A comparative study on acute toxicity of methylarsonic acid,dimethylarsinic acid and trimethylarsine oxide in mice

The acute toxicity of methylarsonic acid, CH₃AsO(OH)₂ (MAA), dimethylarsininc acid, (CH₃)₂AsO(OH) (DMAA), and trimethylarsine oxide, (CH₃)₃AsO (TMAO), were examined in mice with oral administration. The LD₅₀ values of MAA, DMAA and TMAO were 1.8, 1.2 and 10.6 g kg^?1 respectively. The toxicity of MAA and DMAA was very much lower than that for inorganic arsenic compounds. It was shown that TMAO has a similar acute toxicity to arsenobetaine. On the other hand, when the mice were administered 14.4 g kg^?1 of TMAO once only orally, a garlic-like odor (trimethylarsine, (CH₃)₃As) was definitely detectable in the exhalation of the animals by the human olfactory sense within about a few minutes.     

Condensation cascades and methylgroup transfer reactions during the formation of arsane,methyl- and dimethylarsane by aqueous borohydride and (methyl) arsenates

The formation of volatile products during the reaction of As(iii), As(v), MeAsO(OH)₂, and Me₂AsO(OH) with aqueous NaBH₄ has been investigated, and the formation of arsanes, diarsanes, and triarsanes has been detected. The presence of triarsanes is reported here for the first time. Diarsanes and triarsanes are likely formed in condensation cascade reactions, whereas trimethylarsane arises via the transfer of a methyl group. The formation of volatile by-products is considerably reduced by increasing the acidity of the medium and the concentration of NaBH₄ or by the addition of thiols, such as cysteine. A reaction scheme is proposed which reconciles the evidence reported herein and elsewhere in the literature that is valid for both analytical (trace analysis) and non-analytical reaction conditions.     

Raman and infrared spectroscopic investigation of alkyl derivatives of arsenic acid: Part VI. On the AsO-bond - calculation of force constants and vibrational energy distribution in compounds of the type RAsO3X2 And R2A

Normal coordinate analyses and force constant calculations were carried out using frequencies of infrared and Raman-spectra of the molecules and ions RAsO₃^2?, RAs(O)(OR)₂, RAs(O)(OH)₂, RAs(OH)O₂^?, RzAsO₂^?, R₂As(O)OH, and [R'₂As(OH)₂]⁺ (R = CH₃, R' = C₂H₅). Comparing bond orders of the AsO bond with those in corresponding phosphorus, selenium and sulphur compounds, we found influences of the electron deficiency effect and of bond polarity.     

Alternativ-Liganden. XXV. Neue Chelatliganden des Typs Me2ESiMe2(CH2)2E′Me2 (E=P,As; E′=N,P, As)

Alternative Ligands. XXV. New Chelating Ligands of the Type Me₂ESiMe₂(CH₂)₂E′Me₂ (E=P, As; E′=N, P, As) Chelating ligands of the type Me₂EsiMe₂(CH₂)₂E′ Me₂, have been prepared by the following routes: Starting from Me₂Si(Vi)Cl, the compounds with E=N and E′ =N ( 1 ), P ( 2 ), As ( 3 ) are obtained in yields of 65 to 78% by aminolysis to yield Me₂NSiMe₂Vi, followed by the LiE′ Me₂ catalyzed addition of He′Me₂ to the vinyl group. The intermediates ClSiMe₂(CH₂)E′Me₂ [E′=N ( 4 ), P ( 5 ), As ( 6 )] are produced by the reactions of 1 to 3 with PhPCl₂. 5 and 6 can be prepared in a purer form by the photochemical addition of HPMe₂ and HAsMe₂, respectively, to the vinyl group of Me₂Si(Vo)Cl. 4 to 6 react with LiEMe₂, in situ prepared from n-BuLi and HEMe₂, to yield the ligands Me₂ESiMe₂(CH₂)₂E′Me₂ ( 7–12 ) (E=P, As; E′=N, P, As). The new compounds have been characterized by analytical and spectroscopic investigations (NMR, MS).     

