THE FRONTIER ORBITALS OF BUCKMINSTERFULLERENE C_(60)

The frontier orbitals HOMO and LUMO of the fullerene C_(60) hasbeen given in a system of 60 motion-coordinates, of which each origin is ateach C atom of fullerene C_(60) and each z-axis is in the directionperpendicular to C_(60)'S spherical surface. In this motion-coordinate systemthe HOMO and LUMO of fullerene C_(60) obviously display characteristics ofspherical n-molecular orbitals π_n. The Fenske-Hall quantum-chemical methodis used in calculation for the electronic structure of the fullerene C_(60).     

THE STATE OF CHROMIUM (Ⅲ) ION IN AQUEOUS SOLUTION

So far few systematic studies on the hydrolytic polymerization of Cr(Ⅲ) were reported because of inertness of the ion and complication of the process. We studied it in equilibrium by pH method systematically in a wide concentration range (0.0002—0.32 M). The results show that, in the low concentration range, the composition of the polynuclear hydrolysis products may be represented as [Cr_3(OH)_4] (OH)_n (n=1,2,3); in the medium range, the composition of products as Cr[Cr(OH)_2]_n~((3+n))~+ (n=1,2,3); in the high range, the composition of products as Cr[Gr(OH)]_n~((3+2n))~+ (n=1, 2), and in the intermediate range between medium and high range where the hydrolysis system is in a transition state, the composition of products as [Cr_3(OH)_3]~(6+) and [Cr_3(OH)_4]~(5+). The values of hydrolysis constants of the identical species measured in different Cr concentration ranges and calculated by different methods were found in good agreement with each other. A predominance-arca diagram was made by using the hy     

THE INTERACTION OF ETHYL BENZOATE AND TRIFLUOROACETIC ACID IN EXCITED STATE

This paper is concerned with the interaction of ethyl benzoate (EBA) and trifluoroaceticacid (TFA) molecules in the excited state by measurements of steady--state and transient fluo-rescence spectra at room and low temperatures. The results show that not only the 1:1 exci-plex but also the 2:1 triplex between EBA and TFA was formed. The formation pathway ofthe triplex is that the exciplex formed at first, then by the interaction with the EBA mole-cule it transformed into triplex. But it could not be formed by the dimer of EBA by interac-tion with TFA. The dimer of EBA is confirmed in the concentrated solution. So there arefour components in EBA/TFA--concentrated solution and their fluorescence lifetimes aremeasured respectively.     

MOLECULAR AND CRYSTAL STRUCTURE OF (η~6-BENZOPHENONE)TRICARBONYLCHROMIUM(0)

<正> The crystal of (η6-C6H5C(O)C6H5)Cr(CO)3 belongs to monoclinic system with space group P21/n. The cell parameters are: a=ll.068(2), b= 7.501(2), c=17.174(2) A, β=91.22(2)0, V=1425.4(8) A3, Z=4. The structure was solved by the analysis of 1745 observed reflections recorded on CAD-4 diffractometer. The final R=0.053.     

THE CRYSTAL AND MOLECULAR STRUCTURE OF TRIPTONIDE

<正> Triptonide, C20H22O6, was extracted from tripterygium wilfordii Hook F. of Fujian province and its structure was determined by X-ray crystallo-graphic analysis, Mr = 358. 39, monoclinic, P21,a = 11. 144(5), 6 = 6. 467(2), c= 12. 681(6)(?), β=103.54(4)°, V= 888. 4(?)3. Z = 2, F(000) = 380, Dc= 1. 34g/ cm3. The structure was solved by direct methods and refined by full matrix least-squares method to a final R value of 0. 042 for 1934 reflections with I> 3σ(I). Crystals of triptonide are isostructural with those of triptolide.     

THE DEVELOPMENT OF THE THEORY OF MOLECULAR STRUCTURE AND THE NATURE OF THE CHEMICAL BOND

THE development of the theory of molecular structure and thenature of the chemical bond are discussed.Particular atten-tion is given to the theory of hybrid bond orbitals.     

SYNTHESIS AND CHARACTERIZATION OF C_（60）NAr，THE FIRST AZIRIDINE FULLERENE DERIVATIVE

ＳＹＮＴＨＥＳＩＳＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦＣ_（６０）ＮＡｒ，ＴＨＥＦＩＲＳＴＡＺＩＲＩＤＩＮＥＦＵＬＬＥＲＥＮＥＤＥＲＩＶＡＴＩＶＥ￥ＪｕｎＦＥＮＧ，ＪｉＳｈｅｎｇＬａ，ＧｕｏＸｉａｏＤＯＮＧ，ＧａｉＪｉａｏＪＩ（Ｉｎｓｔｉｔｕｔ?..     

STUDIESOF MOLECULAR REORIENTATION OF A NON-SPHERICAL MOLECULE IN THE LIQUID STATE BY DEPOLARIZED RAYLEIGH SCATTERING

Effects of orientational pair correlations on the reorientationrate of non-spherical molecules are studied.The Keyes-Kivelsonequation for the coherent light scattering relaxation time isderived using a different technique.Experimental data on thecoherent light scattering relaxation time and the single parti-cle reorientation for n-butanol are obtained as a function ofthe concentration of n-butanol.The results are compared withthe Stokes-Einstein-Debye equation and are discussed in termsof the orientational pair correlation effect.     

