New dicationic derivatives of dibenzotetraaza[14]annulene: tuning DNA-binding properties

Four new water-soluble derivatives of dibenzotetraaza[14]annulene have been synthesized, bearing meso substituents with different structures and dimensions: 3-(N,N,N-trimethylammonium)propyl, 3-(N-pyridinium-1-yl)propyl, 2-[3-(N,N,N-trimethylammonium)propoxy]benzoyl, and 2-[3-(N-pyridinium-1-yl)propoxy]benzoyl. The crystal structures of 3-(trimethylammonium)propyl and (N,N,N-trimethylammonium)propoxy]benzoyl derivatives were determined by single crystal X-ray analysis. According to the UV-vis titrations, thermal denaturation experiments, and ethidium bromide displacement assays, all compounds presented here interact strongly with double stranded (ct)-DNA. The product equipped with 3-(trimethylammonium)propyl pendant groups and two positive charges interacts with DNA in one dominant binding mode, whereas the other three derivatives revealed more complex mixed-type interactions. The results have been discussed in terms of dimensions, geometry, and electronic properties of the evaluated compounds, on the basis of corresponding crystallographic data.     

5，14－二氢－6，8，15，17－四甲基二苯并［b，i］［1，4，8，11］四氮杂［14］轮烯金属配合物的合成和反应性研究

合成了二苯并四氮杂［１４］轮烯金属配合物ＴＭＴＡＡＮｉ（Ⅱ），ＴＭＴＡＡＣｕ（Ⅱ）和ＴＭＴＡＡＶ＝Ｏ，通过ＴＭＴＡＡＭ（Ⅱ）分子中金属离子Ｍ（Ⅱ）对位碳原子上发生酰化反应，获得了十个酰化产物，用元素分析，ＩＲ，ＵＶ，１￣ＨＮＭＲ，（１９）￣ＦＮＭＲ和ＥＰＲ等进行了表征。酰化反应的发生说明了这类金属配合物具有类芳香性，并为改善这类大环金属配合物的光－电性能提供了良好的途径。     

A new liquid crystalline derivative of dibenzotetraaza[14]annulene: synthesis, characterization and the preliminary evaluation of mesomorphic properties

A new dibenzotetraaza[14]annulene ligand has been synthesized that contains two 2-hydroxybenzoyl and four 3,7-dimethyloctyloxy peripheral substituents. Its mesomorphic textures were observed by means of a polarizing optical microscopy.     

Lacunar derivatives of dibenzotetraaza[14]annulene: synthesis and crystal structure of new receptors produced via bis-alkylation of the macrocyclic precursor

The bis(2-hydroxybenzoyl) derivative of dibenzotetraaza[14]annulene was employed as a substrate for producing new lacunar-type receptors. Alkylation of both phenolic OH groups using aliphatic dibromides and ditosylates efficiently leads to the expected bridged products without recourse to a high dilution procedure. Four new dibenzotetraaza[14]annulene-based lacunar receptors, and one unbridged open-chain bis-octoxy analogue have been synthesized. Synthetic procedures, analytical and spectroscopic characterization are reported. Conformations of the macrocyclic rings in the products as well as non-covalent interactions are discussed on the basis of their crystal structures.     

Tuning the mesomorphic properties of liquid-crystalline dibenzotetraaza[14]annulenes — discotic nematic phases of tetraalkoxy-substituted derivatives

A homologous series of five tetrasubstituted dibenzotetraaza[14]annulene-based discotic mesogens was prepared and studied using polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). A nematic phase was identified for the product bearing two peripheral isobutoxy and two dodecyloxy substituents.     

