首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2-(4-Chloro and 4-fluorophenylamino)-2,4,4,6,6-pentachloro-1,3,5,2λ5,4λ5,6λ5-triazatriphosphinines and poly[bis(4-fluorophenylamino)phosphazene] were synthesized by reactions of 4-fluoroaniline and 4-chloroaniline with 2,2,4,4,6,6-hexachloro-1,3,5,2λ5,4λ5,6λ5-triazatriphosphinin and poly(dichlorophosphazene), respectively, in tetrahydrofuran under argon at ?20°C, followed by heating under reflux. The products were isolated by column chromatography and were characterized by FTIR, NMR (1H, 13C, 31P), and mass spectra, termogravimetry, and high-performance liquid chromatography. Antimicrobial activity of the monomeric compounds and polymer against 9 bacteria and 5 yeast cultures was evaluated by the disk diffusion method in dimethyl sulfoxide relative to a number of commercial antibiotics and antifungal agents. Aminophosphazene derivatives exhibited a broad spectrum of activity against both Gram-positive and Gram-negative bacterial with a magnitude comparable to reference antimicrobial agents. The polymeric product turned out to be more potent than the monomeric compounds.  相似文献   

2.
Transition Metal Complexes of 1,1,3,3-Tetrakis(dimethylamino)-1λ5,3λ5-Diphosphete 1,1,3,3-Tetrakis(dimethylamino)-1λ5,3aλ5-diphosphete, 1 , reacts with W(CO)6 to yield the isomeric complexes {1,1,3,3-tetrakis(dimethylamino)-1λ5,3λ5-diphosphete}(pentacarbonyl)tungsten 4 and {1,1,3,3-tetrakis(dimethylamino)-1,4-dihydro-1λ5,3λ5-[1,3]diphosphetium}(pentacarbonyl)tungsten 5 . With Cr(CO)6 the complex {1,1,3,3-tetrakis(dimethylamino)-1λ5,3λ5-diphosphete}(pentacarbonyl)chromium 6 is formed. From the reaction products of Fe3(CO)12 and Fe2(CO)9 with 1 the complex {1,1,3,3-tetrakis(dimethylamino)-1λ5,3λ5-diphosphete}(pentacarbonyl)iron 7 could be isolated. Properties, nmr, ir and mass spectra of the new compounds are reported. 6 and 7 were characterized by X-ray structure determinations.  相似文献   

3.
Abstract

A new method for the highly stereoselective synthesis of β-O-σ3λ3 and σ4λ4 phosphorus-substituted 2,3,4,6-tetrabcnzylglucose is presented. The β-diastereoselective synthesis of the carbohydrates containing σ3λ3 and σ4λ5 phosphorus groups could be accomplished via two main synthetic routes. The first involves the addition of the σ3λ3-phosphorus derivative 3 to the 2,3,4,6-tetrabenylglucose derivative 1 (αβ = 1:l) in toluene and triethylamine as a catalyst to provide the σ3λ3 phosphorus derivative 4 with practically 100% β-diastereoselectivity.  相似文献   

4.
Phosphole‐substituted phosphaalkenes (PPAs) of the general formula Mes*P?C(CH3)?(C4H2P(Ph))?R 5 a – c (Mes*=2,4,6‐tBu3Ph; R=2‐pyridyl ( a ), 2‐thienyl ( b ), phenyl ( c )) have been prepared from octa‐1,7‐diyne‐substituted phosphaalkenes by utilizing the Fagan–Nugent route. The presence of two differently hybridized phosphorus centers (σ23 and σ33) in 5 offers the possibility to selectively tune the HOMO–LUMO gap of the compounds by utilizing the different reactivity of the two phosphorus heteroatoms. Oxidation of 5 a – c by sulfur proceeds exclusively at the σ33‐phosphorus atom, thus giving rise to the corresponding thioxophospholes 6 a – c . Similarly, 5 a is selectively coordinated by AuCl at the σ33‐phosphorus atom. Subsequent second AuCl coordination at the σ23‐phosphorus heteroatom results in a dimetallic species that is characterized by a gold–gold interaction that provokes a change in π conjugation. Spectroscopic, electrochemical, and theoretical investigations show that the phosphaalkene and the phosphole both have a sizable impact on the electronic properties of the compounds. The presence of the phosphaalkene unit induces a decrease of the HOMO–LUMO gap relative to reference phosphole‐containing π systems that lack a P?C substituent.  相似文献   

