SbCl3 Research Articles

Синтез и строение аддукта дихлорида три(пара-толил)сурьмы с хлоро(4-нитрофенокси)три(пара-толил)сурьмой p-Tol3SbCl2*p-Tol3Sb(Cl)OC6H4(NO2-4)

Шарутин Владимир Викторович – доктор химических наук, профессор, старший научный сотрудник УНИД, Южно-Уральский государственный университет. 454080, г. Челябинск, пр. им. В.И. Ленина, 76. E-mail: vvsharutin@rambler.ru. Шарутина Ольга Константиновна – доктор химических наук, профессор, заведующий ка-федрой теоретической и прикладной химии, Южно-Уральский государственный университет V.V. Sharutin, vvsharutin@rambler.ru O.K. Sharutina, sharutinao@mail.ru South Ural State University, Chelyabinsk, Russian Federation 454080, г. Челябинск, пр. им. В.И. Ленина, 76. E-mail: sharutinao@mail.ru.

Synthesis and Integration of Ultrathin Polyaniline Films into Carbide Derived Carbon Supercapacitors

Utilizing conducting polymers as the active materials for supercapacitors is a novel and promising approach to improve performance [1-4]. Conducting polymers have been shown to have high specific capacity, high energy density, and promising stability. Furthermore, they are less costly than oxide-based materials and have the ability to be p and n-doped. Moreover, conducting polymers enhance charge capacity through Faradaic redox reactions. As reported by Simon and Gogotsi [5], the integration of ultrathin pseudocapacitive materials within porous carbon nanostructures can result in significant improvement in energy and power densities, allowing for having both battery-like (high capacity) and capacitor-like (high rate) behavior in a single electrode. Conducting polymers are typically deposited via solvent-based techniques such as chemical bath deposition, electrodeposition, and casting from suspension. Nevertheless, challenges exist with making uniform conformal coatings, especially with poor solubility of many conducting polymers and poor accessibility of the highly tortuous pore space within nanostructured electrodes. Oxidative chemical vapor deposition (oCVD) allows one to conveniently bypass these challenges as it is a solvent-free method where the reagents for oxidative polymerization, the monomer and oxidizer, are heated to vapor form that can easily penetrate into mesoscale pores and polymerize (Figure 1). By understanding the oCVD PANI synthesis parameters (reagent flow rates, reactor pressure, substrate temperature, saturation pressure), the reaction and diffusion rates can be carefully controlled to optimally coat the CDC electrode. By flowing vapors of aniline and antimony pentachloride (a strong oxidizer), a solid thin PANI film can be polymerized on a substrate. FTIR, UV-vis, and XPS confirm that oCVD produces the electrochemically active emeraldine state of PANI. The pore distribution of the CDC electrode, as determined by N2 sorption, remains mostly unchanged before and after coating because the fine oCVD control over film thickness allows the pores to be coated without filling them, thereby maintaining the electrochemical double layer of the intrinsic carbon electrode while imparting additional energy density through Faradaic redox reactions from PANI. In this work, we demonstrate that charge storage capacity can be improved significantly through the integration of ultrathin (<30 nm) polyaniline (PANI) films into bimodal mesoporous Mo2C-derived carbide derived carbon (CDC, 800 °C synthesis temperature) electrodes using a single-step oCVD process. The ultrathin coating preserves to a large extent the native electrode surface area and pore distribution while simultaneously improving capacitance. The oCVD process allows PANI to be integrated into pores as small as 1.7 nm, and the oCVD PANI integrated supercapacitors have a specific capacitance more than 100% higher than that of bare CDC ones (136 F/g for 11 wt% of PANI in the CDC electrode vs. 60 F/g for bare CDC at 10 mV/s). This yields a PANI-only capacitance of ~690 F/g, which is close to the theoretical value of 750 F/g [6]. Even after high scan rates of over 100 mV/s, the added pseudocapacitance from PANI remains evident (Figure 1). The composite device exhibits excellent cyclability, lowering to only 90% of the initially stabilized value (~100 F/g) after 10,000 cycles. To our knowledge, this work is the first reported synthesis of PANI via oCVD and demonstrates oCVD’s advantages compared to other approaches in the integration of ultrathin PANI films into carbon supercapacitors. Figure 1. Left: oCVD process where the oxidant (SbCl5, orange) and monomer (aniline, green) vapors enter the reaction chamber and surface polymerize onto the electrode. Middle: A comparison of the cyclic voltammograms for both bare (red) and polyaniline (PANI) (green) electrodes at 20 mV/s. Inset shows SEMS of bare and PANI-coated CDC electrodes. Right: Rate performance of both devices based on cyclic voltammetry. [1] A. Laforgue, P. Simon, C. Sarrazin, J.-F. Fauvarque, Journal of Power Sources, 80 (1999) 142-148. [2] D.Y. Liu, J.R. Reynolds, ACS Applied Materials & Interfaces, 2 (2010) 3586-3593. [3] A. Rudge, I. Raistrick, S. Gottesfeld, J.P. Ferraris, Electrochimica Acta, 39 (1994) 273-287. [4] S. Nejati, T.E. Minford, Y.Y. Smolin, K.K.S. Lau, ACS Nano, 8 (2014) 5413-5422. [5] P. Simon, Y. Gogotsi, Nature Materials, 7 (2008) 845-854. [6] G.A. Snook, P. Kao, A.S. Best, Journal of Power Sources, 196 (2011) 1-12. Figure 1

