The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 23 . Naphtho[2′,1′:4,5]thieno‐[2,3‐c]naphtho[2,1‐f]quinoline

A previously unknown heterocyclic ring system, naphtho[2′,1′:4,5]thieno[2,3‐c]naphtho[2,1‐f]quinoline ( 14 ), was synthesized via oxidative photocyclization of 3‐chloro‐N‐(2‐phenanthryl)naphtho[1,2‐b]‐thiophene‐2‐carboxamide ( 9 ). Further elaboration of the lactam 10 yielded the unsubstituted ring system 14 . Structural confirmation of compound 14 was accomplished by a total assignment of its ¹H and ¹³C nmr spectra utilizing the concerted two‐dimensional nmr spectroscopic methods.     

Solid state structure of the molecular complex between a diazadibenzo-30-crown-10 derivative and diquat

X-Ray crystallography has established that, in the 1:1 complex formed between [Diquat]²⁺ and the diazadibenzo-30-crown-10 derivative 5, the noncovalent bonding pattern is similar to that observed previously in [Diquat.DB30C10]²⁺.     

The synthesis of novel polycyclic heterocyclic ring systems. 2. Naphmo[2,1-b:4,3-g]bisbenzo[b]thiophene

The novel polycyclic heterocyclic ring system, naphtho[2,1-b:4,3-g]bisbenzo[b]thiophene was synthesized from 5-[2-(2-bromo-3-thienyl)ethenyl]naphtho[2,1-b][1]benzothiophene. The assignment of its ¹H and ¹³C nmr spectra was also accomplished by utilizing two-dimensional nmr methods.     

The synthesis of novel polycyclic heterocyclic ring system via photocyclization. 18. Benzo[h]naphtho-[1′,2′:4,5]thieno[2,3-c]quinoline and benzo[h]naphtho-[1′,2′:4,5]thieno[2,3-c] [1,2,4]triazolo[4,3-a]quinoline

The synthesis of two previously unknown polycyclic ring systems, benzo[h]naphtho[1′2′:4,5]-thieno[2,3-c]quinoline ( 1 ) and benzo[h]naphtho[1′,2′:4,5]thieno[2,3-c][1,2,4]triazolo[4,3-a]quinoline ( 2 ), was achieved via oxidative photocyclization of 1-chloro-N-(1-naphthyl)naphtho[2,1-b]thiophene-2-carboxamide ( 5 ). The total assignment of their ¹H and ¹³C nmr spectra was determined by the concerted use of two-dimensional nmr methods.     

A Stable All-Thiophene-Based Core-Modified [38]Octaphyrin Diradicaloid: Conformation and Aromaticity Switch at Different Oxidation States

A soluble and stable core-modified [38]octaphyrin, MC-T8 , containing eight thiophene rings was synthesized by Yamamoto coupling followed by oxidative dehydrogenation. X-ray crystallographic analysis revealed a nearly planar backbone, and the molecule is globally aromatic with a dominant 38π conjugation pathway. The dication MC-T8²⁺ is antiaromatic, and the backbone is distorted, with a different orientation of the thiophene rings. The tetracation MC-T8⁴⁺ becomes aromatic again, with a shallow-bowl-shaped geometry. Both the neutral compound and the dication demonstrated open-shell diradical character with a small singlet–triplet energy gap (−2.70 kcal mol⁻¹ for MC-T8 and −3.78 kcal mol⁻¹ for MC-T8²⁺ ), and they are stable owing to effective spin delocalization.     

ESI-MS detection of very weak <Emphasis Type="Italic">π</Emphasis>-Stacking interactions in the mixed-ligand sandwich complexes formed by substituted benzo-crown ethers and metal cations

The stability of the mixed-ligand complex formed by amino-benzo-15-crown-5 and nitro-benzo-15-crown-5, with a metal cation, [NH₂B15C5+NO₂B15C5+K]⁺, was found to be enhanced by π-stacking interactions. This conclusion was deduced by comparison of the abundance of the mixed-ligand complex with the abundances of homo-ligand complexes ([(NH₂B15C5)₂+K]⁺, [(NO₂B15C5)₂+K]⁺), as well as with those of 1:1 complexes ([NH₂B15C5+K]⁺, [NO₂B15C5+K]⁺). Some solvents and some metal cations with large radii were also found to prevent the existence of π-stacking interactions.     

