Solvent-free Synthesis of Dihydrofuran-fused [60]Fullerene Derivatives by High-speed Vibration Milling

Solvent-free organic reactions have been attracting great interest of chemists due to the elimination of the usage of harmful organic solvents,low costs,and simplicity in the procedure1.Solvent-free mechanochemical reactions of fullerenes were explored and are significant for the reactions of fullerenes because the low solubility of fullerenes in common organic solvents requires large quantity of organic solvents and some novel fullerene reactions could only occur in the solid-state reaction2.…     

Studies on New Additions to 5-Methoxy-2 (5H)-Furanone: 1, 4-Addition of Grignard Reagents, and 1,3-Dipolar Cycloaddition of Silyl Nitronates

Recently, much effort has been made in the development of generally applicable organic synthesis of 5-alkyloxy-2(5H)-furanones due to their essential structure entities in the synthesis of some biologically active natural products and their application as useful intermediates in organic synthesis1. Their reactions such as Michael addition, Diels-Alder reaction and photocatalyzed conjugate addition have been studied extensively2-4.However, Michael addition reaction of Grignard reagents to 5-m…     

Synthesis and Structure of Ba3La2（BO3）4 Crystal

1 INTRODUCTION At present the researches on more efficient solid-state laser materials become more important for the rapid development of diode-laser pumped solid-state laser. More researches have been devoted to the double borate compounds RX3(BO3)4 (R = Y, La, Gd and X = Y, Al, Sc), some of which exhibit good chemical and physical properties[1～10]. The rare earth and alkali-halide double borates M3Ln2(BO3)4 (M = Ca, Sr, Ba and Ln = LaLu and Y) were reported in literatures[11…     

Enhanced Acid/Base Catalysis in High Temperature Liquid Water

High temperature liquid water (HTLW), as an environmentally benign medium, has drawn increasing attention for organic chemical reactions and biomass conversion1-3. HTLW has a strong tendency to ionize and can act as an acid and/or base catalyst. In addition, HTLW can dissolve organic compounds to some extent allowing for a homogenous reaction within an aqueous phase. Extensive researches4-10 have been pursued on acid/base-catalysis reactions in HTLW without addition of acid or base. Howe…     

Highly Stereoselective Synthesis of Phenylseleno- and p-Tolylsulfonyl Substituted 1,3-Dienes from Functionalized Allyl Alcohols

Introduction Heteroatom-substituted 1,3-dienes have been exten-sively studied because of their marked abilities to con-struct highly functionalized ring systems in cycloaddi-tions.1 For example, Danishefsky2 developed 1-methoxy-3-trimethyl-siloxy-buta-1,3-diene which has led to many creative applications in complex organic synthesis. Padwa et al.3 demonstrated that 1,3- and 2, 3-bis(phenyl-sulfonyl)-1,3-butadienes are versatile building blocks in organic synthesis via reactions such as [4+2]-c…     

Synthesis of Aryl Allyl Ether in the Recyclable Ionic Liquid [bmim]PF_6

Ionic liquids, especially imidazonium salts, have recently gained recognition as possible environmentally benign alternative chemical process solvents. This is mainly due to their nonvolatile nature, insolubility in some solvents as well as their ability to dissolve a wide range of organic and inorganic materials, allowing the ionic liquids easy recovery and recycling. Examples of their application in organic reactions have been summarized in a number of recent review articles. 1 Aryl allyl et…     

Solid Phase Catalytic Oxidation of Alcohols by Polymer Supported Rare Earth Catalysts

Oxidation of alcohols to the corresponding aldehydes or ketones is one of the most fundamental reactions in organic chemistry [1, . Some of the products of the oxidation exhibit an 2] important role in the organic synthesis as well as pharmaceutical synthesis. In most reactions, the lanthanide complexes show satisfied catalytic activities for some compounds. Furthermore, there has been increasing interest in the lanthanide complexes and several reports have appeared in the literature[3, 4] …     

Ring Contraction Reaction of 4H-1,3-Oxazin-4-ones under Electrospray Ionization Conditions

Ring contraction reactions of heterocyclic compounds under mass ionization conditions are important and interesting phenomenon.[1] It should be very useful to elucidate the fragmentation of some novel heterocyclic compounds and to identify the structures of some effective compounds in a screened library by mass spectrometric method, which is an easy and available method for identification of effective members in a library due to development of LC-MS. Recently several ring contraction reactions have been reported in literatures.     