Removal of cobalt from aqueous solution containing EDTA under UV-C irradiation by antimony oxide

Abstract Antimony oxide was synthesized by a simple method involving the mixing of 6 M HCl and antimony pentachloride, adjusting the synthesis pH with 25% ammonia. The obtained material was characterized using X-ray diffraction, field emission scanning electron microscopy, and surface area and pore size analysis. The material structure resembled that of Sb6O13. The cobalt sorption efficiency of the synthesized antimony oxide was tested in the dark and under UV-C irradiation. The 0.01 M NaNO3 test solution contained varying concentrations of Co2+ and EDTA and was traced with 57Co. The cobalt concentration in the solutions was determined by gamma spectroscopy. The synthesized material proved to have a high cobalt uptake. In the presence of 20 μM EDTA, 99.7% of cobalt was removed from the solution after 2 h of UV-C irradiation.

Synthesis, characterisation and electrochemical evaluation of reduced graphene oxide modified antimony nanoparticles

This paper demonstrates some aspects on the synthesis and characterisation of nanoparticles of metallic alloys using polyvinyl alcohol as a stabiliser, which combines high surface area and superior hybrid properties. The present experimental design was to synthesise a nanocomposite of reduced graphene oxide and antimony nanoparticles to be used as thin films for macro- and micro-carbon electrodes for enhancing sensing of different toxic metal pollutants in the environment. The synthetic process of reduced graphene oxide was done using the modified Hummers method while antimony pentachloride was reduced with sodium borohydride into nanoparticles of antimony using polyvinyl-alcohol as a stabiliser. The systematic investigation of morphology was done by scanning electron microscopy and high resolution-transmission electron microscope, which revealed the synthesis of a product, consists of reduced graphene oxide antimony nanoparticles. The electrochemical behaviour of the reduced graphene oxide antimony nanoparticles coated on a glassy carbon electrode was performed using voltammetric and impedance techniques. Electrochemical impedance measurements showed that the overall resistance, including the charge–transfer resistance, was smaller with reduced graphene oxide antimony nanoparticles than reduced graphene oxide and antimony nanoparticles, on their own. Evaluation of the reduced graphene oxide antimony nanoparticle sensor in the stripping voltammetry has shown a linear working range for concentration of platinum (II) between 6.0×10−6–5.4×10−5μgL−1 with limit of detection of 6×10−6μgL−1 (signal-to-noise ratio=3), which is below the World Health Organisation guidelines for freshwater.

