN the [(C₆F₅)₂IF₂]⁺ cation forms the dinuclear [{(C₆F₅)₂IF₂}₂F]⁺ cation.     

Metal complexes of fluorophosphines : III. Some oxidative addition reactions of a rhodiumtrifluorophosphine complex

Some oxidative addition reactions of (CH₃)₅C₅Rh(PF₃)₂ with various iodine compounds are described. Iodine reacts with (CH₃)₅C₅Rh(PF₃)₂ in benzene at room temperature to give the deep red crystalline diiodide (CH₃)₅C₅Rh(PF₃)I₂. The perfluoroalkyl iodides R_fI (R_f = CF₃, C₂F₅, n-C₃F₇, and n-C₇F₁₅) react with (CH₃)₅C₅Rh(PF₃)₂ in benzene at room temperature to give the orange to deep red (CH₃)₅C₅Rh(PF₃)(R_f)I (R_f = CF₃, C₂F₅, n-C₃F₇, and n-C₇F_l5). The IR and proton and fluorine NMR spectra of these new (pentamethylcyclopentadienyl)rhodium-trifluorophosphine complexes are discussed.