Frustrated Lewis Pair Chemistry Derived from Bulky Allenyl and Propargyl Phosphanes

The dimesitylpropargylphosphanes mes₂P?CH₂?C≡C?R 6 a (R=H), 6 b (R=CH₃), 6 c (R=SiMe₃) and the allene mes₂P?C(CH₃)=C=CH₂ ( 8 ) were reacted with Piers’ borane, HB(C₆F₅)₂. Compound 6 a gave mes₂PCH₂CH=CH(B(C₆F₅)₂] ( 9 a ). In contrast, addition of HB(C₆F₅)₂ to 6 b and 6 c gave mixtures of 9 b (R=CH₃) and 9 c (R=SiMe₃) with the regioisomers mes₂P?CH₂?C[B(C₆F₅)₂]=CRH 2 b (R=CH₃) and 2 c (R=SiMe₃), respectively. Compounds 2 b , c underwent rapid phosphane/borane (P/B) frustrated Lewis pair (FLP) reactions under mild conditions. Compound 2 c reacted with nitric oxide (NO) to give the persistent FLP NO radical 11 . The systems 2 b , c cleaved dihydrogen at room temperature to give the respective phosphonium/hydridoborate products 13 b , c . Compound 13 c transferred the H⁺/H^? pair to a small series of enamines. Compound 13 c was also a metal‐free catalyst (5 mol %) for the hydrogenation of the enamines. The allene 8 reacted with B(C₆F₅)₃ to give the zwitterionic phosphonium/borate 17 . The ‐PPh₂‐substituted mes₂P‐propargyl system 6 d underwent a typical 1,2‐P/B‐addition reaction to the C≡C triple bond to form the phosphetium/borate zwitterion 20 . Several products were characterized by X‐ray diffraction.     

The preparation of 1-hydroperfluorohexyne,octyne and decyne

1-hydroperfluoroalkynes (R_FCCH, R_F  C₄F₉, C₆F₁₃, C₈F₁₇) were prepared from the corresponding alkenes by a multistep process involving bromination, dehydrobromination and debromination reactions. The influence of the perfluorinated chain's length on chemical reactivity is illustrated by the important changes in experimental procedure, with respect to the lower terms, needed for the bromination and debromination steps. Physical data are reported for compounds R_FCBr₂CH₂Br, R_FCBrCHBr and R_FCCH.     

Synthesis of fluorosilicone having highly fluorinated alkyl side chains based on the hydrosilylation of fluorinated olefins with polyhydromethylsiloxane

Hydrosilylation of fluorinated olefins with polyhydromethylsiloxane (PHMS) in the presence of a platinum catalyst was investigated to synthesize fluorosilicone having highly fluorinated alkyl side chains (R_f; C_nF_2n+1? ). The hydrosilylation of 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10‐heptadecafluoro‐1‐decene (C₈F₁₇CH?CH₂) ( 1 ) with poly(dimethylsiloxane‐co‐hydromethylsiloxane) {(CH₃)₃SiO[? (H)CH₃SiO? ]₈[? (CH₃)₂ SiO? ]₁₈Si(CH₃)₃} ( 4 ) converted the hydrogen bonded to silicons into the 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10‐heptadecafluorodecyl group or fluorine bonded to silicons in the ratio of about 52:48, and the formation of the byproduct C₇F₁₅CF?CHCH₃ ( 8 ) was observed. The hydrosilylation of 7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,14‐heptadecafluoro‐4‐oxa‐1‐tetradecene (C₈F₁₇CH₂CH₂OCH₂CH?CH₂) ( 2 ) with 4 converted the hydrogen bonded to silicons into the 7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,14‐heptadecafluoro‐4‐oxa‐tetradocyl group bonded to silicons, but an excess amount of 2 was required to complete the reaction because the isomerization of 2 occurred in part to form C₈F₁₇CH₂CH₂OCH?CHCH₃ ( 9 ). The hydrosilylation of 4,4,5,5,6,6,7,7,8,8,9,9, 10,10,11,11,11‐heptadecafluoro‐1‐undecene (C₈F₁₇CH₂CH?CH₂) ( 3 ) with 4 converted the hydrogen bonded to silicons into the 4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11‐heptadecafluoroundecyl group bonded to silicons. This type of fluorinated olefin was successfully applied to the hydrosilylation with other PHMS's that involved a homopolymer of PHMS and a cyclic PHMS. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3120–3128, 2002     

