Synthesis,optical properties,and photocatalytic activity of lanthanide-doped anatase

Quasi-one-dimensional (1D) Ti_{1 ? x} Ln _x O_{2 ? x/2} anatase solid solutions were prepared by heating Ti_{1 ? x} Ln _x (OCH₂CH₂O)_{2 ? x/2} precursors, where Ln = Nd, Eu, Tb, Er (x = 0.025), or Sm (0.005 ≤ x ≤ 0.025), in air. These solid solution were found to have a photocatalytic activity in hydroquinone oxidation in aqueous solution under exposure to UV radiation. UV-Vis absorption spectra were recorded for Ti_{1 ? x} Ln _x O_{2 ? x/2} (Nd, Sm, Eu, Tb, or Er). The electronic structure and optical absorption spectra were calculated for anatase doped with neodymium, samarium, or terbium.     

A high-yield synthetic approach to trans-[Ir(ER3)2(CO)X] (ER3=PMe3, PEt3, PPhMe2, PPh2Me,P(OMe)3, AsMe3, AsEt3, AsPh3, SbPh3; X=Cl,Br)

The complex [Ir(CO)₂X₂][NBu₄] (X=Cl, Br) forms Vaska-type complexes, trans-[Ir(ER₃)₂(CO)X], when treated with two equivalents of aryl- or alkyl-phosphines, arsines, or stibines under a CO atmosphere. The synthesis is general for a wide range of phosphines, arsines, or stibines irrespective of the cone angle. For small cone-angle ligands, the initial addition of ligand to [Ir(CO)₂X₂][NBu₄] is performed at low temperature. The synthesis and characterisation of three new Vaska-type complexes trans-[Ir(P(OMe)₃)₂(CO)Cl], trans-[Ir(AsMe₃)₂(CO)Cl], and trans-[Ir(AsEt₃)₂(CO)Cl] is also reported.     

Synthesis, structure, and biological evaluation of C-2 sulfonamido pyrimidine nucleosides

The C-2 sulfonamido pyrimidine nucleosides were prepared by opening the 2,2′- or 2,3′-bond in anhydronucleosides under nucleophilic attack of sulfonamide anions. Reaction of the sodium salt of p-toluenesulfonamide or 2-(aminosulfonyl)-N,N-dimethylnicotinamide with 2,2′-anhydro-1-(β-d-arabinofuranosyl)cytosine gave the C-2 sulfonamido derivatives in excellent yields. Ring opening of the less reactive 2,2′-anhydrouridine and 2,3′-anhydrothymidine could be accomplished with DBU/CH₃CN activation of p-toluenesulfonamide, giving moderate yields for C-2 sulfonamido derivatives. The action of acetic acid or ZnBr₂/CH₂Cl₂ on 5-methyl-N²-tosyl-1-(2-deoxy-5-O-trityl-β-d-threo-pentofuranosyl)isocytosine led to the cleavage of both the protection group and the nucleoside bond, yielding 5-methyl-N²-tosylisocytosine as the major product. Structures of the prepared C-2 sulfonamido nucleosides were confirmed by the 1D and 2D NMR experiments, and X-ray structural analysis of 4-imino-N²-tosylamino-1-(β-d-arabinofuranosyl)pyrimidine. Both methods confirmed β-configuration and anti-conformation of the 2-sulfonamido nucleosides. The investigated compounds displayed moderate inhibition of tumor cell growth in vitro, as determined by the MTT assay using six different human tumor cell lines.     

Darstellung von PdCl2-komplexen substituierter cis,cis-cycloocta-1,5-diene aussachtringen und den entsprechenden substituierten cis-1,2-divinylcyclobutanen. cis,trans-zuordnung 3,4-,3,7- und 3,8-disubstituierter cis,cis-cycloocta-1,5-diene

cis-1,2-Divinylcyclobutanes are transformed with dibenzonitrilepalladium(II) chloride into the corresponding cis,cis-cycloocta-1,5-diene-PdCl₂ complexes. When e.g. the 3-methyl-cis,cis-cycloocta-1,5-diene-PdCl₂ complex is prepared using trans- or cis-3-methyl-cis-1,2-divinylcyclobutane or the corresponding eight-membered ring. two PdCl₂ complexes with the methyl group in the equatorial or axial position are formed in different percentages. With the aid of ¹H NMR spectroscopy the cis- or trans-configurations of 3,4-, 3,7- or 3,8-disubstituted cis,cis-cycloocta-1,5-dienes can be determined unambiguously in PdCl₂ complexes.     

