Structural Characterization of (Arylimido)vanadium(V) Compounds with 2,6‐Difluorophenoxide Ligand

The (arylimido)vanadium(V) compound, [(p‐MeOC₆H₄N)V(OiPr)₃] was demonstrated to undergo ligand exchange reaction with one or two equivalents of 2,6‐difluorophenol, affording the (arylimido)vanadium(V) compounds, [(p‐MeOC₆H₄N)V(OiPr)₂(O‐2,6‐F₂Ph)] and [(p‐MeOC₆H₄N)V(OiPr)(O‐2,6‐F₂Ph)₂]. Their X‐ray crystallographic analyses elucidated the μ‐isopropoxido‐bridged dimeric structures, wherein each vanadium atom has a trigonal‐bipyramidal arrangement with the imido and bridging isopropoxide ligands in the apical positions. The isopropoxide ligand was selectively employed as a bridging ligand between two central vanadium atoms. On the other hand, the reaction of the (arylimido)vanadium(V) compound, [(p‐MeOC₆H₄N)VCl₃] and three equivalents of lithium 2,6‐difluorophenoxide gave the (arylimido)vanadium(V) compound, [(p‐MeOC₆H₄N)V(O‐2,6‐F₂Ph)₃]. In the crystal packing, the thus‐obtained compound showed a distorted trigonal‐bipyramidal environment at the vanadium atoms with the μ‐phenoxido‐bridged dimeric structure, wherein the 2,6‐difluorophenoxide ligand was found to serve as a bridging ligand.     

Three p‐xylene‐solvated pseudopolymorphs of bis[1,3‐bis(pentafluorophenyl)propane‐1,3‐dionato]copper(II)

The Cu²⁺ ions in the title compounds, namely bis[1,3‐bis(pentafluorophenyl)propane‐1,3‐dionato‐κ²O,O′]copper(II) p‐xylene n‐solvate, [Cu(C₁₅HF₁₀O₂)₂]·nC₈H₁₀, with n = 1, (I), n = 2, (II), and n = 4, (III), are coordinated by two 1,3‐bis(pentafluorophenyl)propane‐1,3‐dionate ligands. The coordination complexes of (I) and (II) have crystallographic inversion symmetry at the Cu atom and the p‐xylene molecule in (I) also lies across an inversion centre. The p‐xylene molecules in (I) and (II) interact with the pentafluorophenyl groups of the complex via arene–perfluoroarene interactions. In the crystal of (III), two of the p‐xylene molecules interact with the pentafluorophenyl groups via arene–perfluoroarene interactions. The other two p‐xylene molecules are located on the CuO₄ coordination plane, forming a uniform cavity produced by metal...π interactions.     

Bis(dimethyl sulfoxide‐S)tetrakis(μ‐p‐hydroxybenzoato‐O:O′)dirhodium(II)–tetrakis(μ‐butyrato‐O:O′)bis(dimethyl sulfoxide‐S)dirhodium(II) cocrystal ethanol disolvate

The title structure, [Rh₂(C₇H₅O₃)₄(C₂H₆OS)₂]·[Rh₂(C₄H₇­O₂)₄(C₂H₆OS)₂]·2C₂H₆O, contains two discrete neutral Rh–Rh dimers cocrystallized as the ethanol disolvate. Each dimer is situated on an inversion center. The butyrate chain displays disorder in one C‐atom position. In each dimer, the di­methyl sulfoxide ligand (dmso) is bound via S, as expected. The ethanol is a hydrogen‐bond acceptor for one p‐hydroxy­benzoate hydroxyl group and acts as a hydrogen‐bond donor to the dmso O atom of a neighboring p‐hydroxy­benzoate dirhodium complex. A third hydrogen bond is formed from the other p‐hydroxy­benzoate hydroxyl group to the dmso O atom of a butyrate–dirhodium complex.     

