Coordination‐Driven Self‐Assembly and Anticancer Potency Studies of Ruthenium–Cobalt‐Based Heterometallic Rectangles

Three new cobalt–ruthenium heterometallic molecular rectangles, 1 – 3 , were synthesized through the coordination‐driven self‐assembly of a new cobalt sandwich donor, (η⁵‐Cp)Co[C₄‐trans‐Ph₂(4‐Py)₂] (L ; Cp: cyclopentyl; Py: pyridine), and one of three dinuclear precursors, [(p‐cymene)₂Ru₂(OO∩OO)₂Cl₂] [OO∩OO: oxalato ( A₁ ), 5,8‐dioxido‐1,4‐naphthoquinone ( A₂ ), or 6,11‐dioxido‐5,12‐naphthacenedione ( A₃ )]. All of the self‐assembled architectures were isolated in very good yield (92–94 %) and were fully characterized by spectroscopic analysis; the molecular structures of 2 and 3 were determined by single‐crystal X‐ray diffraction analysis. The anticancer activities of bimetallic rectangles 1 – 3 were evaluated with a 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide (MTT) assay, an autophagy assay, and Western blotting. Rectangles 1 – 3 showed higher cytotoxicity than doxorubicin in AGS human gastric carcinoma cells. In addition, the autophagic activities and apoptotic cell death ratios were increased in AGS cells by treatment with 1 – 3 ; the rectangles induced autophagosome formation by promoting LC3‐I to LC3‐II conversion and apoptotic cell death by increasing caspase‐3/7 activity. Our results suggest that rectangles 1 – 3 induce gastric cancer cell death by modulating autophagy and apoptosis and that they have potential use as agents for the treatment of human gastric cancer.     

In‐ and Out‐of‐Cavity Interactions by Modulating the Size of Ruthenium Metallarectangles

Cationic (arene)ruthenium‐based tetranuclear complexes of the general formula [Ru₄(η⁶‐p‐cymene)₄(μ‐N∩N)₂(μ‐OO∩OO)₂]⁴⁺ were obtained from the dinuclear (arene)ruthenium complexes [Ru₂(η⁶‐p‐cymene)₂(μ‐OO∩OO)₂Cl₂] (p‐cymene=1‐methyl‐4‐(1‐methylethyl)benzene, OO∩OO=5,8‐dihydroxy‐1,4‐naphthoquinonato(2?), 9,10‐dihydroxy‐1,4‐anthraquinonato(2?), or 6,11‐dihydroxynaphthacene‐5,12‐dionato(2?)) by reaction with pyrazine or bipyridine linkers (N∩N=pyrazine, 4,4′‐bipyridine, 4,4′‐[(1E)‐ethene‐1,2‐diyl]bis[pyridine]) in the presence of silver trifluoromethanesulfonate (CF₃SO₃Ag) (Scheme). All complexes 4 – 12 were isolated in good yield as CF₃SO salts, and characterized by NMR and IR spectroscopy. The host–guest properties of the metallarectangles incorporating 4,4′‐bipyridine and (4,4′‐[(1E)‐ethene‐1,2‐diyl]bis[pyridine] linkers were studied in solution by means of multiple NMR experiments (1D, ROESY, and DOSY). The largest metallarectangles 10 – 12 incorporating (4,4′‐[(1E)‐ethene‐1,2‐diyl]bis[pyridine] linkers are able to host an anthracene, pyrene, perylene, or coronene molecule in their cavity, while the medium‐size metallarectangles 7 – 9 incorporating 4,4′‐bipyridine linkers are only able to encapsulate anthracene. However, out‐of‐cavity interactions are observed between these 4,4′‐bipyridine‐containing rectangles and pyrene, perylene, or coronene. In contrast, the small pyrazine‐containing metallarectangles 4 – 6 show no interaction in solution with this series of planar aromatic molecules.     