Reductive Cyclodimerization of Arylidenecyanoacetates Promoted by Sm/InCl_3·4H_2O System in Aqueous Media

Metal-mediated reactions in aqueous media have received considerable attention in the last decade1. Such aqueous reactions offer a number of advantages over conventional organometallic reactions in organic solvent in that they are practically convenient, environmentally benign and do not require strict anhydrous conditions2. In recent years, besides zinc and tin, indium has been found to be the metal of choice for promoting organic reactions in aqueous media3. Indium is considered to be mor…     

Electroreduction of Benzoylformic Acid in 1-Ethyl-3-methylimidazolium Bromide Room Temperature Ionic Liquid

The chemical industry is under considerable pressure to replace many volatile organic compounds that are widely used as solvents in organic synthesis. This trend leads to the exploration for novel reaction media. Room temperature ionic liquids as environmentally benign media for organic synthesis and catalytic reactions have been gradually recognized and accepted Owing to their unique chemical and physical properties, ionic liquids become promising candidates as recyclable reaction media for “ Green” applications. These nonvolatile solvents have been used as media or catalysts in dozens of fields, such as organic synthesis, organometallic catalytic reactions, separation and extraction processes.     

Recent Advances in Organic Reactions Catalyzed by Lanthanide(III) Complexes

Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｔｈｅｎａｍｅ“ｒａｒｅｅａｒｔｈ”ａｐｐｌｉｅｓｔｏｔｈｅｌａｎｔｈａｎｉｄｅｓ ,ｙｔｔｒｉｕｍａｎｄｓｃａｎｄｉｕｍ .Ｔｈｅ 15ｅｌｅｍｅｎｔｓｏｆｌａｎｔｈａｎｉｄｅｆｒｏｍｌａｎｔｈａｎｕｍｔｏｌｕｔｅｔｉｕｍｃｏｎｓｔｉｔｕｔｅａｕｎｉｑｕｅｆａｍｉｌｙｏｆｃｌｏｓｅｌｙｒｅｌａｔｅｄｅｌｅｍｅｎｔｓ (ｔｈｅｄｉｆｆｅｒｅｎｃｅｌｙｉｎｇｉｎｔｈｅｎｕｍ ｂｅｒｏｆ 4ｆｅｌｅｔｒｏｎｓ)ｆｒｏｍｗｈｉｃｈｒｅｇｅｎｔｓｏｒｃａｔａｌｙｓｔｓｗｉｔｈ“ｔｕｎａｂ…     

Hydrothermal Syntheses,Crystal Structures and Properties of Two Novel 3‐D Lanthanide(III) Coordination Polymers Constructed with Mixed Heterocyclic Carboxylic Acid

The hydrothermal reactions of Ln₂O₃ (Ln = Nd and Eu) with pyridine‐2,5‐dicarboxylic acid (H₂pydc) resulted in the formation of two isomorphic three‐dimensional (3D) polymeric Ln^III complexes, [Ln(pydc)(nic)·H₂O]_n (Ln = Nd( 1 ) and Eu( 2 )), in which nic (nicotinate; also named as pyridine‐2‐carboxylic acid) might have been formed from the pydc ligands through the C–C bond cleavage and CO₂ molecules releasing. Pydc ligands bridge lanthanide centers to form the three‐dimensional framework featuring hexagonal channels along the axis a which are occupied by bridging nic anions and mono‐coordinated water molecules. From the topological point of view, two three‐dimensional nets are binodal with six‐ and three‐connected nodes, which display a distorted rutile (4.6²)₂(4²·6¹⁰·8³) topology. Magnetic measurements (2‐300 K) reveal that all polymers possess weak antiferromagnetic property. A strong fluorescence emission spectrum of compound 2 was observed.     