5.
Photochemical and thermochemical activation were used to prepare new -complexes of chromium, molybdenum and tungsten containing 2- and 4-coordinated methyl acrylate, methyl cynnamate, and dimethyl fumarate molecules. Geometric, electronic, and energetic parameters of the coordinated ester molecules were found and factors governing 2- and 4-coordination of the oxodiene system were revealed by nonempirical calculations. Monocarboxylic acid esters incorporated in the -complexes react with dialkyl hydrogen phosphites to give dialkyl acyl phosphites coordinated with the metal center and susceptible to oxidation the corresponding phosphates. In this case, the phosphorylation involves the OH-tautomer of dialkyl hydrogen phosphite. Coordinated dimethyl fumarate undergoes phosphorylation by two concurrent pathways, viz. transesterification or Pudovik reaction. In the latter case, fragmentation of the organometallic compound takes place.  相似文献   

6.
Ethyl 2-methylfuran-3-carboxylate is smoothly chloroethylated at 0°C in the 5 position of the ring. The resulting halide alkylates secondary amines but eliminates HCl with sodium diethyl phosphite under the Michaelis-Becker reaction conditions and with trimethyl phosphite under the Arbuzov reaction conditions. In the reaction with sodium diethyl phosphite, small amounts of 5-[1-(diethoxyphosphoryl)ethyl]furan-3-carboxylate and 5-ethylfuran-3-carboxylate are formed. In the Arbuzov reaction at a 1: 1.22 furan: trimethyl phosphite molar ratio, methyl 2,4-dimethyl-1-methoxy-1-oxo-1λ5-1,2-dihydrophospheto[3,2-b]furan-5-carboxylate was isolated.  相似文献   

7.
Reactions of λ5-Diphosphetes with COS and CO2. Dihydro-λ5-Phosphetes 1,1,3,3-Tetrakis(dimethylamino)-1λ5,3λ5-diphosphete, 1 , reacts with COS to yield the (3-oxo-3,4-dihydro-1λ5-phosphete-2-yl)-phosphonothioic bis(dimethylamide) 7 . Reaction of dimethyl substituted 1 , i.e. 1,1,3,3-tetrakis(dimethylamino)-2,4-dimethyl-1λ5,3λ5-diphosphete 4 , with COS and CO2 results in (3-oxo-2,3-dihydro-1λ5-phosphete-2-yl)-phosphonothioic bis(dimethylamide) 9 , and (3-oxo-2,3-dihydro-1λ5-phosphete-2-yl)-phosphonic bis(dimethylamide) 10 , respectively. Reaction mechanisms are suggested. 7, 9 and 10 are characterized by their properties, and their nmr, mass-, and ir-spectra. The results of X-ray structural analyses of 9 and 10 are reported and discussed.  相似文献   

8.
Reactions of 5H,2λ5-Azaphospholes with Arylazocarbonitriles and Dialkyl Acetylenedicarboxylates Azaphospholes 1a – c react with activated arylazocarbonitriles to 1,5,2λ5-diazaphosphorines 2a – c and 3a – c . The reaction of 1a – c with diethyl or dimethyl acetylenedicarboxyiates yields 7H-1,4λ5-azaphosphepines 4a – c . The structures of 2b , 3a , and 4a are established by an X-ray diffraction analysis.  相似文献   

