对苯二甲酸·1,3-二(4-吡啶基)丙烷的水热合成和晶体结构

用1,3-二(4-吡啶基)丙烷、对苯二甲酸和去离子水在413K下通过水热反应法得到了标题化合物(C13H14N2).(C8H6O4).该化合物晶体属于三斜晶系,空间群为P墿,晶胞参数为a=0.95267(19)nm,b=1.1927(2)nm,c=1.6959(3)nm,α=96.40(3)°,β=98.12(3)°,γ=101.52(3)°,Z=2.单晶衍射结果表明标题化合物由对苯二甲酸分子和1,3-二(4-吡啶基)丙烷通过两种类型的分子间π-π堆积作用以及O—H…N氢键作用构成.同时,还对标题化合物进行了元素分析和红外测试.     

Synthesis and characterization of scandium complexes with reduced ligands: Crystal structures of Cp∗ScI2, [Cp∗ScI(bpy)]2, and [Cp∗ScCl(bpy)]2

The synthesis and characterization of complexes containing a Cp∗Sc(R₂bpy) (Cp∗ = pentamethylcyclopentadienyl, bpy = 4,4′-R,R-2,2′-bipyridine, R = H, Me) motif are described. Cp∗ScI₂ (1) was prepared from Cp∗Sc(acac)₂ (acac = acetylacetonate) and AlI₃ (2 equiv) in pentane. Compound 1 reacted with bipyridine and 4,4′-dimethyl-2,2′-bipyridine (dmb) in benzene to yield Cp∗ScI₂(bpy) (3) and Cp∗ScI₂(dmb) (4), respectively. Compound 3 was reduced by alkali metal reductants such as Na/Hg, NaK₂, and K in aromatic solvents to yield [Cp∗ScI(bpy)]₂ (5). The chloride analog of 5, [Cp∗ScCl(bpy)]₂ (7), was prepared from Cp∗ScCl₂ by salt metathesis with Li₂(dme)₂bpy (6) (dme = dimethoxyethane) in toluene. Compounds 1, 5, and 7 have been structurally characterized. Analysis of the bond distances of the bipyridine ligands in 5 and 7, together with infrared and UV/vis spectroscopic data, suggest that the bipyridine ligands in these molecules exist as radical anions. The bipyridine ligands in 5 and 7 are arranged co-facially and are in close proximity (?3.30 Å), suggesting the presence of a π-π interaction.     

Synthesis and Crystal Structure of a Coordination Polymer {[Co(phth)(phen)(H_2O)]·(C_2H_5OH)}_n

1 INTRODUCTION Metal-organic coordination polymer has particu- lar and special structure characters with some caves, holes and channels[1], and can be used in selected catalysis, molecular recognition, reversible exchan- ge of host-guest molecules (ions), super purity sepa- ration, biological conductor[2～5], etc. In the past ten years, polymers with bridging ligand have been widely investigated[6, 7]. The development of supra- molecular architectures of inorganic-organic hybrid molecules …     

Structures and C-H?π interactions in DMF inclusion complexes of homoazacalix[4]arenes

The molecular packing modes of DMF inclusion complexes of three homoazacalix[4]arenes were significantly changed by altering the substituents on the azacalixarene skeleton. As for N-methyl-p-tert-butyl-homoazacalix[4]arene, one of the phenolic OH protons transferred to the nitrogen atom was being accompanied by the inclusion of a DMF molecule. The DMF molecule in the cavity of each azacalixarenes is stabilized by C-H?π interaction.     

Construction of benzene ring-layered polymers

A simple and novel approach for synthesizing the benzene ring-layered polymers using [2.2]paracyclophane and xanthene skeletons was demonstrated. Palladium-catalyzed polymerization of pseudo-p-diethynyl[2.2]paracyclophane 1, 2,7-di-tert-butyl-4,5-diiodo-9,9-dimethylxanthene 2, and ethynylferrocene 3 gave the corresponding polymers 4a-c, which composed of 7-30 face-to-face benzene rings by changing the feed ratio of 1-3.     

All-Z-hexabenzo[24]annulene with a triangular benzene cluster substructure

All-Z-hexabenzo[24]annulene was synthesized via a poly-cis-stilbene intermediate. The single crystal of the annulene has a chiral C₃-symmetry with a central benzene trimer substructure. Although the compound is highly flexible in solution, the C₃-symmetric structure is stabilized by three concurrent CH/π interactions.     

Potential inhibitors of DNA topoisomerase II: ruthenium(II) poly-pyridyl and pyridyl-azine complexes

In search of new DNA probes a series of new mono and binuclear cationic complexes [RuH(CO)(PPh₃)₂(L)]⁺ and [RuH(CO)(PPh₃)₂(-μ-L)RuH(CO)(PPh₃)₂]²⁺ [L=pyridine-2-carbaldehyde azine (paa), p-phenylene-bis(picoline)aldimine (pbp) and p-biphenylene-bis(picoline)aldimine (bbp)] have been synthesized. The reaction products were characterized by microanalyses, spectral (IR, UV-Vis, NMR and ESMS and FAB-MS) and electrochemical studies. Structure of the representative mononuclear complex [RuH(CO)(PPh₃)₂(paa)]BF₄ was crystallographically determined. The crystal packing in the complex [RuH(CO)(PPh₃)₂(paa)]BF₄ is stabilized by intermolecular π-π stacking resulting into a spiral network. Topoisomerase II inhibitory activity of the complexes and a few other related complexes [RuH(CO)(PPh₃)₂(L)]⁺ {L=2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) and 2,3-bis(2-pyridyl)-pyrazine (bppz)} have been examined against filarial parasite Setaria cervi. Absorption titration experiments provided good support for DNA interaction and binding constants have also been calculated which were found in the range 1.2 × 10³-4.01 × 10⁴ M⁻¹.     

同时添加碳纳米管及石墨烯对热致液晶聚酯形状记忆行为及拉伸性能的影响

利用溶液共混的方法将碳纳米管(CNT)及石墨烯(G)同时加入到热致液晶聚酯中制备纳米复合材料.通过透射电镜(TEM)研究纳米粒子的分散及形貌.采用荧光光谱及拉曼光谱研究碳纳米填料与热致液晶聚酯基体之间存在π-π相互作用.利用电子万能试验机(EUTM)研究了材料的拉伸性能,由于CNT与G与基材之间作用力强,且CNT与G间的协效作用能有效地实现应力转移,同时加入CNT及G有助于提升复合材料的拉伸强度.动态热机械分析(DMA)数据表明,同时添加CNT与G对于复合材料的固定率影响不大,但会降低回复率;同时复合材料的回复应力也得到显著的提升.     

Selective Synthesis and Structural Transformation of a 4-Ravel Containing Four Crossings and Featuring Cp*Rh/Ir Fragments

Intricately interwoven topologies are continually being synthesized and are ultimately equally versatile and significant at the nanoscale level; however, reports concerning ravel structures, which are highly entwined new topological species, are extremely rare and fraught with tremendous synthesis challenges. To solve the synthesis problem, a tetrapodontic pyridine ligand L1 with two types of olefinic bond units and two Cp*M-based building blocks ( E1 , M=Rh; E2 , M=Ir) featuring large conjugated planes was prepared to perform the self-assembly. Two unprecedented [5+10] icosanuclear molecular 4-ravels containing four crossings were obtained by parallel-displaced π⋅⋅⋅π interactions in a single-step strategy. Remarkably, reversible structural transformations between the 4-ravel and the corresponding metallocage could be realized by concentration changes and solvent- and guest-induced effects. X-ray crystallographic data and NMR spectroscopy provide full confirmation of these phenomena.