Anticancer activity of tetracationic arene ruthenium metalla-cycles

A series of cationic metalla-cycles of the general formulae [(η(6)-p-cym)(4)Ru(4)(OO∩OO)(2)(N∩N)(2)](4+) and [(η(6)-p-cym)(4)Ru(4)(NO∩NO)(2)(N∩N)(2)](4+) has been prepared from the dinuclear arene ruthenium precursors [(η(6)-p-cym)(2)Ru(2)(OO∩OO)(2)Cl(2)] (OO∩OO = oxalato, 1,4-benzoquinonato-2,5-diolato, 1,4-naphtoquinonato-5,8-diolato, 9,10-anthraquinonato-1,4-diolato, 5,12-tetraquinonato-6,11-diolato) and [(η(6)-p-cym)(2)Ru(2)(NO∩NO)(2)Cl(2)] (NO∩NO = oxamido, oxonico) by reaction with two different bidentate linkers (N∩N = 1,2-bis(4-pyridyl)ethylene, 1,2-bis(4-pyridyl)ethane) in the presence of silver triflate. All complexes were isolated as triflate salts and characterised by NMR, infrared, UV-visible, mass spectrometry and by elemental analysis. The cytotoxicities of the tetranuclear ruthenium complexes have been established using ovarian A2780 and A2780cisR cancer cell lines. All complexes exhibit moderate to excellent activity on both the cisplatin resistant and cisplatin sensitive cells, thus suggesting a mode of action different from cisplatin.     

Reaction of the N‐heterocyclic carbene, 1,3‐dimesityl‐ imidazol‐2‐ylidene,with a uranyl triflate complex,UO2(OTf)2(thf)3

The N‐heterocyclic carbene, 1,3‐dimesityl‐imidazol‐2‐ylidene (IMes) reacts with tetrahydrofuran (THF) in the presence of an oxidizing uranyl triflate complex, UO₂(OTf)₂(thf)₃ (^?OTf = ^?OSO₂CF₃), to give 1,4‐bis(1,3‐dimesityl‐2‐imidazolium)‐1,3‐butadiene bis(trifluoromethanesulfonate), formally understood as the coupling product of two equivalents of IMes with [CH?CH? CH?CH](OTf)₂. Copyright © 2005 John Wiley & Sons, Ltd.     

Encapsulation of Pyrene‐Functionalized Poly(benzyl ether) Dendrons into a Water‐Soluble Organometallic Cage

Two generations of lipophilic pyrenyl functionalized poly(benzyl ether) dendrimers (P₁ and P₂) have been synthesized. The thermal properties of the two functionalized dendrimers have been investigated, and the pyrenyl group of the dendritic molecules encapsulated in the arene–ruthenium metalla‐cage, [Ru₆(p‐cymene)₆(tpt)₂(donq)₃]⁶⁺ ([ 1 ]⁶⁺) (tpt=2,4,6‐tri(pyridin‐4‐yl)‐1,3,5‐triazine; donq=5,8‐dioxydo‐1,4‐naphthoquinonato). The host–guest properties of [P₁⊂ 1 ]⁶⁺ and [P₂⊂ 1 ]⁶⁺ were studied in solution by NMR and UV/Vis spectroscopic methods, thus allowing the determination of the affinity constants. Moreover, the cytotoxicity of these water‐soluble host–guest systems was evaluated on human ovarian cancer cells.     

A Metal‐Containing N‐Heterocyclic Germylene Based on an Oxalamidine Framework

A metal‐containing N‐heterocyclic germylene based on a N‐mesityl (Mes)‐substituted oxalamidine framework is reported. The precursor (MesN=)₂C–C(–N(H)Mes)₂ ( 1 H₂) was converted into its rhodium complex [Rh(κ²N‐ 1 H₂)(cod)][OTf] ( 2 ) (cod = 1,5‐cyclooctadiene; OTf = triflate) in 62 % isolated yield. Subsequent reaction of 2 with Ge{N(SiMe₃)₂}₂ gave the crystalline N‐heterocyclic germylene [Rh(cod)(μ‐ 1 )Ge][OTf] ( 3 ) in 50 % yield. The compounds under study were fully characterized by various methods, also including X‐ray crystallographic studies on single crystals of 2 and 3 . Density functional theory (DFT) calculations revealed that π conjugation in the bridging oxalamidine framework is increased and n(N)–p(Ge) π bonding is decreased upon κ²N metal coordination; a further weakening of the Ge–N bond occurs through triflate coordination to the Ge^II atom. Nevertheless, preliminary coordination studies revealed that 3 behaves as 2‐electron (L ‐type) germylene donor ligand. Treatment of 3 with [Ir(cod)Cl]₂ furnished the heterobimetallic complex [Rh(cod)(μ‐ 1 )Ge‐Ir(cod)Cl][OTf] ( 4 ), as evidenced by NMR spectroscopic investigations and DFT calculations.     

