2-AMINOMETHYLPYRIDINE NICKEL(Ⅱ) COMPLEXES—SYNTHESIS,MOLECULAR STRUCTURE AND CATALYSIS OF ETHYLENE POLYMERIZATION

A series of new nickel(Ⅱ)complexes with 2-aminomethylpyridine ligands,(2-PyCH_2NHAr)_2NiBr_2(Ar=2,6- dimethylphenyl 2a;2,6-diisopropylphenyl 2b,2,6-difluorophenyl 2c),have been synthesized and used as catalyst precursors for ethylene polymerization in the presence of methylaluminoxane(MAO).The catalysts containing ortho-alkyl-substituents afford high molecular weight branched polyethylenes as well as a certain amount of oligomers.Enhancing the steric bulk of the alkyl substituent of the catalyst resulted...     

STUDIES ON RESOLUTION OF RACEMIC GOSSYPOL RACEMIC GOSSYPOL——SEPARATION OF HEXAACETATES OF S-1-METHYLPHEN-ETHYLAMINO DERIVATIVE OF (±) GOSSYPOL

This paper reports the resolution of racemic gossypol to optically active enantiomery by condensationof (±) gossypol with S-1-methylphenethylamine, followed by subsequent actetylation and hydrolysis. Sev-en isomers of hexaacetate of di-S-1-methylphenet-thylamino gossypol have been obtained by chromatog-raphy on silica gel, and also structures of the acetates have been determined.     

CONFORMATIONAL CHARACTERISTICS OF POLY(ACRYLIC ACID) AND POLY(METHACRYLIC ACID)

A full-relaxation optimization of molecule and the Dreiding force field are employed toobtain the geometry parameters and the conformational energy surfaces of meso or racemicdyad of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA). Three differentcarbonyl-bond orientations of side-groups resulted in the differences in depth of potentialwells in their energetic contours for a meso or a racemic dyad. These discrepancies areinterpreted as a result of various fine structures corresponding to grid search conformationsas well as thereby different interactions. The analysis on the most stable conformationsof PMAA confirmed that the ester groups are nearly perpendicular to the plane definedby the two adjacent skeletal bonds but may possibly change their relative orientations tomeet the requirement of lower energy during the conformational state transition. For eachpolyme, two global energy maps of a meso and a racemic dyad were finally constructedfrom the superposition of energy data for the three kinds of side-group orientations by theBoltzmann factors. From an ensemble average, the proposed scheme with three rotationalisomeric states (RIS) allowed us to access the experimentally unperturbed dimensions ofPAA chain via the configurational statistical mechanics. Although the calculation wasbased on the short-range, local interactions, it was interested to note that the experimentalcharacteristic ratios just fell within the range calculated for atactic chains.     

2-AMINOMETHYLPYRIDINE NICKEL(II) COMPLEXES — SYNTHESIS，MOLECULAR STRUCTURE AND CATALYSIS OF ETHYLENE POLYMERIZATION

 A series of new nickel(II) complexes with 2-aminomethylpyridine ligands, (2-PyCH₂NHAr)₂NiBr₂(Ar = 2,6-dimethylphenyl 2a; 2,6-diisopropylphenyl 2b, 2,6-difluorophenyl 2c), have been synthesized and used as catalyst precursors for ethylene polymerization in the presence of methylaluminoxane (MAO)．The catalysts containing ortho-alkyl-substituents afford high molecular weight branched polyethylenes as well as a certain amount of oligomers. Enhancing the steric bulk of the alkyl substituent of the catalyst resulted in higher ratio of solid polymer to oligomer and higher molecular weight of the polymer. Catalyst 2c containing ortho-fluoro-substituents exhibited the highest catalytic activity, but only oligomers in which C₁₂H₂₄ had the maximum content were obtained by the catalyst. The molecular weight, molecular weight distribution, and microstructure of the resulted polymer were characterized by gel permeation chromatography and ¹³C-NMR spectrogram.     