C,N-chelated hexaorganodistannanes, and triorganotin(IV) hydrides and cyclopentadienides

Triorganotin(IV) hydrides and cyclopentadienides as well as hexaorganodistannanes containing the moiety L^CN (2-(N,N-dimethylaminomethyl)phenyl-) as chelating ligand and phenyl, n-butyl or t-butyl substituents were prepared and characterized by NMR and XRD. The compounds reveal trigonal bipyramidal geometry around the central tin atom except for the distannanes in which the tin atom has tetrahedral configuration. The di-n-butyl distannane cannot be oxidized by oxygen or heavier chalcogens and give no tin radical when irradiated by UV light or treated with the TEMPO - free radical at room temperature. L^CN(t-Bu)₂SnH undergoes reaction in solution toward the corresponding distannane. The hydrostannation reaction of L^CN(n-Bu)₂SnH with ferrocenylacetylene was investigated. The CO₂ activation by L^CN(n-Bu)₂SnH was also examined.     

Excess molar enthalpies and excess molar heat capacities of (2-butanone + cyclohexane,or methylcyclohexane,or benzene,or toluene,or chlorobenzene,or cyclohexanone) atT = 298.15 K

Excess molar enthalpies of (2- butanone  +  cyclohexane, or methylcyclohexane, or toluene, or chlorobenzene, or cyclohexanone) and excess molar heat capacities of (2- butanone  +  benzene, or toluene, or chlorobenzene, or cyclohexanone) were measured atT =  298.15 K. Aliphatic systems were endothermic and the chlorobenzene system was exothermic. On the other hand, the toluene system changed sign to be S-shaped similar to the benzene system reported by Kiyohara et al. The values of excess molar enthalpies of the present mixtures were slightly larger than the corresponding mixtures of cyclohexanone already reported. Excess molar heat capacities of aromatic systems were characteristically S-shaped for the mixture containing aromatics. The values of the present mixtures were less than the corresponding mixtures of cyclohexanone. The mixture (2-butanone  +  cyclohexanone) was endothermic forH_m^E and negative for C_p,m^E.     

Modes of coordination of 1,2-aminothiols in organotin(IV) complexes,as demonstrated by 119Sn, 15N and 13C NMR spectroscopy

Three series of organotin(IV) cysteamine complexes have been prepared in which the 1,2-aminothiol may be monodentate, chelating or bridging, on the ¹¹⁹Sn, ¹⁵N or ¹³C NMR spectroscopic and other physical evidence. Triorganotin(IV) complexes [SnR₃(SCH₂ CH₂NR′₂] (R = Me, Buⁿ or Ph; R′ = H, Me or Et) are monomeric and the aminothiol monodentate in non-coordinating solvents. Dialkyltin(IV) chloro complexes [SnR₂Cl(SCH₂CH₂NR′₂)] (R = Me, Et, Buⁿ or Octⁿ; R′ = H, Me or Et), however, are monomeric with chelation of the aminothiol, like the SnR₂Cl complex of ethyl cysteinate, although nitrogen ligation is hindered by N,N-dialkylation. These solution properties contrast with the polymeric solid structures that are likely for [SnR₂Cl(SCH₂CH₂NH₂)] complexes with R = Me or Et, though not for R = Buⁿ or Octⁿ. Dialkyltin bis-cysteamine complexes [SnR₂(SCH₂CH₂NR′₂)₂] (R = Me, Et, Buⁿ or Octⁿ; R′ = H or Et) show an intermolecular association as neat liquids and in non-coordinating solvents, increasingly with concentration, but again, nitrogen ligation is hindered by tertiary amino groups. The ¹⁵N results usefully complement those from ¹¹⁹Sn and ¹³C NMR spectroscopy.     

