首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   9篇
  免费   0篇
  国内免费   14篇
化学   23篇
  2019年   1篇
  2001年   2篇
  2000年   1篇
  1999年   10篇
  1998年   1篇
  1996年   1篇
  1995年   2篇
  1993年   1篇
  1992年   3篇
  1991年   1篇
排序方式: 共有23条查询结果,搜索用时 15 毫秒
1.
The preparation, magnetic properties, and crystal structure of [(salen)Cu]4[(salen)Fe(H2O)2]2(ClO4)2 via hydrogen bonding are described [salen=N,N-ethylenebis (salicylideneiminate)]. Crystals are triclinic, of space group , with cell constants a=12.853(3), b=13.921(3), c=14.251(3) Å, =68.68(3)°, =87.86(3)°, =86.82(3)°, and Z=1. The structure was solved and refined to R=0.064 and R=0.068. The structure comprises the hexanuclear units which result from the linking of four mononuclear fragments [(salen)Cu] and two mononuclear fragment [(salen)Fe(H2O)]+, through Cu -O H -O -Fe -O -H O -Cu hydrogen bonds of coordinating H2O. In this complex, FeIII ions are in almost square-planar surroundings. The temperature dependences of the magnetic susceptibilities of the complex have been studied in the 4.2–300 K range, indicating the presence of an antiferromagnetic interactions between metal ions.  相似文献   
2.
合成了12种稀土金属硫氰酸盐与N-对氯苯基氮杂15-冠-5的固体配合物,进行了元素分析和电导、红外光谱、电子光谱测定及热重-差热分析,并对Sm(SCN)3·L作了X射线单晶结构分析,结果表明:Sm(Ⅲ)离子与冠醚上的5个杂原子及3个硫氰酸根上的氮原子配位,配位数为8.  相似文献   
3.
The title compound has been synthesized and its crystal structure was determined by X-ray crystallographic method. The crystal is triclinic, space group P-1, with unit cell dimensions a = 6.146 (5), b = 8.473(6), c = 14.383(5) Å; α = 77.47 (4), β = 82.84 (4), γ = 69.00 (8)° and Z = 2. The results obtained reveal that the molecule of the title compound keeps a long conjugative system involving CC double bond, cyclopropane ring, carbonyl group and isoxazolinone ring and adopts a low energy conformation including s-trans of CC double bond, s-cis of carbonyl group with respect to the three-membered ring and like-s-trans of carbonyl group with the carbonyl group within the heterocyclic moiety.  相似文献   
4.
1INTRODUCTIONAmongthewidevarietyofphotosystemI(PSI)photosyntheticelectrontrans portinhibitors,thehighlypotentcyanoacrylatePSI...  相似文献   
5.
Bis(N-Phenylsalicylaldiminato)(1,10-Phenanthroline) Co(Ⅱ), C38H28N4O2Co,was synthesized and its crystal structure as been determined by X-ray diffraction method. The crystallographic data are as follows: monoclinic, space group C2/c, α=21.402(7), b=10.060(2), c=14.830(4)Å. β=109.19(2)°, V=3015.8 Å3, Z=4, M=631.57, Dc=1.39g•cm-3, μ=6.35cm-1, F(000)=1308, R=0.061, Rw=1.065. Two N and two O atoms from two bidentate ligands (L), other two N atoms from phen molecule coordinate the central Co(Ⅱ) ion forming octahedral configuration. Co-O, Co-N and Co-N(Phen) bond lengths are 1.995(5), 2.147(5) and 2.224(6) Å, respectively.  相似文献   
6.
合成并表征了两个含有不同阴离子的双核镍(Ⅱ)配合物{[(tacn)Ni(H~2O)]~2(μ-C~2O~4)}I~2·2H~2O(1)和{[(tacn)Ni(H~2O)]~2(μ-C~2O~4)}(ClO~4)~2·2H~2O(2)(tacn=1,4,7-三氮杂环壬烷)。晶体结构分析表明这两个配合物中,两个Ni离子通过草酸根桥联,每个Ni离子还与一个大环配体tacn上的三个氮原子和一个水分子配位形成变形八面体结构。结晶水和配位水之间通过氢键相连。在紫外-可见区测定了配合物的固体反射谱和溶液吸收谱。  相似文献   
7.
报道了含一个结晶水的多齿配体三(2-苯并咪唑亚甲基)胺(NTB·H2O)的合成、红外光谱及晶体结构和理论化学计算。该化合物(C24H23N7O)属单斜晶系,空间群P21/n,a=9.961(2),b=12.318(2),c=18.191(3),β=91.37(1)°,V=2232(1),Z=4,F(000)=896,Dx=1.266g/cm3,Mr=425.5,μ(MoKα)=0.77cm-1。用CAD4四圆衍射仪,MoKα射线收集数据,结构由直接法解出,全矩阵最小二乘修正,最终偏离因子R=0.054,Rw=0.063。量子化学计算结果也证明了NTB具有由三个扇叶构成的螺旋桨式构型,一些氮原子上有负电荷,有利于金属离子进行配位  相似文献   
8.
Tang  Liang-Fu  Wang  Zhi-Hong  Xu  Yu-Ming  Wang  Ji-Tao  Wang  Hong-Gen  Yao  Xin-Kan 《Transition Metal Chemistry》1999,24(6):708-711
Bis(3,5-dimethylpyrazol-1-yl)ethane tetracarbonylmolybdenum (1a) and tungsten (1b) have been synthesized by the direct reaction of bis(3,5-dimethylpyrazolyl)ethane (bmpze) with M(CO)6 (M = Mo or W). The molecular structure (1b), determined by x-ray crystallography, showed the seven-membered ring W–N–N–C–C–N–N to be in the boat conformation. Upon treatment with RSnCl3 (R=Ph or Cl) in CH2Cl2 at room temperature, complexes (1a) and (1b) gave the seven-coordinate oxidative-addition products [(bmpze)M(CO)3(SnCl2R)Cl] [M = Mo, R = Ph, (2a); M = W, R=Ph, (2b); M = Mo, R = Cl, (2c); M = W, R = Cl, (2d)]. When complexes (1b) and (2b) were heated under reflux with 1,2-bis(diphenylphosphino)ethane (dppe), the ligand, bmpze, in these complexes was easily removed. The novel compounds were characterized by 1H-n.m.r., i.r. and elemental analysis.  相似文献   
9.
合成了一个新型草酸根桥联的二维配合物{[Cu(en)~2]~4[KFe(C~2O~4)~3]~4}~n,并进行了晶体结构测试和磁性研究。晶体结构分析显示:K^+离子为罕见的八配位环境,2个C~2O~4^2^-和2个或1个K^+离子长程桥联2个Fe^Ⅲ离子,形成一个二维网状的[KFe(C~2O~4)~3]~n^2^n^-骨架,[Cu(en)~2]^2^+单元通过(en)N-H...O(C~2O~4)氢键与[KFe(C~2O~4)~3]~n^2^n^-骨架连接。变温磁化率测量表明:Fe^Ⅲ与Fe^Ⅲ间存在着弱的磁相互作用,J=-0.17cm^-^1。  相似文献   
10.
合成了[二(2-苯并咪唑亚甲基)胺][咪唑]合Cu(Ⅱ)Zn(Ⅱ)Cu(Ⅱ)高氯酸盐配合物C_(57)H_(57)N_(21)Cu_2Zn(ClO_4)_6·6[(CH_3)_2NCHO],并进行了元素分析、红外和紫外表征,用X射线衍射的方法测定了晶体结构,进行了生物活性测试和量子化学计算  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号