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Sulfonates were incorporated into six novel high-nuclearity silver(I) thiolate clusters under the guidance of anion templates varied from S2- , SO42- , α-[Mo5 O18 ]6- , β-[Mo5 O18 ]6- , [Mo2 O8 ]4- , to [Mo4 O14 (SO4 )]6- . Single crystal X-ray analysis revealed that SD/Ag1, SD/Ag3, SD/Ag5, and SD/Ag6 are discrete [S@Ag60 ], [α-Mo5 O18 @Ag36 ], [Mo2 O8 @Ag30 ]2 , and [Mo4 O14 (SO4 )@Ag73 ] clusters, respectively, whereas SD/Ag2 and SD/Ag4 are one-dimensional (1D) chains based on the [SO4 @Ag20 ] and [β-Mo5 O18 @Ag36 ] cluster subunits, respectively. Their silver skeletons are protected exteriorly by thiolates and sulfonates and interiorly supported by diverse anions as templates. Structurally, cluster SD/Ag1 is a typical core-shell structure comprised of an inner Ag12 cuboctahedron and an outer Ag48 shell. The sulfate-templated drum-like Ag20 cluster subunits are bridged by PhSO3- to give a 1D chain of SD/Ag2. Complex SD/Ag3 and SD/Ag4 are spindle-like Ag36 clusters with isomeric [Mo5 O18 ]6- inside, and the latter is further extended to a 1D chain through PhSO3- bridges. A pair of [Mo2 O8 ]4- templated gourd-like Ag30 clusters are dimerized in a head-to-head fashion to form SD/Ag5. Complex SD/Ag6 is the largest cluster in this family and doubly templated by unprecedented [Mo4 O14 (SO4 )]6- anions. Geometrically, the silver shells of SD/Ag1-SD/Ag5 show the polyhedral features of Johnson solids, instead of the usual Platonic or Archimedean solids. Solution behaviors and luminescent properties were also investigated in detail.

The largest Ln-Fe metal cluster [Gd

A family of six triple-decker complexes, {(MX)2[(pz)4]3} (Hpz = 4-nitropyrazole, MX = NaCl, 1; NaBr, 2; NaI, 3; KCl, 4; KBr, 5, and KI, 6), exhibiting inclusion of halides into inverse 12-metallacrown-4 [inv-(12-MCCu(I),pz-4)] array has been realized. Single-crystal X-ray crystallography of each compound reveals a common structural feature consisting of four CuI ions bonded by four pz to form a square metallomacrocycle comprising four metal centers and eight N atoms, thus giving an inv-[12-MCCu(I),pz-4] motif. Two halides are sandwiched by three inv-[12-MCCu(I),pz-4] to form triple-deckers that are further extended in an offset stacking mode by ligand-unsupported cuprophilicity interactions to form a one-dimensional chain structure. Halides are attached to six CuI centers with weak CuI···halogen interaction, resembling anion templates. High-resolution electrospray ionization mass spectrometry reveals that the predominant fragments corresponding to a half of the triple-decker structures of 1–3 exist in sol...

We report a photochemical synthesis of Pd/CeO2 catalysts with atomically dispersed Pd. Compared to atomically dispersed Pd/CeO2 with a cubic CeO2 support (Pd/CeO2-CP), atomically dispersed Pd/CeO2 with a truncated octahedral CeO2 support (Pd/CeO2-TOP) exhibited higher activity and selectivity, owing to the synergy between Pd atoms and the (111) surface of CeO2. When compared to Pd/CeO2 with Pd clusters and nanoparticles via chemical reduction, Pd/CeO2-TOP showed excellent activity with an enhancement factor of 324 in CO oxidation, as well as an activity enhancement by a factor of 344 in selective oxidation of benzyl alcohol.

Fullerenes with novel structures find numerous potential applications, particularly in the fields of biology and pharmaceutics. Among various fullerene derivatives, those exhibiting amphiphilic character and capable of self-assembly into vesicles are particularly interesting, being suitable for delayed drug release. Herein, we report the synthesis and self-assembly of biocompatible hollow nanovesicles with bilayer shells from amphiphilic functionalized fullerenes C60R5Cl (R=methyl ester of 4-aminobutyric/glutamic acid or phenylalanine). The thus prepared vesicles exhibit sizes of 80-135nm (depending on R) and can be used as delayed-release carriers of anti-cancer drugs such as 5-fluorouracil, cyclophosphamide, and cisplatin, with the time of 5-fluorouracil release from drug-containing vesicles exceeding that of non-encapsulated forms by a factor of three. We further reveal the effect of R on the loading amount and release rate/amount of vesicle-encapsulated drugs, demonstrating a potential pharmaceutical application of the prepared nanovesicles depending on the nature of R.

