The synthesis and thermotropic liquid crystalline behavior of the novel poly(aryl ether ketone)s containing chloro-side group

The novel poly(aryl ether ketone)s containing chloro-side group were synthesized by nucleophilic substitution reactions of 4,4'-biphenol and chlorohydroquinone with either 4,4'-difluorobenzophenone(BP/CH/DF) or 1,4-bis(p-fluorobenzoyl)benzene (BP/CH/BF) and their thermotropic liquid crystalline properties were characterized by a variety of experimental techniques. The thermotropic liquid crystalline behavior was observed in the copolymers containing 50 and 70% biphenol. Melting transition (Tm) and isotropization transition (Ti) both appeared in the DSC thermograms. A banded texture was formed after shearing the sample in the liquid crystalline state. The novel poly(aryl ether ketone)s had relatively higher glass transition temperature (Tg) in the range of 168 similar to 200 degrees C and lower melting temperature (Tm) in the range of 290 similar to 340 degrees C. The thermal stability (Td) was in the range of 430 similar to 490 degrees C.

Ion/neutral complex-mediated reactions generated from some ionized tetrahydroimidazole-substituted methylene beta-diketones

The dissociation of gaseous metastable ions of m/z 153 and the formation of ions of m/z 139 from the unimolecular fragmentations of ionized tetrahydroimidazole-substituted methylene beta-diketones were examined by tandem mass spectrometry. In addition, some other fragments accompanying the elimination of either an H2O molecule or an CHO. radical were also observed in the collision-induced dissociation spectra of molecular ions of the compounds bearing an aromatic ring. Collision-induced dissociation and isotopic labeling showed that these processes may involve reactions of intermediate ion/neutral complexes and multistep rearrangements. The corresponding mechanisms are discussed. (C) 1997 by John Wiley & Sons, Ltd.

Gas-phase ion-molecule reactions of C-60 and theoretical studies of [C60C2H3O](+) adduct cations

Gas-phase ion-molecule reactions of buckminsterfullerene (C-60) with the acetyl cation CH3-C-+=O (m/z 43) and formylmethyl cation (CH2)-C-+-CH=O (m/z 43, or oxiranyl cation), generated from the self-chemical ionization of acetone and vinyl acetate, respectively, were studied in the ion source of a mass spectrometer. Adduct cations [C60C2H3O](+) (m/z 763) and protonated C-60, [C60H](+) (m/z 721), were observed as the major products. AM1 semiempirical molecular orbital calculations on the possible structures, stabilities and charge locations of the isomers of the adducts [C60C2H3O](+) were carried out at the restricted Hartree-Fock level. The results indicated that the sigma-addition product [C-60-COCH3](+) is the most stable adduct for the reaction of C-60 with CH3-C-+=O rather than that resulting from the [2+2] cycloaddition. The [2+3] cycloadduct and the sigma-adduct [C60CH2CHO](+) might be the most possible coexisting products for the reactions of C-60 with (CH2)-C-+-CH=O or oxiranyl cation. Other [C60C2H3O](+) isomers are also discussed. (C) 1997 by John Wiley & Sons, Ltd.

Quantitative structure-property relationships for colour reagents and their colour reactions with cerium using computational neural networks

Quantitative structure-activity/property relationships (QSAR/QSPR) studies have been exploited extensively in the designs of drugs and pesticides, but few such studies have been applied to the design of colour reagents. In this work, the topological indices A(x1)-A(x3) suggested in this laboratory were applied to multivariate analysis in structure-property studies. The topological indices of 43 phosphone bisazo derivatives of chromotropic acid were calculated. The structure-property relationships between colour reagents and their colour reactions with cerium were studied using A(x1-Ax3) indices with satisfactory results. The purpose of this work was to establish whether QSAR can be used to predict the contrasts of colour reactions and in the longer term to be a helpful tool in colour reagent design.