Destruktive Komplexierung des dimeren Diorganylzinn(IV)‐hydroxids [Me2Sn(A)(μ‐OH)]2 (HA = Benzol‐1,2‐disulfonsäureimid): Bildung und Strukturen der Einkernkomplexe [Me2Sn(A)2(OPPh3)2] und [Me2Sn(phen)2]2⊕ · 2 A⊖ · MeCN

Polysulfonylamines. CXVI. Destructive Complexation of the Dimeric Diorganyltin(IV) Hydroxide [Me₂Sn(A)(μ‐OH)]₂ (HA = Benzene‐1,2‐disulfonimide): Formation and Structures of the Mononuclear Complexes [Me₂Sn(A)₂(OPPh₃)₂] and [Me₂Sn(phen)₂]^2⊕ · 2 A^⊖ · MeCN Destructive complexation of the dimeric hydroxide [Me₂Sn(A)(μ‐OH)]₂, where A^⊖ is deprotonated benzene‐1,2‐disulfonimide, with two equivalents of triphenylphosphine oxide or 1,10‐phenanthroline in hot MeCN produced, along with Me₂SnO and water, the novel coordination compounds [Me₂Sn(A)₂(OPPh₃)₂] ( 3 , triclinic, space group P 1) and [Me₂Sn(phen)₂]^2⊕ · 2 A^⊖ · MeCN ( 4 , monoclinic, P2₁/c). In the uncharged all‐trans octahedral complex 3 , the heteroligands are unidentally O‐bonded to the tin atom, which resides on a crystallographic centre of inversion [Sn–O(S) 227.4(2), Sn–O(P) 219.6(2) pm, cis‐angles in the range 87–93°; anionic ligand partially disordered over two equally populated sites for N, two S and non‐coordinating O atoms]. The cation occurring in the crystal of 4 has a severely distorted cis‐octahedral C₂N₄ coordination geometry around tin and represents the first authenticated example of a dicationic tin(IV) dichelate [R₂Sn(L–L′)₂]^2⊕ to adopt a cis‐structure [C–Sn–C 108.44(11)°]. The five‐membered chelate rings are nearly planar, with similar bite angles of the bidentate ligands, but unsymmetric Sn–N bond lengths, each of the longer bonds being trans to a methyl group [ring 1: N–Sn–N 71.24(7)°, Sn–N 226.81(19) and 237.5(2) pm; ring 2: 71.63(7)°, 228.0(2) and 232.20(19) pm]. In both structures, the bicyclic and effectively C_S symmetric A^⊖ ions have their five‐membered rings distorted into an envelope conformation, with N atoms displaced by 28–43 pm from the corresponding C₆S₂ mean plane.     

Synthese „anorganischer”︁ Tintenfisch-Moleküle. II

Synthesis of “Inorganic” Pode-type Molecules. II The reaction of the amino compounds Me_yB? NMe₂ (B ? As, y ? 2; B ? Si, y ? 3) with 1, n-dioles results in the formation of the compounds HO(CH₂)_nOBMe_y. These compounds can be used as the arms of pode-type molecules Me_xA[? O(CH₂)_nOBMe_y]_z with A ? Si, As. The influence of A, B, n, and z in the rearrangement of these molecules is examined. A second type of pode molecules can be prepared by the reaction of Me₂As? R? OH (R ? CH₂CH₂, CH₂CH₂(OCH₂CH₂)₂) with the amino compounds Me_x(NMe₂)_z (A ? As, Si). These reactions result in the formation of molecules as Me_xA(ORAsMe₂)_z.     