VALENCE AND EMISSION OF SAMARIUM IONS IN KMF(M:Mg、Ca)

The SmF_(2.01)was synthesized by reducing SmF_3 in H_2 stream.As it was doped inKM_gF_3 and KCaF_3.there was emission of Sm~(2+) in KMgF_3 but no emission of Sm~(2+) inKCaF_3 was observed.     

STUDY OF THE MOLECULAR MOTION AND COMPATIBILITY IN AB-CROSSLINKED POLYMER BASED ON POLYURETHANE AND POLYSTYRENE-co-ACRYLIC ACID BY SOLID STATE HIGH RESOLUTION NMR

The ~(13)C T_(1s) of --CH_3 side group in PPU/P (St-co-AA), AB-crosslinked polymers (i. e.ABCP) was studied by using high resolution solid state NMR. The rotation motion of --CH_3 sidegroup in PPU was analyzed by means of the average spectral density functions of internal rota-tion. The results showed that the rotation of the --CH_3 side group is related closely to the com-patibility between the two components. The compatibility was studied by analyzing the protonspin-lattice relaxation in rotating frame, spin-spin relaxation and spin-diffusion. The resultsshowed that the hydrogen bonds between the components play a major role in determining thecompatibility. Through spin diffusion studying, the soft phase domain size was calculated. Bystudying proton spin-spin relaxation, the content of each component in each phase and that ofeach phase in the samples can be obtained. The result shows that the content of interphase is related closely to the compatibility.     

ROLE AND IMPORTANCE OF RADIUS OF GYRATION OF CHAINS IN THE MELT IN THE CRYSTALIZATION OF POLY(1-BUTENE)

Crystallization in polymer systems actually is a process that transfers the entangled melts into a semi-crystallinelayered structure. Whether or not a chain disentangles may result in different crystallization mechanism. When compared tothe crystal thickness (d_c), the volume occupied by the chain in the melt, i.e., the radius of gyration (R_g), plays a veryimportant role in polymer crystallization. When d_c≤R_g, crystallization does not necessitate a chain disentangling. Theentanglements are just shifted into the amorphous regions. However, as d_c>R_g, i.e., as the crystal thickness ges larger thanthe radius of gyration of the chain in the melt, it becomes necessary for a chain to disentangle. Then a change ofcrystallization mechanism occurs. Such change has been experimentally observed in the crystallization of poly(1-butene). Achange in the crystal morphologies from spherulite to quadrangle, is seen via PLM, as crystalliation temperatures increase.Even more, such a change is molecular weigh dependent and shifts to lower temperature as molecular weigh decreases.There exists a jump of crystal thickness and crystallinity associated with morphological change, as seen via SAXS. A changeof crystallization kinetics and crystallinity is further evidenced via dilatometry. The unique feature of P1b crystallization hasbeen discussed based on the radius of gyration of chain in the melt (R_g), and very good agreement is obtained.     

THE CRYSTAL AND MOLECULAR STRUCTURE OF DIPOTASSIUM TRIS(HYDROXYACETATO) VANADYL(ⅠⅩ) MONOHYDRATE

The title compound has been prepared by reaction of VOSO_4 with hydroxyacetic acid in aqueous solution, adding KOH to a suitable pH value. The crystals are monoclinic, space group P2_1/b with cell parameters: α=10.075(2), b=9.857(3), c=14.314(3), γ=115.29(2)°, Z=4. Intensities of 1714 independent reflexions having I≥3σ(I) were collected on a CAD4 diffractometer with MoKα radiation. The structure was solved by Patterson and direct methods and refined by full matrix least-squares method to R=0.060. In the complex the ratio of centric V atom to hydroxyacetate ligands is M:L=1:3, two hydroxyacetate ligands are chelated to V atom in a cis arrangement, the other is monodentate ligand with a carboxyl O atom to grasp the cation VO~(2+).     

CATALYTIC ASYMMETRIC EPOXIDATION OF a－FURFURYLAMINE IN THE PRESENCE OF MOLECULAR SIEVE AND CaH_2

ＣＡＴＡＬＹＴＩＣＡＳＹＭＭＥＴＲＩＣＥＰＯＸＩＤＡＴＩＯＮＯＦａ－ＦＵＲＦＵＲＹＬＡＭＩＮＥＩＮＴＨＥＰＲＥＳＥＮＣＥＯＦＭＯＬＥＣＵＬＡＲＳＩＥＶＥＡＮＤＣａＨ_２￥ＺｈｉＨｕｔＬＵ；ＸｕｅＹｏｕＺＨＵａｎｄＷｅｉＳｈａｎＺＨＯＵ（Ｓｈａｎｇｈａ?..     

