Two novel macrocyclic compounds with a crown ether moiety annulated to a tetracyclic thiophene-containing aromatic fragment were synthesized by the Mallory–Katz photocyclization reaction from a single stilbene precursor. These compounds...

Two novel aromatic thiophene-containing annulated compounds, viz. 2-methoxy[b]naphtho[2,1-d]thiophene and 1,3-dimethoxy[b]naphtho[2,1-d]thiophene, were synthesized via the Mallory-type photocyclization. Their optical, redox and photophysical properties have been studied along with phosphorescence spectra and lifetimes at 77 K. The first compound exhibited much higher charge mobility in thin films than the second one suggesting the former being prospective for molecular electronics applications.

A series of tricyclic naphthothiophenes - photocyclization products (8-methoxynaphtho[1,2-b]thiophene; 6,7dimethoxynaphtho[1,2-b]thiophene; 8-methoxynaphtho[2,1-b]thiophene) have been studied. HOMO and LUMO levels, as well as a gap between them was accessed by cyclic voltammetry and optical spectroscopy. Double potential step chronoamperometry showed that the former naphthothiophene exhibits slower current decay than the other substances. Charge carrier mobility measured by the CELIV technique was estimated to be of the order of 10-4 cm2V- 1s- 1 for 0.2 mu m films and approaches 10-1 cm2V- 1s- 1. for the 5 mu m film of 8-methoxynaphtho[1,2b]thiophene. It is believed the high mobility is associated with the ordering of the high conductivity axis of the microcrystals in the layers.

New polycyclic aromatic derivatives annulated both with thiophene and with 15-crown-5 ether moieties, crown naphthothiophenes, were synthesized via the Mallory photocyclization with the use of iodine as the mild oxidizer, while two isomeric products were readily separated by column chromatography. Their complexation with Ba2+ and Mg2+ cations was examined by both optical and electrochemical methods. Spectroelectrochemical studies indicate that the obtained compounds, depending on their structure, can be chemically stable in the oxidized state.

The synthesis o f new compounds possessing 18-crown-6 fragment is reported: 1-(2-thienyl)-2-(meta-benzo-18-crown-6)stilbene and 1-(3-thienyl)-2-(meta-benzo-18-crown-6)stilbene, as well as two isomeric products of Mallory cyclization of 2-thienylstilbene, containing a tricyclic fragment annulated to the crown ether moiety. Binding constants of these compounds with Ca2+ and Ba2+ have been measured. Besides, dependence of the H-1 NMR chemical shifts o f both stilbenes and cyclization products on their binding to Ba2+ has been studied. Redox response on the complexation is also elucidated. Among the studied compounds, a sterically congested photocyclization product exhibits an unusual dependence of chemical shifts upon complexation, as well as redox behaviour.

Photochemical oxidative cyclization of 2- and 3-thienylstilbenes (heterostilbenes) containing mono-, di- and trimethoxy groups in the benzene ring or heterocyclic fragment results in the formation of isomeric thieno-annelated polycyclic aromatic compounds demonstrating optical properties that differ from those of initial stilbene derivatives. The structures of cyclic products were evaluated via1H and 13C NMR, HRMS, elemental analysis and X-ray crystallography. The research was aimed to study the effect of substituents in stilbene derivatives of thiophene as well as the position of the styryl fragment in the thiophene nucleus on the occurrence of photocyclization reactions.

Photochemical oxidative cyclization of 3-[(E)-2-(3,4-di-methoxyphenyl)vinyl]thiophene and its 15-crown-5-analogue (15-[(E)-2-(3-thienyl)vinyl]-2,3,5,6,8,9,11,12-octahydro-1,4,7,10,13-benzopentaoxacyclopentadecine) affords the isomeric thiophene-containing fused aromatic compounds demonstrating photophysical properties different from those of initial styryl derivatives. E-Configuration of the initial styryl dye, 3-[(E)-2-(3,4-dimethoxyphenyl)vinyl]thiophene, has been proved by X-ray analysis.