New metallomesogens derived from unsymmetric 1,3,4-thiodiazoles: synthesis, single crystal structure, mesomorphism, and optical properties

A series of copper(II) complexes 1 derived from unsymmetric 1,3,4-thiadiazoles 2 exhibiting mesogenic properties are reported. All the precursors 2 and 3 exhibited smectic A or/and smectic C phases, whereas, copper complexes formed nematic, SmA or SmC phases. The mesophases formed by derivatives 2 and 3 were probably attributed to the H-bondings induced both intramolecularly or/and intermolecularly between amide (-NH) and phenolic (-OH) groups. The crystal and molecular structures of mesogenic 2-(5-(2-(hexyloxy)naphthalene-6-yl)-1,3,4-oxadiazole-2-yl)phenol (2; n=6, m=6) were determined by means of X-ray structural analysis. It crystallizes in the monoclinic space group P-1, with a=7.4255(18) Å, b=8.209(2) Å, c=17.315(5) Å, and Z=2. An intermolecular H-bond (d=1.89 Å) between N2 and H1A atoms with an angle of 161.5° was observed. All molecules were packed as tilted layer arrangement and a π-π interaction (ca. 3.56 Å) was observed. Variable temperature FTIR and ¹H NMR spectroscopies were also used to probe the possible H-bondings formed in compound 2 (m=0, n=6). The fluorescent properties of these compounds 2 were examined. All λ_max peaks of the absorption and photoluminescence spectra occurred at ca. 359-363 nm and 519-537 nm, respectively. Excited state intramolecular proton transfer (ESIPT) reaction in this type of ortho-hydroxy-1,3,4-thiadiazole was also observed.     

Reactivity of chlorodeoxypseudoephedrines with oxo-, thio-, and selenocyanates

Herein, the reactivity of chlorodeoxypseudoephedrine hydrochlorides with oxo-, thio-, and selenocyanate nucleophiles is reported. 1,3-Heterazolidine-2-iminium or ammonium salts were obtained stereoselectively in most cases. The hard–soft nature of the calcogen atom determines the mechanistic pathway via an S_N2 (X = O), aziridine intermediate (X = Se), or both (X = S). A simple method to synthesize stereoselectively the trans-isomer of 3,4-dimethyl-5-phenyl-oxazolidine-2-iminium chloride and the cis-isomer of 4-methyl-5-phenyl-oxazoline-2-ammonium chloride, was also found. In addition, heterazolidine-2-imines or amines were liberated from the corresponding salts [Cl⁻ or XCN⁻ (X = O, S, Se)] with aqueous NaOH. Finally, cis-3,4-dimethyl-5-phenyl-oxazolidine-2-iminium chloride, cis-4-methyl-5-phenyl-oxazoline-2-amine, and trans-4-methyl-5-phenyl-selenazoline-2-amine compounds were studied by X-ray diffraction.     

Studies towards the synthesis of (1R,2S)- and (1S,2S)-1,2-epoxy-3-hydroxypropylphosphonates and (1S,2S)- and (1R,2S)-2,3-epoxy-1-hydroxypropylphosphonates

The trans-configured fosfomycin analogue, diethyl (1S,2S)-1,2-epoxy-3-hydroxypropylphosphonate, was synthesised by the intramolecular Williamson reaction of diethyl (1S,2R)-1,3-dihydroxy-2-mesyloxypropylphosphonate. The cis-analogue was obtained as O-ethyl or O,O-diethyl (1R,2S)-1,2-epoxy-3-hydroxypropylphosphonates, when (1R,2R)-1,3-dihydroxy-2-mesyloxypropylphosphonate or its 3-O-trityl derivative were used as starting materials, respectively. The intramolecular Williamson cyclisations of diethyl (1S,2R)- and (1R,2S)-1-benzyloxy-3-hydroxy-2-mesyloxypropylphosphonates led to diethyl (1S,2S)- and (1R,2S)-2,3-epoxy-1-benzyloxypropylphosphonates, respectively, with the concomitant formation of diethyl (E)-1-benzyloxy-3-hydroxyprop-1-en-1-phosphonate. From diethyl (1S,2S)- and (1R,2S)-2,3-epoxy-1-benzyloxypropylphosphonates, enantiomerically pure diethyl (1S,2S)- and (1R,2S)-1,2-dihydroxypropylphosphonates were obtained by catalytic hydrogenation, while diethyl (1S,2S)- and (1R,2S)-3-acetamido-1,2-dihydroxypropylphosphonates were produced after epoxide ring opening with dibenzylamine, acetylation and hydrogenolysis.     