The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 6. Naphthothienonaphthyridines

Five novel polycyclic heterocyclic ring systems are reported via photocyclization. The specific final products in these ring systems are: naphtho[1′,2′:4,5]thieno[2,3-c][1,8]naphthyridin-6(5H)-one ( 5 ), naphtho-[1′,2′:4,5]thieno[2,3-c][1,6]naphthyridin-6(5H)-one ( 6 ), naphtho[1′,2′:4,5]thieno[2,3-c]-1,5-naphthyridine ( 9 ), naphtho[1′,2′:4,5]thieno[2,3-c][1,2,4]triazolo[4,3-a]-1,5-naphthyridine ( 12 ), and naphtho[2′,1′:4,5]thieno[2,3-c]-1,5-naphthyridine ( 17 ). The direction of photocyclization to produce 9 was established from a zero quantum two-dimensional nmr spectroscopy experiment (ZQCOSY) using 6-chloronaphtho[1′,2′:4,5]thieno[2,3-c]-1,5-naphthyridine ( 8 ) as the model compound.     

Anion-π interactions—interactions between benzo-crown ether metal cation complexes and counter ions

The loss of X^· radical from [M + Cu + X]⁺ ions (copper reduction) has been studied by the so called in-source fragmentation at higher cone voltage (M = crown ether molecule, X⁻ = counter ion, ClO₄⁻, NO₃⁻, Cl⁻). The loss of X^· has been found to be affected by the presence/lack of aromatic ring poor/rich in electrons. Namely, the loss of X^· occurs with lower efficiency for the [NO₂-B15C5 + Cu + X]⁺ ions than for the [B15C5 + Cu + X]⁺ ions, where NO₂-B15C5 = 3-nitro-benzo-15-crown-5, B15C5 = benzo-15-crown-5. A reasonable explanation is that Anion-π interactions prevent the loss of X^· from the [NO₂-B15C5 + Cu + X]⁺ ions. The presence of the electron-withdrawing NO₂ group causes the aromatic ring to be poor in electrons and thus its enhances its interactions with anions. For the ion containing the aromatic ring enriched in electrons, namely [NH₂-B15C5 + Cu + ClO₄]⁺ where NH₂-B15C5 = 3-amino-benzo-15-crown-5, the opposite situation has been observed. Because of Anion-π repulsion the loss of X^· radical proceeds more readily for [NH₂-B15C5 + Cu + X]⁺ than for [B15C5 + Cu + X]⁺. Iron reduction has also been found to be affected by Anion-π interactions. Namely, the loss of CH₃O^· radical from the ion [B15C5 + Fe + NO₃ + CH₃O]⁺ proceeds more readily than from [NO₂⁻B15C5 + Fe + NO₃ + CH₃O]⁺.     

Cycloaddition of benzothiete and electron-deficient nitriles

The o-quinoid 8π electron system 2 , generated by thermal ring opening of benzothiete ( 1 ), enters regio-specific [8π + 2π] cycloaddition reactions with electron-deficient nitriles 3a-d , yielding the 4H-1,3-benzothiazines 4a-d. A competitive dimerization of 1 leads to 1,5-dibenzo[b,f]dithiocin (5). Depending on the nitrile further competitive or subsequent reactions (2 + 3b → 7b, 2 + 3d → 4d → 8d) can occur. The cycloadducts 10e and 11e gained from 3e anticipate a primary cleavage of 3e to methylisothiocyanate 9e which reacts at the C?N double bond as well as at the C?S double bond.     

Preparation and characterization of tetraaza[14]annulene and its nickel(ii) and copper(II) complexes with crown ether functionalities

Three new organic hosts are described that contain a tetraaza[14]annulene core to which two crown ether voids are attached. These hosts include a free base tetraaza[14]annulene and/or its complexes with benzo-15-crown-5 rings. The crown tetraaza[14]annulene is synthesized from tetraaza[14]annulene and 4′-chloroformylbenzo-15-crown-5. Its nickel(II) and copper(II) complexes are prepared in a similar manner as above. In solution the compounds do not tend to form aggregates. However, aggregation is affected by the presence of alkali-metal salts, which coordinate to the crowns. Li⁺ and Na⁺ cations with diameters that match the diameters of the crown ether rings form 1:2 host-guest complexes. Complexes with 2:2 host-guest stoichiometry are formed when the diameters of K⁺ and Cs⁺ cations exceed that of the crown ether rings. Nevertheless, it is weak for the present macrocycle and its complexes to be inclined to form dimers owing to the steric hindrance of the substituent groups and owing to restraining the rotation of the carbonyl bond connecting the crown ether group.     