Coordination Mode of the Nickel(II) Cation with N‐Diisopropoxyphosphinyl‐p‐bromothiobenzamide

Reaction of the potassium salt of N‐diisopropoxyphosphinyl‐p‐bromothiobenzamide p‐BrC₆H₄C(S)NHP(O)(OiPr)₂ ( HL ) with Ni(NO₃)₂ in aqueous EtOH leads to complex of formula [Ni(HL‐O)₂(L‐O,S)₂] ( 1 ). The structure of 1 was investigated by single crystal X‐ray diffraction analysis, IR, ¹H and ³¹P{¹H} NMR spectroscopy, MALDI and microanalysis. The nickel(II) ion in 1 has a tetragonal‐bipyramidal environment, (O^ax)₂(O^eq)₂(S^eq)₂, with two neutral ligand molecules coordinated in axial positions through the oxygen atoms of the P=O groups. The equatorial plane of bipyramide is formed by two anionic ligands involving 1,5‐O,S‐coordination mode. The chelating ligands are bound in trans configuration.     

Areneruthenium(II) Complexes with Functionalized Phosphines Coordinating as Mono‐, Bi‐ or Tridentate Ligands

Areneruthenium(II) compounds [Ru(p‐cym)Cl₂{κ‐P‐ⁱPrP(CH₂CH₂OMe)₂}], 3 , and [Ru(arene)Cl₂{κ‐P‐RP(CH₂CO₂Me)₂}] 4 – 7 (arene=p‐cym (=1‐methyl‐4‐isopropylbenzene), mes (=1,3,5‐trimethylbenzene); R=ⁱPr, ^tBu) were prepared from the dimers [Ru(arene)Cl₂]₂ and the corresponding functionalized phosphine. Treatment of 6 and 7 with 1 equiv. of AgPF₆ affords the monocationic complexes [Ru(mes)Cl{κ²‐P,O‐RP(CH₂C(O)OMe)(CH₂CO₂Me)}]PF₆, 10 and 11 , while the related reaction of 5 – 7 with 2 equiv. of AgPF₆ produces the dicationic compounds [Ru(p‐cym){κ³‐P,O,O‐^tBuP(CH₂C(O)OMe)₂}](PF₆)₂ ( 12 ) and [Ru(mes){κ³‐P,O,O‐RP(CH₂C(O)OMe)₂}](PF₆)₂, 13 and 14 . Partial hydrolysis of one hexafluorophosphate anion of 12 – 14 leads to the formation of [Ru(arene){κ²‐P,O‐RP(CH₂C(O)OMe)(CH₂CO₂Me)}(κ‐O‐O₂PF₂)]PF₆, 15 – 17 , of which 17 (arene=mes; R=^tBu) has been characterized by X‐ray crystallography. Compounds 13 and 14 react with 2 equiv. of KO^tBu in ^tBuOH/toluene to give the unsymmetrical complexes [Ru(mes){κ³‐P,C,O‐RP(CHCO₂Me)(CH=C(O)OMe)}], 18 and 19 , containing both a five‐membered phosphinoenolate and a three‐membered phosphinomethanide ring. The molecular structure of compound 18 has been determined by X‐ray structure analysis. The neutral bis(carboxylate)phosphanidoruthenium(II) complexes [Ru(arene){κ³‐P,O,O‐RP(CH₂C(O)O)₂}], 20 – 23 are obtained either by hydrolysis of 18 and 19 , or by stepwise treatment of 4 and 5 with KO^tBu and basic Al₂O₃. Novel tripodal chelating systems are generated via insertion reactions of 19 with PhNCO and PhNCS.     

Melaminium bis(4‐hydroxybenzenesulfonate) dihydrate

The crystals of a new melaminium salt, 2,4,6‐tri­amino‐1,3,5‐triazine‐1,3‐diium bis(4‐hydroxy­benzene­sulfonate) dihydrate, C₃H₈N₆²⁺·2C₆H₅O₄S^?·2H₂O, are built up from doubly proton­ated melaminium(2+) residues, dissociated p‐phenol­sulfonate anions and water mol­ecules. The doubly protonated melaminium dication lies on a twofold axis. The hydroxyl group of the p‐hydroxybenzenesulfonate residue is roughly coplanar with the phenyl ring [dihedral angle 13 (2)°]. A combination of ionic and donor–acceptor hydrogen‐bond interactions link the melaminium and p‐hydroxybenzenesulfonate residues and the water mol­ecules to form a three‐dimensional network.     