Kinetics and mechanism of distribution of Am(III) and Eu(III) between thenoyltrifluoroacetone-triphenylarsine oxide mixture in chloroform and aqueous nitrate medium

The kinetics of distribution of Am(III) and Eu(III) between thenoyltrifluoroacetone (HTTA) and triphenylarsine oxide (Ph₃AsO) mixture in chloroform and aqueous nitrate medium has been investigated using a stirred Lewis cell at ionic strength of 0.1M. The effect of the concentration of HTTA, Ph₃AsO, H⁺ and NO ₃ ^– on the rate of distribution of Am(III) and Eu(III) was studied. The results were interpreted by reaction mechanisms where the rate-determining steps are the parallel reactions of Am(OH)²⁺ or Eu(OH)²⁺ with one HTTA molecule and one Ph₃AsO molecule in the aqueous medium. The values at 25 °C of the rate constantk _HLL (HL=HTTA andL=Ph₃AsO) are 1.6±0.3·10⁶M^–2·s^–1 and 2.3±±0.3·10⁸M^–2·s^–1 for Am(III) and Eu(III), respectively.     

Reaktive E=C(p‐p)π‐Systeme. 54 [1] Reaktionen des Perfluor‐2‐arsapropens,F3CAs=CF2 (1), mit H‐aciden Verbindungen Me2EH (E = N,P, As) und MeE′H (E′ = O,S, Se)

Reactive E=C(p‐p)π‐Systems. 54 [1] Reactions of perfluoro‐2‐arsapropene, F₃CAs=CF₂ (1), with H‐acidic compounds Me₂EH (E = N, P, As) and MeE′H (E′ = O, S, Se) The reactions of the perfluoro‐2‐arsapropene ( 1 ) with H‐acidic compounds Me₂EH (E = N, P, As) and MeE′H (E′ = O, S, Se), respectively, proceed via addition to the As=C double bond yielding either secondary arsanes F₃C(H)AsCF₂X (X = NMe₂, PMe₂, OMe, SMe) or AsX derivatives (X = AsMe₂, SeMe). Me₂‐AsH is obviously a border case nucleophile because, besides the AsX derivative as main product, small amounts of the arsane are formed indicative for the reverse addition pathway. With the strong base Me₂NH, the addition is followed immediately by HF elimination producing the fairly stable arsaalkene F₃CAs=C(F)NMe₂ ( 4 ) which had already been obtained by reaction of HAs(CF₃)₂ with three equivalents of Me₂NH. The novel rather labile compounds were identified by spectroscopic (NMR, GC/MS) investigations. – Quantum chemical DFT calculations [B3LYP/6‐311+G(d,p)] were carried out to determine the relative energy of the isomeric products and the thermodynamics of the addition reactions.     

The Other Face of Bunsen's Cacodyl Disulfide,Me2As(S)‐S‐AsMe2: The Lewis‐Base Behaviour Towards Heavy Metal Cations

The reaction of Bunsen's cacodyl disulfide, Me₂As(S)‐S‐AsMe₂, with heavy metal cations in methanol produces insoluble salts (complexes) of dimethyldithioarsinic acid, Me₂AsS₂H, and dimethyl arsenium ion, Me₂As:⁺. This arsenium ion prefers to react with Me₂As(S)‐S‐AsMe₂, when in excess, compared to AcO^? or MeOH/H₂O and it is also reactive towards sulfur (S_x, x = 1‐8) producing the stabilized dimethylarsino sulfenium cation, . The complexes (Me₂AsS₂)_xM (x = 1 or 2) are unstable in the presence of their own heavy metal cations decomposing to colored solids. In an attempt to prepare salts of Me₂AsSH, the reactions of (Me₂AsS₂)_xM with triphenylphosphine and trimethyl phosphite gave the metal sulfide and Me₂As‐S‐AsMe₂ instead.     