A Stable All‐Thiophene‐Based Core‐Modified [38]Octaphyrin Diradicaloid: Conformation and Aromaticity Switch at Different Oxidation States

A soluble and stable core‐modified [38]octaphyrin, MC‐T8 , containing eight thiophene rings was synthesized by Yamamoto coupling followed by oxidative dehydrogenation. X‐ray crystallographic analysis revealed a nearly planar backbone, and the molecule is globally aromatic with a dominant 38π conjugation pathway. The dication MC‐T8²⁺ is antiaromatic, and the backbone is distorted, with a different orientation of the thiophene rings. The tetracation MC‐T8⁴⁺ becomes aromatic again, with a shallow‐bowl‐shaped geometry. Both the neutral compound and the dication demonstrated open‐shell diradical character with a small singlet–triplet energy gap (?2.70 kcal mol^?1 for MC‐T8 and ?3.78 kcal mol^?1 for MC‐T8²⁺ ), and they are stable owing to effective spin delocalization.     

Synthesis and Antimicrobial Activity of Novel Iminophosphocin Derivatives

Iminophosphocins 8a – 8e and 9a – 9e were synthesized in four‐step reactions via Staudinger reaction. 3‐(Bromomethyl)‐1,2,3,4,5‐pentahydro‐3λ⁵‐naphtho[1,8‐f,g][1,5,3]diazaphosphocin‐3‐one ( 3 ) was prepared by reacting tris(bromomethyl)phosphineoxide ( 1 ) with 1,8‐diaminonaphthalene ( 2 ) in the presence of triethylamine (TEA) in dry tetrahydrofuran (THF), and treated with L‐valine methyl ester ( 4 ) and bis(2‐chloroethyl)amine ( 5 ) in the presence of TEA in dry THF to get 3‐methyl‐2‐[(3‐oxo‐1,2,3,4,5‐pentahydro‐3λ⁵‐naphtho[1,8‐f,g][1,5,3]diazaphosphocin‐3‐yl)methylamino]butanoate ( 6 ) and 3‐[di(2‐chloroethyl)aminomethyl]‐1,2,3,4,5‐pentahydro‐3λ⁵‐ naphtho[1,8‐f,g][1,5,3]diazaphosphocin‐3‐one ( 7 ). The compounds 6 and 7 were treated with trichlorosilane (SiCl₃H) in dry tetrahydrofuran (THF) to form the trivalent P(III) intermediates 8 and 9 , which were further treated with various alkyl azides in dry THF in 55–60°C to afford the title compounds 8a – 8e and 9a – 9e . Their structures were established by multi‐nuclear NMR and mass spectra. All the newly synthesized compounds were found to possess moderate anti‐microbial activity.     

Cycloaddition reactions of 2H-benzo[b]thiete and conjugated cyclic dienes

2H-Benzo[b]thiete 1 reacts with cyclopentadiene 3 in consecutive [8π + 2π]cycloadditions yielding the condensed heterocycles 6–8 . Tetracyclone 9 on the other hand gives only the monoadduct 10 . An [8π + 8π]cycloaddition can be observed for 1 and diphenylisobenzofuran 11 . The related π system 13 shows again consecutive [477π + 27π]processes ( 1 + 13 ← 14, 15 ).     

Threaded structures based on the recognition of 1,5-dinaphtho-crown ethers to paraquat and vinylogous viologen derivatives: host–guest complexations,X-ray crystal structures,and self-assembly superstructures

Host–guest complexation between two 1,5-dinaphtho-crown ethers and two paraquat derivatives has been studied. By self-assembly of 1,5-dinaphtho-44-crown-12 (DNP44C12) 1 with vinylogous viologen 4, a linear [2]pseudorotaxane array forms in the solid state by PF₆⁻ anion linkages. Moreover, the complexation between 1,5-dinaphtho-50-crown-14 (DNP50C14) 2 and paraquat 3 also leads to the formation of a linear [2]pseudorotaxane superstructure in the solid state driven by π–π stacking.     

Dipolar additions with 1-(4,6-dimethylpyrimidin-2-yl)- and 1-(4,6-dimethoxy-s-triazin-2-yl)-3-oxidopyridinium betaines

Cycloaddition to 1-(4,6-dimethylpyrimidin-2-yl)- and 1-(4,6-dimethoxy-s-triazin-2-yl)-3-oxidopyridinium betaines across the 2,6-positions of the pyridine rings with indene, acenaphthylene and ethyl cinnamate gave substituted 8-aza[3.2.1]bicycIooct-3-en-2-ones, whereas the [6π + 4π] cycloaddition reaction with 6,6-dimethylfulvene gave a tricyclo[6.3.1.0^2.6]dodeca-2,(6),4,9-trien-11-one. Structural and configurational assignments of the cycloadducts were deduced from ¹H nmr and ir spectral data.     