Copper(II) bromide and copper(II) acetate complexes of 4,4′‐(p‐phenylene)bipyridazine

4,4′‐(p‐Phenylene)bipyridazine, C₁₄H₁₀N₄, (I), and the coordination compounds catena‐poly[[dibromidocopper(II)]‐μ‐4,4′‐(p‐phenylene)bipyridazine‐κ²N²:N^2′], [CuBr₂(C₁₄H₁₀N₄)]_n, (II), and catena‐poly[[[tetrakis(μ‐acetato‐κ²O:O′)dicopper(II)]‐μ‐4,4′‐(p‐phenylene)bipyridazine‐κ²N¹:N^1′] chloroform disolvate], {[Cu₂(C₂H₃O₂)₄(C₁₄H₁₀N₄)]·2CHCl₃}_n, (III), contain a new extended bitopic ligand. The combination of the p‐phenylene spacer and the electron‐deficient pyridazine rings precludes C—H...π interactions between the lengthy aromatic molecules, which could be suited for the synthesis of open‐framework coordination polymers. In (I), the molecules are situated across a center of inversion and display a set of very weak intermolecular C—H...N hydrogen bonds [3.399 (3) and 3.608 (2) Å]. In (II) and (III), the ligand molecules are situated across a center of inversion and act as N²,N^2′‐bidentate [in (II)] and N¹,N^1′‐bidentate [in (III)] long‐distance bridges between the metal ions, leading to the formation of coordination chains [Cu—N = 2.005 (3) Å in (II) and 2.199 (2) Å in (III)]. In (II), the copper ion lies on a center of inversion and adopts CuN₂Br₄ (4+2)‐coordination involving two long axial Cu—Br bonds [3.2421 (4) Å]. In (III), the copper ion has a tetragonal pyramidal CuO₄N environment. The uncoordinated pyridazine N atom and two acetate O atoms provide a multiple acceptor site for accommodation of a chloroform solvent molecule by trifurcated hydrogen bonding [C—H...O(N) = 3.298 (5)–3.541 (4) Å].     

Bis­(O,O′‐di‐p‐tolyldithiophosphato‐S,S′)(1,10‐phenanthroline‐N,N′)nickel(II)

The title coordination complex, [Ni(C₁₄H₁₄O₂PS₂)₂(C₁₂H₈N₂)] or [Ni(pMePh‐dtp)₂(phen)] (phen is 1,10‐phenanthroline; dtp is di­aryl­di­thio­phosphate), has a non‐crystallographic twofold axis of symmetry through the Ni atom and the phen moiety. Two O,O‐di‐p‐tolyl­di­thio­phosphate (dtp) ions act as bidentate ligands. The central metal atom is coordinated by four S atoms from two dtp groups and two N atoms from the phen ligand. The title compound displays distorted octahedral geometry around the central Ni atom.     

Three heterotrinuclear Schiff base complexes of nickel(II) with cobalt(II), copper(II) and manganese(II)