Crystal phase regulations may endow materials with enhanced or new functionalities. However, syntheses of noble metal-based allomorphic nanomaterials are extremely difficult, and only a few successful examples have been found. Herein, we report the discovery of hexagonal close-packed Pt–Ni alloy, despite the fact that Pt–Ni alloys are typically crystallized in face-centred cubic structures. The hexagonal close-packed Pt–Ni alloy nano-multipods are synthesized via a facile one-pot solvothermal route, where the branches of nano-multipods take the shape of excavated hexagonal prisms assembled by six nanosheets of 2.5 nm thickness. The hexagonal close-packed Pt–Ni excavated nano-multipods exhibit superior catalytic property towards the hydrogen evolution reaction in alkaline electrolyte. The overpotential is only 65 mV versus reversible hydrogen electrode at a current density of 10 mA cm−2, and the mass current density reaches 3.03 mA μgPt−1 at −70 mV versus reversible hydrogen electrode, which outperforms currently reported catalysts to the best of our knowledge., While crystal phase modification may endow materials with altered functionality, the fabrication of allomorphic noble metal nanomaterials is challenging. Here, the authors synthesize an unusual hexagonal close-packed platinum-nickel alloy and demonstrate its enhanced hydrogen evolution catalytic activity.

S2-, MoO42-, and Mo6O228- were successfully employed as templates in the formation of six high-symmetry polynuclear silver clusters as exemplified in the single-crystal X-ray structures of [S@Ag18(tBuC6H4S)16(dppp)4]·DMF·5CH3CN·3CH3OH (1), [MoO4@Ag24(MeC6H4S)12(dppm)6(MoO4)4]·2BF4·C2H5NO (2), [MoO4@Ag24(MeC6H4S)12(dppm)6(MoO4)4]·2CF3SO3 (3), [MoO4@Ag24(MeC6H4S)12(dppf)6(MoO4)4]·2CF3SO3 (4), [MoO4@Ag24(MeC6H4S)12(dppb)6(MoO4)4]·2CF3SO3 (5) and [Mo6O22@Ag46(tBuC6H4S)32(dppm)4(CH3CN)8]·6CF3SO3 (6) (dppp = 1,3-bis(diphenylphosphino)propane, dppm = bis(diphenylphosphino)methane, dppf = 1,1'-bis(diphenylphosphino)ferrocene and dppb = 1,4-bis(diphenylphosphino)butane). Cluster 1 is a S2--centered octadecanuclear banana-shaped molecule. Clusters 2-5 have similar structures consisting of a tetrahedron of a MoO42- core and four MoO42- where three silver atoms cap each face and a pair sits on each edge, giving tetraicosanuclear ball-shaped molecules. Although different diphosphine ligands and silver salts were used in the syntheses, 2-5 contain a common building cluster unit with similar geometry and nuclearity. With (Bu4N)2Mo6O19 as a template, a giant 46-silver-atom cluster encapsulates an in situ modified Mo6O228- unit. The nuclearity and geometry depend on the size and shape of the templates. High-resolution electrospray mass spectrometry (HR-ESI-MS) analyses of 4 indicate its exceptionally high stability in acetonitrile. The solid-state luminescence of 1 as a function of the temperature exhibits thermochromism from red to yellow due to the different intensities of the two bands. This work established a new strategy for the construction of polynuclear silver clusters using an anionic template and mixed S- and P-donor ligands where a promising approach for building novel dual emissive materials is unraveled.

Functional nanoparticles encapsulated within metal–organic frameworks (MOFs) as an emerging class of composite materials attract increasing attention owing to their enhanced or even novel properties caused by the synergistic effect between the two functional materials. However, there is still no ideal composite structure as platform to systematically analyze and evaluate the relation between the enhanced catalytic performance of composites and the structure of MOF shells. In this work, taking RhCoNi ternary alloy nanoflowers, for example, first the RhCoNi@MOF composite catalysts sheathed with different structured MOFs via a facile self-sacrificing template process are successfully fabricated. The structure type of MOF shells is easily adjustable by using different organic molecules as etchant and coordination reagent (e.g., 2,5-dihydroxyterephthalic acid or 2-methylimidazole), which can dissolve out the Co or Ni element in the alloy template in a targeted manner, thereby producing ZIF-67(Co) or MOF-74(Ni) shells accordingly. With the difference between the two MOF shells in the aperture sizes, the as-prepared two RhCoNi@MOF composites preform distinct size selectivity during the alkene hydrogenation. This work would help us to get more comprehensive understanding of the intrinsic role of MOFs behind the enhanced catalytic performance of nanoparticle@MOF composites.

Three homometallic high-nuclearity clusters, formulated as [(CO

We report the synthesis and photoelectrochemical activity of three lanthanide–titanium oxo clusters (LTOCs), formulated as [Ln8Ti10(μ3-O)14(tbba)34(Ac)2(H2O)4(THF)2]·2Htbba [Ln = Eu (1), Sm (2), and Gd (3); Htbba = 4-tert-butylbenzoic acid; Ac– = acetate]. These stable compounds are efficient catalysts of photoelectrochemical water oxidation with high turnover numbers (7581.0 for 1, 5172.4 for 2, and 5413.0 for 3) and high turnover frequencies (2527.0 for 1, 1724.1 for 2, and 1804.0 for 3). The differences in the photoelectrochemical activity among these three compounds may be related to the differences in their band gaps. This work shows that the heterometallic LTOCs provide a tunable platform for the design of highly effective water oxidation catalysts.