SYNTHESIS AND CRTYSTAL STRUCTURE OF LUTETIUM (Ⅲ) COMPLEX WITH 1,3,5-BENZENETRICARBOXYLIC ACID

<正> LuC9H3O6(H2O)5·4H2O, Mr = 528. 3, monoclinic, C2/c, a = 14. 673(3), b=16.930(4), c= 14. 383(4)(?) , β=118.77(2)°, Z = 8, 7 = 3132(1) (?)3, Dc = 2. 24g/cm3, μ(MoKα) = 67.0cm-1, F(000) = 2064, R = 0. 052 for 4080 observed reflections. The Lutetium ion is eight-coordinated by three oxygen atoms, one from a 1, 3, 5,-benzenetricarboxylate ligands, two from another one, and five aqua ligands,forming a polymeric zigzag chain along the [101] direction. The Lu -O distances fall in the range of 2. 229 -2. 404(?).     

STUDIES ON THE PRENYLFLAVONOIDS PART Ⅲ.SYNTHESIS OF(±)EUCHRENONE A_8

(±)Euchrenonc a_8,7,2'-dihydroxy-8,5'-di(γ,γ-dimethylallyl)-4'-methoxyflavanone,hasbeen synthesized by the condensation of 2-hydroxy-4-methoxymethoxy-3-(γ,γ-dimethylallyl)acctophenonc with 4-methoxy-2-methoxymethoxy-5-(γ,γ-dimethylallyl)benzaldchyde followed bycyclization and demethoxymethylation.     

STUDIES ON THE PRENYLFLAVONOIDS PART Ⅳ~([1]). SYNTHESIS OF(±)LESPEDEZAFLAVANONEE

(±)Lespedezaflavanone E, 6, 8, 3'-tri (γ,γ-dimethylallyl)-5, 7, 2', 4'-tetrahydroxy-flavanone, has been synthesized by the condensation of 3, 5-di (γ,γ-dimethylallyl)-4, 6-dimethoxymethoxy-2-hydroxyacetophenone and 2, 4-dimethoxymethoxy-3-(γ,γ-dimethylallyl)-benzaldehyde followed by cyclization and demethoxymethylation.     

TIMING OF COLLISION BETWEEN THE NORTH AND SOUTH CHINA BLOCKS——THE Sm-Nd ISOTOPIC AGE EVIDENCE

Sm-Nd isotopic ages for C-type eclogite (243.9±5.6 Ma) and mafic and ultramafic rocks(230.6±30.7 Ma and 402.6±17.4 Ma) from the Qinling-Dabieshan orogenic belt are reported.These ages suggest that at the early Triassic, the North and South China Blocks have beenunited along the Qinling-Dabieshan collision zone, and before the final collision, a se-ries of ophiolite obductions took place successively away from the continental marginduring the Paleozoic.     

A FACILE SYNTHESIS OF(±)-MURICATAIN

(±)-Muricatain has been synthesized employing ringopening of allylic alcohol epoxide with lithium acetonitrileand lactonization.     

SUBSTITUENT CHEMICAL SHIFT (SCS) AND THE SEQUENCE STRUCTURE OF ETHYLENE-VINYL ALCOHOL COPOLYMERS

Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift (SCS) method. The SCS parameters of hydroxy (-OH) in two different solvents were obtained: in deuterium oxide/phenol (20/80 W/W ) the parameters are S_1 = 42.77±0.08ppm, S_2 = 7.15±0.06 ppm, S_3 (s)= -4.08±0.02ppm, S_3 (t) =-3.09±0.20ppm,S_4 = 0.48±0.03ppm, S_5 = 0.26±0.05ppm. In o-dichloro-benzen-d_4 S_1(s)=44.79±0.61ppm, S_2=7.40±0.00ppm, S_3(s)=-4.51±0.17ppm, S_3(t)=-3.13 ±0.00 ppm, S_4 =0.63±0.04ppm, S_5=0.36±0.00ppm.Simultaneously the ~(13)CNMR spectra of EVA copolymers were assigned by using the SCS parameters obtained.     