Phosphino[tris(trimethylsilyl)methyl]Boranes and 2,4‐Bis[tris(trimethylsilyl)methyl]‐1,3,2,4‐diphosphadiboretanes [1]

The reaction of tris(trimethylsilyl)methylboron dihalides (Me₃Si)₃CBX₂ (X = Cl, F) with the lithium phosphides LiPHtBu and LiPHmes leads to the phosphinoboranes (Me₃Si)₃CBX‐(PHR), (Me₃Si)₃CB(PHR)₂ or the 1,3,2,4‐diphosphadiboretanes [(Me₃Si)₃CB(PR)]₂, depending on the ratio of the reagents, the reaction temperature and concentration. High dilution and low temperatures are required for the synthesis of (Me₃Si)₃CB(Hal)PHR ( 1–3 ) in order to prevent the formation of (Me₃Si)₃CB(PHR)₂ ( 4 and 5 ). The latter compounds are best prepared in a two step phosphination from (Me₃Si)₃CBHal₂ and LiPHR. At higher temperatures the four‐membered 1,3,2,4‐diphosphadiboretanes [(Me₃Si)₃CB(PR)]₂ 6 and 7 are the most stable compounds. On the other hand, compounds of type (Me₃Si)₃CB(Hal)PR₂, 8 and 9 , are thermally more stable than the monophosphinoboranes 1 – 3 . Phosphinoboranes of type (Me₃Si)₃CB(PR₂)₂ (R = tBu, mes) could not be prepared. NMR and mass spectral data are in accord with the monomeric nature of compounds 1 to 9 .     

Tetramethylcyclotetraarsoxane Bridging of Copper(I) Halide Units Cu6Br6, Cu2I2, [Cu6I8]2–, and [Cu3I4–] in Porous Coordination Polymers

The polymeric compounds [{Cu₂I₂(C₆H₅CN)₂[cyclo‐(CH₃AsO)₄]} · C₆H₅CN] ( 1 ) and [Cu₆Br₆(C₆H₅CN)₄{cyclo‐(CH₃AsO)₄}] ( 2 ) may be prepared by reaction of the copper(I) halide with methylcycloarsoxane (CH₃AsO)_n in benzonitrile at 100 °C. 1 contains four‐membered (CuI)₂ rings, 2 tricyclic Cu₆Br₆ units, that are connected through bridging (CH₃AsO)₄ ligands into infinite chains. π–π Stacking of terminal C₆H₅CN ligands from parallel chains leads to the construction of porous frameworks, whose cavities are large enough in the case of 1 to accommodate guest C₆H₅CN molecules. In the presence of CsI, the self‐assembly reaction of CuI with (CH₃AsO)₄ in H₂O–CH₃OH–CH₃CN (at 20 °C) or CH₃CN (at 130 °C) affords [Cs(H₂O)₂][Cu₃I₄{cyclo‐(CH₃AsO)₄}₂] · 0.5 CH₃OH ( 3 ) and Cs[Cu₃I₄{cyclo‐(CH₃AsO)₄}₂] ( 4 ), whose 1‐ and 2‐dimensional anionic coordination polymers are linked together through respectively [Cs{cyclo‐(CH₃AsO)₄‐κ⁴O}₂]⁺ and [Cs{Cu₃I₄‐κ⁴I}{cyclo‐(CH₃AsO)₄‐κ⁴O}] sandwiches.     

Facile oxygenation of organic sulfides with H2O2 catalyzed by Mn-Me3TACN compounds

Two binuclear Mn-Me₃TACN (Me₃TACN is 1,4,7-N,N′,N″-trimethyl-1,4,7-triazacyclononane) compounds catalyze the oxygenation of organic sulfides utilizing H₂O₂ under ambient conditions. Both phenyl sulfide and ethyl phenyl sulfide were converted to the corresponding sulfones and chloroethyl phenyl sulfide proceeds to its elimination product of phenyl vinyl sulfone.     