The title compounds, bis­(di­methyl­form­amide)‐1κO,3κO‐bis{μ‐2,2′‐[2,2′‐di­methyl­propane‐1,3‐diyl­bis­(nitrilo­methylidyne)]­diphenolato}‐1κ⁴N,N′,O,O′:2κ²O,O′;2κ²O,O′:3κ⁴N,N′,O,O′‐di‐μ‐nitrito‐1:2κ²N:O;2:3κ²O:N‐dinickel(II)­cobalt(II), [CoNi₂(NO₂)₂(C₁₉H₂₂N₂O₂)₂(C₃H₇NO)₂], (I), ‐copper(II), [CuNi₂(NO₂)₂(C₁₉H₂₂N₂O₂)₂(C₃H₇NO)₂], (II), and ‐manganese(II), [MnNi₂(NO₂)₂(C₁₉H₂₂N₂O₂)₂(C₃H₇NO)₂], (III), consist of centrosymmetric linear heterotrinuclear metal complexes. The three complexes are isostructural. There are three bridges across the Ni–M atom pairs (M is Co²⁺, Cu²⁺ or Mn²⁺) in each complex, involving two O atoms of a μ‐N,N′‐bis­(salicyl­idene)‐2,2′di­methyl‐1,3‐propane­diaminate ligand and an N—O moiety of a μ‐nitrito group. The coordination sphere around each metal atom, whether Co²⁺, Cu²⁺, Mn²⁺ or Ni²⁺, can be described as distorted octahedral. The Ni?M distances are 2.9988 (5) Å in (I), 2.9872 (5) Å in (II) and 3.0624 (8) Å in (III).     

New rac‐XP(O)(OC6H5)(NHC6H4‐p‐CH3) [X = N(CH3)(cyclo‐C6H11) and NH(C3H5)] and rac‐(C6H5CH2NH)P(O)(OC6H5)(NH‐cyclo‐C6H11) mixed‐amide phosphinates

The mixed‐amide phosphinates, rac‐phenyl (N‐methylcyclohexylamido)(p‐tolylamido)phosphinate, C₂₀H₂₇N₂O₂P, (I), and rac‐phenyl (allylamido)(p‐tolylamido)phosphinate, C₁₆H₁₉N₂O₂P, (II), were synthesized from the racemic phosphorus–chlorine compound (R,S)‐(Cl)P(O)(OC₆H₅)(NHC₆H₄‐p‐CH₃). Furthermore, the phosphorus–chlorine compound ClP(O)(OC₆H₅)(NH‐cyclo‐C₆H₁₁) was synthesized for the first time and used for the synthesis of rac‐phenyl (benzylamido)(cyclohexylamido)phosphinate, C₁₉H₂₅N₂O₂P, (III). The strategies for the synthesis of racemic mixed‐amide phosphinates are discussed. The P atom in each compound is in a distorted tetrahedral (N¹)P(=O)(O)(N²) environment. In (I) and (II), the p‐tolylamido substituent makes a longer P—N bond than those involving the N‐methylcyclohexylamido and allylamido substituents. In (III), the differences between the P—N bond lengths involving the cyclohexylamido and benzylamido substituents are not significant. In all three structures, the phosphoryl O atom takes part with the N—H unit in hydrogen‐bonding interactions, viz. an N—H...O=P hydrogen bond for (I) and (N—H)(N—H)...O=P hydrogen bonds for (II) and (III), building linear arrangements along [001] for (I) and along [010] for (III), and a ladder arrangement along [100] for (II).     

Dimeric hexakis(4‐methyl­benzoato)­bis(1,10‐phenanthroline)didyspros­ium(III)

The title compound, [Dy₂(C₈H₇O₂)₆(C₁₂H₈N₂)₂], forms binuclear complexes, viz. di‐μ‐4‐methyl­benzoato‐κ⁴O:O′‐bis[bis(4‐methyl­benzoato‐κ²O,O′)(1,10‐phenanthroline‐κ²N,N′)dyspros­ium(III)] tetra‐μ‐4‐methyl­benzoato‐κ⁸O:O′‐bis[(4‐methyl­benzoato‐κ²O,O′)(1,10‐phenanthroline‐κ²N,N′)dyspros­ium(III)]. There are two independent binuclear com­plexes in the asymmetric unit, both of which are centrosymmetric. In one, the Dy^III ions are linked by two bridging 4‐­methyl­benzoate groups, while in the other, the Dy^III ions are linked by four bridging 4‐methyl­benzoate groups. The remaining 4‐methyl­benzoate groups and 1,10‐phenanthroline units coordinate to just one metal ion in bidentate modes.     