二苯并四氮杂[14]轮烯金属配合物电子结构和性质

用量子化学半经验方法和从头算对二苯并四氮杂[14]轮烯（Tmtaa)离子及其金属配合物的电子结构进行了详细的研究.讨论了轮烯金属配合物合成的模板效应及金属离子半径大小对模板效应的影响作用,对其亲电取代反应的活性位置作了相应理论解释.依据理论计算结果指导了轮烯配合物的定向亲电取代反应及新金属配合物的合成尝试,理论计算与实验事实基本一致.Tmtaa-Ni等配合物及其亲电取代反应产物的1HNMR谱、19FNMR谱表明金属配合物中金属离子对位C7、C16上的H原子被取代,与理论计算结果十分一致.     

New lacunar-type and pendant groups containing derivatives of β-unsubstituted dibenzotetraaza[14]annulenes—syntheses and crystal structures

Three new lacunar-type derivatives of β-unsubstituted dibenzotetraaza[14]annulene have been synthesized along with a range of their open-chain pendant group containing counterparts. The crystal structures of two representative products have been determined and the noncovalent interactions explored. A number of C-H?π and π?π interactions involving aliphatic chains and aromatic regions of the macrocycle have been evidenced. The relative ease and high yield of lacunization are suggested to be largely due to self-assembly processes, driven by favorable noncovalent interactions between reacting units.     

New tetraaza[14]annulene receptors derived from 2,3-diaminonaphthalene: synthesis and crystal structures

The first synthesis of the bis(2-hydroxybenzoyl)dinaphthotetraaza[14]annulene ligand and its O,O-bis-alkylated derivatives containing a decanedioxy bridging moiety, pendant bis-alkoxy groups as well as dicationic butoxypyridinium substituents is reported. The synthetic procedures, full analytical and spectroscopic characterisation (NMR, MS and IR) and crystal structures of the new products are described. The crystal structures show that naphthylene moieties incorporated into the investigated derivatives provide additional opportunities for non-covalent interactions between the molecules.     

Synthesis of New Dibenzo-tetraaza and Dibenzo-dioxadiaza[14]annulene Derivatives Using 3-Bromo-substituted Vinamidinium Salt

Novel bromo-substituted derivatives of dibenzo-tetraaza and dibenzo-dioxadiaza[14]annulenes B–G were synthesized by a twofold condensation reaction of a symmetrical bromo-substituted vinamidinum salt A with ortho-diamino- and ortho-amino-hydroxyarenes such as 1,2-diaminobenzene, 1,2-diamino-4,5-dimethylbenzene, 2,3-diaminonaphthalene, 1,2-diamino-4-methylbenzene, 2-amino-1-hydroxybnzene, and 2-amino-1-hydroxy-5-methyl-benzene in acetonitrile/acetic acid as reaction medium. The ultraviolet/visible spectral behavior of these [14]annulenes was examined in dimethyl sulfoxide (DMSO). Elemental analysis, infrared, ¹H NMR, ¹³C NMR, and mass spectra confirm the molecular structure of the newly synthesized compounds.     

Dinaphthotetraaza[14]annulene copper(II) complexes in the electrocatalytic reduction of carbon dioxide and bisulfite anion

A modified synthetic route for the complexes [Cu(II)5,7,12,14-tetramethyldinaphtho [b,i][1,4,8,11]tetraaza[14]annulene], [Cu(II)tmdnTAA], and [Cu(II) 5,7,12,14-tetramethyl-6,13-dichloro-dinaphtho[b,i][1,4,8,11]tetraaza[14]annulene], [Cu(II)dCltmdnTAA], is presented in this work. The electrochemical characterization of both complexes and their precursors, [bis(2,4-pentanedionato)copper(II)], [Cu(II)(acac)₂] and [bis(3-chloro-2,4-pentanedionato)copper(II)], [Cu(II)(3-Cl-acac)₂], respectively, under nitrogen and carbon dioxide is also presented. The voltammetric response of [Cu(II)(acac)₂] and [Cu(II)(3-Cl-acac)₂] are different compared to [Cu(II)tmdnTAA] and [Cu(II)dCltmdnTAA] under nitrogen. Precursors show the reduction of Cu(I) to Cu(0) and the tetraazadinaphtho[14]annulene complexes do not. The chlorine substituted complex has a lower reduction potential than the unsubstituted homologue under nitrogen atmosphere. However, the contrary response is obtained in the presence of carbon dioxide: the unsubstituted complex is more catalytic in terms of potential because the current discharge appears 270?mV shifted to the anodic region. These facts can be explained in terms of electronic and steric effects. The modified electrode obtained by oxidative electropolymerization of [Cu(II)tmdnTAA] over glassy carbon electrode presented a suitable amperometric response for the sulfite reduction in acidic medium (pH?=?2.7). A linear correlation was observed for the catalytic current and sulfite concentration between 0.6–6.0?mM range.     