Adsorption characteristics of strontium on synthesized antimony silicate

Radioactive strontium (90Sr) is one of the major contaminants in low-level radioactive wastewaters from nuclear power plants. Antimony silicate is regarded as a selective inorganic adsorbent for 90Sr removal. In this paper, a safe method was developed to prepare antimony silicate adsorbents. In the synthetic process, stable and low-toxic antimony trichloride (SbCl3) was used as an antimony source instead of volatile antimony pentachloride (SbCl5). Besides an Sb-rich phase with well-crystalized pyrochlore structure, an Si-rich phase with amorphous structure can be detected, which may facilitate strontium adsorption due to its large specific surface area. The batch experiments demonstrate that the synthesized material can offer a favorable adsorption of Sr(II) over a broad pH range of 1.2–11 and a wide concentration range of co-existing ions. The highest Kd value amounts to nearly 108mL/g at an Si/Sb ratio of 2.9. Calcium ions have a significant negative influence on strontium adsorption. The Kd value drops to 102mL/g at a Ca2+ concentration of 0.1M. The kinetic performance of Sr(II) adsorption onto antimony silicate follows the pseudo-second-order model and the adsorption isotherms coincide well with the Freundlich model. Moreover, the thermodynamic study reveals that the adsorption is an endothermic and spontaneous process.

Complexes of Antimony(III)

Lewis acidity of antimony(III) halides and their organo substituted derivatives is well known. The molecules SbX3 are good acceptor and a wide range of neutral complexes have been prepared but it seems antimony trichloride is a weak acceptor as compared to antimony pentachloride. The halide complexes are more interesting because of the part played by the lone pair in determining the stereochemistry where 1:1 complexes have trigonal bipyramidal and 1:2 complexes have square pyramidal configurations. Complexes of antimony trichloride with aromatic hydrocarbon are also known but the presence of organic group in a molecule reduces its capacity to form complexes.DOI: http://dx.doi.org/10.3126/av.v4i0.12357Academic Voices Vol.4 2014: 45-48

Structural, spectroscopic and computational examination of the dative interaction in constrained phosphine-stibines and phosphine-stiboranes.

A series of phosphine-stibine and phosphine-stiborane peri-substituted acenaphthenes containing all permutations of pentavalent groups -SbCln Ph4-n (5-9), as well as trivalent groups -SbCl2 , -Sb(R)Cl, and -SbPh2 (2-4, R=Ph, Mes), were synthesised and fully characterised by single crystal diffraction and multinuclear NMR spectroscopy. In addition, the bonding in these species was studied by DFT computational methods. The P-Sb dative interactions in both series range from strongly bonding to non-bonding as the Lewis acidity of the Sb acceptor is decreased. In the pentavalent antimony series, a significant change in the P-Sb distance is observed between -SbClPh3 and -SbCl2 Ph2 derivatives 6 and 7, respectively, consistent with a change from a bonding to a non-bonding interaction in response to relatively small modification in Lewis acidity of the acceptor. In the Sb(III) series, two geometric forms are observed. The P-Sb bond length in the SbCl2 derivative 2 is as expected for a normal (rather than a dative) bond. Rather unexpectedly, the phosphine-stiborane complexes 5-9 represent the first examples of the σ(4) P→σ(6) Sb structural motif.

Oxidative Chemical Vapor Deposition (oCVD) Synthesis of Ultrathin Polythiophene Films for Enhanced Charge Storage in Nanostructured Devices

