MASS SPECTRA OF BIS (CYCLOPENTADIENYL)-BIS (ORTHO-PHENYLAMINOBENZOATO) TITANIUM AND ITS DERIVATIVES

<正> Four complexes of the types of Cp2Ti (OOCC6H4NHPh-o)2 and Cp2TiCl2(Cp=Cp, MeCp= (CH3C5H4-)) have been investigated under the electron impact condition. The experimental results of Cp2Ti(OOCC6H4NHPh-o)2 complexes suggest that the Ti -L (L =OOCC6H4NHPh-o) bond is weaker than Ti -Cp bond and their molecular ions are characterized by the ready loss of L ligands. On the other hand, the molecular ions of Cp2TiCl2 are characterized by the loss of Cp ligands. The characteristic ions [M-HCl]+ and [M - 2HCl]+ are observed in the spectra of (MeCp)2TiCl2.     

STUDIES ON ORGANOMETALLIC COMPOUNDS OF TITANIUM,ZIRCONIUM AND HAFNIUM TITANIUM, ZIRCONIUM AND HAFNIUM——SYNTHESES AND PROPERTIES OF BIS (CYCLOPENTADIENYL) DI-(ARYLOXY) DERIVATIVES

The dichlorides of bis(cyclopentadienyl) or bis(methylcyclopentadienyl) titanium, zircon-ium and hafnium reacting with phenol or substituted phenols in the presence of base give aseries of new aryloxymetal derivatives. The activities of chlorine atoms in the dichlorides ofbis(cyclopentadienyl)titanium, zirconium and hafnium molecules towards phenols are compared.The influence upon HNMR of the cyclopentadienyl ring due to the electronegativities of themetals and the substituents on the phenyl rings, as well as the number and position of thesubstituents are discussed.     

STUDIES ON ORGANOMETALLIC COMPOUNDS OF TITANIUM,ZIRCONIUM AND HAFNIUM——THE SYNTHESES AND PROPERTIES OF BIS (CYCLOPENTADIENYL) AND BIS (METHYLCYCLOPENTADIENYL) DI(ARYL)-METAL DERIVATIVES

Aryllithium reacts with Cp_2MCl_2 and Cp'_2 MCl_2 (C_p=η~5-C_5H_5, C_P′=η~5-CH_3C_5H_4:M=Ti, Zr, Hf) respectively to prepare a series of new bis (cyclopentadienyl), bis (methy-lcyclopentadienyl) diaryl derivatives of titanium, zirconium and hafnium. The hydrolysicreaction of these organometallic compounds are studied, the derivatives of zirconium andhafnium can be easily hydrolyzed with the exception of that of titanium. They react withhydrogen chloride, acetyl chloride, bromine and haloacids to form the respective bis(cyclo-pentadionyl) dihalides of these metals. The NMR and IR spectra were discussed in regardto the structure of (η~5--CH_3C_5H_4)_2 MAr_2 and (η~5--CH_3C_5H_4)_2 MX_2.     

THE CONDENSATION REACTION OF BIS(PERFLUOROALKANESULFONYL)METHANES WITH AROMATIC ALDEHYDES

The ccndensation reactions occurred when heating bis(perfluoroalkane-sulfonyl)methanes with aromatic aldehydes in acetic acid anhydrideand gave high yields of 1-aryl-2,2-di(perfluoroalkanesulfonyl)ethylenesThe perfluoroalkanesulfonyl groups R_FSO_2 are known as the strongestelectron-attracting substituents~(1-2).This property is often used in theactivation of C-C multiple and 2,2'-C-H bonds.The synthesis and reactionsof perfluoroalkanesulfonyl substituted alkenes and alkynes are of greatinterest in synthetic organic chemistry~(3-6).Recently,Hanack~7 reported the preparation of 2-aryl-l-(perfluoroalkane-sulfonyl)acrylonitrile R_FSO_2C(CN)=CHAr.However,he failed to obtainthe 1,1-di(perfluoroalkanesulfonyl)alkenes by the Knoevenagel reactionof bis(perfluoroalkanesulfonyl)methane with aldehydes.     