Synthesen und Eigenschaften von Bis(perfluoralkyl)zink‐Verbindungen

Syntheses and Properties of Bis(perfluoroalkyl)zinc Compounds The conditions for the syntheses of bis(perfluoroalkyl)zinc compounds Zn(R_f)₂ · 2 D (R_f = C₂F₅, n‐C₃F₇, i‐C₃F₇, n‐C₄F₉, n‐C₆F₁₃, n‐C₇F₁₅, and n‐C₈F₁₇; D = CH₃CN, tetrahydrofurane, dimethylsulfoxide) are described. Mass spectra, thermal decompositions, ¹⁹F‐ and ¹³C‐NMR spectra are discussed.     

Synthesis and characterization of fluorous (S)- and (R)-1-phenylethylamines that effect heat facilitated resolution of (±)-2-(8-carboxy-1-naphthylsulfinyl)benzoic acid via diastereomeric salt formation and study of their circular dichroism

Perfluoroalkyl- or nonafluoro-tert-butoxy-alkyl-substituted enantiopure amines having the structure PhCHCH₃(NR¹R²) [R¹ = H, CH₃; R² = (CH₂)₃C₈F₁₇, (CH₂)₂OC(CF₃)₃; R¹ = R² = (CH₂)₃C₈F₁₇, (CH₂)₂OC(CF₃)₃] are obtained in high yields, when (S)-(−)-1-phenylethylamine is reacted with readily accessible alkylating reagents or fluorous 2° amines (R¹ = H; R² = (CH₂)₃C₈F₁₇, (CH₂)₂OC(CF₃)₃) are methylated in a Leuckart-Wallach reaction. The solubility patterns of these novel chiral amines and their hydrochlorides are qualitatively described for a broad spectrum of solvents and the fluorous partition coefficients of the free bases are determined by GC. A novel method for the resolution of enantiomers is disclosed here, which involves the use a half-equivalent of the selected resolving agent in solvent water that displays low solubility for the crystalline diastereomeric salt(s) formed even at temperatures near to its boiling point. Compound (S)-(−)-PhCHCH₃[NH(CH₂)₃C₈F₁₇] is found to satisfy all the latter conditions and successfully used for the heat facilitated resolution of the title racemic acid. The circular dichroism (CD) spectra of six novel fluorous (S)-(−)-1-phenylethylamine derivatives are measured in ethanol, trifluoroethanol and hexafluoropropan-2-ol and discussed in detail.     

UHMWPE with short‐chain branches synthesized by alkenyl substituted phenoxy–imine catalysts in ethylene polymerization

The alkenyl substituted phenoxy–imine complexes [2‐C₃H₅‐6‐(2, 3, 5, 6‐C₆F₄H‐N?CH)C₆H₃O]₂TiCl₂ (C₃H₅=? CH₂? CH?CH₂ or ? CH?CH? CH₃) are synthesized and characterized by ¹H NMR, ¹³C NMR, and elemental analysis. When activated by MAO, they show high activity for the polymerization of ethylene to UHMWPE under different conditions (temperatures and polymerization time). Most of the resulting polymers have high molecular weights (>1.0 × 10⁶ g·mol^?1) and high melting points as well as crystallinity. To clarify the effect of the alkenyl group on the catalytic performance and the resultant polymer microstructure, the corresponding saturated complexes of type [2‐C₃H₇?6‐(2, 3, 5, 6‐C₆F₄H‐N?CH)C₆H₃O]₂TiCl₂ where C₃H₇ = –CH₂? CH₂? CH₃ or ? CH(CH₃)₂ were synthesized and tested as catalysts in ethylene polymerization under the same reaction conditions. The microstructure and morphologies of these two species of PE samples were fully compared by the analysis of ¹³C NMR, GPC, DSC, and SEM. As a result, the allyl substituted complex show the highest activity to prepare the highest molecular weight polyethylene of all the catalysts. An interesting feature of the UHMWPE produced by these four catalysts is that they contain only a few short‐chain branches (mainly methyl, isobutyl and 2‐methylhexyl branches) in a low amount (<2.7 branches/1000 C). © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3808–3818     

