三维超分子化合物[2-(3-pyridyl)benzimidazoleH2]24+·[Cd2Cl8]4-的水热合成、晶体结构及发光性质

将邻苯二胺、3-吡啶甲酸与二氯化镉在1:1的盐酸溶液中经水热反应,合成了一种超分子化合物[2-(3-pyridyl)benzimidazoleH2]24+·[Cd2Cl8]4-.通过元素分析、红外光谱、热重对其结构和性质进行了表征,用X-射线单晶衍射测定了该化合物的晶体结构.化合物晶体为单斜晶系,P21/c空间群.超分子化合物中的Cd2+与其周围4个氯离子配位,构成畸变三角锥构型的离子[CdCl4]2-,2个配阴离子[CdCl4]2-之间通过双氯桥键[Cd-Cl-Cd]构成五配位双核镉(Ⅱ)四元环状结构,并与2个2-(3-吡啶基)苯并咪唑两价阳离子,通过静电引力、氢键及π-π呵堆积作用形成三维网状超分子化合物.荧光测试表明该化合物具有较好的光致发光性能.     

A first one-pot synthesis, isomerization and synthetic utility of mono- and bis Morita-Baylis-Hillman adducts of 1,1′-ferrocenedialdehyde

A one-pot synthesis of mono- and bis-Morita-Baylis-Hillman adducts of 1,1′-ferrocenedialdehyde has been achieved. These adducts undergo a facile and efficient stereoselective isomerization with a number of saturated, unsaturated, aromatic alcohols, phenols and thiophenol with a montmorillonite K10 clay catalyst to afford highly functionalized trisubstituted alkene derivatives of ferrocene. The synthetic utility of isomerized derivatives has been demonstrated by a ferrocene appended novel macrocycle synthesis, a ferrocenyl bis-triazole synthesis and an evaluation of the liquid crystalline property of a cholesterol derivative of ferrocene.     

Hydrogen Bonding Induced Supramolecular Self‐Assembly of Linear Doubly Discotic Triad Supermolecules

A series of linear doubly discotic triad supermolecules based on a porphyrin (P) core and two triphenylene (Tp) arms linked by amide bonds are synthesized. The samples are denoted as P(Tp)₂. Hydrogen bonding along the P stacks is the primary driving force for the supramolecular self‐assembly of P(Tp)₂ triad supermolecules. Meanwhile, the degree of coupling between P and Tp disks also plays an important role. For samples with the spacer lengths longer than or similar to the alkyl chain lengths in the Tp arms, P and Tp are decoupled to a large degree. This decoupling result in non‐uniform tilt angles for P and Tp disks along both the a‐ and c‐axes. Therefore, large unit cells are observed with eight P(Tp)₂ supermolecules per cell. For a sample with the spacer length much shorter than the alkyl chains in the Tp arms, P and Tp are strongly coupled. Therefore, both P and Tp have uniform tilt angles along the a‐ and c‐axes. A small unit cell is obtained with only one P(Tp)₂ supermolecule per cell.     

Synthesis of chiral allene moiety from Morita–Baylis–Hillman adduct of isatin derivatives via Claisen rearrangement

Chiral allenes are synthesized from Morita–Baylis–Hillman adduct of isatin derivatives via Claisen rearrangement for the first time. The chiral 1,3-substituted allene entity is achieved using (R)-but-3-yn-2-ol. The details of the work are elaborately discussed in this letter.     

Gas chromatographic study of the urea-cetyl alcohol adduct and its components. III. A study of the urea-cetyl alcohol adduct

Summary Phase changes in urea-cetyl alcohol inclusion compounds prepared by various methods were monitored gas chromatographically. The decomposition temperature interval and the presence of the free components could be found from the temperature dependence of the retention data. Study of the clathration process yielded facts that can be used in the preparation of this type of inclusion compound.     

Crystal structure analysis of norbornadiene adduct of diphenyl hexamethylenimino phosphiniminocyclotrithiazene

The title compound (C₆H₁₂N)Ph₂P-N S₃N₃ C₇H₈ crystallizes in the monoclinic space group P2₁/n with unit cell dimensions: a = 9.9200(5), b = 16.3316(11), c = 15.7009(17) Å, = 91.99(1)°, and Z = 4. The cyclotrithiazene ring adopts a chair conformation with equal bond distances and the norbornadiene is fused in an exo, exo fashion to the heterocycle. Norbornadiene addition to the cyclotrithiazene influences the bonding pattern in the ring as well as the P N S moiety.     