Syntheses and reactions of heterometallic complexes of nickel and copper with tetrathiotungstates. The molecular structures of [Ph(4)P](2)[S2W(mu-S)(2)Ni(S-2)] and W(mu-S)(4)Cu-2(PPh(3))(4)center dot py

Reaction of [Ph(4)P]2WS4 With NiCl2 in methanol solution in the presence of NaOCH3 leads to the formation of [Ph(4)P](2) [S2W(mu-S)(2)Ni(S-2)] (I) A Similar reaction between (NH4)(2)WS4 and NiCl2 under O-2 atmosphere in the presence of Ph(4)PCl or (n)Bu(4)NCl affords [Ph(4)P](2)([(S-2)W(O)(mu-S)(2)]Ni-2] (IIa) and [(n)Bu(4)N](2)([(S-2)W(O)(mu-S)(2)]Ni-2} (IIb) Under argon the same reaction gives [Ph(4)P](2)[Ni(WS4)(2)] (IIIa) and [(n)Bu(4)N](2)[Ni(WS4)(2)] (IIIb). [Ph(4)P](2)[Ni(WOS3)(2)] (IV) and [Ph(4)P](2)[Ni(WO2S2)(2)] (V) can be prepared from the reaction of [Ph(4)P]2WOS3 and [Ph(4)P]2WO2S2 with NiCl2. Treatment of (NH4)(2)WS4 with CuCl in the presence of PPh(3) in boiling pyridine produces W(mu-S)(4)Cu-2(PPh(3))(3) (VI), which can further react with excess PPh(3) to give W(mu-S)(4)Cu-2(PPh(3))(4) . py (VII). Complex I crystallizes in the space group P2(1)/n with the cell parameters: a = 20.049(4), b = 17.010(4), c = 14.311(7) Angstrom; beta = 110.24(3)degrees and Z = 4; R = 0.058 for 4267 independent reflections. The structural study confirms that complex I contains two terminal sulfide ligands, two bridging sulfide ligands, a side-on disulfide ligand, and a planar central W(mu-S)(2)Ni four membered ring. Complex VII crystallizes in the space group C2/c with the cell parameters: a = 26.436(8), b = 20.542(6), c = 19.095(8) Angstrom; beta = 125.00(3)degrees and Z = 4; R = 0.080 for 3802 independent reflections. The structural study reveals a perfect linear arrangement of the three metal atoms Cu-W-Cu.

Reactions of C-60 with R(3)SnH: A new synthetic route to C-60(RH)(n) and the property of C-60 to catalyze radical reactions

A new method for the preparation of polyalkyl and polyarenefullerene derivatives C-60(RH)(n)(R=Bu,n=1-3; R=Ph,n=1-10) by the reaction of C-60 with organotin hydride in toluene is described. Another series of products of stannanes R(a)Sn(b)H(c) (R=Bu, a=3-8, b=1-4, c=0-3 R=Ph, a=3-11, b=1-5, c=0-4) were also obtained, which shows that C-60 can catalyze polymerization of organic-tin. These products were determined by mass and infrared spectrometry. And the possible reaction mechanisms are discussed.

C-118 from fullerenols: Formation, structure and intermolecular nC(2) transfer reactions in mass spectrometry

In fast atom bombardment, two fullerenols C-60(OH)(x) (x=13-15) and C-60(OH)(x) (x-24-26) gave rise to a group of ions centered at C-118 with intervals of 24 mass units in the high mass region. In contrast, no such ions appeared in the mass spectra of pure C-60, C-70 and other fullerene derivatives such as C-60(C6H5)(10), under the same conditions. It is proposed that the pinacol rearrangement of C-60(OH)(2), resulting from partial rupture of the polyhydroxy molecules, produces C-59 with two carbon atoms bearing an unpaired electron, and that dimerization of this reactive intermediate is responsible for the formation of the predominant product C-118. An intermolecular nC(2) transfer process is used to explain the symmetrical abundance distribution of these product ions in the spectra of fullerenols.

Prediction of molar absorptivities of color reagents during their color reactions with cerium using multiple regression analysis and neural network

A quantitative structure-property study has been made on the relationship between molar absorptivities (epsilon) of asymmetrical phosphone bisazo derivatives of chromotropic acid and their color reactions with cerium by multiple regression analysis and neural network. The new topological indices A(x1) - A(x3) suggested in our laboratory and molecular connectivity indices of 43 compounds have been calculated. The results obtained from the two methods are compared. The neural network model is superior to the regression analysis technique and gave a prediction which was sufficiently accurate to estimate the molar absorptivities of color reagents during their color reactions with cerium.