The assembly of 1,4-bis(pyrid-4-yl)benzene (bpb) and Fe(NCS)2 affords three supramolecular isomeric frameworks formulated as [Fe(bpb)2(NCS)2]·X (X = 3EtOH for 1, 2.5H2O for 2, and 0 for 3, respectively). Crystallographic studies reveal that 1 belongs to the monoclinic space group C2/c and crystallizes into a threefold self-interpenetrated 3D 65·8 CdSO4-type framework, whereas 2 crystallizes in the monoclinic space group P2/c and features a 2D 44 square-grid network. The immersion of red crystals of 1 into a methanol/ethanol (1:3) solvent led to the formation of yellow crystals of 3, showing structural transformation via crystal disassembly and reassembly process. 3 crystallizes in the triclinic space group P1 and is a 2D 44 rhombus-grid network, but showing nonporous feature (compared with 2) because of more compact network stacking. The most interesting feature is that crystals of 3 are not able to be synthesized by the direct reaction of Fe(NCS)2 with ligand bpb. We suppose that this structural isomeri...

Regioselective reaction of C60Cl6 with thioamides via a radical annulation to form fullereno thiazole derivatives is reported. The reaction is promoted by K2CO3, which might deprotonate thioamide to initiate a single electron transfer from thioamide anion to C60Cl6. The experiments with various thioamides establish the proposed base-promoted reaction as a facile route for synthesis of fullereno fused thiazole derivatives starting from C60Cl6, a prevalent synthon in fullerene chemistry. In addition, the tunable electrochemical properties of the fullereno thiazole products have been investigated for their potential photovoltaic application.

Four fullerene derivatives, benzocyclopentane-C 60 mono-adduct (BPCMA) and its bis-adduct (BPCBA), acenaphthene-C 60 mono-adduct (ACMA) and its bis-adduct (ACBA), were synthesized by cyclopropanation reaction. Geometrical structures and molecular packing of the mono-adduct compounds (BPCMA and ACMA) were identified by X-ray crystallography. As measured by cyclic voltammetry, LUMO energy levels of BPCBA and ACBA are about 0.08 and 0.09 eV higher than their corresponding mono-adducts. Even though the power conversion efficiency remains to be improved, the polymer solar cells (PSCs) incorporating P3HT as donor and BPCBA (or ACBA) as acceptor exhibit open-circuit voltage ( V oc ) of 0.67 V (or 0.68 V), which is about 0.22 V (or 0.23 V) higher than the PSCs with the mono-adduct BPCMA (or ACMA) as electron acceptor. In addition, the short-circuit current density ( J sc ) of the PSCs involving bis-adducts (BPCBA and ACBA) are obviously higher than those based on BPCMA and ACMA. The photovoltaic difference between mono- and bis-adducts can be rationalized by their different behaviors in LUMO energy and molecular packing.

Two novel [Ag 2 pyd] n ( 1 ) and [Ag 4 (apyz) 3 (pyd) 2 ·3H 2 O] n ( 2 ) supramolecular frameworks constructed by H 2 pyd (2,3-pyridinedicarboxylic acid) were synthesized and characterized by X-ray single crystal diffraction, elemental analyses and IR spectra. The pyd building block was extended into well-ordered supramolecular frameworks by Ag O and Ag···Ag interaction. Ligand-supported weak argentophilic interactions are observed in compounds 1 and 2 , but novel 1D Ag···Ag silver-wire structure is only in 1 . The linkers of pyd and apyz (aminopyrazine) play an important role in the self-assembly process. The combination of pyd ligands and Ag ions generate a 2D layer structure in complex 1 and pyd ligands adopt different coordination modes to connect Ag atoms to form 3D supramolecular framework in complex 2 . Comparing the experimental results, it is clear that the apyz ligand plays a crucial role in the formation of the resulting structures. The results are reported in this article.

Four silver(I) coordination polymers (CPs), namely, [Ag2(mpyz)(ipa)]n (1) [Ag3(mpyz)(btc)]n (2) [Ag4(apyz)2(ipa)·0.5 DMF]n (3) [Ag3(apyz)2(btc)]n (4), have been purposefully synthesized under ultrasonic treatment of methylpyrazine (mpyz), aminopyrazine (apyz), isophthalic acid (H2ipa), 1,3,5-benzenetricarboxylic acid (H3btc) and AgNO3. And they were characterized by elemental analysis and X-ray single-crystal diffraction. Complexes 1 and 2 based on the same auxiliary ligand mpyz show various structures with silver chain. Complex 1 features a three-dimensional (3D) structure which consists of 1D helical silver chains. Complex 2 possesses an infinite silver chain with repeated Ag-triangle units. Complexes 3 and 4 with apyz as auxiliary ligand exhibit different structures. Complex 3 exhibits a 2D 44-sql network with the 1D double chains and complex 4 shows Ag6 units which are connected by Ag⋯Ag interaction in the 3D coordination network. Effects of the aromatic polycarboxylates on the structures and the intricacy of the self-assembly process were discussed. Additionally, results about infrared spectroscopy (IR), thermogravimetric analyses (TGA) and photoluminescence spectra behaviours of the compounds were also discussed.