THE EFFECTS OF MOLECULAR STRUCTURE ON PARAMETERS a, b AND c IN RETENTION EQUATION AND PREDICTION OF CAPACITY FACTORS IN RP-HPLC

In this paper, the effects of molecular structure on the parameters a, b and c in retention equation are investigated theoretically and experimentally. Parameter b in RP-HPLC approaches a small constant, because there is very weak displacement adsorption. Parameter c in RP-HPLC is mainly determined by the difference between solute-strong solvent and solute-weak solvent interaction and can be quantitatively correlated with the structural parameters of solute such as van der Waals volume (Vw), dipole moment (μA) and hydrogen bond energy (XAH). Parameter a has similar rules to parameter c. The prediction of k' value for non-polar, homologous compounds is studied. The linear relationship between k' and coverage of amount of the bonded chain in RP-HPLC is confirmed.     

CRYSTAL AND MOLECULAR STRUCTURE OF IPOHARDINE CHLORIDE, C_(15)H_(16)NOCl

<正> INTRODUCTION. Ipohardine is an alkaloid which can be dissolved in water. It was obtained by Reineckate method from the aqueous solution of Ipomoea Hardwickii Hemsl. In the previous paper we have reported the crystal and molecular structure of Ipohardine Picrate. The structure determination of the title compound is described here. The structure analysis shows that the structure of the title compound is slightly different from the former.     

CRYSTAL AND MOLECULAR STRUCTURE OF { CNa(15-crown-5)]_n [Cd(SCN)_3]}_n

<正> The complex [Na(15-crown-5)] [Cd(SCN)3] (15-crown-5 = C10H20 O5) crysializes in monoclinic space group P21/c with a=10. 219(2) ,b= 10. 575(2) ,c= 20. 572(2) A ,β=98. 45(1)°,V= 2198. 7A3,Mr=529. 89,Z = 4,Dx=1. 600g/cm3,F (000) -1052,μ= 15. 708cm-1. The structure was solved by direct methods with the final R=0. 064. Results of structure analysis indicate that the Na ion is bonded by 15-crown-5 to form a complex cation and the Cd(Ⅱ) is bonded by six SCN ion to form an anion chain with a distorted octahedral coordination.     

THE ROLE OF LOW FREQUENCY (ACOUSTIC) PHONONS IN DETERMINING THE PREMELTING AND MELTING BEHAVIOUS OF DNA

THIS paper discusses the role of low frequency (acoustic) pho-nons in determining the premelting and melting behavior of DNA.It is shown that acoustic phonons play an important role in de-termining the magnitude of energy fluctuations along the DNAmolecule--this reflects heterogeneity in DNA flexibility as-sociated with different stacking energies that stabilize variouscombinations of nucleotide sequences in its structure.Regionsof DNA having greater flexibility undergo larger energy fluctua-tions.As a result,these regions have higher probability thatconformational changes occur and that (once occurring) such re-gions undergo still larger energy fluctuations.This can in-crease the rates of such kinetic processes as drug intercalation,DNA breathing and protein-DNA recognition.Acoustic phonons play an important role in determining thestructural and energeticaspects of DNA premelting and meltingand lead to an understanding of the cooperativity in DNA melting.We discuss these questions here.     

THE SOLID STATE CONTROLLED CONDENSATION REACTION OF FERROCENEALDEHYDE AND INDOLE

The ZnCl_2-catalyzed condensation reaction of ferrocenealdehyde and indole in the solid state gave a new product (di-3-indolyi)-methylferrocene(3). The crystal structure of product 3 was determined by X-ray diffraction method. Reactions in solution and photochemical reactions were also carried out.     

CONFORMATIONAL ANALYSIS ON ANTICHOLINERGIC DRUG (Ⅰ) MOLECULAR MECHANICS MMPM CALCULATION OF ATROPINE AND OTHER ALKALOIDS IN THE BELLADONNA PLANT

Alkaloids of balladonna plant were studied by molecular mechanics MMPM calculation. The results showed that the ideal conformation was quite different from the structure found in the crystals of the alkaloids in belladonna plant. The intramolecular hydrogen bond was present between the hydroxy group and carbonyl oxygen atom in the ideal conformation for these alkaloids. The origin of asymmetrical molecules in nature obeys the lowest energy principle. This may be a reason why only S-(-) not R-(+)-isomer, only hyoscyamine not pseudotropine were found to be present in natural belladonna plant, The model of four recognition sites between anticholinergic drug-receptor interaction in mydriasis was suggested, in which the hydroxy group with 8～9 A distanced from nitrogen atom is possibly necessary for maximum mydriasis activity.     

CRYSTAL AND MOLECULAR STRUCTURE OF (CYANOETHYLOXY-FERROCENYL)-p-FLUOROPHENYL METHANE

<正> The crystal structure of (Cyanoethyloxy-ferrocenyl)-p-fluoro-phenyl methane (Fc-C(H)OCH2CH2CN, Mr=363.23) belongs to the monoclinic spacegroup P21/c with unit cell parameters: a =9.751(3), b =18.448(4), c =9.891(4)A,β= 105.71(3)°,V= 1712.7A3,Z=4,Dc=1.409g/cm3,μ=8.930cm-1,λ=0.71073A (MoKα),R=0.05. The structure and reactivities of the title compound are compared with those of its isomer.