STUDIES ON ANTIHEPATITIC DRUGS——TOTAL SYNTHESIS OF (±)SCHIZANDRIN C AND ITS ANALOGS

This paper reports the total synthesis of (±) schizandrin, C, namely S, 6, 7, 8-tetrahydro-1,12-dimethoxy-2, 3, 10, 11-bismethylenedioxy-6, 7-cis-dimethyldibenzo (a, c) cyclooctene (12B), a new active SGPT lowering principle isolated from the Chinese medical plant Schizandra chinensis, and its 6, 7-trans-dimethyl isomer (16B). We also synthesized two more isomers, namely 5, 6, 7, 8-tetrahydro-3, 10-dimethoxy-1, 2, 11, 12-bismethylenedioxy-6, and 7-cis-(and trans-) dimethyldibenzo (a, c) eyelooctene (12A and 16A). The NMR, UV and mass spectra of these four isomers are discussed. IR (in chloroform), UV, NMR and MS of synthetic schizandrin C (12B) are identical with those of the natural compound.     

(±)-Seudenol和(±)-Frontalin的简便合成

从易得的油酸出发 ,经关键中间体 2 ,6 庚二酮合成了云杉红翅小蠹集合信息素 (± ) Seudenol (3 甲基 2 环己烯 1 醇 )和南部松小蠹集合信息素 (± ) Frontalin (1 ,5 二甲基 6,8 二氧双环 [3 .2 .1 ]辛烷 )。所合成化合物的结构经IR、MS、1HNMR和13CNMR证实。     

SYNTHESIS OF (±)-FARNESYL FLAVANONE AND FARNESYL ACETOPHENONE

ＳＹＮＴＨＥＳＩＳ　ＯＦ　（±）－ＦＡＲＮＥＳＹＬ　ＦＬＡＶＡＮＯＮＥ　ＡＮＤ　ＦＡＲＮＥＳＹＬ　ＡＣＥＴＯＰＨＥＮＯＮＥ￥ＳＹＮＴＨＥＳＩＳＯＦ（±）－ＦＡＲＮＥＳＹＬＦＬＡＶＡＮＯＮＥＡＮＤＦＡＲＮＥＳＹＬＡＣＥＴＯＰＨＥＮＯＮＥ￥ＣｈｕＳｈｅｎ...     

SYNTHESIS OF MACROPOROUS HUMIC ACID RESINS AND THEIR CHELATING PROPERTIES FOR HEAVY METAL IONS

Macroporous HA resins (HAR) can be prepared in pearl form by grafting HA onto crosslinked PS through azo or through ester and / or ether linkages. At pH 13 and the HA / PSNH_2 weight ratio 0.7—1.0, PSN_2~+-Cl~-couples with HA and results in the formation of a7o-type HA resin (HAR-A), which shows good adsorbility towards heavy metal ions. The Cu~(2+) sorption capacity of ester / ether type humic acid resin (HAR-E) is increased by lengthening the reaction time of HA and PSCH_2Cl. The structure of HAR is discussed on the basis of the IR spectra. The sorption capacity of HAR-A is 1.01 mmol / g for Cd~(2+) and 0.6—0.53 mmol/g for Ni~(2+), Mn~(2+), Cu~(2+), Co~(3+) and Zn~(2+). respectively. The calculated distribution coefficients of heavy metal ions on HAR-A can be arranged in the following order: Cu~(2+)(8.7×10~3)>Cd~(2+) (3.8×10~2)>Zn~(2+)(2.4×10~2)>Ni~(2+)(1.8×10~2)>Mn~(2+)(4.9×10). At pH 6.5, Cu~(2+), Cd~(2+), Ni~(2+), Mn~(2+) can be quantitatively adsorbed by HAR-A and completely eluted with 1N HNO_3. HAR-A can be regenerated and reused. Trace quantities of the above-mentioned heavy metal ions in four samples of the natural occurring water and one sample of the tap water were analyzed by using HAR-A.     