Synthesis of lithium,sodium, cesium,and calcium salts of (E)-4- or (E,S)-3-methyl-2-(5-arylisoxazol-3-yl)-methyleneaminobutanoic, (E,S)-4-methyl-2- or (E,2S,3S)-3-methyl-2-(5-arylisoxazol-3-yl)methyleneaminopentanoic,and (E)-6-(5-arylisoxazol-3-yl)methyleneaminohexanoic acids

Preparative method for the synthesis of lithium, sodium, cesium, and calcium salts of (E)-4-(5-arylisoxazol-3-yl)methyleneaminobutanoic, (E)-6-(5-arylisoxazol-3-yl)methyleneaminohexanoic, (E,S)-3-methyl-2-(5-arylisoxazol-3-yl)methyleneaminobutanoic, (E,S)-4-methyl-2-(5-arylisoxazol-3-yl)methyleneaminopentanoic and (E,2S,3S)-3-methyl-2-(5-arylisoxazol-3-yl)methyleneaminopentanoic acids was developed by reacting 5-phenyl(4-tolyl)isoxazole-3-carbaldehydes with amino acids like 4-aminobutyric and 6-aminocaproic acids, L-valine, L-leucine or L-isoleucine in the presence of lithium hydride, sodium methoxide, cesium carbonate or calcium hydride in boiling methanol.     

Zur Chemie der 2,4-Diaminothiopyranyliumjodide Synthese von α,β,γ,δ-ungesättigten Thiocarbonsäureamiden

Aminolysis of 4-dialkylamino- and 4-alkylamino-2-methylthiothiopyranyliden iodides2 resp. under various reaction conditions leads to assymmetrically or symmetrically substituted 2,4-bisamino- or 2,4-bisdialkylamino- and 2-alkylamino-4-dialkylamino-or 2-dialkylamino-4-alkylamino- or 2-amino-4-dialkylaminodihydrothiopyranylium iodides3, 4, 5, 6 resp. On treatment with alkali 4-alkylamino- and 4-dialkylamino-2-alkylaminothiopyranylium iodides3,4 are hydrolysed to the 2-alkylimino-2H-thiopyranes7. 4-Alkylamino-2-dialkylaminothiopyranylium iodides5 react with alkali to give three products: the two stereoisomeres 2-dialkylamino-4-alkylimino-4H-thiopyranes9 A,B and theN,N-substituted α,β,γ,δ-unsaturated thiocarboxamide10. The hydrolysis of 2,4-bisdialkylaminothiopyranylium iodide6 a leads to the 2-dialkylamino-4H-thiopyran-4-one11 a, the 4-dialkylamino-2H-thiopyrane-2-one12 and theN,N-substituted unsaturated thiocarboxamide10 d. α,β,γ,δ-unsaturated thiocarboxamides10 a-c are formed by the reaction of 2-amino-4-dialkylaminothiopyranylium iodides3 a-c with diluted alkali. By heating with acids10 a-c are cyclisized to the 2-aminothiopyranylium derivates3.     

Complexes containing phosphorus lignads—161: New phosphinite,phosphonite and phosphite derivatives of ruthenium,osmium and iridium

The complexes [MHCl(CO)(PPh₃)₃] (M = Ru or Os) readily undergo substitution at the site trans to the hydride ligand to afford phosphinite-, phosphonite-, or phosphite-containing products [MHCI(CO)(PPh₃)₂L] [L = P(OR)Ph₂, P(OR)₂Ph or P(OR)₃ respectively; R = Me or Et]. The ruthenium complexes alone undergo further substitution to afford complex cations [RuH(CO)(PPh₃)_nL_4?n]⁺ [n = 2, L = P(OMe)₃; n = 1, L = P(OR)₃; n = 0, L = P(OR)₂Ph or P(OR)Ph₂] which were isolated and characterised as their tetraphenylborate salts. Synthesis of the cationic complexes [IrHL₅][BPh₄]₂ [L = P(OR)₃, R = Me or Et] is also reported. Stereochemical assignments based on NMR data are given, and second order ³¹P and high field ¹H NMR patterns are analysed.     