Manganese(II) and cobalt(II) complexes of 1,4‐bis(diphenylphosphinoyl)butane

The title complexes, catena‐poly[[[diaquadiethanolmanganese(II)]‐μ‐1,4‐bis(diphenylphosphinoyl)butane‐κ²O:O′] dinitrate 1,4‐bis(diphenylphosphinoyl)butane solvate], {[Mn(C₂H₆O)₂(C₂₈H₂₈O₂P₂)(H₂O)₂](NO₃)₂·C₂₈H₂₈O₂P₂}_n, (I), and catena‐poly[[[diaquadiethanolcobalt(II)]‐μ‐1,4‐bis(diphenylphosphinoyl)butane‐κ²O:O′] dinitrate 1,4‐bis(diphenylphosphinoyl)butane solvate], {[Co(C₂H₆O)₂(C₂₈H₂₈O₂P₂)(H₂O)₂](NO₃)₂·C₂₈H₂₈O₂P₂}_n, (II), are isostructural and centrosymmetric, with the M^II ions at centres of inversion. The coordination geometry is octahedral, with each metal ion coordinated by two trans ethanol molecules, two trans water molecules and two bridging 1,4‐bis(diphenylphosphinoyl)butane ligands which link the coordination centres to form one‐dimensional polymeric chains. Parallel chains are linked by hydrogen bonds to uncoordinated 1,4‐bis(diphenylphosphinoyl)butane molecules, which are bisected by a centre of inversion. Further hydrogen bonds, weak C—H...O interactions to nitrate anions, and weak C—H...π interactions serve to stabilize the structure. This study reports a development of the coordination chemistry of bis(diphenylphosphinoyl)alkanes, with the first reported structures of complexes of the first‐row transition metals with 1,4‐bis(diphenylphosphinoyl)butane.     

A dinuclear zinc complex containing a diamond‐core geometry: [Zn2(μ2‐GueO)2(GueO)2(py)2]·0.5(toluene) (GueOH is guethol)

The title zinc alkoxide, bis(μ‐2‐ethoxyphenolato)‐κ³O¹,O²:O¹;κ³O¹:O¹,O²‐bis[(2‐ethoxyphenolato‐κ²O¹,O²)(pyridine‐κN)zinc(II)] toluene hemisolvate, [Zn₂(C₈H₉O₂)₄(C₅H₅N)₂]·0.5C₇H₈, crystallizes with two independent complex molecules located on inversion centres and one independent toluene solvent molecule disordered about an inversion centre. The Zn^II atoms are six‐coordinated in distorted octahedral geometries with O₅N donor sets. The Zn^II ions and bridging alkoxide groups are arranged in a diamond Zn₂O₂ core structure. The guetholate (2‐ethoxyphenolate) ligands adopt two different coordination modes, viz. peripheral chelating and μ₂‐bridging. Preliminary investigations of the catalytic activity of the compound in the ring‐opening polymerization of L‐lactide demonstrate rapid and efficient generation of polylactide.     

trans‐Bis(hinokitiolato)copper(II) trans‐bis(hinokitiolato)palladium(II) cocrystals with (5/1) and (3/2) formulations

trans‐Bis(3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)copper(II) trans‐bis(3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)palladium(II) as the (5/1) and (3/2) composites [Cu(C₁₀H₁₁O₂)₂]·0.2[Pd(C₁₀H₁₁O₂)₂] and [Cu(C₁₀H₁₁O₂)₂]·0.67[Pd(C₁₀H₁₁O₂)₂], respectively, where 3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olate is the systematic name for the hinokitiolate anion (hino), are the first mixed‐metal cocrystalline products isolated from the M_x(hino)_y family of complexes. These cocrystals contain square‐planar trans‐Cu(hino)₂ and trans‐Pd(hino)₂ molecules possessing crystallographic inversion symmetry. The bulk formulation for these cocrystalline compounds is Cu_1−xPd_x(hino)₂, where x is 0.166 (4) for the (5/1) product and 0.399 (4) for the (3/2) product. This bulk formulation is simply a convenient average expression of the whole‐molecule substitutional disorder present in these compounds. The M—O bonds are in the range 1.9210 (11)–1.9453 (10) Å, the O—M—O bite angles are in the range 82.94 (4)–83.36 (4)°, and all of the hinokitiolate O atoms are involved in C—H...O hydrogen‐bonding interactions.     

