X‐ray analysis of the bisphenol‐A‐type macrocyclic carbonate trimer

Collection of the single crystal X‐ray refraction data of the Bisphenol‐A‐type Macrocyclic oligocarbonate trimer (c‐3mer) at room temperature was carried out. The single crystal of the cyclic trimer that is recrystallized from ethyl acetate showed solvent molecule in the center of macro ring. Similarly, cyclic tetramer (c‐4mer) contained two p‐xylene molecules. Smaller dimer (c‐2mer) did not afford co‐crystal with solvent. Conformation of the carbonate in c‐3mer was s‐cis and s‐cis as in c‐4mer. A relationship between the conformation of carbonate and noncatalyst polymerization activity was not found. Copyright © 2000 John Wiley & Sons, Ltd.     

Synthesis of macrocycles incorporating azo‐bis(azofurazan) framework

A series of macrocycles containing four furazan rings bonded by three azo bonds 2, 5 and 7 have been synthesized from the common precursor, 3‐amino‐3′‐nitro(azofurazan) 3 . The macrocycles closure is a result of N?N bond formation at oxidative cyclization of corresponding bis(3‐aminofurazan‐4‐yl) precursors. X‐Ray crystal structures of macrocycles 2, 2 ?AcOH, 11 and 13 are reported.     

Crystal Structures of β‐Cyclodextrin Inclusion Complexes with 7‐Hydroxycoumarin and 4‐Hydroxycoumarin and Substituent Effects on Inclusion Geometry

Two inclusion complexes of β‐cyclodextrin‐7‐hydroxycoumarin ( 1 ) and β‐cyclodextrin‐4‐hydroxycoumarin ( 2 ) were prepared and their crystal structures were investigated by single crystal X‐ray crystallography under cryogenic condition. Both structures consist of stacks of face‐to‐face cyclodextrin dimers arranged in brickwork‐like pattern along the crystallographic a‐axis. For complex 1 , each of the two dimeric β‐cyclodextrins includes one 7‐hydroxycoumarin molecule that penetrates deeply into the cyclodextrin dimer and locates its lactonering at the center of the dimer cavity. For complex 2 , each cyclodextrin dimer accommodates three 4‐hydroxycoumarin molecules. One of them is sandwiched between two units of the cyclodextrin dimer, the other two are shallowly included in the cavities of the dimeric cyclodextrins respectively and protrude their lactone rings from the primary end of the cyclodextrin. The substituent effects of guest molecules on inclusion geometry of various coumarin molecules in β‐cyclodextrin were examined.     

Hydrindacene‐Based Acetylenic Macrocycles with Horizontally and Vertically Ordered Functionality Arrays

The macrocyclization of 2,6‐diethynyl hydrindacenes ( 1 ) with functional groups at mutually perpendicular positions results in the formation of novel macrocycles which, as a result of the hindered rotation of the hydrindacene units, possess directionally persistent peripheral functionalities. The two hydrindacene units in the dimer macrocycle ( 2 ) have been shown to interact electronically through their respective butadiyne moieties, whereas the trimer macrocycle ( 3 ) demonstrates a moderate degree of geometrical flexibility as a result of the five‐membered hydrindacene rings. In addition, these trimer macrocycles contain a central cavity suitably sized for the inclusion of various solvent molecules. These new macrocycles can be further modified by introducing π‐conjugated side groups, such as styryl and thienyl groups, as well as by attaching a variety of peripheral ester groups.     

A Phosphine‐Coordinated Boron‐Centered Gomberg‐Type Radical

The P‐coordinated boryl radical [Ph₂P(naphthyl)BMes]^. (Mes=mesityl) was prepared by (electro)chemical reduction of the corresponding borenium salt or bromoborane. Electron paramagnetic resonance (EPR) analysis in solution and DFT calculations indicate large spin density on boron (60–70 %) and strong P–B interactions (P→B σ donation and B→P negative hyperconjugation). The radical is persistent in solution and participates in a Gomberg‐type dimerization process. The associated quinoid‐type dimer has been characterized by single‐crystal X‐ray diffraction.     

One—dimesional Infinite Chain Organotin Compounds： Synthesis and structural Characterization of Triphenyltin Thiazole—2—carboxylate and Triphenyltin 3—Pyridinylcarboxylate

Triphenyitin thiazole-2-carboxylate(1) and triphenyltin 3-pyridinylcar boxylate(2) were synthesized by the reaction of sodium thiazole-2-carboxylate or sodium 3-pyridinylcarboxylate with the triphenyltin chloride and their crystal structures were determined by single crystal X-ray diffraction analysis.In the structure of 1, the tin atom is five-coordinated in a distorted trigonal bipyramidal structure.Due to the presence of a close intermolecular Sn…S interaction distance of 0.3666nm,the structre can be described as a weakly-bridged on-dimensional chain compound.In the structure of 2,the tin atom is five-coordinated with bridging 3-pyridinylcarboxylate ligands N atom and resulting structure is one-dimensional chain compound.     