Preparation and structure of the light rare-earth copper selenides LnCuSe2 (Ln=La, Ce, Pr, Nd, Sm)

The ternary selenides LnCuSe₂ (Ln=La, Ce, Pr, Nd, Sm) have been synthesized by the reaction at 1173 K of Ln, Cu, and Se in a KBr or KI flux. The compounds, which are isostructural with LaCuS₂, crystallize with four formula units in the space group P2₁/c of the monoclinic system. The structure may be thought of as consisting of layers of CuSe₄ tetrahedra separated by double layers of LnSe₇ monocapped trigonal prisms along the a-axis. Cell constants (Å or deg) at 153 K are: LaCuSe₂, 6.8142(5), 7.5817(6), 7.2052(6), 97.573(1)°; CeCuSe₂, 6.7630(5), 7.5311(6), 7.1650(6), 97.392(1)°; PrCuSe₂, 6.740(1), 7.481(1), 7.141(1), 97.374(2)°; NdCuSe₂, 6.7149(6), 7.4452(7), 7.1192(6), 97.310(1)°; SmCuSe₂, 6.6655(6), 7.3825(7), 7.0724(6), 97.115(1)°. There are no Se-Se bonds in the structure of LnCuSe₂; the formal oxidation states of Ln/Cu/Se are 3+/1+/2−.     

Synthesis, characterization, and biological evaluation of new oxime-phosphazenes

Hexachlorocylotriphosphazene (1) was reacted with 4-hydroxy-3-methoxybenzaldehyde to give hexakis[(4-formyl-2-methoxy)phenoxy]cyclotriphosphazene (2). Hexakis[(4-(hydroxyimino)2-methoxy)phenoxy]cyclotriphosphazene (3) was synthesized by reaction of 2 with hydroxlamine hydrochloride in pyridine. Compound 3 was reacted with benzyl chloride, acetyl chloride, allyl bromide, benzoyl chloride, propanoyl chloride, 4-methoxybenzoyl chloride, 2-chlorobenzoyl chloride, chloroacetyl chloride, methyl iodide, and thiophene-2-carbonyl chloride. From these reactions, full or partially substituted compounds were obtained, usually in high yields. Pure or defined products could not be obtained from reaction of 3 with methacryloyl chloride and O-acetylsalicyloyl chloride. The structures of the compounds were determined by elemental analysis, and IR, ¹H, ¹³C, and ³¹P NMR spectroscopy. The synthesized compounds were screened for in-vitro antimicrobial activity against two Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis), two gram-negative bacteria (Escherichia coli and Klebsiella pneumonia), and fungal strains (Aspergillus niger, and Candida albicans) by the agar well diffusion method. Few compounds had significant activity against both Gram-positive and Gram-negative bacteria. None of the compounds had antifungal activity except compounds 7 and 9, which had moderate activity.     

Phase Equilibria Laws in the SrS-Ln2S3 (Ln = Yb-Lu,Y, or Sc) Systems

Complex sulfides with the SrS: Ln₂S₃ ratio equal to 3: 1, 1: 3, or 1: 4 for Ln = Y or Lu have been predicted on the basis of thermodynamic analysis of previously designed SrS-Ln₂S₃ (Ln = Tb, Dy, or Er) phase diagrams. Phase diagrams for the SrS-Ln₂S₃ (Ln = Tm, Lu, or Sc) systems have been designed for the first time. These systems form congruently melting compounds SrLn₂S₄ (CaFe₂O₄ type structure, orthorhombic crystal system). Unit cell parameters, heats of melting, and microhardnesses have been determined. For SrTm₂S₄, the respective values are as follows: a = 1.181 nm, b = 1.421 nm, c = 0.396 nm, 2040 K, ΔH _m = 188 kJ/mol, 3500 MPa; for SrLu₂S₄: a = 1.187 nm, b = 1.416 nm, c = 0.392 nm, 2070 K, ΔH _m = 190 kJ/mol, 3540 MPa; and for SrSc₂S₄: a = 1.180 nm, b = 1.410 nm, c = 0.390 nm, 2100 K, ΔH _m = 206 kJ/mol, 3650 MPa. The increase in the melting temperatures and the heats of melting calculated for the SrLn₂S₄ compounds correlate with their classification as thio salts.     