P−P Condensation and P−N/P−P Bond Metathesis: Facile Synthesis of Cationic Tri‐ and Tetraphosphanes

[L_C^RP((PhP)₂C₂H₄)][OTf] ( 4 a,b [OTf]) and [L_C^iPrP(PPh₂)₂][OTf] ( 5 b [OTf]) were prepared from the reaction of imidazoliumyl‐substituted dipyrazolylphosphane triflate salts [L_C^RP(pyr)₂][OTf] ( 3 a,b [OTf]; a : R=Me, b =iPr; L_C^R=1,3‐dialkyl‐4,5‐dimethylimidazol‐2‐yl; pyr=3,5‐dimethylpyrazol‐1‐yl) with the secondary phosphanes PhP(H)C₂H₄P(H)Ph) and Ph₂PH. A stepwise double P?N/P?P bond metathesis to catena‐tetraphosphane‐2,3‐diium triflate salt [(Ph₂P)₂(L_C^MeP)₂][OTf]₂ ( 7 a [OTf]₂) is observed when reacting 3 a [OTf] with diphosphane P₂Ph₄. The coordination ability of 5 b [OTf] was probed with selected coinage metal salts [Cu(CH₃CN)₄]OTf, AgOTf and AuCl(tht) (tht=tetrahydrothiophene). For AuCl(tht), the helical complex [{(Ph₂PPL_C^iPr)Au}₄][OTf]₄ ( 9 [OTf]₄) was unexpectedly formed as a result of a chloride‐induced P?P bond cleavage. The weakly coordinating triflate anion enables the formation of the expected copper(I) and silver(I) complexes [( 5 b )M(CH₃CN)₃][OTf]₂ (M=Cu, Ag) ( 10 [OTf]₂, 11 [OTf]₂).     

Synthesis of LnII‐in‐Cryptand Complexes by Chemical Reduction of LnIII‐in‐Cryptand Precursors: Isolation of a NdII‐in‐Cryptand Complex

Lanthanide triflates have been used to incorporate Nd^III and Sm^III ions into the 2.2.2‐cryptand ligand (crypt) to explore their reductive chemistry. The Ln(OTf)₃ complexes (Ln=Nd, Sm; OTf=SO₃CF₃) react with crypt in THF to form the THF‐soluble complexes [Ln^III(crypt)(OTf)₂][OTf] with two triflates bound to the metal encapsulated in the crypt. Reduction of these Ln^III‐in‐crypt complexes using KC₈ in THF forms the neutral Ln^II‐in‐crypt triflate complexes [Ln^II(crypt)(OTf)₂]. DFT calculations on [Nd^II(crypt)]²⁺], the first Nd^II cryptand complex, assign a 4f⁴ electron configuration to this ion.     

A Silyliumylidene Cation Stabilized by an Amidinate Ligand and 4‐Dimethylaminopyridine

The synthesis and reactivity of a silyliumylidene cation stabilized by an amidinate ligand and 4‐dimethylaminopyridine (DMAP) are described. The reaction of the amidinate silicon(I) dimer [ L Si:]₂ ( 1 ; L =PhC(NtBu)₂) with one equivalent of N‐trimethylsilyl‐4‐dimethylaminopyridinium triflate [4‐NMe₂C₅H₄NSiMe₃]OTf and two equivalents of DMAP in THF afforded [ L Si(DMAP)]OTf ( 2 ). The ambiphilic character of 2 is demonstrated from its reactivity. Treatment of 2 with 1 in THF afforded the disilylenylsilylium triflate [ L′ ₂( L )Si]OTf ( 3 ; L′ = L Si:) with the displacement of DMAP. The reaction of 2 with [K{HB(iBu)₃}] and elemental sulfur in THF afforded the silylsilylene [ L SiSi(H){(NtBu)₂C(H)Ph}] ( 4 ) and the base‐stabilized silanethionium triflate [ L Si(S)DMAP]OTf ( 5 ), respectively. Compounds 2 , 3 , and 5 have been characterized by X‐ray crystallography.     