9.
Thermal behaviour of intimate mixtures of chromium(III) oxide and lithium1, potassium2, rubidium3, cesium3 and thallium(I)4 perchlorates revealed that chromium(III) oxide not only catalyses the decomposition by lowering the decomposition temperatures of the pure metal perchlorates but also chemically interacts resulting in the formation of metal dichromate. The oxidation of chromium(III) into the hexavalent state is attributed to the abstraction of oxygen from the perchlorate moiety during the decomposition. In this context, it was thought interesting to study the thermal behaviour of chromium(III) perchlorate and to identify the decomposition products in order to find out whether chromium(III) is oxidized into chromium(VI) by the perchlorate group. Except for a report5 on the preparation of chromium(III) perchlorate with different molecules of water of hydration no work seems to have been carried out on the thermal decomposition of this compound. In the present study, the decomposition characteristics are followed by TG and DTA techniques and the decomposition products have been examined by chemical analysis, X-ray powder diffraction patterns and infrared spectral measurements.  相似文献   

10.
Four stereoisomeric monoether derivatives, based on axially chiral (R)- or (S)-BINOL bearing a chiral (+)- or (−)-neomenthyloxy group were synthesised and fully characterised by NMR spectroscopy and X-ray crystallography. The respective tris-monophosphites were thereof prepared and fully characterised. The coordination ability of the new bulky phosphites with Rh(CO)2(acac), was attested by 31P NMR, which presented a doublet in the range of δ = 120 ppm, with a 1J(103Rh-31P) coupling constant of 290 Hz. The new tris-binaphthyl phosphite ligands were further characterised by DFT computational methods, which allowed us to calculate an electronic (CEP) parameter of 2083.2 cm−1 and an extremely large cone angle of 345°, decreasing to 265° upon coordination with a metal atom. Furthermore, the monophosphites were applied as ligands in rhodium-catalysed hydroformylation of styrene, leading to complete conversions in 4 h, 100% chemoselectivity for aldehydes and up to 98% iso-regioselectivity. The Rh(I)/phosphite catalytic system was also highly active and selective in the hydroformylation of disubstituted olefins, including (E)-prop-1-en-1-ylbenzene and prop-1-en-2-ylbenzene.  相似文献   

11.
Addition of dimethyl phosphite to racemic 3,3′,4,4′-tetramethyl-1,1′-diphosphaferrocene-2-carboxaldehyde gives almost exclusively one diastereomer of the corresponding α-hydroxyphosphonate (d.r. ?96:4). Its absolute configuration (SRp)-(RSp) was established by X-ray diffraction.  相似文献   

12.
The first negative-ion fast atom bombardment mass spectra of a related series of monosubstituted Group VIB transition metal pentacarbonyls, M(CO)5L (M = Cr), Mo or W and L = P(Ph)3, As(Ph)3 or Sb(PH)3), have been obtained. Instead of molecular ion radicals, pseudomolecular adduct ions, [M + H]? and [M + 15]?, were detected, with the hydride species being much more abundant. High-resolution measurements and comparison of observed isotope clusters with computer-generated theoretical isotope patterns confirmed that ionization occurred by several mechanisms, including electron capture, charge dissociation and formation of adducts with charged species. Fragmentation consisted primarily of elimination of neutral ligands, i.e. ([MH - L]?, [MH - CO]?, [MH - 2CO]?, etc. B/E and constant neutral loss linked scanning with collisional activation were used to confirm fragmentation pathways and characterize the site of hydride attachment on the transition metal complex. The information obtained demonstrates the utility of fast atom bombardment mass Spectrometry in the analysis of metal carbonyls.  相似文献   

13.
β-Bromo-β-(methylsulfonyl)styrene reacted with dimethyl malonate and methyl cyanoacetate in the presence of sodium hydride to give sulfonyl-substituted cyclopropanes, and sulfonyl-substituted 2,3-dihydrofuran was also formed in the reaction with methyl acetoacetate. Reactions of α-bromo-β-(bromomethylsulfonyl) styrene with dimethyl malonate and methyl cyanoacetate led to the formation of 2,3-dihydro-λ6-thiophene S,S-dioxide derivatives. In the reaction of α-bromo-β-(bromomethylsulfonyl)styrene with methyl acetoacetate, 2,3-dihydro-λ6-thiophene S,S-dioxide and 2,5-dihydro-λ6-thiophene S,S-dioxide derivatives and methyl acetoacetate O-alkylation product, methyl 3-[(E)-2-(bromomethylsulfonyl)-1-phenylvinyloxy]but-2-enoate, were obtained at a ratio of 2.7: 1.2: 1. α-Bromo-β-(methylsulfonyl)styrene reacted with dimethyl malonate to produce dimethyl 2-[2-(methylsulfonyl)-1-phenylethylidene]malonate. The reaction of β-bromo-β-(bromomethylsulfonyl) styrene with dimethyl malonate and methyl cyanoacetate were strictly stereoselective, and they afforded tetrahydro-λ6-thiophene S,S-dioxide derivatives. The reaction of the same substituted styrene with methyl acetoacetate was not stereoselective, and the products were two diastereoisomeric tetrahydro-λ6-thiophene S,S-dioxides and sulfonyl-substituted 2,3-dihydrofuran at a ratio of 2.3: 2.7: 1.  相似文献   