Significant enhancement of charge storage capacity has been found with the integration of ultrathin unsubstituted polythiophene into porous nanostructured materials using oxidative chemical vapor deposition (oCVD). Through a single step process, conformal coatings have been successfully integrated into the porous nanostructure of anodized aluminum oxide, titanium dioxide, and activated carbon. The ultrathin coatings preserve the surface area and pore space of these nanostructures while simultaneously improving capacitance (Figure 1). Activated carbon integrated with ultrathin polythiophene yields a pseudocapacitor with 50% and 250% improvement in specific and volumetric capacitance compared to bare activated carbon. Capacitance decreased by only 10% over 5000 tested cycles (Figure 2).Utilizing conducting polymers as the active material for supercapacitors is a novel approach which has recently shown much promise1-3. Conducting polymers have been shown to have high specific capacity, high energy density, and promising stability. Furthermore, they are less costly than oxide-based materials and have the ability to be p and n- doped. Moreover, conducting polymers enhance charge capacity through Faradaic redox reactions. As stated by Simon and Gogotsi, the integration of ultrathin pseudocapacitive materials within porous carbon nanostructures could result in significant improvement in energy density and power density that can deliver both battery-like (high capacity) and capacitor-like (high rate) behavior in a single electrode4.Conducting polymers are sometimes deposited via liquid techniques. However the high porosity and tortuosity of nanostructured devices pose many challenges for integrating ultrathin coatings. Utilizing oCVD allows one to bypass the challenges associated with liquid methods and effectively integrate ultrathin polymer conformally inside nanostructured devices with high porosity and tortuosity. oCVD is a solvent free method where the reagents for oxidative polymerization, the monomer and oxidizer, are heated to a vapor that can easily penetrate into the mesoscale pore and polymerize. One advantage of oCVD is the ability to integrate intractable and insoluble conducting polymers such as unsubstituted polythiophene, which is a challenging conjugated polymer to work with as chains longer than eight repeat units are practically insoluble and processing of this polymer is very difficult. By flowing vapors of thiophene and antimony pentachloride (a strong oxidizer), a solid thin film polymer can be polymerized on a substrate. This step-growth mechanism is believed to follow an oxidative mechanism that allows the dehydro-coupling of heterocyclic rings. Simultaneously, the deposited polymer is doped to its conductive form with counter-ions like chloride that are contributed by the oxidant. By understanding the oCVD polythiophene synthesis parameters (reagent flow rates, reactor pressure, substrate temperature, saturation pressure), we were able to control the polymer conjugation length and the film electrical conductivity.We attribute the charge capacity enhancement to come from both additional faradaic contributions and double layer capacitance of the polythiophene rather than solely from an electrical double layer – the bare TiO2 nanostructure had negligible measurable capacitance while the coated TiO2 nanostructure had significant charge capacity (Figure 1). For coatings on activated carbon, at a polymer-to-activated carbon mass ratio of ~1.5, specific capacitance reaches a maximum value ~50% higher than that for bare activated carbon, 145 vs. 92 F/g. This capacitance translates to over a 250% increase in volumetric capacitance since the volume contribution of the ultrathin polymer coating is negligible (120 vs. 47 F/cm3).

Binuclear Oxidative Addition of Sb–Cl Bonds: A Facile Synthetic Route to Main Group–Transition Element Clusters and Rings

Binuclear oxidative addition of Sb–Cl bonds with the clusters Os3(CO)11(NCCH3), 1, or Os3(CO)10(NCCH3)2, 2, was found to be an effective synthetic route to organometallic clusters and rings containing μ2-SbPh2 or μ3-SbPh moieties. Thus, the reaction of SbPh2Cl with 1 afforded the tetranuclear ring Os3(CO)11(Cl)(μ-SbPh2), 3, while its reaction with 2 afforded the pentanuclear ring Os3(CO)10(Cl)2(μ-SbPh2)2, 6. In each case, two or three isomeric products were isolated depending on the reaction conditions. The analogous reaction of SbPhCl2 with 1, on the other hand, afforded the spiked triangular cluster Os3(CO)11(Cl)2(μ3-SbPh), 7, which also existed as two isomers. Pathways for these reactions have been proposed, and the experimental and computational evidence presented.

Di-chlorido-(5,10,15,20-tetra-phenyl-porphyrinato-κ(4) N)anti-mony(V) hexa-chlorido-anti-monate(V).

The asymmetric unit of the title compound, [Sb(C44H28N4)Cl2][SbCl6], consists of one half of an anti­mony(V) tetra­phenyl­porphyrin complex cation and one half of an hexa­chlorido­anti­monate(V) anion. In the complex cation, the SbV atom lies on an inversion center and is octa­hedrally coordinated by four N atoms from a macrocyclic tetra­phenyl­porphyrinate ligand and two chloride ions. The complex cation has approximately a planar core with a maximum deviation of 0.018 (5) Å from the porphyrin mean plane. The average Sb—N distance is 2.062 (11) Å, while the Sb—Cl distance is 2.355 (1) Å. The SbV atom of the anion is also located on an inversion center. The [SbCl6]− octa­hedron exhibits rhombic distortion characterized by the Sb—Cl bond lengths [2.311 (3), 2.374 (2) and 2.393 (4) Å]. In the crystal, the cations and anions are linked C—H⋯ Cl hydrogen bonds, forming a layer parallel to (211).