Synthesis and Characterisation of Bismuth(III) Aminoarenesulfonate Complexes and Their Powerful Bactericidal Activity against Helicobacter pylori

The synthesis and characterisation of nine new tris‐substituted bismuth(III) aminoarenesulfonates of the general formula [Bi(O₃S‐R^N)₃] (R^N=o‐aminophenyl 1 , m‐aminophenyl 2 , 6‐amino‐3‐methoxyphenyl 3 , p‐aminophenyl 4 , 2‐pyridyl 5 , o‐aminonaphthyl 6 , 5‐aminonaphthyl 7 , 4‐amino‐3‐hydroxynaphthyl 8 and 5‐isoquinolinyl 9 ) is described. Two synthetic strategies, using Ag₂O and [Bi(OtBu)₃], were explored and compared. The possibility to access heteroleptic bismuth(III) complexes with the new silver(I) metathesis reaction is demonstrated with the synthesis of the heteroleptic bismuth(III) aminoarenesulfonate complexes [PhBi(O₃S‐P2)₂(dmso)] 10 , [Ph₂Bi(O₃S‐P2)]_∞ 11 and [PhBi(O₃S‐P2)₂]_∞ 12 , of which the solid state structures 10 and 12 are presented (2P‐SO₃^?=2‐pyridinesulfonate). These complexes offer remarkable in‐vitro activity against three standard laboratory strains of Helicobacter pylori (H. pylori) as demonstrated by their exceptionally low minimum inhibitory concentration (MIC) values of 0.049 μg mL^?1 for the strains 251 and B128, which places most MIC values in the nano‐molar region. These results demonstrate the importance of the amino functionality in addition to the sulfonate group on the bactericidal properties against H. pylori.     

具有β-(1→6)-半乳吡喃糖骨架和α-L-(1→3)-阿拉伯呋喃糖侧链的阿拉伯半乳寡糖的简易合成

4-Methoxyphenyl glycoside of β-D-Galp-(1→6)-[α-L-Araf-(1→3)-]β-D-Galp-(1→6)-β-D-Galp-(1→6)-{β-D-Galp-(1→6)-[α-L-Araf-(1→3)-]β-D-Galp-(1→6)-β-D-Galp-(1→6)-}2β-D-Galp-(1→6)-[α-L-Araf-(1→)3)-]β-D-Galp-(1→)6)-β-D-Galp was synthesized with 2,3,4,6-tetra-O-benzoyl-α-D-galactopyranosyl trichloroacetimidate (1), 6-O-acetyl-2,3,4-tri-O-benzoyl-α-D-galactopyranosyl trichloroacetimidate (11), 4-methoxyphenyl 3-O-allyl-2,4-tri-O-benzoyl-β-D-galactopyranoside (2),isopropyl 3-O-allyl-2,4-tri-O-benzoyl--thio-β-D-galactopyranoside (12),4-methoxyphenyl 2,3,4-tri-O-benzoyl-β-D-galactopyranoside (5), and 2,3,5-tri-O-benzoyl-α-L-arabinofuranosyl trichloroacetimidate (8) as the key synthons.     