Halide Anion Mediated Dimerization of a meso‐Unsubstituted N‐Confused Porphyrin

The new N‐confused porphyrin (NCP) derivatives, meso‐unsubstituted β‐alkyl‐3‐oxo N‐confused porphyrin (3‐oxo‐NCP) and related macrocycles, were synthesized from appropriate pyrrolic precursors by a [3+1]‐type condensation reaction. 3‐Oxo‐NCP forms a self‐assembled dimer in dichloromethane that is stabilized by complementary hydrogen‐bonding interactions arising from the peripheral amide‐like moieties. The protonated form of 3‐oxo‐NCP was observed to bind halide anions (F^?, Cl^?) through the outer NH and the inner pyrrolic NH groups, thus affording a dimer in dichloromethane. The structure of the chloride‐bridged dimer in the solid state was determined by X‐ray diffraction analysis.     

Concomitant polymorphic forms of 3‐cyclopropyl‐5‐(2‐hydrazinylpyridin‐3‐yl)‐1,2,4‐oxadiazole

The dipharmacophore compound 3‐cyclopropyl‐5‐(2‐hydrazinylpyridin‐3‐yl)‐1,2,4‐oxadiazole, C₁₀H₁₁N₅O, was studied on the assumption of its potential biological activity. Two concomitant polymorphs were obtained on crystallization from isopropanol solution and these were thoroughly studied. Identical conformations of the molecules are found in both structures despite the low difference in energy between the four possible conformers. The two polymorphs differ crucially with respect to their crystal structures. A centrosymmetric dimer formed due to both stacking interactions of the `head‐to‐tail' type and N—H…N(π) hydrogen bonds is the building unit in the triclinic structure. The dimeric building units form an isotropic packing. In the orthorhombic polymorphic structure, the molecules form stacking interactions of the `head‐to‐head' type, which results in their organization in a column as the primary basic structural motif. The formation of N—H…N(lone pair) hydrogen bonds between two neighbouring columns allows the formation of a double column as the main structural motif. The correct packing motifs in the two polymorphs could not be identified without calculations of the pairwise interaction energies. The triclinic structure has a higher density and a lower (by 0.60 kcal mol^?1) lattice energy according to periodic calculations compared to the orthorhombic structure. This allows us to presume that the triclinic form of 3‐cyclopropyl‐5‐(2‐hydrazinylpyridin‐3‐yl)‐1,2,4‐oxadiazole is the more stable.     

C—H…Cl Hydrogen Bond and π-π Interaction Based Two 3D Supramolecular Architectures of Cu(II) and Co(II) Complexes with Chiral 1,2-Bis(benzimidazol-2-yl) ethane Ligand Containing 2D Grids

合成了两个新的配合物CuLCl₂•2EtOH(1) 和CoLCl₂ (2) [L是( S , S )－1,2－二N－甲基苯并咪唑－1,2－二甲氧基－乙烷],并通过单晶X衍射确定它们的结构。配合物1中,L作为三齿[N, N, O]配体,而配合物2 中,L作为二齿[N, N]配体。这两个配合物共同的结构特点都是通过分子内氢键形成2维的格子结构,然后通过分子间的C－H···Cl型氢键和π–π堆积作用形成3维结构。     

Naphthocrown‐Strapped Calix[4]pyrroles: Formation of Self‐Assembled Structures by Ion‐Pair Recognition

A new approach to the construction of self‐assembled structures is reported that is based on ion‐pair recognition. Towards this end, the calix[4]pyrrole naphthocrown‐4 hybrid structures 2 and 3 were prepared. These multitopic receptors contain recognition sites for both anions and cations. On the basis of solution‐phase ¹H NMR spectroscopic analysis and solid‐state single‐crystal X‐ray diffraction structural studies, it was established that receptors 2 and 3 are able to bind specific ion pairs with high selectivity via different binding modes. In the case of CsF and CsCl, the ion‐pair complexes formed from receptors 2 and 3 were found to self‐assemble to produce either linear supramolecular polymeric crystalline solids or nanotube‐like cyclic hexamers depending on the specific choice of ion pairs and crystallization solvents. Proton NMR studies provided evidence for solution‐phase self‐association in organic media.     