Chemoselectivity as a Delineator of Cuprate Structure in Catalytic 1,4‐Addition of Diorganozinc Reagents to Michael Acceptors

Reaction of the cyclic thioacetal (RS)₂CHCHO [R=1/2×? (CH₂)₃? ] with HCCCOMe, followed by treatment with TsCl/DABCO (Ts=tosyl, DABCO=1,4‐diazabicyclo[2.2.2]octane) affords the mono‐protected 1,4‐benzoquinone dithioacetal. The reactivity of this SR‐protected 1,4‐benzoquinone has been compared with the behavior of the analogous OR‐protected acetal in copper‐catalyzed additions of ZnMe₂ by using chiral phosphoramidite ligands. The activation energy for 1,4‐methylation of the latter OR‐acetals with ZnMe₂ (>95 % ee) has been determined for two CuX₂ pre‐catalysts (X=OAc, 12.2 kcal mol^?1; X=OTf, 6.7 kcal mol^?1; Tf=triflate). The dithioacetal SR aromatizes in the presence of Cu^I/ZnMe₂ giving 1,4‐HOC₆H₄S(CH₂)₃SMe through C? S bond formation. The disparate behavior of these two very closely related substrates is in accordance with the formation of closely related cuprate intermediates that were optimized by DFT calculations, supporting the synthetic and kinetic studies and thus defining the mechanisms of both pathways.     

Synthesis,structural and chemosensitivity studies of arene d6 metal complexes having N‐phenyl‐N´‐(pyridyl/pyrimidyl)thiourea derivatives

The d⁶ metal complexes of thiourea derivatives were synthesized to investigate its cytotoxicity. Treatment of various N‐phenyl‐N´ pyridyl/pyrimidyl thiourea ligands with half‐sandwich d⁶ metal precursors yielded a series of cationic complexes. Reactions of ligand (L1‐L3) with [(p‐cymene)RuCl₂]₂ and [Cp*MCl₂]₂ (M = Rh/Ir) led to the formation of a series of cationic complexes bearing general formula [(arene)M(L1)к²_(N,S)Cl]⁺, [(arene)M(L2)к²_(N,S)Cl]⁺ and [(arene)M(L3)к²_(N,S)Cl]⁺ [arene = p‐cymene, M = Ru ( 1 , 4 , 7 ); Cp*, M = Rh ( 2 , 5 , 8 ); Cp*, Ir ( 3 , 6 , 9 )]. These compounds were isolated as their chloride salts. X‐ray crystallographic studies of the complexes revealed the coordination of the ligands to the metal in a bidentate chelating N,S‐ manner. Further the cytotoxicity studies of the thiourea derivatives and its complexes evaluated against HCT‐116 (human colorectal cancer), MIA‐PaCa‐2 (human pancreatic cancer) and ARPE‐19 (non‐cancer retinal epithelium) cancer cell lines showed that the thiourea ligands displayed no activity. Upon complexation however, the metal compounds possesses cytotoxicity and whilst potency is less than cisplatin, several complexes exhibited greater selectivity for HCT‐116 or MIA‐PaCa‐2 cells compared to ARPE‐19 cells than cisplatin in vitro. Rhodium complexes of thiourea derivatives were found to be more potent as compared to ruthenium and iridium complexes.     

Self‐Assembly of Ambidentate Pyridyl‐Carboxylate Ligands with Octahedral Ruthenium Metal Centers: Self‐Selection for a Single‐Linkage Isomer and Anticancer‐Potency Studies

The synthesis of six new [2+2] metallarectangles through the coordination‐driven self‐assembly of octahedral Ru^II‐based acceptors with ambidentate pyridyl‐carboxylate donors is described. These molecular rectangles are fully characterized by ¹H NMR spectroscopy, high‐resolution electrospray mass spectrometry, and single‐crystal X‐ray diffraction. In each case, despite the possible formation of multiple isomers, based on the relative orientation of the pyridyl and carboxylate groups (head‐to‐head versus head‐to‐tail), evidence for the formation of a single preferred ensemble (head‐to‐tail) was found in the ¹H NMR spectra. Furthermore, the cytotoxicities of all of the rectangles were established against A549 (lung), AGS (gastric), HCT‐15 (colon), and SK hep 1 (liver) human cancer cell lines. The cytotoxicities of rectangles that contained the 5,8‐dihydroxy‐1,4‐naphthaquinonato bridging moiety between the Ru centers ( 9 – 11 ) were particularly high against AGS cancer cells, with IC₅₀ values that were comparable to that of reference drug cisplatin.     