Synthetic,spectral, thermal and antimicrobial studies on some bis(N,N′‐dialkyldithiocarbamato) antimony(III) alkylenedithiophosphates

Bis(N, N′‐dialkyldithiocarbamato)antimony(III) alkylenedithiophosphates of the type [R₂NCS₂]₂ SbS(S)POGO [where NR₂ = N(CH₃)₂, N(C₂H₅)₂ and N(CH₂)₄; G = ? CH₂? C(C₂H₅)₂? CH₂? , ? CH₂? C(CH₃)₂? CH₂? , ? CH(CH₃)? CH(CH₃)? and ? C(CH₃)₂? C(CH₃)₂? ] were synthesized and characterized by physico‐chemical, spectral [UV, IR and NMR (¹H, ¹³C and ³¹P)] and thermal (TG, DTA and DSC) analysis. The TG decomposition analysis step of the complex indicated the formation of Sb₂S₃ as the final product. The first endothermic peak in DSC indicated the melting point of the complexes. These complexes were screened for their antimicrobial activities using the disk diffusion method. All the complexes showed good activity as antibacterial and antifungal agents on some selected bacterial and fungal strains, which increased on increasing the concentration. Chloroamphenicol and terbinafin were used as standards for comparison. Copyright © 2007 John Wiley & Sons, Ltd.     

Structure and formation of gaseous [C4H6O]+˙ ions: 1—The enolic ions [CH2C(OH)?CHCH2]+˙ and [CH2CH?CHCH(OH)]+˙ and their relationship with their keto counterparts

The [C₄H₆O]^+˙ ion of structure [CH₂?CHCH?CHOH]^+˙ (a) is generated by loss of C₄H₈ from ionized 6,6-dimethyl-2-cyclohexen-1-ol. The heat of formation ΔH_f of [CH₂?CHCH?CHOH]^+˙ was estimated to be 736 kJ mol^?1. The isomeric ion [CH₂?C(OH)CH?CH₂]^+˙ (b) was shown to have ΔH_f, ? 761 kJ mol^?1, 54 kJ mol^?1 less than that of its keto analogue [CH₃COCH?CH₂]^+˙. Ion [CH₂?C(OH)CH?CH₂]^+˙ may be generated by loss of C₂H₄ from ionized hex-1-en-3-one or by loss of C₄H₈ from ionized 4,4-dimethyl-2-cyclohexen-1-ol. The [C₄H₆O]^+˙ ion generated by loss of C₂H₄ from ionized 2-cyclohexen-1-ol was shown to consist of a mixture of the above enol ions by comparing the metastable ion and collisional activation mass spectra of [CH₂?CHCH?CHOH]^+˙ and [CH₂?C(OH)CH?CH₂]^+˙ ions with that of the above daughter ion. It is further concluded that prior to their major fragmentations by loss of CH₃˙ and CO, [CH₂?CHCH?CHOH]⁺˙ and [CH₂?C(OH)CH?CH₂]^+˙ do not rearrange to their keto counterparts. The metastable ion and collisional activation characteristics of the isomeric allenic [C₄H₆O]^+˙ ion [CH₂?C?CHCH₂OH]^+˙ are also reported.     