8-Phenyl- and 8-(4-nitrophenyl)-BODIPYs with thien-2-ylthio- and (2,2'-dithien-5-yl)-thio-substitution at the 3,5-positions were synthesized. 2-Thienylthio derivatives were obtained using two different sequences, i.e., via nucleophilic substitution in the corresponding 1,9-dichlorodipyrromethenes, followed by BODIPY formation and via the same reaction using 3,5-dichloro-BODIPY dyes. The "dipyrromethene route" was observed to result in better overall yields. All the dyes were characterized by UV-Vis and fluorescence spectroscopy as well as cyclic voltammetry (CVA) studies. The UV-Vis spectra exhibited slight dependence on the thiophene chain length. The thienylthio derivatives fluoresce with modest quantum yields; conversely, no fluorescence has been detected for their dithienylthio counterparts. 8-Phenyl-3,5-di(thien-2-ylthio)-BODIPY was characterized by X-ray crystallography, which showed the layered arrangement of the molecules. The thienyl fragments of different molecules in the same layer form pairs alike H-aggregates, whereas the BODIPYs moieties in the different layers are arranged in a J-aggregate fashion. Solid fluorescence was observed for these crystals with a broad emission from 600 nm to longer than 850 nm. The CVA results correspond to those for known substituted BODIPYs except for the unusually high current observed for the oxidation process of the dithienyl derivatives with respect to the reduction process. This finding indicates oxidative film deposition.

This paper deals with the functionalization of nanocrystalline SnO2 with Cu(II) complexes with organic ligands, aimed at the improvement of sensor selectivity towards gas molecules. For the synthesis of metalorganic/SnO2 hybrid material complexes of Cu(II) with phthalocyanine, porphyrinines, bipyridine and azadithiacrown etherwere used. The analysis of gas sensor properties showed the possibility of increasing the sensitivity and selectivity of hybrid materials in H2S detection due to the electron transfer from SnO2 to an adsorbed organic molecule, which changes during the interaction between H2S and Cu(II) ions.

5-Aryl-1,9-dichlorodipyrrins react with a series of S- and N- nucleophiles (both alkyl- and aryl- ones). Reagents with mercapto group yield product of double nucleophilic substitution of 5-pheny-1,9-dichlorodipyrrin, i.e. the respective 1,9-bis(alkyl-of arylthio)dipyrrin. On the contrary, 5-(4-nitrophenyl)-1,9-dichlorodipyrrin causes disulfides formation from the S-aliphatic substrates, whereas nucleophilic substitution remains the main path of the reaction for S-aryl ones. The reaction of N-Alkyl nucleophiles proceeds as mono-substitution. UV–Vis spectra feature a batochromic shift for bis-S-substituted products and a hypsochromic shift for mono-N-substituted ones, with respect to the starting dichlrorides.

Complexes of 5-(4-diphenylphosphinophenyl)dipyrromethene with trivalent cobalt (Ph 2 PC 6 H 4 DP) 3 Co (DP for dipyrromethene) were obtained for the first time, and their reaction with dicarbonylrhodium(I) acetylacetonate was investigated. The formed complex [Ph 2 P(Rh)C 6 H 4 DP] 3 Co was characterized by 1 H, 13 С, and 31 P NMR spectroscopy. The dimensions of the ligand were estimated (by geometry optimization with PM3 method) and of the formed rhodium complex (by 2D diffusion NMR spectroscopy DOSY). The size of the complex makes it possible to detain it on membranes with the pore size of 2 nm providing an opportunity to use it in catalytic processes with subsequent separation of the catalyst and the reaction products in the nanofiltration mode. Test of 1-octene hydroformylation with the use of this catalytic system showed results similar to those with the system Rh–PPh 3 both with respect to conversion in aldehydes and to the ratio of n / iso -products. Thus the fundamental possibility was demonstrated of applying the synthesized complexes in catalysis.

meso -Aryl-substituted (biscyclohexano)bis(ethoxycarbonyl)BODIPY [aryl = phenyl, 3,4-dimethoxyphenyl, and 2,3,5,6,8,9,11,12-octahydro-1,4,7,10,13-benzopentaoxacyclopentadecin-15-yl-( m -{benzo-15-crown-5}-yl)] were synthesized. The effect of alkaline-earth metals on the absorption and fluorescence spectra of these compounds was investigated. In all compounds along with the mechanism of the photoinduced electron transfer (PET), well-known for the crown-containing BODIPY-based sensors, one more response pattern is observed. The large excess of Ca 2+ and Ba 2+ ions in the system leads to the changes both in the UV-Vis and emission spectra. The complex formation results in the decrease of emission intensity and in its red shift. Besides, a new longwave absorption band appears in the UV-Vis spectrum of the BODIPY-metal ion complex. The formation constants of the complexes corresponding to this response pattern is about 100 times less than the formation constant of Ca 2+ -crown ether complex. 1 H, 13 C, 11 B, and 19 F NMR spectra, the results of quantum-chemical calculations, and their comparison with the literature data of X-ray diffraction study suggest that the binding of Ca 2+ and Ba 2+ ions occurs in the cavity formed by the fluorine atoms and the carbonyl oxygen atoms of the ester groups.

