二维配位聚合物[K2(5-nbdc)2Cd(Ⅱ)·imH·H2O]∞的合成和晶体结构(英)

The crystal structure of the title complex, [K₂(5-nbdc)₂Cd(Ⅱ)·imH·H₂O]_∞ (5-nbdc=5-nitro-1,3-benzenedicarbonate, imH=imidazole) has been determined by X-ray diffraction analysis. The crystal data are: tetragonal, space group P4₁, M_r=694.93 for CdC₁₉H₁₂N₄O₁₃K₂, a=1.018 6(10) nm, b=1.018 6(10) nm, c=2.436 7(5) nm; Z=4, V=2.528 2(6) nm³, F(000)=1 376, D_c=1.826 Mg·m^-3, μ=1.267 mm^-1. The title polymeric complex exhibits a two-dimensional framework, in which adjacent Cd(Ⅱ) ions are bridged by μ-O₄-5-nitro-1,3-benzenedicarbonate groups forming one-dimensional chains that are further linked by μ-O₃-5-nitro-1,3-benzenedicarbonate groups into two-dimensional anion rectangle sheets with large 32-membered rings. The strong π-π stacks of the benzene rings link these adjacent sheets into a three-dimensional van der Waals network. CCDC: 245527.     

超球谐展开的收敛行为He原子的^3S态

利用相关函数－超球谐－广义Ｌａｇｕｅｒｒｅ函数方法，研究Ｈｅ原子＾３Ｓ态波函数向超球谐函数展开的收敛行为。截止于ｌ＝０，１，２的超球谐函数给出的本征能分别与组态相互作用的ｓ－，ｓｐ－，ｓｐｄ－极限能一致。仅用４４个超球谐函数，便得到了与精确的ＨｙｌｌｅｒａａｓＣＩ变分能量小数点后第５位的２＾３Ｓ，３＾３Ｓ的４＾３Ｓ态本征能吻合。     

用ICP研究鹿科动物骨质疏松症的微量元素特征

鹿科动物的骨质疏松症是近几年出现的一种疾病，它影响鹿的生长发育和繁殖，病重者死亡。我们采集梅花鹿和白唇鹿的毛，血样，用低温灰化方法和温法消解处理样品，用ＩＣＰ分析了毛，血清中微量元素的含量。病梅花鹿毛样中Ｍｇ，Ａｌ，Ｃａ，Ｔｉ，Ｆｅ，Ｃｕ，Ｚｎ的含量比正常组高，Ｔｉ，Ｃｕ，Ｚｎ的偏差率大于１５％，而Ｓｉ，Ｍｎ，Ｐ，Ｐ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ比正常组低，Ｖ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ存在...     

汞电极表面电荷的快速估算

本文报导了用交流示波极谱快速估算电极表面电荷的方法。该方法使用仪器简单,测量快速,操作简便,在吸附研究中很有用处。     

Potentiometric pH response of membranes prepared with various aminated-poly (vinyl chloride) products

The preparation and potentiometric pH response properties of membranes formulated with various aminated-poly(vinyl chloride) (PVC-NH₂) products are described. Products containing secondary and/or primary amino functional groups are obtained by modifying PVC with mono- and/or diamines, respectively. Blank membranes prepared with either type of aminated-polymer exhibit nearly Nernstian potentiometric pH responses over different pH ranges. In general, membranes based on diamino products exhibit pH response over a wider range (5–10.5) than membranes formulated with monoamino products (<8.0). These potentiometric results are used to estimate the basicity of the various primary and secondary amino sites in the membrane phases.Dedicated to Professer W. Simon on the occasion of his 60th birthday     

Oxythallation of norbornene derivatives with thallium(III) acetate in methanol

Treatment of norbornene, norbornadiene, benzonorbornadiene, and chloro- and methoxy-benzonorbornadiene with thallium(III) acetate in methanol affords only the corresponding cis-exo-acetoxythallation adducts in a sharp contrast to oxymercuration of such strained olefins where methoxymercuration prevails. In the cases of substituted benzonorbornadienes the products are obtained as the regioisomeric mixtures, the isomer ratio being determined by ¹³C NMR. In the cases of 5-norbornene-2,3-dicarboxylic anhydride, 5-norbornene-2-methyl-2,3-dicarboxylic anhydride, and 5-norbornen-2-endo-carboxylic acid, lactonization occurs to give a trans-oxythallation adduct having a lactone ring, no introduction of either methoxy or acetoxy groups being observed. ¹H and/or ¹³C NMR data for several new oxythallation adducts are provided. The alkaline sodium borohydride reduction of adducts in methanol affords mainly the parent olefin together with 10–16% yields of the corresponding exo-alcohol.     