Chemie Polyfunktioneller Molekülle: XCIX. Hydrolyse und oxidative Hydrolyse von Tetrakis[(diiodarsino) methyl]methan. Kristallstrukturanalyse eines Organoarsenoxid-Arsonigsäure-Derivats

Hydrolysis of C(CH₂AsI₂)₄ (V) gives the combined arsonous acid-organoarsenic oxide compound (HO)₂AsCH₂C(CH₂AsO)₃ (VIa). Boiling VIa with D₂O results in the formation of (DO)₂AsCH₂C(CH₂AsO)₃ (VIb). The crystal structure of VIb was solved by X-ray diffraction studies. Crystals and monoclinic, space group P2₁/c, with a 661.5(3), b 852.8(3), c 1922.4(4) pm, β 97.95(3)°, and Z = 4. Data collection yielded 3261 reflections, of which 2098 with I ≥ 3σ(I) gave R = 0.045. The molecule consists of a heteroadamantane, containing a six-membered As₃O₃ ring as basis, and a methylarsonous acid substituent in the bridgehead position. The solid state shows appreciable evidence for the existence of two different intermolecular AsOD ⋯ O bonding systems.Heating VIa gives the insoluble compound [C(CH₂AsO)₄]_n (VII) and water is eliminated. The oxidative solvolysis of V or VII with H₂0₂ results in the formation of C[CH₂AsO(OH)₂]₄ (VIII). Reduction of VIII with sulfur dioxide in methanol regenerates VIa.     

Oxidation of Alkenes and Sulfides with Transition Metal Catalysts

Alkenes and sulfides were oxidized with transition-metal catalysts. The oxidant sources include molecular dioxygen, air and iodosylbenzene. The metal ions Mn(III), Fe(III), Co(II) and Ni(II) were used. The Catalysts 1-18 of 1,3-dioxo-, β-ketoimine- or salen-types were prepared and their efficacy was examined. 1,2-Dihydronaphthalene is most efficiently epoxidized with O₂/Me₂CHCHO or PhIO in the presence of Mn(III)-salen catalysts. The Ni(II)-, Co(II)- and Fe(III)-catalysts of either β-ketoimine- or salen-types are useful for epoxidation of styrene, (E)-stilbene and (E)-benzalacetone in the O₂/Me₂HCHO system; these epoxidations are stereospecific without formation of corresponding diastereomeric epoxides. Oxidation of methyl p-tolyl sulfide with O₂/Me₂CHCHO is facilitated by the 1,3-dioxo-catalyst Co(II)-1. Monooxidation is achieved with Me₂CHCHO in equimolar proportions to give the corresponding sulfoxide, whereas overoxidation is realized with excess Me₂CHCHO to give the sulfone. These epoxidation and sulfide oxidations all occur at 25 °C and are complete in less than a day.     

Speciation and NMR Spectrometric Studies of Interaction of Di- and Tri-organotin(IV) Moieties with 5′-Guanosine Monophosphate and Guanosine in Aqueous Solution