Structural investigation of one‐ and three‐dimensional lanthanide(III) coordination polymers based on functionalized terpyridine carboxylate and aromatic dicarboxylate ligands

Three series of lanthanide coordination polymers, namely catena‐poly[[lanthanide(III)‐μ₂‐(benzene‐1,2‐dicarboxylato)‐μ₂‐[2‐(2,2′:6′,2′′‐terpyridin‐4′‐yl)benzoato]] monohydrate], {[Ln(C₈H₄O₄)(C₂₂H₁₄N₃O₂)]·H₂O}_n or {[Ln(1,2‐bdc)(L)]·H₂O}_n, with lanthanide (Ln) = dysprosium (Dy, 1 ), holmium (Ho, 2 ) and erbium (Er, 3 ), poly[bis(μ₂‐benzene‐1,3‐dicarboxylato)bis[μ₂‐2‐(2,2′:6′,2′′‐terpyridin‐4′‐yl)benzoato]dilanthanide(III)], [Ln₂(C₈H₄O₄)₂(C₂₂H₁₄N₃O₂)₂]_n or [Ln₂(1,3‐bdc)₂(L)₂]_n, with Ln = gadolinium (Gd, 4 ), Ho ( 5 ) and Er ( 6 ), and poly[(μ₂‐benzene‐1,4‐dicarboxylato)[μ₂‐2‐(2,2′:6′,2′′‐terpyridin‐4′‐yl)benzoato]lanthanide(III)], [Ln(C₈H₄O₄)(C₂₂H₁₄N₃O₂)]_n or [Ln(1,4‐bdc)(L)]_n, with Ln = Dy ( 7 ), Ho ( 8 ), Er ( 9 ) and ytterbium (Yb, 10 ), were synthesized under hydrothermal conditions and characterized by elemental analysis, IR and single‐crystal X‐ray diffraction. Compounds 1 – 3 possess one‐dimensional loop chains with Ln₂(COO)₂ units, which are extended into three‐dimensional (3D) supramolecular structures by π–π interactions. Isostructural compounds 5 and 6 show 6‐connected 3D networks, with pcu topology consisting of Ln₂(COO)₂ units. Compounds 7 – 10 display 8‐connected 3D frameworks with the topological type rob , consisting of Ln₂(COO)₂ units. The influence of the coordination orientations of the aromatic dicarboxylate groups on the crystal structures is discussed.     

2D l‐Di‐toluoyl‐tartaric acid Lanthanide Coordination Polymers: Toward Single‐component White‐Light and NIR Luminescent Materials

A series of five l ‐di‐p‐toluoyl‐tartaric acid (l ‐DTTA) lanthanide coordination polymers, namely {[Ln₄K⁴ L₆(H₂O)_x]?yH₂O}_n, [Ln=Dy ( 1 ), x=24, y=12; Ln=Ho ( 2 ), x=23, y=12; Ln=Er ( 3 ), x=24, y=12; Ln=Yb ( 4 ), x=24, y=11; Ln=Lu ( 5 ), x=24, y=12] have been isolated by simple reactions of H₂L (H₂L= L ‐DTTA) with LnCl₃?6 H₂O at ambient temperature. X‐ray crystallographic analysis reveals that complexes 1 – 5 feature two‐dimensional (2D) network structures in which the Ln³⁺ ions are bridged by carboxylate groups of ligands in two unique coordinated modes. Luminescent spectra demonstrate that complex 1 realizes single‐component white‐light emission, while complexes 2 – 4 exhibit a characteristic near‐infrared (NIR) luminescence in the solid state at room temperature.     

Core‐Shell Structured Layered Lanthanide‐Organic Complexes with Stilbazolium‐type Dye Encapsulation for Multifunctional Performances

Host‐guest encapsulation of functional organic dye into a porous metal‐organic framework can give rise to the development of new functional materials. In this work, by intercalating the stilbazolium‐type dye (DEAST)I (4′‐diethylamino‐N‐methyl stilbazolium) into four lanthanide layered metal‐organic complexes (Ln‐LMOCs), i. e. {[Ln(BTB)(H₂O)₂]?3(DMF)?2(H₂O)}_n (Ln=La (1), Nd (2), Sm (3), Er (4)), four responsive (DEAST)I@Ln‐LMOC composites have been prepared, serving as multifunctional performance platform. The core–shell structures of (DEAST)I@Ln‐LMOC composites have been fully characterized by IR, UV/Vis, PXRD, SEM, TEM, TGA and ESR. Significantly, after intercalation of dyes, the (DEAST)I@Ln‐LMOC composites exhibit enhanced luminescent sensing properties in detecting Fe³⁺ with much higher water stabilities. The luminescent sensing behavior stems from the fluorescence resonance energy transfer (FRET) from the π‐electron‐rich BTB ligands to the Fe³⁺, and their higher water stabilities are induced by electrostatic interactions and lower porosity. Specially, the characteristic emissions of Sm³⁺ will not be affected after the encapsulation guest dyes, which provide a theoretical guide for the modulation of luminescence devices. Finally, better ion conductivities and diminished photocurrents can be achieved after the embedding of the functional organic dye. In all, the formation of (DEAST)I@Ln‐LMOC composites with core–shell structures can be utilized as a multifunctional platform with good stability.     