STUDIES ON ORGANOMETALLIC COMPOUNDS OF TITANIUM,ZIRCONIUM AND HAFNIUM——THE CRYSTAL AND MOLECULAR STRUCTURES OF OXO-BRIDGED TETRAKIS(CYCLOPENTADIENYL)BIS (o.TOLYL)AND TETRAKIS(METYLCYCLOPEN-TADIENYL) BIS(p-TOLYL)BINUCLEATED ZIRCONIUM COMPOUNDS

This paper reports the crystal and molecular structures of tetrakis (cyclopentadienyl) bis(o-tolyl)-μ-oxo-dizirconium [dimer (Ⅰ)] and tetrakis (methylcyclopentadienyl) bis (p-tolyl)-μ-oxo-dizirconium [dimer (II)]. Both of them belong to monoclinic system and possess the same spacegroup C_2~5h- 2_1/a. The cell dimer (Ⅰ) containing four molecules is defined by a=19.122A,b=16.319A, c = 9.296A, β= 92°1′; the cell dimer (Ⅱ) containing two molecules is defined bya = 20.076A, b = 8.205A, c = 10.016A, β= 104°41′. The important difference of molecular configurations between the two dimers lies in thatthe dimer (Ⅰ) has no symmetry center and its Zn-O-Zr oxo-bridge presents a slightly bentconfiguration while the dimer (Ⅱ) takes the oxgen atom as a symmetry center and its oxo-bridge present linear linkage. In accordance with the above-mentioned molecular configuration, steric effect and elec-tronic structure have been further discussed.     

ASYMMETRIC REDUCTION OF S-ALKYL-S-ARYL-N-p-TOSYLSULFILIMINES WITH L(–)CYSTEINE

Abstract

Partial reduction of racemic mixture of S-alkyl-S-aryl-p-tosyl sulfilimines with L(–)cysteine affords optically active recovered sulfilimine. In the case of S-methyl-S-p-tolyl-N-p-tosylsuifilimine the absolute configuration and the optical yield were determined.     

ONE''''POT REACTION OF TRIVALENTPHOSPHORUS COMPOUNDS (Ⅰ)——A NOVEL ONE-STEP REACTION OF ADDITION,REDUCTION AND CYCLIZATION OF SUBSTITUTED β-NITROSTYRENE WITH O,O-DIALKYL PHOSPHITES

In this paper the reaction of substituted β-nitrostyrene with O,O-dialkyl phosphite under cocatalysis of trimethylsilyl chloride (TMS-C1) and triethylamine (or other acidbinding agent) has been first studied and the new cyclization reaction leading to the formation of product Ⅱ, as a new class of derivatives of 1-hydroxyindoles, difficultly accessible or inaccessible with usual methods has been observed. In the related reaction it is surprising that when the Arbuzov rearrangement occurs under mild conditions, the addition, reduction and cyclization as a one-pot reaction take place simultaneously with the formation of products Ⅰ, Ⅱ, Ⅲ. By controlling the reaction conditions the products were formed almost in specificity, and thus the most interesting cyclic products Ⅱ_(a-h) containing phosphorus-carbon bond were obtained. Their structures were confirmed by elemental analysis, IR, ~1H or ~(31)p NMR and MS spectra. The crystal structure of representative compound Ⅱ_h was determined by X-ray diffract     

MAGNESIUM-NETHAN0L REDUCTION OF 2-(1, 3-DITHIAN-2-YLIDENE)-I-ARYL KETONES:A FACILE ROUTE TO α-ARYL-β-(1,3-DITHANE)ALCOHOLS

In a facile procedure, 2-(1, 3-dithian-2-ylidene)-l-arylketones 1 vere reduced with magnesium in methanol to give α-aryl-β-(1, 3-dithane) alcohols 2 in good to high yields.     

CRYSTAL AND MOLECULAR STRUCTURES OF BIS (CYCLOPENTADIENYL) BIS (2,4,6-TRICHLOROPHENOXY)TITANIUM, Cp_2Ti(OC_6H_2Cl_3-2,4,6)_2 (Ⅰ) AND TETRAKIS(CYCLOPENTADIENYL)BIS (4-CHLOROPHENOXY)-μ-OXO-DIZIRCONIUM,[Cp_2Zr(OC_6H_4Cl-p)]_2O (Ⅱ)

The crystal and molecular structures of (Ⅰ) and (Ⅱ) have been determined from single-crystal, X-ray diffraotion data collected by counter methods. Compound (Ⅰ) crystallizes inthe monoclinic space group C 2/c with a=19.618(11) ?, b=9.356(4) ?, c=15.985(8) ?,β=128.84 (3)°, Z=4. The molecule possesses C_2 point symmetry. Compound (Ⅱ) erystallizesin the monoclinic space group P 2_1/a with a=8.329(2) ?, b=36.509(13) ?, c=10.647(4)?, β=96.04(2)°, Z=4. The oxo-bridge links two [Cp_2Zr(OC_6H_4Cl-p)] units together withthe bond angle Zr-O-Zr of 161.1(9)°. The relatively shorter Zr-O bond lengths show the pre-sence of partial double-bond character. Both Ti and Zr atoms have d° electronic configura-tion in (Ⅰ) and (Ⅱ). The M-O bonds of the two compounds are discussed.     