Synthesis, crystal structures and the preliminary evaluation of the new dibenzotetraaza[14]annulene-based DNA/RNA binding agents

A series of water-soluble dicationic dibenzotetraaza[14]annulenes have been prepared in order to examine their interactions with nucleic acids. Pendant water-solubilizing N-pyridinium, 4,4′-bipyridinium and N-methyl pyridinium moieties have been attached to the central core via linkers generated by direct N-alkylations and ester creating couplings, respectively. The crystal structures of derivatives equipped with 3-(N-pyridinium-1-yl)propyl and 3-(4,4′-bipyridinium-1-yl)propyl substituents have been determined. Interactions with ct-DNA have been studied and evidenced by means of spectrophotometric titrations with Scatchard analysis and thermal denaturation experiments.     

Spectral and Electrochemical Characterization of Dibenzotetraaza[14]annulenes

The UV/Vis absorption spectra and cyclic voltammograms (CV) of the Cu(II) and Ni(II) complexes of γ,γ'-alkoxycarbonyl derivatives of α,α'- diphenyldibenzo-tetraaza[14]annulene are analyzed and compared. The observed ratio of absorption intensities at the peaks of π-π* transitions is linearly correlated with the difference of HOMO and LUMO energy levels of the substituents. Moreover, the measured values of the mid-peak potential of metal redox reactions on a Pt electrode in DMF are linearly correlated with the ionization potential values of the appropriate substituents.     

Oxidative-addition to a four-coordinate tin(II) complex supported by octamethyldibenzotetraaza[14]annulene dianion ligation, [η-Me8taa]Sn: The syntheses and structures of [η-Me8taa]SnI2 and *[η-Me8taa]SnI(THF)**I3*

The four-coordinate tin(II) complex [η⁴-Me₈taa]Sn undergoes oxidative addition of I₂ to give six-coordinate [η⁴-Me₈taa]SnI₂, in which the iodide ligands exhibit a trans arrangment. Abstraction of I⁻ from [η⁴-Me₈taa]SnI₂ is facile, as indicated by the rapid formation of the triiodide derivative *[η⁴-Me₈taa]SnI(THF)**I₃* upon treatment with I₂ in the presence of THF. The molecular structures of [η⁴-Me₈taa]SnI₂ and *[η⁴-Me₈taa]SnI(THF)**I₃* have been determined by X-ray diffraction.     

Electronic Structure,Aromaticity and Optical Properties of Dehydro[10]annulene

Dehydro[10]annulene had been prepared experimentally recently, which is considered to be a highly rigid structure with planar configuration. In this paper, the electronic structure and bonding character of dehydro[10]annulene had been studied by means of molecular orbital (MO), density of states (DOS), bond order (BO) and interaction region indicator (IRI) analyses. The delocalization characters of out-of-plane and in-plane π-electrons (π^out- and πⁱⁿ-electrons) of the bond regions were studied by using localized orbital locator (LOL). The anisotropy of the induced current density (AICD), iso-chemical shielding surface (ICSS) and anisotropy of the gauge-including magnetically induced current (GIMIC) were used to investigate the molecular response to external magnetic field, including the induced ring current and the magnetic shielding characteristic. The results showed that the electron delocalization of dehydro[10]annulene is mainly contributed by π^out system. The apparent clockwise current in the π^out system proved that dehydro[10]annulene is π^out aromatic. Finally, the photophysical properties and (hyper)polarizability of dehydro[10]annulene were studied by TD-DFT calculation. The results showed that dehydro[10]annulene has strong local excitation characters. Its (hyper)polarizability decreases with the increase of frequency and has the characteristics of nonlinear anisotropy.     