Polysulfonylamine. VII. Aliphatische Trisulfonylamine

Polysulfonyl Amines. VII. Aliphatic Trisulfonyl Amines The compounds N(SO₂R¹)₂(SO₂R²) with R¹ = R² = CH₃ ( 2a ), R¹ = R² = C₂H₅ ( 2b ) and R¹ = CH₃, R² = C₂H₅ ( 2c ) are prepared by cleavage of aminostannanes (CH₃)₃SnN(SO₂R¹)₂ with sulfonyl chlorides R²SO₂Cl. A simple synthesis of 2a from AgN(SO₂CH₃)₂ and CH₃SO₂Cl is described. From the vibrational spectra of 2a , evidence is obtained for a planar NS₃ group in this compound. X-ray structure determinations of 2b and HN(SO₂C₂H₅)₂ ( 3 ) are reported. In 2b , the NS₃ group is approximately planar (S? N? S bond angles 119.0 ± 0.6°, sum of bond angles at N 356.9°); the S? N bond lengths of ca. 173 pm indicate a bond order of 1. In compound 3 , the nitrogen atom has a planar coordination (S? N? S angle 125.3°, sum of bond angles at N 359.3°), the S? N bond lengths of ca. 165 pm correlate with a bond order of 1.3? 1.4.     

The Reactivity of Potassium Polyfluoroaryl‐, Polyfluoroalkenyl‐, and Perfluoroalkyltrifluoroborates and their Hydrocarbon Analogues towards Acids of Different Strength: A Systematic Study of the Hydrodeboration

The hydrodeboration of the (fluoroorgano)trifluoroborates K [R_FBF₃] [R_F = C₆F₅, XCF=CF (X = F, cis‐ and trans‐Cl, C₃F₇O, cis‐C₂F₅, trans‐C₄F₉, ‐C₄H₉) and C₆F₁₃] and of the organotrifluoroborates K [RBF₃] (R = C₆H₅, cis‐ and trans‐C₄H₉CH=CH, C₄H₉ and C₈H₁₇) with CH₃CO₂H (100 %), CF₃CO₂H (100 %), aqueous HF and anhydrous HF was investigated. In the alkenyltrifluoroborates K [R'CF=CFBF₃] the formal replacement of BF₃ by a proton occurred stereospecifically under retention of the configuration. The ¹⁹F NMR spectra of K [R_FBF₃] in acids indicate strong interactions of the BF₃ group with protons or acid molecules.     

Fluorinated tropylium ions in the mass spectra of some polyfluoroaromatic compounds

The most prominent ion in the mass spectra of C₆F₅CH₂X (X ? H, Br, CH:CH₂, COCl, and CH₂C₆F₅) is C₇F₅H₂⁺, formulated as the pentafluorotropylium cation. This ion is also found, in an amount comparable to the parent ion, in the spectrum of (C₆F₅)₂CH₂. The heptafluorotropylium cation is found similarly in the spectrum of C₆F₅CF₃. The mass spectra of (C₆F₅)₂CHBr and [(C₆H₅)₂CH]₂ exhibit an ion C₁₃F₁₀H⁺ as the base peak, which is probably a pentafluorophenylpentafluorotropylium cation. The alcohol (C₆F₅)₂CHOH shows loss of C₆F₅, followed by 2H, as a major breakdown pathway. The mode of formation, and the subsequent fragmentation, of the major ions in these spectra, are discussed.     

Metallkomplexe mit biologisch wichtigen Liganden. CLVII [1] Halbsandwich‐Komplexe mit Isocyanoacetylaminosäureestern und Isocyanoacetyldi‐ und tripeptidestern („Isocyano‐Peptide”︁)