Two new metal–organic framework namely, [ Ag 3 ( dmpyz ) 1.5 ( btc ) ] n (1), and [ Ag 2 ( dmpyz ) ( pta ) ] n (2), have been synthesized and structurally characterized. Compound 1 is a 3D structure incorporating μ 5 - ( η 1 , η 1 ) : ( η 1 , η 1 ) : ( η 1 , η 1 ) btc and μ 2 - N 1 , N 1 , μ 2 - N 2 , N 3 dmpyz ligands. In compound 2, the μ 5 - η 1 : η 2 : η 3 : η 1 pta and the dmpyz ligands link the [ Ag 4 O 2 ] units into a 2D structure. It is noteworthy that the Ag⋯Ag interactions were observed in the two coordination polymers. The results show that the structural diversity of the polymers is mainly attributed to the usage of diverse ancillary carboxylate ligands. The thermal stabilities and photoluminescence behaviors were addressed.

Surface functionalization of inorganic nanomaterials through chemical binding of organic ligands on the surface unsaturated atoms, forming unique organic-inorganic interfaces, is a powerful approach for creating special functions for inorganic nanomaterials. Herein, we report the synthesis of hierarchical MgO nanocrystal clusters (NCs) with an organic-inorganic interface induced multi-fluorescence and their application as new alternative labels for cellular imaging. The synthetic method was established by a dissolution and regrowth process with the assistance of carboxylic acid, in which the as-prepared MgO NCs were modified with carboxylic groups at the coordinatively unsaturated atoms of the surface. By introducing acetic acid to partially replace oleic acid in the reaction, the optical absorption of the produced MgO NCs was progressively engineered from the UV to the visible region. Importantly, with wider and continuous absorption profile, those MgO NCs presented bright and tunable multicolor emissions from blue-violet to green and yellow, with the highest absolute quantum yield up to (33±1) %. The overlap for the energy levels of the inorganic-organic interface and low-coordinated states stimulated a unique fluorescence resonance energy transfer phenomenon. Considering the potential application in cellular imaging, such multi-fluorescent MgO NCs were further encapsulated with a silica shell to improve the water solubility and stability. As expected, the as-formed MgO@SiO2 NCs possessed great biocompatibility and high performance in cellular imaging.

Ultrathin crystalline nanosheets give an extremely high surface area of a specific crystal facet with unique physical and chemical properties compared with normal three-dimensionally polyhedral nanocrystals (NCs). However, the ultrathin metal nanosheets tend to curl themselves or assemble with each other sheet by sheet, which may reduce the effective surface area and accordingly the catalytic activity to a great extent. Here we report a facile wet-chemical route that allows the fabrication of novel excavated rhombic dodecahedral (ERD) PtCu3 alloy NCs with ultrathin nanosheets of high-energy {110} facets. The surface area was measured to be 77 m(2) g(-1) by CO stripping, although the particle size is about 50 nm. Electrochemical characterizations showed that the ERD PtCu3 NCs exhibit excellent electrocatalytic performance and high antipoisoning activity in comparison with commercial Pt black and PtCu3 alloy NCs with {111} surfaces.

Two mixed-ligand silver(I) coordination complexes (CCs), [Ag 4 (mpyz)(npt) 2 ·(H 2 O) 2 ] n ( 1 ) and [Ag 4 (mpyz) (npt) 2 ] n ( 2 ) were synthesized with reactions of methyl-pyrazine(mpyz) and 3-nitro-1,2-benzenedicarboxylic acid (H 2 npt) with silver nitrate in different solvent systems and were structurally characterized by single-crystal X-ray crystallography. Structural differences of CCs are due to the effects of solvent systems and the intricacy of the self-assembly process for these systems. For 1 , the Ag 4 unit which is like Y letter which stand upside and down and repeat to form a 1D-6 3 -silver-ring which shares Ag1 and Ag2 only with npt ligands. The eight Ag ions of complex 2 are in a shape like the branches of a tree which repeat to form a 1D silver chain. Effects of solvents on the structures, as well as the intricacy of the self-assembly process were discussed. The photoluminescence, infrared spectroscopy (IR) and thermogravimetric analyses (TGA) behaviors of the compounds were also discussed.

Four 3D POM-based silver coordination polymers, namely, [Ag17(ptz)11(PW12O40)2]n (1), [Ag17(ptz)11(PMo12O40)2]n (2), [Ag12(ptz)6(CN)2(SiW12O40)]n (3), and [Ag19(ptz)8(H2ptz)(H3ptz)(AgP5W30O110)·7H2O]n (4), have been obtained by solvothermal reaction of AgNO3 and 5-phenyl-1H-tetrazole (Hptz) ligand in the presence of four types of polyoxometalates. Structural analysis shows that four types of Ag(I)···π interactions, m-η(1), m/p-η(2), o/m-η(2), and o/m/p-η(3), were observed in compounds 1-4, depending on the polyoxometalates used. The in situ generated CN(-) ion in compound 3 shows unprecedented mixed σ and π bonding modes, similar to the C2(2-) ion in well-studied silver acetylides. For 4, the Na(+) ion in the Preyssler heteropolyoxoanion, [NaP5W30O110](14-), was exchanged by Ag(I) under solvothermal conditions, generating a novel [AgP5W30O110](14-) anion. In addition, the photoluminescence behavior of 1-4 was also investigated.

