首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
The title phanes were synthesized. Examination of their physical properties including X-ray crystallography disclosed that 1) the p-tropoquinone ring is still bent in both compounds though to a lesser extent than in the corresponding [2.2]phanes, 2) the metacyclo compound prefers syn conformation in solution, and 3) the intramolecular CT interaction is very similar in two compounds.  相似文献   

3.
4.
5.
Two cyclophanes, [2.2](2,6)biphenylenophane and [2](2,6)biphenyleno[2](2,6)naphthalenophane, were prepared.  相似文献   

6.
1,3-bis(4-vinylnaphthyl)propane and 1-(4-vinylnaphthyl)-3-(p-vinylphenyl)propane, were cyclocodimerized with indene to afford indenyl-substituted [3.3](1,4)naphthalenophanes and [3.3]paracyclo(1,4)naphthalenophanes.  相似文献   

7.
8.
9.
Variable temperature NMR spectroscopy was used to study the conformational behavior of [2.2](2,5)furanoparacyclophane (1), [2.2](2,5)furano(1,4)naphthalenophane (2) and [2.2](2,5)furano(9,10)anthracenophane (3). While the method was useful in studying 1, it was not adequate for 2 and 3. Variable temperature UV absorption and fluorescence emission studies provided information on the conformations of 2 and 3. The UV absorption and emission spectra of 1 were blue-shifted relative to their ambient temperature spectra. Those of 2 were not shifted at all and those for 3 were red-shifted. The data is consistent with an anti-orientation of the aromatic rings in 2 both at ambient and low temperture. The aromatic rings in 3 are perpendicular to one another at low temperature and probably at room temperature as well. Exiplex bands were absent in the room temperature emission spectra of 1, 2 and 3 as well as the low temperature spectra of 2 and 3. An exciplex band was observed in the low temperature emission spectrum of 1.  相似文献   

10.
The title compound 1 a novel cyclophane containing p-tropoquinone, was synthesized starting from 5-methoxytropolone and its physical properties were discussed comparing with those of 3,7-dimethyl-p-tropoquinone and p-benzoquinonophane. The reduced quinone character exhibited by 1 was ascribed to the intramolecular CT interaction and the deformation of the quinone ring.  相似文献   

11.
12.
Synthesis of the titled tropolonophones has been attempted. Though the [7]-compound was obtained, the lower homolog was failed to be synthesized probably because of the strain imposed on the desired compound. The former tropolonophane was shown to exist in the enolone form. PMR and electronic spectra of [7] and [8]-homologs and their methylethers revealed some nonplanarity in the 7-membered rings. PMR spectrum also established the conformation of the bridge in the former compound.  相似文献   

13.
14.
15.
16.
17.
Formation of NH4[Hg3(NH)2](NO3)3 and Transformation to [Hg2N](NO3) NH4[Hg3(NH)2](NO3)3 ( 1 ) and [Hg2N](NO3) ( 2 ) are obtained from conc. aqueous ammonia solutions of Hg(NO3)2 at ambient temperature and under hydrothermal conditions at 180 °C, respectively, as colourless and dark yellow to light brown single crystals. The crystal structures {NH4[Hg3(NH)2](NO3)3: cubic, P4132, a = 1030.4(2) pm, Z = 4, Rall = 0.028; [Hg2N](NO3): tetra gonal, P43212, a = 1540.4(1), c = 909.8(1) pm, Z = 4, Rall = 0.054} have been determined from single crystal data. Both exhibit network type structures in which [HNHg3] and [NHg4] tetrahedra of the partial structures of 1 and 2 are connected via three and four vertices, respectively. 1 transforms at about 270 °C in a straightforward reaction to 2 whereby the decomposition products of NH4NO3 are set free. 2 decomposes at about 380 °C forming yellow HgO. Most certainly, 1 is identical with a mineral previously analyzed as “Hg(NH2)(NO3)” with the same Hg:N:O ratio.  相似文献   

18.
Preparation and Crystal Structures of Ag[N(CN)2](PPh3)2, Cu[N(CN)2](PPh3)2, and Ag[N(CN)2](PPh3)3 The coordination compounds Ag[N(CN)2](PPh3)2 ( 1 ), Cu[N(CN)2](PPh3)2 ( 2 ), and Ag[N(CN)2](PPh3)3 ( 3 ) are obtained by the reaction of AgN(CN)2 or CuN(CN)2 with triphenylphosphane in CH2Cl2. X‐ray structure determinations were performed on single crystals of 1 , 2 , and 3 · C6H5Cl. The three compounds crystallize monoclinic in the space group P21/n with the following unit cell parameters. 1 : a = 1216.07(9), b = 1299.5(2), c = 2148.4(3) pm, β = 99.689(13)°, Z = 4; 2 : a = 1369.22(10), b = 1257.29(5), c = 1888.04(15) pm, β = 94.395(7)°, Z = 4; 3 · C6H5Cl: a = 1276.6(4), b = 1971.7(3), c = 2141.3(5) pm, β = 98.50(3)°, Z = 4. In all structures the metal atoms have a distorted tetrahedral coordination. The crystal structure of 3 · C6H5Cl shows monomeric molecular units with terminal coordinated dicyanamide. The crystal structure of 1 is built up by dinuclear units, which are bridged by dicyanamide ligands. However, the crystal structure of 2 corresponds to a onedimensional coordination polymer, bridged by dicyanamide anions.  相似文献   

19.
20.
Pyrenophane (6) and an octaphenyl derivative (16) were synthesized using two different routes. Both cyclophanes contain a severely bent pyrene unit (6: theta = 93.6 degrees and 16: theta = 95.8 degrees , according to DFT-calculations (B3LYP/6-311G**)), which was generated at room temperature by a valence isomerization/dehydrogenation (VID) reaction. HOMA and NICS indicate 92-98% retention of aromaticity of the highly distorted pyrene systems compared to planar pyrene.  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