Potentiometric studies of the interaction of (Me₂Sn)²⁺ and (Me₃Sn)⁺ with 5′-guanosine monophosphate [(5′-HGMP)^2?, abbreviated as (HL-1)^2?] and guanosine [(HGUO), abbreviated as (HL-2)] in aqueous solution (I = 0.1 mol·dm^?3 KNO₃, 298.15 ± 0.1 K) were performed, and the speciation of various complex species was evaluated as a function of pH. The species that exist at physiological pH ~7.0 are Me₂Sn(HL-1)/[Me₂Sn(HL-2)]²⁺ (87.0/88.8 %), [Me₂Sn(HL-1)(OH)]^?/[Me₂Sn(HL-2)(OH)]⁺ (3.0/0 %) and [Me₂Sn(HL-1H_?1)]/[Me₂Sn(HL-2H_?1)]²⁺ (9.4/6.6 %) for 1:1 dimethyltin(IV):5′-guanosine monophosphate/dimethyltin(IV): guanosine systems, whereas for the corresponding 1:2 systems, the species are Me₂Sn(HL-1)/[Me₂Sn(HL-2)]²⁺ (44.0/92.0 %), [Me₂Sn(HL-1H_?1)]/[Me₂Sn(HL-2H_?1)]²⁺ (5.0/6.0 %), Me₂Sn(OH)₂ (49.0/0 %), [Me₂Sn(HL-1)(OH)]^?/[Me₂Sn(HL-2)(OH)]⁺ (1.5/2.0 %), and [Me₂Sn(OH)]⁺ (1.0/0 %). For 1:1 trimethyltin(IV):5′-guanosine monophosphate/trimethyltin(IV):guanosine systems, only [Me₃Sn(HL-1)]^?/[Me₃Sn(HL-2)]⁺ (99.9 %) are found at pH = 7.0, whereas for 1:2 systems, [Me₃Sn(HL-1)]^?/[Me₃Sn(HL-2)]⁺ (49.8/100 %), Me₃Sn(OH) (15.0/0 %) and [Me₃Sn(HL-1)(OH)]^2?/Me₃Sn(HL-2)(OH) (0.2/0 %) are the species found. No polymeric species were detected. Beyond pH = 8.0, significant amounts of [Me₂Sn(OH)]⁺, Me₂Sn(OH)₂, [Me₂Sn(OH)₃]^? and Me₃Sn(OH) are formed. Multinuclear (¹H, ¹³C and ¹¹⁹Sn) NMR studies at different pHs indicated a distorted octahedral geometry for the species Me₂Sn(HL-1)/[Me₂Sn(HL-2)]²⁺ in dimethyltin(IV)-(HL-1)^2?/(HL-2) systems and a distorted trigonal bipyramidal/distorted tetrahedral geometry for the species [Me₃Sn(HL-1)]^?/[Me₃Sn(HL-2)]⁺ in trimethyltin(IV)-(HL-1)^2?/(HL-2) systems.     

Bifunctional decamethylcyclohexasilanes X<Subscript>2</Subscript>Si<Subscript>6</Subscript>Me<Subscript>10</Subscript> (X = Cl,H, or OH): molecular and crystal structures and mesomorphic properties

Isomer separation of mixtures, which were prepared by chlorination followed by transformations of dodecamethylcyclohexasilane (Me₂Si)₆ into bifunctional decamethylcyclohexasilanes X₂Si₆Me₁₀ (X = Cl, H, or OH), was carried out. As a result, mixtures of the corresponding 1,3- and 1,4-derivatives were separated to obtain structural isomers, and stereoisomers, viz., cis- and trans-1,4-dihydrocyclohexasilanes, were isolated in individual form. The molecular and crystal structures of the resulting bifunctional decamethylcyclohexanes X₂Si₆Me₁₀ (X = H or OH) and decamethyl-7-oxahexasilanorbornane were established by X-ray diffraction analysis. Bifunctional cyclohexasilanes form a mesophase as a plastic crystal. The temperature range of its existence was determined. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1566–1575, July, 2005.     

Ethylcycloarsoxan, (C2H5AsO)n,ein Ionophor mit anpassungsfähiger Ringgröße in den Alkalimetallkomplexen [Na{cyclo-(C2H5AsO)4}2]SCN und [K{cyclo-(C2H5AsO)5}2]SCN

Ethylcycloarsoxane, (C₂H₅AsO)_n, an Ionophore with Adaptable Ring-Size in the Alkali Metal Complexes [Na{cyclo-(C₂H₅AsO)₄}₂]SCN and [K{cyclo-(C₂H₅AsO)₅}₂]SCN Ethylcycloarsoxane, (C₂H₅AsO)_n, is an ionophore for alkali metal cations with adaptable ring-size, [Na{cyclo-(C₂H₅AsO)₄}₂]SCN ( 1 ) and [K{cyclo-(C₂H₅AsO)₅}₂]SCN ( 2 ) have been prepared by the reaction of (C₂H₅AsO)_n with MSCN (M = Na, K) in acetonitrile and characterised by X-ray structural analysis. The sodium atom in 1 is coordinated in an approximately quadratic-antiprismatic fashion by 8 oxygen atoms and displays Na? O distances in the range 2.516(5) and 2.662(5) Å. A virtually undistorted pentagonal-antiprismatic coordination geometry with K? O distances between 2.90(1) and 3.06(1) Å is observed for the potassium atom in 2 . As a result of the smaller diameter of the arsoxane rings the antiprisms in 1 and 2 are significantly stretched along their main axis in comparison to analogous crown ether complexes.     