Gold(I) ‐Nickel(II)‐4,4′‐bpy‐Phosphine Complexes: Synthesis and Multinuclear NMR Study

Silver triflate [AgOTf] assisted de‐bromination gives [Ni(dppm/dppe/(PPh₃)₂) (OTf)₂], which on reaction with 4,4′‐bpy and gold(I) phosphines in dichloromethane medium by the self assemble technique leads to [{(L)Ni}{(4,4‐bpy)Au(PPh₃)}₂](OTf)₄, ( 1,2,3 ) [{(L)Ni(4,4‐bpy)}₄](OTf)₈, ( 4,5,6 ) [L = dppm/dppe/(PPh₃)₂ = diphenyl phosphino‐methane, ‐ethane, bis‐triphenylphosphine, OSO₂CF₃ is the triflate anion]. The maximum molecular peak of the corresponding molecule is observed in the ESI mass spectrum. Ir spectra of the complexes show ‐C=C‐, ‐C=N‐, as well as phosphine stretching. The ¹H NMR spectra as well as ³¹P (¹H)NMR suggest solution stereochemistry, proton movement, and phosphorus proton interaction. Considering all the moieties, there are a lot of carbon atoms in the molecule reflected by the ¹³C NMR spectrum. In the ¹H‐¹H COSY spectrum of the present complexes and contour peaks in the ¹H^?13C HMQC spectrum, we assign the solution structure and stereoretentive transformation in each step.     

Synthesis,spectroscopic characterization,thermal behaviour,in vitro antimicrobial and anticancer activities of novel ruthenium tricarbonyl complexes containing monodentate V‐shaped Schiff bases

The interaction of Ru₃(CO)₁₂ with a novel family of monodentate V‐shaped Schiff base ligands (L^1–4; L¹: (E)‐1‐(4‐((4‐bromobenzylidene)amino)phenyl)ethanone, L²: (E)‐1‐(3‐(4‐(dimethylamino)benzylideneamino)phenyl)ethanone, L³: (E)‐1‐(4‐(4‐(dimethylamino)benzylideneamino)phenyl)ethanone, L⁴: (E)‐1‐(3‐(3,4‐dimethoxybenzylideneamino)phenyl)ethanone) in air under atmospheric pressure afforded the novel complexes [Ru(CO)₃(L^1–4)₂]. The parent ligands and their complexes were characterized using elemental analyses and spectroscopic techniques. In addition, the structure of the representative ligand L¹ was determined using single‐crystal X‐ray analysis. The stereochemistry and theoretical optimization of the three‐dimensional geometry of the ligands and their complexes were justified. In vitro antimicrobial screening against bacterial stains Escherichia coli and Staphylococcus aureus and fungus Candida albicans was conducted. Cytotoxicity of the compounds as anti‐tumour agents was evaluated against liver carcinoma (HepG2), breast carcinoma (MCF7) and colon carcinoma (HCT‐116) cell lines relative to cisplatin and doxorubicin. The complexes showed variable in vitro cytotoxic activities against the three studied cell lines, with IC₅₀ values less than those of cis‐platin, and thus appear to be building blocks for promising anti‐tumour agents.     