AQUEOUS POLYMERIZATION OF METHYL METHACRYLATE INITIATED BY TITANIUM(III)—SALICYLALDOXIME REDOX SYSTEM: A KINETIC STUDY

The polymerization of methyl methacrylate initiated by the titanium(III)-salicylaldoxime redox system was studied in an aqueous sulfuric acid-ethanol medium in the temperature range of 20–30°C. The rates of polymerization were investigated at various concentrations of reductant, oxidant, ethanol, sulfuric acid, and monomer. Cyclic voltammetric sensing of salicylaldoxime kinetic conditions demonstrated its reduction behavior. From the results obtained, it was inferred that the polymerization reaction was initiated by an organic free radical arising from the titanium(III)-salicylaldoxime redox system and termination took place predominantly by mutual coupling and small fraction by chain transfer mechanism involving solvent molecules. The effects of some water-miscible organic solvents and surfactants on the rate of polymerization were investigated. The temperature dependence of the rate was studied and the activation parameters were computed using Arrhenius and Eyring plots. A suitable kinetic scheme has been proposed on the basis of experimental observations.     

SYNTHESIS OF FUNCTIONAL POLYETHYLENE via COPOLYMERIZATION OF ETHYLENE AND SUBSTITUTED ALLENE USING BIS(β-ENAMINOKETONATO)TITANIUM CATALYSTS

Novel copolymerization of ethylene with substituted allenes(CH_2=C = CH—R,1:R = n-butyl,2:R =n-octyl) using bis(β-enaminoketonato)titanium catalysts[PhN = C(R_2)CHC(R_1)O]_2TiCl_2(1a:R_1 = CF_3,R_2 = CH_3;1b:R_1 = Ph,R_2 = CF_3) has been investigated.In the presence of modified methylaluminoxane,these catalysts can copolymerize ethylene with substituted allenes,affording copolymers with unimodal molecular weight distributions and homogeneous compositions.By varying the reaction conditions,the comonomer i...     

PHOTOCHEMISTRY OF HYPOCRELLIN A (Ⅶ)——PHOTO-INDUCED ONE-ELECTRON REDUCTION OF HYPOCRELLIN PIGMENTS

The photo-induced one-electron reduction of hypocrellin A (abbreviated as HA) and hy-pocrellin B (abbreviated as HB) in the presence of cysteine or ascorbic acid has been studied in this paper. The semiquinone radical anions of HA and HB obtained from the photo-reduction of HA and HB respectively, and the following protonation and disproportionation of these radical anions were detected via the ESR and UV-Vis spectra. Through comparison of their UV-Vis spectra with those of the chemically synthesized compounds of similar structures, it has been suggested that the metastable products formed after the acceptance of net two electrons and two protons in the photoreduction of HA and HB were tetrahydroxyl-per-ylene derivatives.     

A FACILE TOTAL SYNTHESIS OF (±)-SELINA-3,11-DIEN-9-OL

Ａ　ＦＡＣＩＬＥ　ＴＯＴＡＬ　ＳＹＮＴＨＥＳＩＳ　ＯＦ　（±）－ＳＥＬＩＮＡ－３，　１１－ＤＩＥＮ－９－ＯＬＡＦＡＣＩＬＥＴＯＴＡＬＳＹＮＴＨＥＳＩＳＯＦ（±）－ＳＥＬＩＮＡ－３，１１－ＤＩＥＮ－９－ＯＬＬｉＪｕｎＬＩＵ；ＺｈａｏＭｉｎｇＸＩＯＮＧ；...     

A NEW APPROACH TO THE SYNTHESES OF THE PHEROMONES OF JAPANESE BEETLE AND BONTEBOK WITH(Z)-VINYL CUPRATES

The dl-form of the sex pheromone of Japanese b(?)tle and the trail pheromone of Bontebok were synthesised in high purity of (Z)-olefinic configuration. The key step of the syntheses of compounds (1) and (2) involved stereospecific addition of n-alkyl cuprates to acetylene followed by addition of vinyl cuprates to aldehyde (7) and 3-buten--2-one.     