ABSOLUTE CONFIGURATION OF (-)ANISODINE (A NEW GANGLIO BLOCKING AGENT) AND (-)ANISODINIC ACID

A new tropane alkaloid, (-)anisodlne (Ⅰ), was isolated from the plant of Anisodus tanguticus. It is a novel ganglio blocking agent. The absolute configuration of (-)anisodinic acid (Ⅶ), which-is the side chain of (-)anisodine, was determined by chemical correlation with (R) (-)-2-phenyl-1, 2-propanediol (Ⅳ) and (R) (-)-2-hydroxy-2-phenylpropionic acid (Ⅵ). Thereby (-)anisodine with the absolute configuration shown as (Ⅰ) is 6β, 7β-epoxy-1αH, 5αH-tropan-3α-ol (S) 2'-phenyl-2', 3'-dihydroxypropionate. Two new tropane alkaloids: 6β, 7β-epoxy-1αH, 5αH-tropan-3α-ol 2',3'-epox-ypropionate (Ⅲ) and 2'-phenyl-2'-hydroxypropionate (Ⅴ) were prepared and its physical constant is reported in this paper.     

CRYSTAL STRUCTURES OF COPPER (Ⅱ) AND COBALT (Ⅲ) COM- PLEXES OF o-HYDROXYBENZYLGLYCINATE (HBG)

<正> The structures of two complexes C(CuOC6H4CH2NHCH2COO)2 (H2 O)]·H2P(1) and [Co(NH3)6[Co(OC6H4CH2NHCH2COO)2]2[C1]·10H2O (2) were determined by X-ray analyses. Compound (1) crystallizes in the orthorhombic space group P212121 with a=11. 357(1),b= 24. 304(2),c=7.317(4) A,Z= 4;While compound (2) in the monoclinic space group A2/a(C2/c) with a=23. 486(9) ,b=26. 605(6) ,c= 10. 542(1) A,γ= 128. 42(4)°,Z= 4. In compound (1),two Cu(Ⅱ) ions are bonded together by the phenolic oxygen atoms of two tridentate chelating ligands and each of them is separately coordinated by the carboxyl oxygen,amino nitrogen of each chelate ligand and by the fifth oxygen atom as well (from aqua or the carbonyl group in adjacent molecule). Thus the coordination of each Cu(Ⅱ) is a square pyramid with distances of 1. 93- 1. 97A to the four corner atoms and 2. 30 and 2. 32 A to the apex atoms. The whole molecule has an approximately planar configuratioir with the two pyramid apexes pointing towards one side. Compound (2) consists of     

PREPARATION AND CHARACTERIZATION OF BINUCLEAR μ-PHENOLATOCOPPER(II)CHELATES.

Two new water-soluble binuclear copper(II)chelates derived from the condensationof 2,6-diformyl-4-methylphenol with glycylglycine were characterized with spectral.magnetic and electrochemical techniques.     

STRUCTURE OF N-(p-CHLORO )-PHENYL ZMINODIACETIC ACID

<正> N-(para-chloro)-phenyl iminodiacetic acid hydrate ethanol solvate ClC6H4N(CH2COOH)2· H2O·C2H5OH, Mr = 307.73, monoclinic, P21/n, Cu-Ka (λ=1. 5410(?)), a = 16. 732(1), b = 5. 337(1), c=16. 300(1)(?) ,β=108. 52(1)°, V = 1380. 1(?)3, Z = 4, Dc=1.481g.cm-3, * = 27. 172cm-1, F(000) = 648, final R = 0. 072 for 1610 observed reflections. The crystal structure consists of discrete molecule of N-(para-chloro)-phenyl iminodiacetic acid, hydrate as well as ethanol solvate. A big ring consisting of atoms O(3), C(3), C(4), N(1), C(2), C(1), O(2) and H(2) is nearly planar with the maximum deviation of the atom N(1) of 0. 54 (?). Owing to the intramolecular hydrogen bond O(2)-H(2)…O(3) , the bond C(3) -O(3) in the COOH group is longer than the bond C(3)-O(4).     

DETERMINATION OF PHOSPHORUS AND FLUORINE IN POLYMERS AND ORGANIC COMPOUNDS WITH Nd~(3+)

Percentages of P or/and F in polymers and organic compounds are found by using Nd~(3+) as pre-cipitant and subsequent titration of excess Nd~(3+) with EDTA after decomposing sample in oxygenflask. The errors of determination are for P<±0.20% and F<±0.30% except fully fluorinatedcompounds.