14.
Correlations are established between selected substituent parameters (σIP, σRPPORO) and the carbonyl stretching force constant, k(CO), for 28 mono and poly-substituted tricarbonylchromium-complexed arene compounds. On the basis of the statistical results it is concluded that the overall electronic substituent effect transmitted to the carbonyl groups involves both mesomeric and inductive mechanisms. Within the restricted domain, including substituent group and benzene ring, transmission proceeds largely by resonance, with a minor inductive (through-bond and field) effect operative in the same domain. Further transmission from the substituted arene ring to the chromium atom predominantly involves an inductive mechanism. This result, in support of existing literature data, suggests appreciable participation of the ring carbon σ framework in the metal—ring bond formation.  相似文献   

15.
A continuum rheological theory, endowed with generalized structural significance, has recently been developed. Based on nonequilibrium thermodynamics, it relates stress σ, strain rate \documentclass{article}\pagestyle{empty}\begin{document}$\dot \varepsilon$\end{document} and temperature in terms of material evolution through a series of structural states. The theory has previously had success in dealing with crystalline metals and surface physics, and here it is applied to crosslinked rubbery polymers in the nominally amorphous condition. Structure is believed to be related to interchain associations, chain entanglements, chain ends, and other defects in the hypothetical ideal network which by itself would lead to neo-Hookean predictions in uniaxial deformation, σnH ∝ λ2 — λ?1, where λ is the stretch ratio. Predictions are made for σ(λ) in both tension and compression and shown to be more compatible with data than either σnH(λ) or the Mooney—Rivlin expression σMR(λ). Only two parameters are required, moduli Go (reflecting initial structure) and Gs (the steady-state condition), and rate effects are incorporated through Go(\documentclass{article}\pagestyle{empty}\begin{document}$\dot \varepsilon$\end{document}) and Gs(\documentclass{article}\pagestyle{empty}\begin{document}$\dot \varepsilon$\end{document}). The phenomena of yielding and stress softening in cyclic tensile loading are also predicted, suggesting advantages to this approach relative to conventional viscoelastic continuum models.  相似文献   

16.
Reactions of 1,1,3,3-Tetrakis(dimethylamino)-1λ5,3λ5-diphosphete with N? H and P? H Acidic Compounds 1,1,3,3-Tetrakis(dimethylamino)-1λ5,3λ5-diphosphete, 1 , reacts with aniline to give by opening of the ring 2,2,4,4-tetrakis(dimethylamino)-1-phenyl-1,2λ5,4λ5-azadiphosphapenta-1,3-diene, 2 , with p-CN? C6F4? NH2 the product is 1-(4-cyano-2,3,5,6-tetrafluorophenyl)-2,2,4,4-tetrakis(dimethylamino)-1,2λ5,4λ5-azadiphosphapenta-1,3-diene, 3 . t-Butylamine or diethylamine do not react with 1 . Mesitylphosphane opens the ring system 1 forming by reduction of one phosphorus atom {[bis(dimethylamino)phosphanyl]methylidene}bis(dimethylamino)methylphosphorane, 4 . The same product 4 is obtained by reaction with phenylphosphane. The reaction products 2–4 are characterized by their nmr, mass, and ir spectra. Their way of formation is discussed. In 4 a 5J(PH), in 3 a 7J(CF) long range coupling constant could be identified.  相似文献   