Crystal,molecular structure and tautomerism of (5-methyl-1H-[1,2,4]triazol-3-ylsulfanyl)-acetic acid

Molecular structure, relative stability of conformers, and tautomers of (5-methyl-1H-[1,2,4]triazol-3-ylsulfanyl)-acetic acid (MTSA) have been investigated by experimental (X-ray diffraction) and theoretical (B3LYP/aug-cc-pVDZ) methods. It was demonstrated that in the solid state MTSA exists in N1H tautomeric form. This tautomer is not the most stable in gas phase and its stabilization is provided by environment effects.     

Oxalic acld as a catalyst for efficient synthesis of bis-(indolyl)methanes,and 14-aryl-14H-dibenzo[a,j]xanthenes in water

A simple,efficient,and environment benign route was developed for the preparation of bis-(indolyl)methanes and 14-aryl-14H-dibenzo[a,j]xanthenes from condensation of various aromatic aldehydes or ketones with indole,and 2-naphthol,respectively,using oxalic acid catalyst in aqueous medium.Use of cheap and easily available catalyst,better yields and simple reaction protocol are the advantages of the present method.     

Oxalic acid as a catalyst for efficient synthesis of bis-（indolyl）methanes,and 14-aryl- 14H-dibenzo[a,j]xanthenes in water

A simple, efficient, and environment benign route was developed for the preparation of bis-（indolyl）methanes and 14-aryl-14H- dibenzo[aj]xanthenes from condensation of various aromatic aldehydes or ketones with indole, and 2-naphthol, respectively, using oxalic acid catalyst in aqueous medium. Use of cheap and easily available catalyst, better yields and simple reaction protocol are the advantages of the present method.     

Green catalytic synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes using recyclable mesoporous zirconia modified with tungstophosphoric acid

Abstract

A simple and efficient procedure has been developed for the preparation of aryl-14H-dibenzo[a,j]xanthenes by a one-pot condensation of 2-naphthol and aryl aldehydes, in the presence of mesoporous zirconia modified with tungstophosphoric acid (ZrTPA60B_T100), to be used as a heterogeneous catalyst in a solvent-free medium using conventional heating. The present approach offers the advantages of clean reaction, simple methodology, short reaction time, and high yield. The reaction work-up is very simple and the catalyst can be easily separated from the reaction mixture and reused several times in subsequent reactions without appreciable loss of the catalytic activity.     

Hydrazides of glycine-containing decasubstituted pillar[5]arenes: Synthesis and encapsulation of Floxuridine

Hydrazides of glycine-containing decasubstituted pillar[5]arenes were synthesized and characterized. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed that self-assembly into monodisperse spherical nanoparticles (28?nm) was typical in water for pillarene hydrazides containing glycylglycide fragments (1?×?10^?3?M). Binding of the antitumor drug Floxuridine in water by the substituents of the macrocycle was established by NMR spectroscopy. It was shown by DLS and TEM, that heating the macrocycle-Floxuridine system in a 1:1 ratio at 1?×?10^?4?M led to its self-organization into monodisperse spherical particles 132?nm in diameter.     

Hetero-calix[4]pyrroles: incorporation of furans, thiophenes, thiazoles or fluorenes as a part of the macrocycle

Furans, thiazoles, fluorene or thiophene incorporated calix[4]pyrrole analogues were synthesized and characterized. The synthesis was achieved by utilization of various building blocks such as 7, 13, 14, 18 and 21. Acid catalyzed condensation of those building blocks with acetone or meso-disubstituted dipyrromethanes afforded desired macrocycles.