Preparation of Hydride‐Ethylene Complexes of Osmium

Ethylene complexes [OsH(η²‐CH₂=CH₂)L₄]Y ( 1 , 2 ) [L = PPh(OEt)₂, P(OEt)₃; Y = OTf, BPh₄] were prepared by reacting the dihydride OsH₂L₄ first with methyl triflate CH₃OTf and then with ethylene (1 atm). Alternatively, the compound [OsH(η²‐CH₂=CH₂){PPh(OEt)₂}₄]OTf was prepared by allowing the dinitrogen derivative [OsH(N₂){PPh(OEt)₂}₄]OTf to react with ethylene. Acrylonitrile CH₂=C(H)CN reacts with OsH(OTf)L₄ [L = P(OEt)₃] to give the complex [OsH{κ¹‐NCC(H)=CH₂}{P(OEt)₃}₄]BPh₄ ( 3 ). The complexes were characterized spectroscopically (IR and ¹H, ¹³C, ³¹P NMR) and by X‐ray crystal structure determination of the [OsH(η²‐CH₂=CH₂){PPh(OEt)₂}₄]BPh₄ derivative.     

Half‐sandwich ruthenium,rhodium and iridium complexes featuring oxime ligands: Structural studies and preliminary investigation of in vitro and in vivo anti‐tumour activities

Half‐sandwich ruthenium, rhodium and iridium complexes ( 1 – 12 ) were synthesized with aldoxime ( L1 ), ketoxime ( L2 ) and amidoxime ( L3 ) ligands. Ligands have the general formula [PyC(R)NOH], where R = H ( L1 ), R = CH₃ ( L2 ) and R = NH₂ ( L3 ). Reaction of [{(arene)MCl₂}₂] (arene = p ‐cymene, benzene, Cp*; M = Ru, Rh, Ir) with ligands L1 – L3 in 1:2 metal precursor‐to‐ligand ratio yielded complexes such as [{(arene)MLκ²_(N∩N)Cl}]PF₆. All the ligands act as bidentate chelating nitrogen donors in κ²_(N∩N) fashion while forming complexes. In vitro anti‐tumour activity of complexes 2 and 10 against HT‐29 (human colorectal cancer), BE (human colorectal cancer) and MIA PaCa‐2 (human pancreatic cancer) cell lines and non‐cancer cell line ARPE‐19 (human retinal epithelial cells) revealed a comparable activity although complex 2 demonstrated greater selectivity for MIA PaCa‐2 cells than cisplatin. Further studies demonstrated that complexes 3 , 6 , 9 and 12 induced significant apoptosis in Dalton's ascites lymphoma (DL) cells. In vivo anti‐tumour activity of complex 2 on DL‐bearing mice revealed a statistically significant anti‐tumour activity (P  = 0.0052). Complexes 1 – 12 exhibit HOMO–LUMO energy gaps from 3.31 to 3.68 eV. Time‐dependent density functional theory calculations explain the nature of electronic transitions and were in good agreement with experiments.     

Structural analysis of interpenetrated methyl‐modified MOF‐5 and its gas‐adsorption properties

The first example of an interpenetrated methyl‐modified MOF‐5 with the formula Zn₄O(DMBDC)₃(DMF)₂, where DMBDC^2? is 2,5‐dimethylbenzene‐1,4‐dicarboxylate and DMF is N,N‐dimethylformamide (henceforth denoted as Me₂MOF‐5‐int ), namely, poly[tris(μ₄‐2,5‐dimethylbenzene‐1,4‐dicarboxylato)bis(N,N‐dimethylformamide)‐μ₄‐oxido‐tetrazinc(II)], [Zn₄(C₁₀H₈O₄)₃O(C₃H₇NO)₂]_n, has been obtained from a solvothermal synthesis of 2,5‐dimethylbenzene‐1,4‐dicarboxylic acid and Zn(NO₃)₂·6H₂O in DMF. A systematic study revealed that the choice of solvent is of critical importance for the synthesis of phase‐pure Me₂MOF‐5‐int , which was thoroughly characterized by single‐crystal and powder X‐ray diffraction (PXRD), as well as by gas‐adsorption analyses. The Brunauer–Emmett–Teller surface area of Me₂MOF‐5‐int (660 m² g^?1), determined by N₂ adsorption, is much lower than that of nonpenetrated Me₂MOF‐5 (2420 m² g^?1). However, Me₂MOF‐5‐int displays an H₂ uptake capacity of 1.26 wt% at 77 K and 1.0 bar, which is comparable to that of non‐interpenetrated Me₂MOF‐5 (1.51 wt%).     