Ru(II) complexes with 5-(3-thienyl)-4,6-dipyrrin (3-TDP), containing 2,2'-bipyridine (bpy) or 4,4'-bis(methoxycarbonyl)-2,2'-bipyridine (dcmb) as coligands, have been prepared and extensively characterized. Crystal structure determination of [Ru(bpy)(2)(3-TDP)]PF(6) (1a) and [Ru(bpy)(3-TDP)(2)] (2) reveals that the 3-thienyl substituent is rotated with respect to the plane of the dipyrrinato moiety. These complexes, as well as [Ru(dcmb)(2)(3-TDP)]PF(6) (1b), act as panchromatic light absorbers in the visible range, with two strong absorption bands observable in each case. A comparison to known Ru(II) complexes and quantum-chemical calculations at the density functional theory (DFT) level indicate that the lower-energy band is due to metal-to-ligand charge transfer (MLCT) excitation, although the frontier occupied metal-based molecular orbitals (MOs) contain significant contributions from the 3-TDP moiety. The higher energy band is assigned to the π-π* transition of the 3-TDP ligand. Each complex exhibits an easily accessible one-electron oxidation. According to DFT calculations and spectroelectrochemical experiments, the first oxidation takes place at the Ru(II) center in 1a, but is shifted to the 3-TDP ligand in 1b. An analysis of MO energy diagrams suggests that complex 1b has potential to be used for light harvesting in the dye-sensitized (Grätzel) solar cell.

Palladium and copper tetracyclohexenoporphyrins (cyclohexano rings annelated to pyrrole rings), tri-mesophenylsubstituted and mono-meso-substituted with benzo-15-crown-5 ether moiety (PdPh 3 [benzo-15-crown-5]TCP and CuPh 3 [benzo-15-crown-5]TCP) have been synthesized.Coupling of 1,1-(arylmethylene)bis-4,5,6,7-tetrahydro-2H-isoindole with the corresponding aldehyde in Lindsey conditions has been used.Two variations of the reagents combinations have been tested.Phenyl substituted dipyrromethane reacted with the mixture of m-formylbenzo-15-crown-5 and benzaldehyde gave the best cyclization results.Separation of the mixture of the scrambled products was greatly enhanced by metallation prior to column chromatography, thus rendering the yields of PdPh 3 [benzo-15-crown-5]TCP and CuPh 3 [benzo-15-crown-5]TCP 16% and 18% respectively.An alternative combination of the reagents, i.e. benzo-15-crown-5-substituted isoindole and benzaldehyde, afforded no porphyrin products besides H 2 Ph 4 TCP.Oxidation of PdPh 3 [benzo-15-crown-5]TCP by DDQ yielded the corresponding tetrabenzoporphyrin (PdPh 3 [benzo-15-crown-5] TBP) in 71%.Phosphorescence spectrum of the latter has been studied.

A series of 2,3;7,8-biscyclohexano-fused diethyl 5-aryldipyrrin-1,9-dicarboxylates have been synthesized [aryl = phenyl, 3,4-dimethoxyphenyl and 2,3,5,6,8,9,11,12-octahydro-1,4,7,10,13-benzopentaoxacyclopentadecine-15-yl (m-benzo-15-crown-5)]. The obtained compounds were shown to exist in two equilibrium forms in solution, with one exhibiting a visible absorption band (λabs 468–485 nm), and the other, “vis-silent” form, having no absorption band in the visible region. The “vis-silent” form has been isolated and characterized by NMR analysis, including two-dimensional techniques. Quantum chemical calculations have also been performed, yielding two main conformations with proximate and distant arrangements of the nitrogen atoms. In the latter conformation the pyrrole–pyrrolene fragments were found to be nearly orthogonal, with no long chain of conjugation. Computational results confirm the spectroscopic findings. Two different forms were also characterized as their Mg2+ complex and investigated by UV/Vis and by NMR spectroscopic analyses and a clear difference was noted.

Bromination of palladium meso-tetraphenyl tetrabenzoporphyrin (Pd Ph4TBP, 1) by Me4NBr3 or Me4NBr/Br-2 was shown to proceed regioselectively to the benzo-rings annelated to main porphyrin macrocycle. Conditions for preferential mono-and octa-bromination have been established. The respective mono-and octa-bromide (Pd Ph4TBP(Br), 2 and Pd Ph4TBP(Br)(8), 3) have been isolated and characterized by UV-vis, NMR and LDI-TOF spectroscopy. Changes of electrochemical properties of tetrabenzoporphyrins induced by Br atoms were found to follow the same trends as the changes in analogous non-extended porphyrins. Room temperature phosphorescence is not substantially influenced by the substitution.