Electrical,magnetic, and EPR studies of the quaternary chalcogenides Cu2AIIBIVX4 prepared by iodine transport

Electrical, magnetic, and electron paramagnetic resonance (EPR) measurements have been made on crystals and powders of several quaternary chalcogenides of the type Cu₂A^IIB^IVX₄, where A^II = Zn, Mn, Fe, or Co, B^IV = Si, Ge, or Sn, and X = S or Se. The electrical properties of these compounds are extrinsic, but their magnetic properties do not appear to be affected by impurities. The magnetic moments of the Cu₂MnBX₄ compounds decrease with increasing covalency of the MnX bond, and those of Cu₂FeGeS₄ and Cu₂CoGeS₄ reflect an orbital contribution to the moment. Both the Weiss constants and magnetic ordering temperatures in these compounds show an evolution from antiferromagnetism to ferromagnetism with increasing separation between the moments. Magnetic measurements on single crystals of Cu₂MnGeS₄, Cu₂CoGeS₄, and Cu₂FeGeS₄ indicate that only the latter is anisotropic. EPR measurements on crystals and powders of Cu₂ZnGeS₄ doped nominally with 0.1% Mn reveal that Mn²⁺ experiences an axial distortion and that the bond ionicity is the same as in ZnS.     

Coordination compounds of cobalt,nickel, copper,and zinc with N 1,N 2-bis(pyridin-2-ylmethylidene)benzene-1,2-diamine and its derivatives

o-Phenylenediamine reacts with 2-formyl-, 2-acetyl-, or 2-benzoylpyridine in ethanol in the presence of cobalt, nickel, copper, or zinc chlorides to form monomeric complexes ML^1–3Cl₂·nH₂O {M = Co, Ni, Cu, Zn; L¹ = N ¹,N ²-bis(pyridin-2-ymethylidene)benzene-1,2-diamine, L² = N ¹,N ²-bis(pyridin-2-ylethylidene) benzene-1,2-diamine, L³ = N ¹,N ²-bis[phenyl(pyridin-2-yl)methylidene]benzene-1,2-diamine; n = 0–3}. The condensation products (L¹–L³) act in the complexes as tetradentate N,N,N,N-ligands. Thermolysis of the complexes occurs in two stages: dehydration (70–95°C) and complete degradation (320–450°C). At concentrations of 10^?5–10^?7 M, the complexes inhibit in vitro growth and proliferation of HL-60 human promyelocytic leukemia cells.     

Inorganic Polymers : by N.H. Ray,Academic Press,New York/San Francisco/London, 1978, 174 pages, $ 17.35.

Insertion of CO or p-TolNC into a ZrC bond of [Zr(η-C₅H₅).(R)R′] under ambient conditions in C₆H₆ leads to the stable η²-acyl- or η²-iminoacyl-complex [Zr(η-C₅H₅)₂{η²-C(X)R}R′] (X = O or NTol-p); with [Zr(η-C₅H₅)₂{CH(SiMe₃)₂}Me] as substrate there is exclusive preference for scission of the more hindered ZrC bond.     

New chiral phosphine-phosphonites derived from (2R,3R)-dimethyl tartrate, (S)-binaphthol and (1R,2S)-ephedrine

The reaction of 2-lithiophenyldiphenylphosphine with phosphorus trichloride afforded the new unsymmetric phosphine, dichloro(2-diphenylphosphinophenyl)phosphine (4). Condensation of 4 with (a) (2R,3R)-dimethyl tartrate or (b) (S)-binaphthol in the presence of triethylamine gave new chiral phosphine-phosphonite ligands, (2R,3R)-[2-(2′-(diphenylphosphino)phenyl)-4,5-bis(carbomethoxy)-1,3,2-dioxaphospholane] ((2R,3R)-5) and (S)-[2-(diphenylphosphino)benzene][1,1′-binaphthalen-2,2′-diyl]phosphonite] ((S)-6). The analogous reaction of 4 with (1R,2S)-ephedrine using N-methylmorpholine as the base, gave [2-(2′-(diphenylphosphino)phenyl)-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine] (7) as a 95:5 mixture of diastereoisomers.