Two heterometallic cage-like Dy24M2 (M = Ni, Mn) cluster compounds have been synthesized through self-assembly of the metal ions and the myo-inositol ligand templated by three ClO4− anions.

Two one-dimensional acetate chains, GdIII–MnII (1) and GdIII–CoII (2), have been prepared. Magnetic investigations indicate that the magnetic entropy changes in 1 and 2 are up to 38.70 and 35.18 J kg−1 K−1 at ΔH = 7 T, and 31.08 and 28.67 J kg−1 K−1 at ΔH = 3 T, respectively.

A tripodal amide based ligand, tris-{(2-carbamoyl-5-carbomethoxy-pyridine)-2-ethyl}amine (H3L, 1), was synthesized and structurally characterized by single crystal X-ray diffraction. Investigation of the cation recognition behavior showed that the ligand has selective colorimetric sensing properties for cobalt(II) ions by an obvious color change from colorless to yellow. To investigate the sensing mechanism of H3L for Co(2+) ions, UV-vis absorption spectroscopy and single-crystal structural analysis were performed. The mixture of the ligand and cobalt(II) ions displayed selective colorimetric sensing properties for weak acid anions, such as CO3(2-), Ac(-), HCO3(-), SO3(2-), and PO4(3-). Detailed (1)H NMR experiments revealed that the basicity of the anions played an important role in the intensity of the interaction between the ligand and anions. The structures of compounds CoL (2), Co-Ac-HL (3), H4L-NO3 (4), and H4L-ClO4 (5) were also determined by single crystal diffraction studies.

Seven new silver(I) coordination compounds based on dimethylpyrazine (dmpyz), [Ag4(2,5-dmpyz)(ndc)2]n (1), [Ag2(2,5-dmpyz)(pma)0.5]n (2), [Ag4(2,3-dmpyz)2(mpa)2]n (3), [Ag2(2,3-dmpyz)(npa)]n (4), [Ag(2,3-dmpyz)0.5(opa)0.5]n (5), [Ag6(2,3-dmpyz)3(mpa)3]n (6) and [Ag6(2,3-dmpyz)2(tma)2·5H2O]n (7), have been synthesized and have been characterized by elemental analyses, IR spectra and single-crystal X-ray diffraction. In compound 1, two types of Ag4 units are linked by organic ligands to form a three-dimensional supramolecular framework. Compound 2 also shows a 3D network structure based on [Ag4O2] six-membered rings. Compounds 3 and 6 are both 2D 44-sql nets, in which Ag4 units and Ag6 units are observed, respectively. In compound 4, the npa ligand adopts a μ5-η1:η1:η1:η2 mode to link zigzag Ag4 subunits (SBUs), giving a 2D network. Compound 5 shows a 1D infinite silver chain clamped by the opa ligands. In 7, six coordinated Ag(I) ions propagate to an infinite 1D silver strap and the 2,3-dmpyz and tma ligands link the silver strap into a 3D framework. The high structural diversity of the compounds and the Ag units is highly dependent on the solvent and the coordination mode of the carboxylate. The thermal stabilities and photoluminescence behaviours of the compounds were also discussed.

Assembly of nanosized polynuclear metal clusters from simple building blocks usually involves complicated self-organization processes and lacks controllability, thus is a challenge task for a long time. Here we demonstrate the controllable assembly, single crystal structures and solution behaviors of four molecular assemblies based on nanosized silver alkynyl clusters. In the presence of concomitant CrO42- and Cl- templates, we could isolated a discrete cluster 1 and a polymeric chain-like compound 2 based on similar [(CrO4)Cl@Ag42] cluster units by using different silver salts. Both 1 and 2 have a similar 42-metallic cage which traps two CrO42- and one Cl- as anion templates. Using sole CrO42- template, 3 and 4 were simultaneously isolated in one-pot reaction. Both of them are 1D chain structures based on single CrO42- templated Ag18 and double CrO42- templated Ag30 clusters, respectively. High-resolution electrospray mass spectrometry (HR-ESI-MS) was also used to study the solution behaviors of 1-4. This work i) presents the cluster engineering concept used in the assembly of polynuclear silver alkynyl clusters; ii) exemplifies template effects from hetero and homo anions; and iii) provides a controllable way to achieve assembly of silver alkynyl clusters.