Metal Complexes of Biologically Important Ligands, CLVII [1] Halfsandwich Complexes of Isocyanoacetylamino acid esters and of Isocyanoacetyldi‐ and tripeptide esters (?Isocyanopeptides”?) N‐Isocyanoacetyl‐amino acid esters CNCH₂C(O) NHCH(R)CO₂CH₃ (R = CH₃, CH(CH₃)₂, CH₂CH(CH₃)₂, CH₂C₆H₅) and N‐isocyanoacetyl‐di‐ and tripeptide esters CNCH₂C(O)NHCH(R¹)C(O)NHCH(R²)CO₂C₂H₅ and CNCH₂C(O)NHCH(R¹)C(O)NHCH (R²)C(O)NHCH(R³)CO₂CH₃ (R¹ = R² = R³ = CH₂C₆H₅, R² = H, CH₂C₆H₅) are available by condensation of potassium isocyanoacetate with amino acid esters or peptide esters. These isocyanides form with chloro‐bridged complexes [(arene)M(Cl)(μ‐Cl)]₂ (arene = Cp*, p‐cymene, M = Ir, Rh, Ru) in the presence of Ag[BF₄] or Ag[CF₃SO₃] the cationic halfsandwich complexes [(arene)M(isocyanide)₃]⁺X^? (X = BF₄, CF₃SO₃).     

Cis- und trans-1-Phosphabicyclo[4.4.0]decan

Cis- and trans-1-Phosphabicyclo[4.4.0]decane A mixture of cis-( 5a ) and trans-1-phosphabicyclo [4.4.0] decane 5b has been prepared by free-radical cyclization of (CH₂ = CH? CH₂? CH₂)₂CH? PH₂ 10 . The isomers could be separated in a pure state. Stereostructures have been assigned by ¹³C n.m.r. at 153—302 K. Equilibration of 5a and 5b by u.v. irradiation gave ?G°₃₅ ≈? 0 kJ ° mol^?1 · Activation parameters for ring inversion of “cis” stereoisomer 5a and its “cis” P-sulfid 17a are found to be ΔG° = 41.9 kJ · mol^?1 and 39.7 kJ · mol^?1, respectively. Treatment of 5a and 5b with H₂O₂, sulfur, selenium, HSO₃F, CH₃I, CS₂, and Ni(CO)₄, respectively, yield the corresponding derivatives. ¹H, ¹³C, ³¹P, ⁷⁷Se n.m.r. and i.r. data are reported.     

Some approaches to the synthesis of fluorinated alcohols and esters. II. Use of F-alkyl iodides for the synthesis of F-alkyl alkanols

Free radical addition of an F-alkyl iodide (R_FI) to an alkenol or ester, followed by appropriate reduction is an efficient method for preparing the corresponding F-alkyl-alkanols of the homologous series, R_F(CH₂)_n?OH. When n = 2,4 or higher, the two steps take place smoothly. The 1,2,3-substituted systems R_FCH₂CHYCH₂Z, however, are susceptible to surprising difficulties. Reduction of R_FCH₂CHICH₂ON to R_F(CH₂)₃OH by hydrogen and catalyst (strong base acid acceptor), can be done either in one step or $\text{via}$ R_FCHCHCH₂OH; however, dehydrohalogenation may also give the epoxide, and reduction in this case leads to the secondary alcohol, R_FCH₂CH(CH₃)OH. By contrast, reduction of R_FCH₂CHICH₂OAc by tributyltin hydride or with hydrogen over palladium (diethylamine acid acceptor) goes smoothly. Zinc and acid reduction of R_FCH₂CHICH₂OAc gives elimination to R_FCH₂CHCH₂; even R_FCHCICH₂OH gives R_FCHCCH₂ besides R_FCHCHCH₂OH. R_FCHCICH₂CH₂OH, however, with zinc and acid is reduced cleanly to R_FCHCHCH₂CH₂OH.     

Cyclocondensation between fatty acid hydrazides and 1,1,1-trifluoro-4-alkoxy-3-alken-2-ones: Introducing a trifluoromethylated head onto fatty acid moieties