Proton exchange membrane fuel cell of polybenzimidazole electrolyte doped with phosphoric acid and antimony chloride

Abstract The proton conductivity of phosphoric acid (PA) doped polybenzimidazole (PBI) membrane is improved through imbibing antimony pentachloride before doping PA. The antimony involvement diminishes the temperature dependence of proton conductivity in the targeted temperature range 160–260 °C. Among the compositions being prepared, the most conductive one exhibits 8.08 × 10−2 S cm−1 at 180 °C, with a small temperature sensitivity 6.3 × 10−5 S cm−1 °C−1. Several membrane-electrode assemblies (MEAs) have been prepared with the Pt/C catalyst layers to evaluate the practicality of co-doped PBI membrane. After proper activation, the hydrogen/air cell generates substantial electric power, denoted by its peak value over 500 mW cm−2 at 180 °C. Impedance analysis indicates carbon monoxide poisoning affects overall MEA kinetics, as evidenced in the rising resistances of electrolyte, cathode, and anode. But the poisoned performance due to 3% CO/H2 fuel can be rejuvenated after the fuel is switched back to pure hydrogen in one or two hours.

Analysis of Carotenoid Production by Halorubrum sp. TBZ126; an Extremely Halophilic Archeon from Urmia Lake.

Carotenoids are of great interest in many scientific disciplines because of their wide distribution, diverse functions and interesting properties. The present report describes a new natural source for carotenoid production. Halorubrum sp., TBZ126, an extremely halophilic archaeon, was isolated from Urmia Lack following culture of water sample on marine agar medium and incubation at 30 °C. Then single colonies were cultivated in broth media. After that the cells were collected and carotenoids were extracted with acetone-methanol (7:3 v/v). The identification of carotenoids was performed by UV-VIS spectroscopy and confirmed by thin layer chromatography (TLC) in the presence of antimony pentachloride (SbCl5). The production profile was analyzed using liquid-chromatography mass spectroscopy (LC-MS) techniques. Phenotypic characteristics of the isolate were carried out and the 16S rRNA gene was amplified using polymerase chain reaction (PCR). LC-MS analytical results revealed that produced carotenoids are bacterioruberin, lycopene and β-carotene. Bacterioruberin was found to be the predominant produced carotenoid. 16S rRNA analysis showed that TBZ126 has 100% similarity with Halorubrum chaoviator Halo-G*T (AM048786). Halorubrum sp. TBZ126, isolated from Urmia Lake has high capacity in the production of carotenoids. This extremely halophilic archaeon could be considered as a prokaryotic candidate for carotenoid production source for future studies.

Complexes of different nitrogen donor heterocyclic ligands with SbCl3 and PhSbCl2 as potential antileishmanial agents against SbIII-sensitive and -resistant parasites

Novel trivalent antimony complexes with the nitrogen donor heterocyclic ligand 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen) or dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq) have been synthesized by the reaction with SbCl3 or PhSbCl2. The crystal structures of [Sb(phen)Cl3] and [PhSb(phen)Cl2]CH3COOH were determined and shown to adopt a distorted square pyramid geometry with a five-coordinated Sb center. Surprisingly, all the complexes, the ligands and PhSbCl2 showed very high antileishmanial activities, with IC50 in the nanomolar range against SbIII-sensitive and -resistant Leishmania infantum (syn. Leishmania chagasi) and Leishmania amazonensis strains. These compounds were much more active against these Leishmania strains than the old trivalent drug potassium antimonyl tartrate. [PhSb(phen)Cl2]CH3COOH complex was found to be the most active compound and the lack of cross-resistance of PhSbCl2 suggests that the transport pathways of this compound across the cell membrane differ from those responsible for the resistance of Leishmania to Sb(OH)3. In the case of the complexes with PhSbCl2, our data supports the model that both ligand and metal contributed to the overall activity of the complex. Furthermore, among the complexes with SbCl3, only bipy showed an improved activity upon complexation. Cytotoxicity evaluations of these compounds against murine peritoneal macrophages showed high selective indexes in the range of 7–70 for [Sb(phen)Cl3], [Sb(bipy)Cl3] and [Sb(dpq)Cl3] complexes, being much more selective than potassium antimonyl tartrate. In conclusion, this study presents a set of new antileishmanial agents including one of the most active Sb-based compounds ever reported, which can contribute to the development of new chemotherapeutic strategies against leishmaniasis including Sb-resistant cases.