We carried out photopolymerization by [2 + 2] dimerization of a photoreactive guest molecule in the channels of a photoreactive porous coordination polymer. The photoreactions of the guest and two host ligands were monitored by single-crystal X-ray crystallography, providing snapshots of the interplay between the reactive centers. By correlating the structures of these three photocenters, a strong synergism was discovered among three reaction (quasi)equilibria and three types of photochemical reactions (isomerization, dimerization, and polymerization). This result indicates a strong coupling and feedback mechanism among the photocenters moderated by the coordination backbone.

High quality graphene materials that readily disperse in water or organic solvents are needed to achieve some of the most ambitious applications. However, current synthetic approaches are typically limited by irreversible structural damages, little solubility, or low scalability. Here, we describe a fundamental study of graphene chemistry and covalent functionalization patterns on sp2 carbon lattices, from which a facile, scalable synthesis of high quality graphene sheets was developed. Graphite materials were efficiently exfoliated by reductive, propagative alkylation. The exfoliated, propagatively alkylated graphene sheets (PAGenes) not only exhibited high solubility in common solvents such as chloroform, water, and N-methyl-pyrrolidone, but also showed electrical conductivity as high as 4.1 × 103 S/m, which is 5 orders of magnitude greater than those of graphene oxides. Bright blue photoluminescence, unattainable in graphene, was also observed. We attribute the rise of blue photoluminescence in PAGenes...

The ultrasonic reactions of Ag2O with 1, 4-bis(imidazol-1-ylmethyl) benzene (bix) and ancillary carboxylate ligands under the ammoniacal condition lead to two new coordination compounds, namely [Ag4(bix)4(pma)·(H2O)18]n(1) and [Ag(bix)(onb)·H2O]n(2)(H4pma = pyromellitic acid, Honb = o-nitrobenzoic acid). Both of the complexes have been characterized by elemental analyses, IR spectra and single-crystal X-ray diffraction. In complex 1, the Ag-bix 1D chains are connected with the 2D nets containing [Ag4(bix)2(pma)2] to form a 3D framework by Ag⋯Ag interaction. In complex 2, the coordination bonds link Ag(I) ions and bix ligands to form 1D chains which are extended into a 2D layer by inter-chain hydrogen bonds. The Ag⋯Ag interaction is also observed in 2. Moreover, the photoluminescence properties of the complexes were also investigated in the solid state at room temperature.

Four 3D coordination polymers, [Co7(OH)4(H2O)2(ina)4(ip)3]·10H2O (1·10H2O, ina = isonicotinate, ip = isophthalate), [Ni7(OH)4(H2O)2(ina)4(ip)3]·10H2O (2·10H2O), [Co7(OH)4(H2O)2(ina)4(pip)3]·5H2O (3·5H2O, pip = 5-phenyl-isophthalate), and [Ni7(OH)4(H2O)2(ina)4(pip)3]·5H2O (4·5H2O), respectively, were hydrothermally synthesized. They crystallized in the orthorhombic space group Pba2 for 1·10H2O and 2·10H2O and monoclinic space group P2/n for 3·5H2O and 4·5H2O, respectively, and were constructed with the identical 8-connected heptanuclear {M7(OH)4} (M = Co(II) or Ni(II)) clusters, possessing uninodal hexagonal primitive net with the point symbol {3(6)·4(18)·5(3)·6}. The four coordination polymers showed dominant antiferromangetic properties, in which 1·10H2O shows spin-canted behavior and 2·10H2O exhibits the coexistence of spin canting and spin glass. Meanwhile, the activated polymers 1 and 2 possessed permanent porosity, displaying relatively large H2 uptake capacity (77 K, 1 atm) of 114 and 133 cm(3) g(-1), and CO2 uptake capacity (273 K, 1 atm) of 65.8 and 73.3 cm(3) g(-1), for 1 and 2, respectively.

Four Zn(II) coordination complexes, namely {[Zn(pmbm) 2 (tpa)]·H 2 O} n (1), {[Zn(pmbm)(phda)]·2(H 2 O)} n (2), [Zn(pmbm)(aze)] n (3), {[Zn(pmbm)(1,4-ndc)]·2(CH 3 OH)} n (4) [pmbm = 1-(4-pyridylmethyl)-benzimidazole, H 2 tpa = terephthalic acid, H 2 phda = phenylenediacetic acid, H 2 aze = azelaic acid, 1,4-ndcH 2 = 1,4-naphthalenedicarboxylic acid] have been synthesized by solution phase ultrasonic reactions of Zn(AC) 2 ·2H 2 O with pmbm and various dicarboxylates ligands under the ammoniacal condition. All the complexes have been characterized by elemental analyses, IR spectra and X-ray diffraction. Complexes 1 and 2 exhibit one-dimensional chains structure and complex 3 and 4 are two-dimensional sheets structure with (4,4) topology. Complexes 1 – 4 spanning from one-dimensional chains to two-dimensional sheets suggest that dicarboxylates play significant roles in the formation of such coordination architectures. The photoluminescences of the complexes were also investigated in the solid state at room temperature.