Crystal structure of the addition compound of [Ni(meso-cth)][Cr(ox)2(bpy)](H2O)(ClO4) with weak coordination bonds and hydrogen bonds

A new ionic complex [Ni(meso-cth)][Cr(ox)₂(bpy)](H₂O)(ClO₄) [meso-cth = meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, ox = oxalato ainon, bpy = 2,2-bipyridine] was prepared and its structure was determined. The complex was found to crystallized in monoclinic space group P2(1)/n, with a = 13.6000(4) Å, b = 18.763(5) Å, c = 14.995(4) Å, =106.958(5)°, V = 3659.9(17) ų, and Z = 4. The structure consisted of cationic [Ni(meso-cth)]²⁺, anionic [Cr(ox)₂(bpy)]^–, and perchlorate anions; the cationic [Ni(meso-cth)]²⁺ and anionic [Cr(ox)₂(bpy)]^– units were related by weak coordination bonds and hydrogen bonds.     

Crystal structure of 3-amino-5-methyl-1,2,4-benzotriazine 1-oxide: Evidence for formation of a covalent attachment between a carbon-centered radical and the antitumor agent tirapazamine

The compound 3-amino-1,2,4-benzotriazine 1,4-dioxide (tirapazamine, 1) is a potent antitumor agent. We isolated 3-amino-5-methyl-1,2,4-benzotriazine 1-oxide (5) from the reaction tirapazamine with methyl radical and characterized this compound by X-ray crystallography. The crystal structure of 5 provides clear evidence that this carbon-centered radical forms a covalent attachment with the drug tirapazamine. Given that tirapazamine generates carbon-centered DNA radicals as part of its mechanism of action, this finding may provide a chemical basis for understanding the small but significant levels of drug that become covalently associated with DNA during the damage process. The title compound C₈H₈N₄O crystallized in the monoclinic space group P2₁/c with unit cell parameters: a = 15.670(8), b = 7.381(4), c = 13.491(7) Å, = 90(1), = 95.623(9), = 90(1)°, and Z = 8.     

Boron Tunneling in the “Weak” Bond-Stretch Isomerization of N−B Lewis Adducts

Some nitrile-boron halide adducts exhibit a double-well potential energy surface with two distinct minima: a “long bond” geometry (LB, a van der Waals interaction mostly based on electrostatics, but including a residual charge transfer component) and a “short bond” structure (SB, a covalent dative bond). This behavior can be considered as a “weak” form of bond stretch isomerism. Our computations reveal that complexes RCN−BX₃ (R=CH₃, FCH₂, BrCH₂, and X=Cl, Br) exhibit a fast interconversion from LB to SB geometries even close to the absolute zero thanks to a boron atom tunneling mechanism. The computed half-lives of the meta-stable LB compounds vary between minutes to nanoseconds at cryogenic conditions. Accordingly, we predict that the long bond structures are practically impossible to isolate or characterize, which agrees with previous matrix-isolation experiments.     

氢键构筑网络结构的三正丁基锡羧酸酯的合成、结构及抗癌活性

微波辐射条件下,μ-氧-双(三正丁基锡)分别与二苯乙醇酸、2-氯烟酸反应,合成了三正丁基锡羧酸酯(n-Bu)₃SnO₂CR(H₂O)[R:C(OH)Ph₂(1),C₅NH₃Cl(2)]。经IR、¹H和¹³C NMR、元素分析及X-射线单晶衍射表征结构。配合物1、2均属正交晶系,空间群分别为Pbca和P2₁2₁2₁,配基与中心锡原子均构成五配位畸变三角双锥构型。1和2晶体中,存在着多种氢键作用,分别连接扩展成二维和三维超分子网络。初步测试表明:1和2对人癌细胞Colo205、HepG2、MCF-7、Hela、NCI-H460增殖均有较强的抑制作用,尤其对MCF-7、Hela、NCI-H460的抑制作用均大大优于卡铂,且1的抗肿瘤活性更优于2。