ChemInform Abstract: Antimony(V) Chloride as an Efficient Reagent for Deprotection of Methyl Ethers.

This paper proposes a new and efficient method for the deprotection of methyl ethers using antimony pentachloride at ambient temperature. The procedure described here is a facile and practical method for the removal of the methyl group from aryl and benzyl methyl ethers. High selectivity was observed for the removal of the methyl group from dimethoxyarenes. The notable advantages of this protocol are mild reaction conditions, high yields, and the ­facility of workup procedure. The mechanism of the ether cleavage is proposed to explain this new reaction.

SULFENYL HALIDES IN THE SYNTHESIS OF HETEROCYCLES. 4. HETEROCYCLIZATION IN REACTIONS OF ALKENES WITH SULFENYLATING REAGENTS BASED ON DI(2-PYRIDYL) DISULFIDE

Sulfenylating reagents have been obtained by the action of sulfuryl chloride or antimony pentachloride on di(2-pyridyl) disulfide. Their interaction with alkenes proceeds as addition-cyclization with ring closure by the nitrogen atom of the pyridine fragment of the sulfur-containing electrophile with the formation of 2,3-dihydro[1,3]thiazolo[3,2- a ]pyridinium derivatives. Authors: A. V. Borisov, Zh. V. Matsulevich, V. K. Osmanov, G. N. Borisova, G. Z. Mammadova, A. M. Maharramov, and V. N. Khrustalev. English Translation in Chemistry of Heterocyclic Compounds , 2012, 48 (7), pp 1098-1104 http://link.springer.com/article/10.1007/s10593-012-1104-1

CYCLOADDITION OF DI(2-PYRIDYL) DITELLURIDE TO NORBORNENE STIMULATED BY ANTIMONY PENTACHLORIDE

The interaction of norbornene with the di(2-pyridyl) ditelluride–antimony pentachloride system in methylene chloride proceeds with the formation of exo -9-telluro-3-azoniatetracyclo-[9.2.1.0 2.10 .0 3,8 ]tetradeca-3(8),4,6-triene chloroantimonates(III), which are the products of polar cycloaddition of tellurium-containing electrophiles at the multiple bond. The structure of the heterocyclization products was established by X-ray structural analysis. Authors: A. V. Borisov, Zh. V. Matsulevich, V. K. Osmanov, G. N. Borisova, G. Z. Mammadova, A. M. Maharramov, and V. N. Khrustalev. English Translation in Chemistry of Heterocyclic Compounds , 2012, 48 (7), pp 1085-1089 http://link.springer.com/article/10.1007/s10593-012-1103-2

Synthesis, spectroscopic characterization and DNA cleavage studies of dibutyltin(IV) complexes of bidentate Schiff bases

Reactions of di-n-butyltin(IV)dichloride with sodium salts of Schiff bases in tetrahydrofuran-benzene solution in 1:1 and 1:2 stoichiometry afforded complexes of the types [(n-Bu)2Sn(sb)Cl] and [(n-Bu)2Sn(sb)2], respectively, [where sb=Schiff bases: N-salicylidene-2-aminopyridine (sapH), N-salicylidene-2-methylaniline (o-smabH) and N-salicylidene-4-methylaniline (p-smabH)]. All these complexes which are colored solids and are soluble in common organic solvents were characterized by elemental (C, H, N, Cl and Sn) analysis and spectral [IR, (1H, 13C and 119Sn) NMR] and Mass studies. On the basis of spectroscopic studies plausible structures have been proposed. The DNA cleavage activity of these complexes has been studied by agarose gel electrophoresis method.