This paper reports the regioselective synthesis of new trifluoromethylated lipid derivatives, namely, 1-(5-hydroxy-5-trifluoromethyl-3-alkyl-4,5-dihydro-1H-pyrazol-1-yl)alkan-1-ones, through cyclocondensation reactions between a series of fatty hydrazides (palmitoyl, stearoyl, and oleoyl hydrazides) obtained from fatty acids from renewable resources (1,1,1-trifluoro-4-alkoxy-3-alken-2-ones [F₃CC(O)CH?C(R¹)OR, where R¹?=?H and R?Et; R¹?=?–(CH₂)₆CH₃, –(CH₂)₆CH₃, –(CH₂)₈CH₃, –(CH₂)₉CH₃, –(CH₂)₁₀CH₃, –(CH₂)₁₂CH₃, –(CH₂)₂Ph], and R?Me). Experimental observations showed that the lipophilic characteristic of 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-pyrazoles (5–7) prevent the acid catalyzed dehydration to aromatization of 1H-pyrazole ring, although in some cyclocondensations a proportion of the aromatic derivative 1-(5-trifluoromethyl-3-alkyl-1H-pyrazol-1-yl)alkan-1-one was obtained. All products were characterized using multinuclear (¹H, ¹³C, ¹⁹F) NMR spectroscopy.     

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.     

Reactions of perfluoronitriles. II. Interactions with phenylphosphine

Treatment of perfluoro-n-octanonitrile with phenylphosphine gave tetraphenyltetraphosphine and a spectrum of reduction and interaction products. Fifteen compounds were identified. The imine, (R_fC₇F₁₅) R_fCHNH, and the amine, R_fCH₂NH₂, were the primary reduction products. Secondary phosphorus-free products, some formed following ammonia evolution, were the following: R_fCHNCH₂R_f, R_fCH₂CH(NH₂)R_f, R_fC(NH)NCR_f(NH₂), R_fCH₂NHCR_f(NH), (R_fCN)₃, R_fCHNCR_fNCR_f(NH), R_fCH₂NCR_fNHCH₂R_f, and R_fCH₂NCR_fNHCR_f(NH). Only three phosphorus-containing materials were definitely identified: R_fCH(NH₂)P(C₆H₅)H, R_fCH[P(C₆H₅)H]NCHR_f, and R_fC(NH)P(C₆H₅)CR_f(NH). Depending on reaction conditions, specific phosphorus-containing compounds could be preferentially produced. All the structure assignments are based solely on mass spectral breakdown patterns, since pure compounds were not isolated.     

Relationships between the acidity of the Z and E isomers of N-Nitroso-N-alkyl-α-amino acids and their conformations

The acidity constants of both Z and E conformational isomers of five N-nitroso-N-alkyl-α-amino acids, ON? N(R₁)? CH(R₂)? COOH, are determined by the observation of selected pH titrated ¹H NMR signals. For two glycine derivatives (1, R₁?CH₃, R₂?H, ON? Sar; 2, R₁?C₂H₅, R₂?H, ON? EtGly) and two alanine derivatives (3, R₁?CH₃, R₂?CH₃, ON? MeAla; 4, R₁?C₂H₅, R₂?CH₃, ON? EtAla) the E isomers appear to be stronger acids than the Z while for the third alanine derivative (5, R₁?n-C₃H₇, R₂?CH₃, ON? PrAla) the opposite is observed. These results, also including anisotropy effects associated with the N? NO group, are discussed in terms of conformations. A 7-membered ring conformation with an ? NO…HOOC? intramolecular hydrogen bond is proposed to be statistically important in the Z isomers of 1, 2, 3 and, to a lesser extent, 4.     

Über Chalkogenolate. 194 [1]: S-Bis(trimethylsilyl)aminoester von Dithiocarbamidsäuren 3. Kristall- und Molekülstruktur vom Methyl-und i-Propylderivat [1]