LABELING OF PROTEIN WITH A NEW EUROPIUM CHELATE OF 5-CHLOROSULFOYL-2-THENOYLTRIFLUOROACETONE(CTTA)AND APPLICATION TO IMMUNOASSAY

We describe for the first time the synthesis and the optimal conditions for proteinlabeling with a new fluorescent probe,5-chlorosulfoyl-2-thenoyltrifluoroacetone(CTTA),whicb forms ahighly fluorescent conplex with Eu~(3+) when conjugated to protein.The labeled proteins werecharacterized by absorbance and fluorescence measurements and the effect of labeling on thebiological activity of sone proteins was also studied.It is shown that the new label is suitablefor applications in time-resolved fluoroimmunoassay.     

SYNTHESIS OF BENZOFURAN DERIVATIVES USING MANGANESE (III) ACETATE MEDIATED ADDITION OF β-DICARBONYL COMPOUNDS TO ALKYNE AND ALKENES – A COMPARATIVE STUDY

β-Dicarbonyl compounds were easily oxidized with manganese (III) acetate in acetic acid to form the corresponding α-carboradicals, which attacked alkyne and alkenes to give furan derivatives in good yield.     

THE INTERACTION OF BIS[2-MERCAPTOETHANESULFONATO (2−)-Sl,BIS[L-CYSTEINATO(1−)-S], AND BIS[L-PENICILLAMINATO(1−)-Sl- DIMETHYLTIN (IV), WITH RAT HEMOGLOBIN: A119Sn MöSSBAUER SPECTROSCOPIC STUDY

Abstract

The title compounds, representative of classes of diorganotin (IV) derivatives active against murine leukemia P-388. interact with rat hemoglobin (selected as a model protein) by: i) co-crystallization. with formation of microcrystalline pellets, and: ii) diffusion into hemoglobin crystals from the supernatant solution (as determined for the 2-mercaptoethanesulfonato derivative). The nature of the Me₂Sn^IV species in hemoglobin has been investigated by ¹¹⁹Sn Mössbauer spectroscopy, and a C₂SnS₂ tetrahedral geometry has been assigned by the point-charge model rationalization of the nuclear quadrupole splitting parameter.

Binding into crystalline hemoglobin has been ascribed to Coulomb interactions and to hydrogen bonding between the sulfonate and the aminoacid tails of the organotin (IV) derivatives and functional groups of the globin.     

REACTION OF BIS(β-ALANINATO)COPPER(II) WITH FORMALDEHYDE: X-RAY CRYSTAL STRUCTURE OF AQUABIS(N,N-DIMETHYL-β-ALANINATO)COPPER(II) HEXAHYDRATE

Abstract

The reaction of bis(β-alaninato)copper(II) with formaldehyde results in the formation of blue crystals of aquabis(N,N-dimethyl-β-alaninato)copper(II) hexahydrate, [Cu(C₅H₁₀NO₂)₂(OH₂)].6H₂O which crystallize in the monoclinic space group C2/c with unit cell dimensions a = 20.799(2), b = 8.112(1), c = 23.639(1)Å, β = 96.50(1)° and Z = 8. The structure has been refined to final R = 0.047 and R_w = 0.053 for 1690 reflections with I ≥ 2.55σ(I).     

REACTIONS OF C_(60) WITH R_3SnH: A NEW SYNTHETIC TO C_(60)(RH)n AND THE PROPERTY OF C_(60) TO CATALYZE RADICAL REACTIONS

ＲＥＡＣＴＩＯＮＳＯＦＣ_（６０）ＷＩＴＨＲ_３ＳｎＨ：ＡＮＥＷＳＹＮＴＨＥＴＩＣＴＯＣ_（６０）（ＲＨ）ｎＡＮＤＴＨＥＰＲＯＰＥＲＴＹＯＦＣ_（６０）ＴＯＣＡＴＡＬＹＺＥＲＡＤＩＣＡＬＲＥＡＣＴＩＯＮＳ￥ＹｉＭｉｎＳＨＥ；ＹａＰｉｎｇＴＵ；ＸｉｎｇＨｕ...     

A SENSITIZED PHOTOINITIATION SYSTEM ——BIS (7-DIETHYLAMINO COUMARIN ) KETONE-3 AND DIPHENYLIODONIUM SALT COMBINATION

Bis (7-diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO leads to bleaching of DACK and decomposition of DPIO to generate initiating radical species. The electron transfer sensitization occurs mainly from the triplet state of DACK. The photobleaching obeyed a second-order kinetics and the rate constant was evaluated to be 31.3mol~(-1)·1·s~(-1) Photopolymerization of MMA initiated by DACK/DPIO was carried out in acetonitrile solution. The polymerization rate was found to be proportional to the concentration of DACK, DPIO and MMA with the exponents of 0.34, 0.40 and 1.0 respectively. The initiated efficiency is comparable to those of small molecular ketones.The sensitized photoinitiation mechanism has been discussed.