Two tetranuclear zinc clusters, [Zn4(μ3‐OEt)2(μ2‐MalO)4Et2] and [Zn4(μ3‐GueO)2(μ2‐GueO)2(μ2‐MalO)2(MalO)2]·2C7H8, containing defective dicubane core geometries (MalOH is maltol and GueOH is guethol)

The zinc alkoxide molecules in di‐μ₃‐ethanolato‐diethyltetrakis(μ₂‐2‐methyl‐4‐oxo‐4H‐pyran‐3‐olato‐κ³O³,O⁴:O³)tetrazinc(II), [Zn₄(C₂H₅)₂(C₂H₅O)₂(C₆H₅O₃)₄], (I), and bis(μ₃‐2‐ethoxyphenolato‐κ⁴O¹,O²:O¹:O¹)bis(μ₂‐2‐ethoxyphenolato‐κ³O¹,O²:O¹)bis(μ₂‐2‐methyl‐4‐oxo‐4H‐pyran‐3‐olato‐κ³O³,O⁴:O³)bis(2‐methyl‐4‐oxo‐4H‐pyran‐3‐olato‐κ²O³,O⁴)tetrazinc(II) toluene disolvate, [Zn₄(C₆H₅O₃)₄(C₈H₉O₂)₄]·2C₇H₈, (II), lie on crystallographic centres of inversion. The asymmetric units of (I) and (II) contain half of the tetrameric unit and additionally one molecule of toluene for (II). The Zn^II atoms are four‐ and six‐coordinated in distorted tetrahedral and octahedral geometries for (I), and six‐coordinated in a distorted octahedral environment for (II). The Zn^II atoms in both compounds are arranged in a defect dicubane Zn₄O₆ core structure composed of two EtZnO₃ tetrahedra and ZnO₆ octahedra for (I), and of four ZnO₆ octahedra for (II), sharing common corners. The maltolate ligands exist mostly in a μ₂‐bridging mode, while the guetholate ligands prefer a higher coordination mode and act as μ₃‐ and μ₂‐bridges.     

Gold‐Nanoparticle‐Loaded Carbonate‐Modified Titanium(IV) Oxide Surface: Visible‐Light‐Driven Formation of Hydrogen Peroxide from Oxygen

Gold nanoparticle‐loaded rutile TiO₂ with a bimodal size distribution around 10.6 nm and 2.3 nm (BM‐Au/TiO₂) was prepared by the deposition precipitation and chemical reduction (DP‐CR) technique. Visible‐light irradiation (λ>430 nm) of the BM‐Au/TiO₂ plasmonic photocatalyst yields 35 μm H₂O₂ in aerated pure water at irradiation time (t_p)=1 h, and the H₂O₂ concentration increases to 640±60 μm by the addition of 4 % HCOOH as a sacrificing electron donor. Further, a carbonate‐modified surface BM‐Au/TiO₂ (BM‐Au/TiO₂‐CO₃^2?) generates a millimolar level of H₂O₂ at t_p=1 h with a quantum efficiency (Φ) of 5.4 % at λ=530 nm under the same conditions. The recycle experiments confirmed the stable performance of BM‐Au/TiO₂.     

Facile synthesis of pyridinium aryltetrachlorotellurates: crystal and molecular structure of [C5H6N][RTeCl4] (R = m‐O2NC6H4, p‐NCC6H4)

Arylation of TeCl₄ with arylboroxine–pyridine complexes [(RBO)₃·C₅H₅N, where R = m‐O₂NC₆H₄ ( 1 ), p‐O₂NC₆H₄ ( 2 ), m‐NCC₆H₄ ( 3 ), p‐NCC₆H₄ ( 4 )] and advantageous moisture provided good yields of the pyridinium aryltetrachlorotellurates [C₅H₆N][RTeCl₄] [R = m‐O₂NC₆H₄ ( 5 ), p‐O₂NC₆H₄ ( 6 ), m‐NCC₆H₄ ( 7 ), p‐NCC₆H₄ ( 8 )]. Compounds 5 and 8 have been investigated by X‐ray crystallography. Key features of both crystal structures are intermolecular secondary Te???Cl interactions between the aryltetrachlorotellurate anions and weak association of the cations and anions. Electrospray mass spectra of compound 5 reveal that the associative interactions also play a role in solution. Copyright © 2005 John Wiley & Sons, Ltd.