17.
The reaction of Bunsen's cacodyl disulfide, Me2As(S)‐S‐AsMe2, with heavy metal cations in methanol produces insoluble salts (complexes) of dimethyldithioarsinic acid, Me2AsS2H, and dimethyl arsenium ion, Me2As:+. This arsenium ion prefers to react with Me2As(S)‐S‐AsMe2, when in excess, compared to AcO? or MeOH/H2O and it is also reactive towards sulfur (Sx, x = 1‐8) producing the stabilized dimethylarsino sulfenium cation, . The complexes (Me2AsS2)xM (x = 1 or 2) are unstable in the presence of their own heavy metal cations decomposing to colored solids. In an attempt to prepare salts of Me2AsSH, the reactions of (Me2AsS2)xM with triphenylphosphine and trimethyl phosphite gave the metal sulfide and Me2As‐S‐AsMe2 instead.  相似文献   

18.
Alkylation of K[η5-C9H7Cr(CO)3] (Xa) with CH3I and C6H5CH2Br leads to σ-alkyl derivatives of η5-C9H7Cr(CO)3Alk type. These complexes undergo innersphere “ricochet” rearrangement, with the alkyl group being shifted to the endo position at C(1) and the chromium tricarbonyl group shifted to the benzene nucleus. The structure of the product of such a rearrangement in the case of η5-C9H7(CO)3CrCH2C6H5, i.e. (1-benzyl-3a,4-7,7a-η6-indene)chromium tricarbonyl (XVIII), is established by a low temperature X-ray study, indicating an endo position for the benzyl radical.On alkylation of equilibrium tautomeric mixtures of η5- and η6-fluorenylchromium tricarbonyl anions XIa ? XIb under similar conditions, the η5-anion (Xa) yields a σ-alkyl derivative, which is rearranged to (9-endo-alkyl-1-4,4a,9a-η6-fluorene)chromium tricarbonyl. Electrophilic attack of the η6-anion (XIb) takes place on the outer side at C(9) and leads to a corresponding 9-exo-alkyl derivative.  相似文献   

19.
The hydrothermal synthesis, crystal structure and some properties of a zinc phosphite with a neutral cluster, [Zn(2,2′-bipy)]2(H2PO3)4, are reported. This compound crystallizes in the triclinic system of space group P-1 (No. 2), a=8.3067(5) Å, b=8.9545(4) Å, c=10.0893(6) Å, α=95.448(2)°, β=99.7530(10)°, γ=103.461(2)°, V=712.23(7) Å3, Z=1. The cluster consists of 4-membered rings formed by alternating ZnO3N2 square pyramids and H2PO3 pseudo pyramids, with two “hanging” H2PO3 groups attached to each of the Zn centers. The clusters are linked together by extensive multipoint hydrogen bonding involving the phosphite units to form a sheet-like structure. This compound represents the first example of zinc phosphite with P---OH bonds. An intense photoluminescence was observed from this compound upon photoexcitation at 388 nm.  相似文献   

20.
Acyl- and Alkylidenephosphines. XXIV. (N,N-Dimethylthiocarbamoyl)trimethylsilyl-phosphines and 1.2-Di(tert-butyl)-3-dimethylamino-1-thio-4-trimethylsilylsulfano-1λ5, 2λ3-diphosphet-3-ene In contrast to bis(trimethylsilyl)phosphines R? P[? Si(CH3)3]2 1 {R ? H3C a ; (H3C)3C b ; H5H6 c ; H11C9 d ; (H3C)3Si e }, the more nucleophilic lithium trimethylsilylphosphides 4 react with N,N-dimethylthiocarbamoyl chloride already at ?78°C to give (N,N-dimethylthiocarbamoyl)trimethylsilylphosphines 2 . Working up the reaction, a dismutation of the mesityl derivative 2d is observed, whereas the tert-butyl compound 2b dissolved in toluene, eliminates dimethyl(trimethylsilyl)amine to form 1,2-di(tert-butyl)-3-dimethylamino-1-thio-4-trimethylsilyl-sulfano- 1λ5, 2λ3-diphosphet-3-ene 6b , nearly quantitatively within several days at +20°C.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号