Three novel bimetallic Au-Cu nanoclusters stabilized by a mixed layer of thiolate and phosphine ligands bearing pyridyl groups are synthesized and fully characterized by X-ray single crystal analysis and density functional theory computations. The three clusters have an icosahedral Au13 core face-capped by two, four, and eight Cu atoms, respectively. All face-capping Cu atoms in the clusters are triply coordinated by thiolate or pyridyl groups. The surface ligands control the exposure of Au sites in the clusters. In the case of the Au13Cu8 cluster, the presence of 12 2-pyridylthiolate ligands still leaves open space for catalysis. All the 3 clusters are 8-electron superatoms displaying optical gaps of 1.8-1.9 eV. The thermal decomposition studies suggest that the selective release of organic ligands from the clusters is possible.

National Natural Science Foundation of China (NSFC) [90922012, 20971106, 21021061, 21271091]; Natural Science Foundation of the Jiangsu Higher Education Institutions [11KJA430009]; PAPD of Jiangsu Higher Education Institutions

NNSFC [20901064, 20825103, 21021061, 21071119, 90922031]; Foundation for the Author of National Excellent Doctoral Dissertation of China [201219]; Ministry of Science and Technology of China [2012CB821704]

A discrete dihalide–decahydrate cluster of [X2(H2O)10]2– has been observed in a solid-state structure of {[Na2(H2O)6(H2O@TMEQ[6])]·2(C6H5NO3)}X2(H2O)10} (TMEQ[6] = α,α′,δ,δ′-tetramethylcucurbit[6]uril; X = Cl (1), Br (2)). Its structure can be viewed as a connection of two [X(H2O)3]− clusters with a uudd water tetramer through hydrogen-bonding interactions.

Mass spectrometry with desorption electrospray ionization (DESI) is demonstrated to be useful for probing the strength of hydrogen bonding, exemplified by various complexes of benzothiazoles and carboxylic acids in the solid state. Efficiencies for fragmentation of the complexes, quantified by collision-induced dissociation (CID) technology, correspond well with energies of the hydrogen bonds of O-H···N and N-H···O bridging each pair of benzothiazole and carboxylic acid. Linear correlations (with correlation factors of 0.8953 and 0.9928) have been established for the calibration curves of normalized collision energy at 100% fragmentation rate vs the length between donor and acceptor (in the hydrogen bond of O-H···N) as well as the slope of the fragmentation efficiency curve vs the average length difference between O-H···N and N-H···O in the complex. The mechanism responsible for determination of the hydrogen bonds is proposed on the basis of the experiments starting from the mixtures of the complexes as well as labeling with deuterium. As a complement of previously available methods (e.g., X-ray diffraction analysis), expectably, the proposed mass spectrometric method seems to be versatile for probing hydrogen bond energies.

Dielectric anisotropy of anilinium perchlorate is investigated at various temperatures. Crystal structures at different temperatures reveal that significant dielectric change between low and high dielectric states is closely related to the disorder of the anilinium cation and perchlorate anion at high dielectric state; meanwhile, the conductivity after phase transition also contributes a lot to the high dielectric state.

Twelve coordination compounds of Mn2+, Fe2+, Co2+, Ni2+, Cu2+ and Zn2+, with mixed organic ligands 5-methylisophthalic acid, 2,2′-bipyridine or phenanthroline, have been hydrothermally synthesised and characterised. The magnetic properties of the Mn2+, Co2+, Ni2+ and Cu2+ compounds have been investigated. Structure analysis shows that the assemblies with a bridging ligand possessing a smaller methyl group (compared to the tert-butyl group) afford coordination compounds containing multinuclear metal centres and structures of higher dimension. The result shows that the structures and properties of the metal–organic materials can be finely tuned by the substituent on the organic bridging ligands.

Metal-organic frameworks (MOFs) and related material classes are attracting considerable attention for their applications in gas storage/separation as well as catalysis. In contrast, research concerning potential uses in electronic devices (such as sensors) is in its infancy, which might be due to a great challenge in the fabrication of MOFs and semiconductor composites with well-designed structures. In this paper, we proposed a simple self-template strategy to fabricate metal oxide semiconductor@MOF core-shell heterostructures, and successfully obtained freestanding ZnO@ZIF-8 nanorods as well as vertically standing arrays (including nanorod arrays and nanotube arrays). In this synthetic process, ZnO nanorods not only act as the template but also provide Zn(2+) ions for the formation of ZIF-8. In addition, we have demonstrated that solvent composition and reaction temperature are two crucial factors for successfully fabricating well-defined ZnO@ZIF-8 heterostructures. As we expect, the as-prepared ZnO@ZIF-8 nanorod arrays display distinct photoelectrochemical response to hole scavengers with different molecule sizes (e.g., H(2)O(2) and ascorbic acid) owing to the limitation of the aperture of the ZIF-8 shell. Excitingly, such ZnO@ZIF-8 nanorod arrays were successfully applied to the detection of H(2)O(2) in the presence of serous buffer solution. Therefore, it is reasonable to believe that the semiconductor@MOFs heterostructure potentially has promising applications in many electronic devices including sensors.