Ubiquity of arsenobetaine in marine animals and degradation of arsenobetaine by sedimentary micro-organisms

Arsenic compounds were extracted with chloroform/methanol/water from tissues of marine animals (four carnivores, five herbivores, five plankton feeders). The extracts were purified by cation and anion exchange chromatography. Arsenobetaine [(CH₃)₃As⁺CH₂COO^?], dimethylarsinic acid [(CH₃)₂AsOOH], trimethylarsine oxide [(CH₃)₃AsO] and arsenite, arsenate, and methylarsonic acid [(CH₃)AsO(OH)₂] as a group with the same retention time were identified by high-pressure liquid chromatography. Arsenic was determined in the collected fractions by graphite furnace atomic absorption spectrometry. Arsenobetaine found in all the animals was almost always the most abundant arsenic compound in the extracts. These results show that arsenobetaine is present in marine animals independently of their feeding habits and trophic levels. Arsenobetaine-containing growth media (ZoBell 2216E; solution of inorganic salts) were mixed with coastal marine sediments as the source of microorganisms. Arsenobetaine was converted in both media to trimethylarsine oxide and trimethylarsine oxide was converted to arsenite, arsenate or methylarsonic acid but not to dimethylarsinic acid. The conversion rates in the inorganic medium were faster than in the ZoBell medium. Two dominant bacterial strains isolated from the inorganic medium and identified as members of the Vibro–Aeromonas group were incapable of degrading arsenobetaine.     

Synthesis,Characterization, Thermal,and Antibacterial Studies of Organotin(Iv) Complexes of Indole-3-Butyric Acid and Indole-3-Propionic Acid

Abstract

Six organotin(IV) complexes of type Me₂SnL₂, Bu₂SnL₂, and Ph₃SnL [where L = indole-3-butyric acid (1, 2 and 3) or indole-3-propionic acid (4, 5 and 6)] have been synthesized by the reactions of the corresponding diorganotin(IV) oxide and triphenyltin(IV) hydroxide with respective indole-3-butyric acid (IBH) or indole-3-propionic acid (IPH) in the desired molar ratios of 1:2/1:1. All of the compounds have been characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR, and ¹¹⁹Sn NMR spectroscopy. Thermal studies of all synthesized complexes have been carried out using thermogravimetry (TG) technique under a nitrogen atmosphere. The thermal decompositions for compounds Me₂SnL₂ and Bu₂SnL₂ occurred in two steps, whereas in compounds Ph₃SnL, it exhibited as three steps decomposition and resulted into the formation of pure SnO₂. The complexes were also screened against three gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, and Micrococcus luteus) and three gram-negative (Escherichia coli, Pseudomonas aeruginosa, and Enterobacter aerogenes) bacteria using minimum inhibition concentration (MIC) method, and all of these complexes showed significant antibacterial activity.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, tables, and figures.]     

Sulfide oxygenation by tert-butyl hydroperoxide with mononuclear (Me3TACN)Mn catalysts

Mononuclear (Me₃TACN)MnX₃ compounds, where X is Cl⁻, Br⁻, or N₃⁻, and Me₃TACN is 1,4,7-N,N′,N″-trimethyl-1,4,7-triazacyclononane, have been tested for catalyzing both sulfide oxygenation and styrene epoxidation by tert-butyl hydroperoxide (TBHP) and display turnover frequencies (TOF) up to 200 h⁻¹ at room temperature. Sulfoxides or sulfones may be produced selectively by varying reaction conditions. Product distribution from the oxygenation reactions of ethyl phenyl sulfide, 2-chloroethyl phenyl sulfide, and styrene is consistent with a mechanism involving an early single-electron transfer (SET) step.