A Luminescent Cage‐Like Complex Constructed by Bidentate Pyridine‐Containing Ligand and Silver Nitrate

The cage‐like complex, Ag₄L₄(NO₃)₄ ( 1 ) [L = 1, 4‐bis(pyridine‐2‐ylmethoxy)benzene] was synthesized by the reaction of the flexible bidentate ligand and silver nitrate. It was characterized by elemental analysis, IR spectroscopy, TG, and single‐crystal X‐ray analysis. Complex 1 is reported as the first cage‐like cluster constructed by four nitrate anions bridging two [2+2] macrocycles. A blue luminescent emission and luminescent enhancement effect are observed in complex 1 .     

Synthesis of Electron‐Deficient Corona[5]arenes and Their Selective Complexation with Dihydrogen Phosphate: Cooperative Effects of Anion–π Interactions

Reported here are the syntheses, conformational structures, electrochemical properties, and noncovalent anion binding of corona[5]arenes. A (3+2) fragment coupling reaction proceeded efficiently under mild reaction conditions to produce a number of novel heteroatom‐ and methylene‐bridged corona[3]arene[2]tetrazine macrocycles. Selective oxidation of the sulfur atom between two phenylene rings afforded sulfoxide‐ and sulfone‐linked corona[5]arenes in good yields. All corona[5]arenes synthesized adopted similar 1,2,4‐alternate conformational structures, forming pentagonal cavities. The cavity sizes and the electronic properties such as redox potentials, were measured with CV and DPV, and were influenced by the different bridging units. As electron‐deficient macrocycles, the acquired corona[3]arene[2]tetrazines served as highly selective hosts, forming complexes with the hydrogen‐bonded dimer of dihydrogen phosphate through cooperative anion–π interactions.     

Synthesis,Characterization and Crystal Structure of Some Novel 1‐Aryl‐2‐Thioxo‐2,3‐Dihydro‐1H‐Quinazolin‐4‐Ones

The base catalyzed intramolecular nucleophilic cyclization of 1‐(2‐haloaroyl)‐3‐aryl thioureas ( 1a‐i ), in the presence of DMF afforded the 1‐aryl‐2‐thioxo‐2,3‐dihydro‐1H‐quinazolin‐4‐ones ( 2a‐i ). The structures were confirmed by spectroscopic data, elemental analyses and in case of the 2c by single crystal X‐ray diffraction data. The mechanistic studies support an intramolecular nucleophilic substitution (S_NAr mechanism) rather than intramolecular aromatic substitution (S_RN1 mechanism).     

Polymorphism of 3‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)‐ and 3‐[5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazol‐2‐yl]‐2H‐chromen‐2‐ones

This study of 3‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)‐2H‐chromen‐2‐one, C₁₇H₁₀N₂O₃, 1 , and 3‐[5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazol‐2‐yl]‐2H‐chromen‐2‐one, C₁₆H₉N₃O₃, 2 , was performed on the assumption of the potential anticancer activity of the compounds. Three polymorphic structures for 1 and two polymorphic structures for 2 have been studied thoroughly. The strongest intermolecular interaction is stacking of the `head‐to‐head' type in all the studied crystals. The polymorphic structures of 1 differ with respect to the intermolecular interactions between stacked columns. Two of the polymorphs have a columnar or double columnar type of crystal organization, while the third polymorphic structure can be classified as columnar‐layered. The difference between the two structures of 2 is less pronounced. Both crystals can be considered as having very similar arrangements of neighbouring columns. The formation of polymorphic modifications is caused by a subtle balance of very weak intermolecular interactions and packing differences can be identified only using an analysis based on a study of the pairwise interaction energies.     

The Reagent‐depending Nitration of 1,3‐Dihydroxyacetone Dimer

Two highly energetic nitric acid esters were synthesized from the dimer of dihydroxyacetone. 1,3‐Dinitratoacetone ( 1 ) and its dimer 2,5‐bis(nitratomethyl‐2,5‐nitrato)‐1,4‐dioxane ( 2 ) were characterized by single‐crystal X‐ray diffraction, vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, and elemental analysis. The thermal behavior was investigated with DTA measurements. Although showing the same atomic stoichiometry, dimer 2 shows significantly higher sensitivities measured by BAM methods (drophammer and friction tester). Due to the high oxygen content of 62.2 %, 1 and 2 were evaluated as potential high energy dense oxidizers.     