Ln3UO6Cl3 (Ln=La,Pr, Nd) -. Die ersten Oxochlorouranate der Seltenen Erden

Ln₃UO₆Cl₃ (Ln=La, Pr, Nd) — The First Oxochlorouranates of the Rare Earths . The new compounds Ln₃UO₆Cl₃ (Ln=La, Pr, Nd) were prepared by heating stoichiometric amounts of LnOCl/Ln₂O₃/U₃O₈ (7 : 1 : 1) (Ln=La, Nd) and PrOCl/Pr₆O₁₁/U₃O₈ (12 : 1 : 2) in silica ampoules (5 d, 1000°C, Ln=La; 9 d 800°C, Ln=Pr, Nd) in the presence of an excess of chlorine [p(Cl₂, 25°C)=1 atm]. Single crystals were obtained by chemical transport reactions using chlorine [p(Cl₂, 25°C)=1 atm] as transport agent [T₂=1000°C→T₁=900°C (Ln=La); T₂=840°C→T₁=780°C (Ln=Pr, Nd)]. Crystals of Ln₃UO₆Cl₃ (Ln=La, Pr, Nd) were investigated by X-ray diffraction methods and La₃UO₆Cl₃ additionally by high resolution electron microscopy. The compounds Ln₃UO₆Cl₃ crystallize in the hexagonal spacegroup P6₃/m (No. 176) with Z=2 formula units per unit cell. Isotypical structure refinements resulted in R=3.04% respectively R_w=1.91% (Ln=La), R=4.72% respectively R_w=3.80% (Ln=Pr) and R=3.99% respectively R_w=2.49% (Ln=Nd). Uranium is coordinated with six oxygen atoms forming a trigonal prism. Lanthanide ions are 10-coordinated (6 oxygen atoms, 4 chlorine atoms).     

Synthese und Kristallstrukturen neuer komplexer Chloride der Lanthanide mit 3, 5‐Dimethylpyridiniumkationen: (3, 5‐Dimethylpyridinium)2[LnCl4(H2O)2]Cl (Ln = La,Pr) und (3, 5‐Dimethylpyridinium)3[TbCl6]

Preparation and Crystal Structures of New Complex Clorides of Lanthanides containing 3, 5‐Dimethylpyridinium Cations: (3, 5‐Dimethylpyridinium)₂[LnCl₄(H₂O)₂]Cl (Ln = La, Pr) and (3, 5‐Dimethylpyridinium)₃[TbCl₆] Crystals of the complex chlorides (3, 5‐dimethylpyridinium)₂[LaCl₄(H₂O)₂]Cl ( 1 ), (3, 5‐dimethylpyridinium)₂[PrCl₄(H₂O)₂]Cl ( 2 ) and (3, 5‐dimethylpyridinium)₃[TbCl₆] ( 3 ) have been prepared by reaction of LnCl₃ · x H₂O (Ln = La, Pr, Tb; x = 6‐7) with 3, 5‐dimethylpyridiniumchloride in ethanol/butanol solution. The crystal structures have been determined from single crystal X‐ray diffraction data. The compounds 1 and 2 are isotypic with each other and crystallize in the triclinic space group P1¯ (Z = 2). The 3, 5‐dimethylpyridinium cations are linked by hydrogen bonds to the anionic part of the structure built up by isolated chloride ions and strings of edge coupled triangulated dodecahedra [LnCl_4/2Cl₂(H₂O)₂]^—. The organic units are arranged forming a “π‐stacking”. 3 cristallizes monoclinically in the space group P2₁/c (Z = 4). The structure contains octahedral building units [TbCl₆]^3—. These octahedra are interconnected by the organic cations via hydrogen bonds forming chains parallel to [0 0 1].     