STUDIES ON REGULARITY OF POLY PHENYLSILSESQUIOXANE CHAINS

IR and ~(29)Si NMR were used to determine the structures of ladderlike polymer polyphenylsilsesquioxanes (PPS). It was found that PPS with lots of defects had a wide and strong absorption band in 1000—1400 cm~(-1) with only one sharp peak at 1137 cm~(-1) while two peaks (1130 and 1045 cm~(-1) were observed for PPS with perfect ladderlike structure. Branching and crosslinking of PPS lead to the reduction of 1045 cm~(-1) peak. ~(29)Si NMR spectra, however, showed two peaks (δ=-78 ppm and -87 ppm when δ_(HMDS)=0 ppm) for defective or branched PPS. The -87 ppm peak is related to the ladderlikely constructed Si atoms and -78 ppm corresponds to defective Si atoms. PPS with defects less than 0.1% chain units was obtained by azeotropic polycondensations.     

Water soluble cyclodextrin polymers: Their interaction with drugs

The complex forming ability of a water-soluble -cyclodextrin epichlorohydrin, polymer (CDPS) and its different molecular weight fractions was studied and compared with the complexing properties of -cyclodextrin (CD) and dimethyl-CD (DM-CD). CDPS was separated into two main fractions. CDPS and its fractions formed well soluble inclusion compounds with the studied drugs. The low molecular weight fraction formed rather stable complexes with small guest molecules, the high molecular weight fraction was found to be more efficient in binding larger substrates. Structural studies of furosemide-CD complexes were attempted by NMR spectroscopy.Presented at the Fourth International Symposium on Inclusion Phenomena and the Third International Symposium on Cyclodextrins, Lancaster, U.K., 20–25 July 1986.     

Die Berechnung von Einelektronen-Integralen in der SCF-Xα-SW-Methode: I. Die Normierung

A normalization of the wave functions by means of the theoretical exact Multiple-Scattering-(MS)-formalism is discussed within the framework of the SCF-X-SW-method. For the atomic and extramolecular regions the integrals of normalization can be easily determined and the results can be described by the corresponding electronic charges. The calculation of the integral of the interatomic region is problematic. The needful volume integration is only necessary to theGreen's functions of the wave functions and can be solved by means of the residual theory. The further analytical calculation of the surface integrals leads to a complicated formalism which can be numerically evaluated.

     

Synthesis of poly(2-cyclohexenone-4-yl methacrylate) and acidolysis of pendant protecting groups in the polymer

4-Acetoxy-2-cyclohexenone (ACH) and 2-cyclohexenone-4-yl methacrylate (CHM) were obtained from the condensation reaction of 4-bromo-2-cyclohexenone (BCH) with acetic acid and methacrylic acid using 1,8-diazabicyclo-[5,4,0]-7-undecene (DBU), respectively. Poly(2-cyclohexenone-4-yl methacrylate) ( P-1 ) containing acid-sensitive 2-cyclohexenone-4-yl group was prepared from the radical polymerization of CHM and the esterification of poly(methacrylic acid) with BCH using DBU. Furthermore, P-1 and CHM copolymers ( P-2 and P-3 ) were easily synthesized from the radical polymerization of methacrylic acid and comonomers in dimethylsulfoxide using 1 mol % of 2,2′-azobis (isobutyronitrile) followed by esterification of the resulting polymers with BCH using DBU by one-pot method. The deprotection reaction of ACH and P-1 was carried out in dichloromethane using an acid catalyst. The reaction proceeded smoothly in solution to give phenol and the corresponding carboxylic acid. Therefore, the 2-cyclohexenone-4-yl group is a useful protecting group for carboxylic acids, because the protection and deprotection reactions are very easy. In the case of polymer films, however, the acid was trapped by carbonyl group on the 2-cyclohexenone-4-yl group, and did not cause the deprotection reaction. © 1993 John Wiley & Sons, Inc.