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1.
The title compound,[Zn(5-hydroxynicotinate) 2 2H 2 O] n,has been synthesized by reacting zinc sulfate vitriol with 5-hydroxynicotinic acid under hydrothermal conditions,and its structure was determined by X-ray crystallography with the following data:monoclinic,space group C2/c,C 12 H 12 N 2 O 8 Zn,M r=377.61,a=10.223(3),b=10.319(3),c=13.613(4),β=105.922(6)°,Z=4,V=1380.9(8)3,F(000)=768,D c=1.816 g/cm 3,μ(MoKα)=1.826 mm-1,the final R=0.0401 and wR=0.1380 for 1157 observed reflections (I > 2σ(I)).In the structure of the title compound,the Zn II ion located in an inversion center lies in a distorted tetrahedral environment at a N 2 O 2 coordination mode,and the 5-hydroxynicotinic acid ligand links symmetry-related Zn II ions at a μ 2-N,O bridging way forming a two-dimensional covalent structure.In the crystal,solvent water molecules form intermolecular O-H O hydrogen bonds and pyridine rings of adjacent layers form π-π stacking (3.346),which connect adjacent two-dimensional sheets into a three-dimensional supramolecular network. 相似文献
2.
设d,a,k,n是适合4k^2n+1=da^2,k〉1,n〉2,d无平方因子的正整数;又设C(K)和h(K)分别是实二次域K=Q(√d)的理想类群和类数。本文证明了:当a〈0.5k^0.56n时,则h(K)≡0(mod n)和C(K)必有n阶循环子群。 相似文献
3.
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, Mr=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, Dc=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. 相似文献
4.
本文给出赋值Near-环,S-系统赋值与F-位值的定义,并分别对S-系统的赋值和值伴进行了研究,从而得出S-系统的等价赋值类和赋值Near-环之间的对应关系以及等价的值位类和赋值Near-环之间的对应关系。 相似文献
5.
实二次域Q(P(1/2))(p≡3(mod 4))类数的上界 总被引:1,自引:0,他引:1
设p是适合p≡3(Pod4)的奇素数,h,ε分别是实二次域Q的类数和基本单位.本文运用初等方法证明了:εh<(p+a+2)a+2/4(a+2)!,其中 相似文献
6.
Recentstudyattentionsoncoordinationchem-istryhavebeendevotedtothedesignandsynthesisofmulti-dentateligandswithlarge仔-conjugationsystemsastheirabilitiesonintramolecularelectro/energy-transferevenifmostreportedligandscontainonlyonetypeofcoordinationsite(suc… 相似文献
7.
A new ligand N, N′-Bis(salicyidene)-5,6-phenanthrolinenediamine (H2L) 1 and its four binuclear complexes [M2+LM2+(B-)2]( M=Cu2+, B-=Ac-, 1a; M=Ni2+, B-=Ac-, 1b; M=Co2+, B-=Cl-, 1c; M=Ni2+, B-=Cl-, 1d) have been prepared by condensing 1 equiv. of 5,6-diamino-1,10-Phenanthroline with 2 equiv. of 2-hydroxybenzaldehyde and reaction of 1 with metal salts, and characterized by IR, 1H and 13C NMR, UV-Vis and EI-MS analysis. 相似文献
8.
设d,a,k,n是适合4k2n+1 =da2, k>1, n>2, d无平方因子的正整数;又设C(K)和h(K)分别是实二次域K=Q(√d)的理想类群和类数.本文证明了:当a<0.5k0.56n时,则h(K)≡0(mod n)和C(K)必有n阶循环子群. 相似文献
9.
S-系统的赋值与值位 总被引:1,自引:0,他引:1
本文给出赋值Near─环,S─系统赋值与F─位值的定义,并分别对S─系统的赋值和值位进行了研究,从而得出S─系统的等价赋值类和赋值Near─环之间的对应关系以及等价的值位类和赋值Near─环之间的对应关系。 相似文献
10.
In recentyears,asym m etric organic ligands (suchas m 鄄pyridinecarboxylates) have been used as bi/tri鄄dentate bridges to build chiral coordination polym ersofCd髤orZn髤forexploring non鄄linearopticalm ate鄄rials[1]. In these reported coordination polym 相似文献