Quantitative structure-property relationships for colour reagents and their colour reactions with ytterbium using regression analysis and computational neural networks

In this paper, the new topological indices A(x1)-A(x3) suggested in our laboratory and molecular connectivity indices have been applied to multivariate analysis in structure-property studies. The topological indices of twenty asymmetrical phosphono bisazo derivatives of chromotropic acid have been calculated. The structure-property relationships between colour reagents and their colour reactions with ytterbium have been studied by A(x1)-A(x3) indices and molecular connectivity indices with satisfactory results. Multiple regression analysis and neural networks were employed simultaneously in this study.

Study on structure-property relationships between color reagents and sensitivity of color reactions with yttrium by topological indices

In this paper, three topological indices, Am-1, Am-2, and Am-3, multivariate analysis in structure-property studies. The topological indices of twenty asymmetrical phosphosphono bisazo derivatives of chromotropic acid have been calculated. The structure-property relationships between color reagents and molar absorptivity of color reactions with yttrium have been studied by A(m) indices and structure selective factors. Good results have been obtained by using correlation equation to predict the molar absorptivity of new color reagents.

Studies on structure-property relationship between color reagents and contrast of their color reactions with cerium by topological indices

In this paper, three topological indices A(m1), A(m2) and A(m3) have been applied to multivariate analysis in structure property relationship studies. The topological indices oi fourty-three asymmetrical phosphono bisazo derivatives of chromotropic acid have been calculated, The structure-property relationship between color reagents and contrast of color reactions with cerium has been studied by A, indices and structure selective factors, Good results have been obtained.

GAS-PHASE REACTIONS OF C-60 WITH THE ION SYSTEMS OF CYCLOHEXANE AND CYCLOHEXENE

The DCI MS of C-60 with the reactions of gaseous cyclohexane and cyclohexene have been studied. Several kinds reactions of C-60 have been observed. The results show that the gasphase C-60 has very active chemical properties. The adduct ions of [C60C4H7](+) and [C60C5H7](+) may be formed by [2+4] cycloaddition where one of double bonds of C-60 acted as a dienophilic unit.

GAS-PHASE ION-MOLECULE REACTIONS OF BUCKMINSTERFULLERENE C-60 WITH SOME SMALL ORGANIC-COMPOUNDS IN MASS-SPECTROMETER

In chemical ionization mass spectrometry (CIMS) gas phase C-60(+) or C-60 can react with fragment ions from three chloromethane and four multichloroethane molecular ions via ion-molecule reactions. A dozen of gas-phase adduct ions of C-60 are observed, and most of them contain chlorine atoms. The results of the comparison and analysis show that the relative intensities of adductions are not directly proportional to the corresponding fragment ions in the MS of reagents,which implies that some fragment ions containing radicals are more reactive with C-60(+) or C-60. This indicates that the alkene-like C-60(+) or C-60 can act as a radical sponge in addition reactions.

STUDIES ON STRUCTURE-PROPERTY RELATIONSHIP BETWEEN COLOR REAGENTS AND SENSITIVITY OF THEIR COLOR-REACTIONS WITH YTTERBIUM BY TOPOLOGICAL INDEXES

In this paper A, topological indices and molecular connectivity inidces have been applied to multivariate analysis in structure-property studies. The topological indices of twenty asymmetrical phosphone bisazo derivatives of chromotropic acid have been calculated. The structure-property relationships between color reagents and molar absorptivity of color reactions with ytterbium have been studied by A(m) indices and molecular connectivity indices. Good results have been obtained.

UNIMOLECULAR DISSOCIATION REACTIONS OF DOUBLY-CHARGED IONS [C12H12N2O](2+) AND [C12H12N2S](2+) IN GAS-PHASE

The unimolecular dissociation reactions of doubly charged ions were reported, which resulted from a tandem mass spectrometer and a reversed geometry double focusing mass spectrometer by electron impact, Mass analyzed ion kinetic energy spectrometry (MIKES) was used to obtain the kinetic energy releases in charge separation reactions of doubly charged ions, The intercharge distances between the two charges at transition states can be calculated from the kinetic energy releases, Transition structures of unimolecular dissociation reactions were infered from MIKES and MS/MS.