Indium‐Catalyzed Synthesis of Keto Esters from Cyclic 1,3‐Diketones and Alcohols and Application to the Synthesis of Seratrodast

Esterification reactions from cyclic 1,3‐diketones and alcohols are carried out in the presence of several Lewis acids. In particular, indium(III) triflate, In(OTf)₃, iron(III) triflate, Fe(OTf)₃, copper(II) triflate, Cu(OTf)₂, and silver(I) triflate, AgOTf, show high catalytic activities. These reactions proceed through the carbon–carbon bond cleavage by a retro‐aldol reaction and were found to be highly regioselective even in the presence of other functional groups. This type of reaction can also be applied to the preparation of the keto esters during the synthesis of seratrodast, which is an antiasthmatic and eicosanoid antagonist.     

Acid‐, Water‐ and High‐Temperature‐Stable Ruthenium Complexes for the Total Catalytic Deoxygenation of Glycerol to Propane

The ruthenium aqua complexes [Ru(H₂O)₂(bipy)₂](OTf)₂, [cis‐Ru(6,6′‐Cl₂‐bipy)₂(OH₂)₂](OTf)₂, [Ru(H₂O)₂(phen)₂](OTf)₂, [Ru(H₂O)₃(2,2′:6′,2′′‐terpy)](OTf)₂ and [Ru(H₂O)₃(Phterpy)](OTf)₂ (bipy=2,2′‐bipyridine; OTf^?=triflate; phen=phenanthroline; terpy= terpyridine; Phterpy=4′‐phenyl‐2,2′:6′,2′′‐terpyridine) are water‐ and acid‐stable catalysts for the hydrogenation of aldehydes and ketones in sulfolane solution. In the presence of HOS(O)₂CF₃ (triflic acid) as a dehydration co‐catalyst they directly convert 1,2‐hexanediol to n‐hexanol and hexane. The terpyridine complexes are stable and active as catalysts at temperatures ≥250 °C and in either aqueous sulfolane solution or pure water convert glycerol into n‐propanol and ultimately propane as the final reaction product in up to quantitative yield. For the terpy complexes the active catalyst is postulated to be a carbonyl species [(4′‐R‐2,2′:6′,2′′‐terpy)Ru(CO)(H₂O)₂](OTf)₂ (R=H, Ph) formed by the decarbonylation of aldehydes (hexanal for 1,2‐hexanediol and 3‐hydroxypropanal for glycerol) generated in the reaction mixture through acid‐catalyzed dehydration. The structure of the dimeric complex [{(4′‐phenyl‐2,2′:6′,2′′‐terpy)Ru(CO)}₂(μ‐OCH₃)₂](OTf)₂ has been determined by single crystal X‐ray crystallography (Space group P (a=8.2532(17); b=12.858(3); c=14.363(3) Å; α=64.38(3); β=77.26(3); γ = 87.12(3)°, R=4.36 %).     

Synthesis of three new 1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl) pyrrole‐based donor polymers and their bulk heterojunction solar cell applications

A series of three new 1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole‐based polymers such as poly[1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole] ( PTPT ), poly[1,4‐(2,5‐bis(octyloxy)phenylene)‐alt‐5,5'‐(1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole)] ( PPTPT ), and poly[2,5‐(3‐octylthiophene)‐alt‐5,5'‐(1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole)] ( PTTPT ) were synthesized and characterized. The new polymers were readily soluble in common organic solvents and the thermogravimetric analysis showed that the three polymers are thermally stable with the 5% degradation temperature >379 °C. The absorption maxima of the polymers were 478, 483, and 485 nm in thin film and the optical band gaps calculated from the onset wavelength of the optical absorption were 2.15, 2.20, and 2.13 eV, respectively. Each of the polymers was investigated as an electron donor blending with PC₇₀BM as an electron acceptor in bulk heterojunction (BHJ) solar cells. BHJ solar cells were fabricated in ITO/PEDOT:PSS/polymer:PC₇₀BM/TiO_x/Al configurations. The BHJ solar cell with PPTPT :PC₇₀BM (1:5 wt %) showed the power conversion efficiency (PCE) of 1.35% (J_sc = 7.41 mA/cm², V_oc = 0.56 V, FF = 33%), measured using AM 1.5G solar simulator at 100 mW/cm² light illumination. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010