Synthesis and catalytic activity of novel heteronuclear Ln (III) -Cu(II) complexes with noncyclic polyether-amino acid Schiff base

A series of novel heteronuclear Ln(III)-CU(II) complexes with noncyclic polyether-amino acid Schiff base were synthesized. The general formula is (LnCu₂(H₂TALY) (NO₃)₅] (NO₃)₂·nH₂O (Ln= La, Nd, Sm, Gd,n = 4; Ln = Yb, Y,n = 3), where H₂TALY = tetraglycol aldehyde bis-lysine Schiff base. It is the first time to report the synthetic method for this new Cu(II) complexes and Ln(III)-Cu(II) heteronuclear complexes. The complexes were characterized by elemental analysis, IR spectra. TG-DTA, magnetic susceptibility, and especially by a 500 MHz NMR spectrometer for 2D-COSY NMR. Coordination mechanism and structures of complexes have been suggested as well. Of particular interest is the potential that the novel complexes obtained may be used as a catalyst. which prompted us to investigate them. It shows 100% conversion with the viscosity-average molecular weight 120 000 for the polymerization of methyl methacrylate (MMA) without addition of any cocatalyst. Furthermore, the complexes with such aliphatic Schiff bases can be used as a good catalyst, which has been confirmed and discussed here. They may be a new kind of catalyst system with the above speciality. Project supported by the National Natural Science Foundation of China (Grant No. 29671026) and Natural Science Foundation of Zhejiang Province (Grant No. 296062) and the Laboratory of MRAMP (Grant No. 971502).     

Reversible coordinative chain transfer polymerization of styrene by rare earth borohydrides,chlorides/dialkylmagnesium systems

The ability of various rare earth borohydride and chloride complexes/n‐butylethylmagnesium systems to operate styrene chain transfer polymerization in mild conditions has been assessed. Thirteen precatalysts have been considered: the rare earth trisborohydrides Ln(BH₄)₃(THF)_x (x = 3, Ln = Nd (1), La (2), Sm (3), x = 2, Ln = Y (4), Sc (5)), the rare earth chlorides LnCl₃(THF)_x (x = 3, Ln = Nd (6), La (7), Sm (8), Y (9), x = 2, Ln = Sc (10)), the mixed La(BH₄)₂Cl(THF)_2.6 (11) and the half‐lanthanidocenes Cp*Ln(BH₄)₂(THF)₂ (Ln = Nd (12), La (13)). Six systems were found to be active precatalysts for the polymerization of styrene. 1 , 2 , and 11 led to an efficient transmetalation of the growing polystyrene chain with the simultaneous occurrence of βH elimination, whereas 7 , 12 , and 13 led to catalyzed chain growth behavior. It is noteworthy that the catalyzed chain growth obtained with 12 and 13 occurs with significant stereoselectivity. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 802–814, 2010     

CuII?GdIII Cryogenic Magnetic Refrigerants and Cu8Dy9 Single‐Molecule Magnet Generated by In Situ Reactions of Picolinaldehyde and Acetylpyridine: Experimental and Theoretical Study

A series of heterometallic [Ln^III_xCu^II_y] complexes, [Gd₂Cu₂]_n ( 1 ), [Gd₄Cu₈] ( 2 ), [Ln₉Cu₈] (Ln=Gd, 3?Gd ; Ln=Dy, 3?Dy ), were successfully synthesized by a one‐pot route at room temperature with three kinds of in situ carbonyl‐related reactions: Cannizzaro reaction, aldol reaction, and oxidation. This strategy led to dysprosium analogues that behaved as single‐molecule magnets (SMMs) and gadolinium analogues that showed significant magnetocaloric effect (MCE). In this study a numerical DFT approach is proposed by using pseudopotentials to calculate the exchange coupling constants in three polynuclear [Gd_xCu_y] complexes; with these values exact diagonalization or quantum Monte Carlo simulations have been performed to calculate the variation of the magnetic entropy involved in the MCE. For the [Dy₉Cu₈] complexes, local magnetic properties of the Dy^III centers have been determined by using the CASSCF+RASSI method.