Pt-Cu alloy octahedral nanocrystals (NCs) have been synthesized successfully by using N,N-dimethylformamide as both the solvent and the reducing agent in the presence of cetyltrimethylammonium chloride. Cu underpotential deposition (UPD) is found to play a key role in the formation of the Pt-Cu alloy NCs. The composition in the Pt-Cu alloy can be tuned by adjusting the ratio of metal precursors in solution. However, the Cu content in the Pt-Cu alloy NCs cannot exceed 50%. Due to the fact that Cu precursor cannot be reduced to metallic copper and the Cu content cannot exceed 50%, we achieved the formation of the Pt-Cu alloy by using Cu UPD on the Pt surface. In addition, the catalytic activities of Pt-Cu alloy NCs with different composition were investigated in electrocatalytic oxidation of formic acid. The results reveal that the catalytic performance is strongly dependent on Pt-Cu alloy composition. The sample of Pt(50)Cu(50) exhibits excellent activity in electrocatalytic oxidation of formic acid.

Due to the fact that crystal facets with high surface energy usually exhibit superior performance in many fields, such as catalysis, the importance of the synthesis of micro/nano-crystals with exposed high surface energy facets is becoming a hot research field. In this article, concave Cu2O microcrystals mainly enclosed by {hhl} high-index facets have been successfully prepared by reducing Cu(CH3COO)2 with glucose in the presence of sodium dodecyl sulphate (SDS). SDS was proved to be important in the formation of the concave Cu2O microcrystals. The concave degree of truncated octahedra can be controlled by adjusting the concentration of SDS. In addition, we found the reaction rate also affected the morphology of Cu2O microcrystals. Octahedron-based branched particles, truncated concave octahedra and truncated octahedra can be obtained by adjusting the concentration of glucose. In the catalytic oxidation of CO, truncated concave octahedral Cu2O enclosed by {332} high-index facets exhibited the highest catalytic activity among the high-index {332} facets, low index {111} and {100} facets, due to the existence of high density steps on {332} facets and the CO catalytic activities of the crystal facets are in the sequence: {332} > {111} > {100}.

Four new silver(I) coordination polymers (CPs) based on 3-nitrophthalic acid (H2npt), [Ag2(NH3)2(npt)]n (1), [Ag2(NH3)(npt)]n (2), {(NH4)[Ag(npt)·H2O]}n (3) and [Ag4(NH3)4(npt)2·H2O]n (4), have been synthesized and structurally characterized. Compound 1 shows a 1D chain based on a binuclear Ag(I) SBU (secondary building unit). The [Ag(NH3)2] units are bound on the two sides of the 1D chain through the ligand-unsupported argentophilic interactions. Compound 2 is a 2D 44-sql net constructed from npt ligand-bridged centrosymmetric Ag4 rhombus SBUs. Compound 3 exhibits an anionic 2D sheet, in which the infinite chain-like [Ag2(COO)2]n SBUs are observed along the b axis. In compound 4, infinite silver nets are fabricated by ligand-unsupported argentophilic interactions and the npt ligands are anchored on the net to form the 2D sheet structure. Four CPs exhibit unprecedentedly high structural diversity dependent on the solvent and induction agent. In detail, 1, 2 and 3, 4 are mainly controlled by the induction agent, but 1, 3 and 2, 4 are controlled by the solvent systems. The thermal stabilities and photoluminescence behaviours of the compounds were also discussed.

The surface structure-controlled synthesis of noble metal nanocrystals (NCs) bounded by high-index facets has become a hot research topic due to their potential to significantly improve catalytic performance. This study reports the preparation of monodisperse Au-Pd alloy NCs with systematic shape evolution from rhombic dodecahedral (RD) to trisoctahedral (TOH), and hexoctahedral (HOH) structures by varying the concentration of surfactant in the surfactant-mediated synthesis. The as-prepared three kinds of alloy NCs possess almost the same size and composition as each other. It is suggested that the surfactant containing long-chain octadecyltrimethyl ammonium (OTA(+)) ions plays a key role in the formation of high index facets, and the crystal growth kinetics may also have an effect on the formation of different nanocrystal morphologies. In addition, the catalytic activities of these NCs are evaluated by structure-sensitive reactions, including ethanol electro-oxidation and the catalytic reduction of 4-nitrophenol (4-NPh). These three types of Au-Pd alloy NCs exhibit different catalytic selectivities towards these two reactions. The catalytic activities toward electro-oxidation of ethanol are in the order of HOH > RD > TOH, which follows the order of their corresponding surface energies. However, the activities toward catalytic reduction of 4-NPh are in the order of RD > TOH > HOH, which should be related to the local structure of the surfaces.

Although tremendous advances in fullerene sciences have been achieved since the first discovery of fullerene in the middle of 1980’, the formation of these all-carbon cages still remains a mystery. Based on available experimental and computational evidences, some interpretations responsible for fullerene formation have been suggested in literatures. Most of them can be classified as bottom-up, top-down or size-up/size-down models. Suffering from limitation of powerful evidences, however, most of them still require validation. Herein we review the most important hypothetic fullerene formation models that have been proposed to date.