Synthese und Kristallstruktur des Nonaselenids [Sr(15-Krone-5)2]Se9

Synthesis and Crystal Structure of the Nonaselenide [Sr(15-crown-5)₂]Se₉ The title compound was prepared by the reaction of excess selenium with strontium diselenide in DMF in the presence of 15-crown-5. [Sr(15-crown-5)₂]Se₉ forms black crystals, which are soluble in DMF. They were characterized by FIR spectroscopy and by an X-ray structure determination. Space group P2₁/n, Z = 4, 2 381 observed unique reflections, R = 0.073. Lattice dimensions at 19°C: a = 1 228.7, b = 1 893.4, c = 1 575.7 pm, β = 99.15°. The compound consists of [Sr(15-crown-5)₂]²⁺ ions in which the strontium ion is coordinated by the oxygen atoms of the crown ether molecules in a sandwich-like fashion, and of Se₉^2? ions with a chain structure, which has a topolocical resemblance with the bicyclic ion Se.     

Structure elucidation of [1,3]oxazolo[4,5‐e][2,1]benzisoxazole and naphtho[1,2‐d][1,3]‐ and phenanthro[9,10‐d]oxazoles using gradient selected gHMBC,gHMQC and gHMQC‐TOCSY NMR techniques

Structure elucidation of compounds in the benzisoxazole series ( 1 – 6 ) and naphtho[1,2‐d][1,3]‐ ( 7 – 10 ) and phenanthro[9,10‐d][1,3]oxazole ( 11 – 14 ) series was accomplished using extensive 2D NMR spectroscopic studies including ¹H–¹H COSY, long‐ range ¹H–¹H COSY, ¹H–¹³C COSY, gHMQC, gHMBC and gHMQC‐TOCSY experiments. The distinction between oxazole and isoxazole rings was made on the basis of the magnitude of heteronuclear one‐bond ¹J_{C2, H2} (or ¹J_{C3, H3}) coupling constants. Complete analysis of the ¹H NMR spectra of 11 – 14 was achieved by iterative calculations. Gradient selected gHMQC‐TOCSY spectra of phenanthro[9,10‐d][1,3]oxazoles 11 – 14 were obtained at different mixing times (12, 24, 36, 48 and 80 ms) to identify the spin system where the protons of phenanthrene ring at H‐5, H‐6 and at H‐9 and H‐7 and H‐8 were highly overlapping. Copyright © 2003 John Wiley & Sons, Ltd.     

Protonation-induced switching of pleated foldamers of diaminonaphthalene-bipyridinium polymers

1,5-diaminonaphthalene (DAN) and bipyridinium (BIPY²⁺) were copolymerized into NP1 and NP2 linked by acylhydrazone bonds. The formed intramolecular charge-transfer (CT) complex drove the linear foldamers to adopt pleated folding conformation. Upon protonation of the DAN units by triflic acid (TFSA), the pleated folding conformation unfolded to linear structure because of electron repulsion. And this linear structure can be refolded to pleated structure by titrating with triethylamine (TEA). 1,5-dinaphtho[38]crown-10 (DN38C10) can encapsulate bipyridinium group on the polymers after protonation. These processes were supported by UV–vis and fluorescence spectroscopy studies.     

Complexation of chalocogenadiazoles with 3<Emphasis Type="Italic">d</Emphasis> metals: Crystal and molecular structure of naphtho[1,2-<Emphasis Type="Italic">c</Emphasis>][1,2,5]thiazol-9-ol

Nine complexes of copper(II), cobalt(II), Ni(II), and Zn(II) chlorides with naphtho[1,2,-c][1,2,5]oxadiazol-9-ol (HL¹), naphtho[1,2-c][1,2,5]thiadiazol-9-ol (HL²), and naphtho[1,2-c][1,2,5]selenadiazol-9-ol (HL³) have been synthesized, isolated in the crystalline state, and studied by physicochemical methods. The composition of the complexes in solutions as been determined and their stability constants have been calculated from spectrophotometric data. The electronic structures of the ligands and complexes have been calculated by quantum-chemical methods. The crystal and molecular structure of HL² has been determined by X-ray crystallography.     

The synthesis of azoniadithia[6]helicenes

A new short‐step synthesis of 8a‐azonia[6]helicene (1) and the novel dithieno derivatives ( 2 and 3 ) is described. Double photocyclization of 2,8‐distyrylquinolizinium salt (8) gave 1 in 35% yield. Similarly, 2,8‐bis[2‐(2‐thienyl)vinyl]‐ and 2,8‐bis[2‐(3‐thienyl)vinyl]‐quinolizinium salts ( 9 and 10 ) afforded new azonia[6]helicenes containing two thiophene rings at the ends of helix, that is 7a‐azonia‐3,12‐dithia[6]helicene (2) and 7a‐azonia‐1,14‐dithia[6]helicene (3) , in 43 and 35% yields, respectively. The total assignment of their ¹H‐ and ¹³C‐nmr spectra was performed by utilizing two‐dimensional and NOE nmr spectroscopic methods.