Columnar Mesophase Formation of Cyclohexa‐m‐phenylene‐Based Macrocycles

Two novel discotic macrocycles, substituted cyclohexa‐m‐phenylene (CHP) and cyclo‐3,6‐trisphenanthrylene (CTP), and the linear oligomer 3,3′:6′,3′′‐terphenanthrene (TP) as a model substance have been synthesized by repetitive cross‐coupling reactions. To correlate the molecular design with the supramolecular architecture and the established macroscopic order, 2D wide‐angle X‐ray scattering experiments were performed on mechanically extruded filaments. At room temperature in their crystalline phases, all three compounds revealed columnar assemblies in which the macrocycles self‐organized by π‐stacking interactions. The degree of macroscopic order was found to depend upon the planarity and stiffness of the aromatic core. The flexible CHP ring showed a poor macroscopic order of the columnar structures and a low isotropization temperature, whereas the more‐planar, less‐flexible CTP self‐assembled into well‐defined superstructures. The larger π‐stacking area and the more‐pronounced intermolecular interactions for CTP led to the formation of a mesophase over a very large temperature range. The surprising columnar organization of the “open” TP system was explained by back‐folding of the molecule into a ringlike structure.     

Allyl‐Functionalized Dioxynaphthalene[38]Crown‐10 Macrocycles: Synthesis,Self‐Assembly,and Thiol‐ene Functionalization

Five dioxynaphthalene[38]‐crown‐10 ( DNP38C10 ) macrocycles bearing one, two, three, or four allyl moieties have been synthesized and their ability to spontaneously self‐assemble with methyl viologen to form [2]pseudorotaxanes has been evaluated. Association constants between methyl viologen and several of the allyl‐functionalized DNP38C10 macrocycles are found to be comparable to that of methyl viologen and unfunctionalized DNP38C10 , however, the enthalpic and entropic factors that underlie overall binding free energy vary systematically with increasing allyl substitution. These variations are explained through a combination of solution phase and solid‐state analysis of the macrocycles and their complexes. The utility of endowing DNP38C10 macrocycles with allyl moieties is further demonstrated by the ease with which they can be functionalized through thiol‐ene click chemistry.     

A High‐Performance Organic Field‐Effect Transistor Based on Platinum(II) Porphyrin: Peripheral Substituents on Porphyrin Ligand Significantly Affect Film Structure and Charge Mobility

Organic field‐effect transistors incorporating planar π‐conjugated metal‐free macrocycles and their metal derivatives are fabricated by vacuum deposition. The crystal structures of [H₂(OX)] (H₂OX=etioporphyrin‐I), [Cu(OX)], [Pt(OX)], and [Pt(TBP)] (H₂TBP=tetra‐(n‐butyl)porphyrin) as determined by single crystal X‐ray diffraction (XRD), reveal the absence of occluded solvent molecules. The field‐effect transistors (FETs) made from thin films of all these metal‐free macrocycles and their metal derivatives show a p‐type semiconductor behavior with a charge mobility (μ) ranging from 10^?6 to 10^?1 cm² V^?1 s^?1. Annealing the as‐deposited Pt(OX) film leads to the formation of a polycrystalline film that exhibits excellent overall charge transport properties with a charge mobility of up to 3.2×10^?1 cm² V^?1 s^?1, which is the best value reported for a metalloporphyrin. Compared with their metal derivatives, the field‐effect transistors made from thin films of metal‐free macrocycles (except tetra‐(n‐propyl)porphycene) have significantly lower μ values (3.0×10^?6–3.7×10^?5 cm² V^?1 s^?1).     

Sterically‐Limited Self‐Assembly of Pt4 Macrocycles into Discrete Non‐covalent Nanotubes: Porous Supramolecular Tetramers and Hexamers

We report a template‐free strategy based on steric repulsion for the isolation of discrete columnar aggregates of macrocycles. Specifically, introduction of sterically‐demanding trityl‐derived substituents at the periphery of Pt₄ Schiff base macrocycles limits the otherwise infinite one‐dimensional columnar aggregation to discrete tetrameric and hexameric assemblies. Single crystal X‐ray diffraction studies of these compounds reveal discrete nanotubes of finite length that pack inefficiently resulting in three‐dimensional networks of interconnected void space. The discrete assemblies were studied by N₂ adsorption and show enhanced surface area when stacked. In the absence of bulky substituents the macrocycles are nonporous. This strategy for engineering discrete supramolecular macrocyclic aggregates may be generalized to other columnar assembling systems.     

o‐Carborane‐Based Anthracene: A Variety of Emission Behaviors

An o‐carborane‐based anthracene was synthesized, and single crystals, with incorporated solvent molecules, were obtained from the CHCl₃, CH₂Cl₂, and C₆H₆ solutions. The anthracene ring in the crystal is highly distorted by the formation of a π‐stacked dimer between the anthracene units. The crystals exhibited a variety of emission behaviors such as aggregation‐induced emission (AIE), crystallization‐induced emission (CIE), aggregation‐caused quenching (ACQ), and multichromism.