Photochemical Properties of Mono-, Tri-, and Penta-Cationic Antimony(V) Metalloporphyrin Derivatives on a Clay Layer Surface

Three types of mono-, tri-, and penta-cationic antimony(V) porphyrin derivatives (Sb(V)Pors) were synthesized, and their photochemical properties on the anionic clay were systematically investigated. Sb(V)Por derivatives are dihydroxo(5,10,15,20-tetraphenylporphyrinato)antimony(V) chloride ([Sb(V)(TPP)(OH)2](+)Cl(-)), dihydroxo[5,10-diphenyl-15,20-di(N-methyl-pyridinium-4-yl)porphyrinato]antimony(V) trichloride ([Sb(V)(DMPyP)(OH)2](3+)3Cl(-)), and dihydroxo[5,10,15,20-tetrakis(N-methyl-pyridinium-4-yl)porphyrinato]antimony(V) pentachloride ([Sb(V)(TMPyP)(OH)2](5+)5Cl(-)). The photochemical behaviors of three cationic Sb(V)Pors with and without clay were examined in aqueous solution. For all Sb(V)Por, aggregation behaviors were not observed in the clay complexes even at high density adsorption conditions. The transition probabilities and fluorescence quantum yields of Sb(V)Por showed a tendency to be increased by the complex formation with clay. The less cationic Sb(V)Por/clay complex showed the larger fluorescence quantum yield. The more cationic Sb(V)Por/clay complex showed the longer fluorescence lifetime. These effects of complex formation with clay on the photochemical properties of Sb(V)Pors were discussed using the molecular potential energy curves of the porphyrin ground state and excited state. It is concluded that two types of effects work in the Sb(V)Por/clay system: effect i (structure resembling effect) is that the most stable structure becomes relatively similar between the ground and excited states, mainly by hydrophobic interactions between the porphyrin molecule and the clay surface, and effect ii (structure fixing effect) is that sharpened potential energy curves of clay complexes can lead to the increase of activation energy for the internal conversion from excited state to a high vibration level of ground state, mainly by electrostatic interactions between cationic porphyrin and anionic clay. Like this, the unique effects of the clay surface on the photochemical behavior of dyes were observed and the mechanisms were rationally discussed.

Oxidation and reductive bromination of Bis(4-tert-butylphenyl)aminoxyl

One-electron oxidation of bis(4-tert-butylphenyl)aminoxyl with antimony pentachloride and bromine leads to the formation of oxoammonium salts with anions SbCl6− and Br3− respectively. The salt with the Br3− anion converted at heating into a mixture of bromodiphenylamines which formed also from the aminoxyl as a result of previously unknown reaction of three-electron reductive bromination. The mechanisms of these reactions were assumed.

Assigning Hapticity to Cyclopentadienyl Derivatives of Antimony and Bismuth

The chelating diamide [Me2Si{NAr}2]2– (Ar = 2,6-i-Pr2C6H3) has been used as an ancillary ligand in antimony and bismuth chemistry. In contrast to the monomeric antimony chloride compound Sb(Me2Si{NAr}2)Cl (1a), the bismuth derivative (1b) exists as a trimer in the solid state, linked by Bi···(arene) π-bonding and Bi···Cl interactions. Compounds 1a,b are used as an entry point into rare antimony and bismuth compounds incorporating Cp and Cp* ligands. Reactions of the chlorides with LiCp and KCp* afford the organometallic species E(Me2Si{NAr}2)(C5R5) (2a, R = H, E = Sb; 2b, R = H, E = Bi; 3a, R = Me, E = Sb; 3b, R = Me, E = Bi). Variable-temperature NMR experiments indicate different fluxional processes occur in solution involving facile haptotropic shifts of the [C5R5]− ring. Structural characterization of 2b and 3a,b reveals monomeric compounds in which the cyclopentadienyl-derived ligand adopts a low hapticity in the solid state.