Inhaltsübersicht. Die Titelverbindungen R₂N–CS–S–N[Si(CH₃)₃]₂ mit Ii = CH₃ bzw. CH(CH₃)₂ kristallisieren orthorhombisch bzw. monoklin: Gitterkonstanten für R = CH₃ (bei ?165°C) a = 8,397(4) Å, b = 11,917(4) Å, c = 31,966 (11) Å, Pbca (Nr. 61), Z = 8. R = CH(CH₃)₂ (bei ?80°C) a =13,183(3) Å, b = 10,873(11) Å, c = 14,865(2) Å, β = 105,86(2)° P2₁/n (Nr. 14), Z = 4. Die Kristallstrukturen wurden unter Verwendung von 4227 bzw. 3 433 symmetrieunabhängigen Reflexen (gemessen bei ?165 bzw. ?80 °C) bestimmt und bis auf Zuverlässigkeitsfaktoren von R = 0,081 bzw. 0,082 verfeinert (R_w = 0,084 bzw. 0,114). Bei beiden Verbindungen ist der C₂N–CS–S–N-Teil des Moleküls nahezu planar. Zwischen dem Thiocarbonyl-S-Atom und dem N-Atom der silylierten Aminogruppe bestehen Wechselwirkungen. On Chalcogenolates. 194. S-Bis (trimethylsilyl) amino Esters of Dithiocarbamic Acids. 3. Crystal and Molecular Structure of the Methyl and i-Propyl Derivative The title compounds R₂N–CS–S–N[Si(CH₃)₃]₂ with R = CH₃ and CH(CH₃)₂, respectively, crystallize orthorhombic and monoclinic, resp.; cell dimensions and space group see “Inhaltsübersicht”. The structures of both compounds have been determined from single crystal X-ray data measured at ?165°C and ?80°C, resp., and refined to R's of 0.081 and 0.082, resp., (R_w = 0.084 and 0.114, resp.) using 4227 and 3433, resp., independent reflections. In both compounds the C₂N–CS–S–N core of the molecule is nearly plane. Between the thiocarbonyl sulfur atom and the nitrogen atom of the amino group interactions exist. In Fortführung unserer Untersuchungen [1, 2] über N, N-Dialkyldithiocarbamidsäure-S-bis(trimethylsilyl)aminoester R₂N–CS–S–N[Si(CH₃)₃]₂ haben wir die Kristall- und Molekülstrukturen der Verbindungen mit R = CH₃ und CH(CH₃)₂ bestimmt. Dabei sollte untersucht werden, welchen Einfluß sterisch anspruchsvollere Alkylgruppen (R = CH₃ → CH(CH₃)₂) auf die Molekülgeo-metrie haben. Eine strukturchemische Charakterisierung dieser Verbindungs-klasse ist bis jetzt noch nicht erfolgt; vgl. die Literaturzusammenstellung bei [3].     

Fluorinated phosphorus compounds: Part 6. The synthesis of bis(fluoroalkyl) phosphites and bis(fluoroalkyl) phosphorohalidates

Reaction of phosphorus trichloride with tert-butanol and fluoroalcohols gave bis(fluoroalkyl) phosphites (R_FO)₂P(O)H in 42-89% yield, where R_F=HCF₂CH₂, H(CF₂)₂CH₂, H(CF₂)₄CH₂, CF₃CH₂, C₂F₅CH₂, C₃F₇CH₂, (CF₃)₂CH, (FCH₂)₂CH, CF₃(CH₃)₂C, (CF₃)₂CH₃C, CF₃CH₂CH₂, C₄F₉CH₂CH₂ and C₆F₁₃CH₂CH₂. Treatment of these with chlorine in dichloromethane gave the bis(fluoroalkyl) phosphorochloridates (R_FO)₂P(O)Cl in 49-96% yield. The chloridate (CF₃CH₂O)₂P(O)Cl was isolated in much lower yield from the interaction of thionyl chloride with bis(trifluoroethyl) phosphite. Heating the latter in dichloromethane with potassium fluoride and a catalytic amount of trifluoroacetic acid gave the corresponding fluoridate (CF₃CH₂O)₂P(O)F in 84% yield. Treatment of bis(trifluoroethyl) phosphite with bromine or iodine gave the bromidate (CF₃CH₂O)₂P(O)Br and iodidate (CF₃CH₂O)₂P(O)I in 51 and 46% yield, respectively. The iodidate is the first dialkyl phosphoroiodidate to have been isolated and characterised properly—its discovery lags behind the first isolation of a dialkyl phosphorochloridate by over 130 years. The fluoroalkyl phosphoryl compounds are generally more stable than known unfluorinated counterparts.