Coupled cluster treatments of periodic systems from strongly localized reference functions: 1-D and 2-D spin and electron lattices

A modified coupled cluster method is applied to the research of the ground-state energy of periodic systems described by model Hamiltonians. The reference function is always a strongly localized function. The method is applied first to Heisenberg Hamiltonians and spin-frustrated one-dimensional (1-D) chain and square lattices, starting from Neel functions or from products of bond singlets. The same method is then applied to Hubbard Hamiltonian for 1-D chain and two-dimensional (2-D) square lattices starting from Neel function or products of bond molecular orbitals (MOs). In both cases the wave operators involve a very limited number of local operators. Despite its simplicity, the method is able to treat quite satisfactorily highly degenerate situations, approaching correctly the highly delocalized regime from the Neel function or the highly correlated regime from a product of bond MOs. However, the method is not precise enough to treat the subtle phenomenon of bond alternation of polyacetylene. The coupled cluster method from strongly localized reference functions represents an elegant and quite efficient exploratory tool, but its accuracy is limited by the poor treatment of collective effects. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 67: 115–132, 1998     

Zinc complexes of T-shaped trans-1,2,3-propenetricarboxylic acid with 1-D ribbon-like chain, 2-D rhombus-grid-like and herringbone-like layers, and non-interpenetrating 3-D open framework

Five zinc complexes of T-shaped trans-1,2,3-propenetricarboxylic acid (H(3)L) with 1-D ribbon-like chain, 2-D rhombus-grid-like and herringbone-like layers, and non-interpenetrating 3-D open framework have been obtained based on different building blocks. X-ray single crystal analyses show that the T-shaped information of H(3)L was nicely expressed in the construction of herringbone-like or ladder-like structure. All compounds were found to display blue fluorescent emissions.     

Solution-based synthetic strategies for 1-D nanostructures

One-dimensional (1-D) nanostructures of materials have received great research attention because of their unique photochemistry, photophysical, and electron-transport properties different from those of bulky or nanoparticle materials. One of the main challenges in this field is how to precisely control the sizes, dimensionalities, compositions, and crystal structures of materials in nanoscale. This review summarizes the recent progress in the solution-based routes to prepare 1-D nanostructures, highlighting the contribution from this laboratory. Crystal structure as one of the inherent factors that may determine the growth behavior of the nanocrystals is emphasized in this paper. Particularly compounds with layered structures or anistropic crystal structures are given special attention in the controlled growth of 1-D nanostructures. This review aims to present a relatively general understanding of the correlation between the crystal structure and growth behavior of materials under solution-based conditions and show how to choose appropriate conditions for the growth of 1-D nanostructures.     

Ionization of 1-D model atom in an intense laser field based on asymptotic boundary conditions and symplectic algorithm

In this paper the asymptotic boundary condition (ABC) of 1-D model atom in the intense laser field at the spatial sufficiently far distance is presented using Fourier transformation on the condition that the initial state is local and the atomic potential in the model falls off rapidly. On the basis of this ABC, the symplectic algorithm is developed for computing the model atom in the intense laser field. The ABC and symplectic algorithm are applied to compute the ionization behaviors for 1-D Pöschl–Teller short-range potential. The numerical results illustrate that the ABC and the symplectic algorithm presented are reasonable and effective for 1-D model atom in the intense laser field.     

Two 1-D europium coordination polymers: synthesis,crystal structure and fluorescence

Two new complexes {[Eu(2, 4-DFBA)₃ · (H₂O)₂] · H₂O} _n (1) and [Eu(2-BrBA)₃ · H₂O] _n (2) (2, 4-DFBA = 2, 4-difluorobenzoate, 2-BrBA = 2-bromobenzoate) have been synthesized and characterized by single crystal X-ray diffraction. 1 has a 1-D chain structure, in which Eu(III) ions are bridged by single COO^? groups and a 2-D supramolecular network is formed by hydrogen bond interactions. In 1, each Eu(III) is eight-coordinate with six oxygens from four 2,4-DFBA ligands and two waters. 2 has a 1-D chain structure, in which Eu(III) ions are bridged by bridging-chelating-bridging COO^? groups. In 2, each Eu(III) ion is nine-coordinate with eight oxygens from five 2-BrBA ligands and one water. The two complexes exhibit intense luminescence at room temperature. The ⁵D₀ → ⁷F _j (j = 0–4) transition emissions of Eu(III) have been observed.     

Structural Assignment of Side Chain Liquid Crystalline Monomer and Polymer by 1-D and 2-D Solution NMR Studies

In the present study, the synthesis and characterization of a methacrylic-based side chain liquid crystalline monomer and its polymer were investigated with the aid of both 1-D and 2-D nuclear magnetic resonance (NMR) techniques. The mesophase characteristics of the monomer and polymer were determined by hot-stage optical polarized microscopy (HOPM). The nematic and smectic phases were observed for the monomer and polymer. Furthermore, ¹³C spin-lattice relaxation time measurements were performed on the above systems in order to monitor molecular dynamics. The present study provides an opportunity to carry out a systematic comparison of the evolution of structural as well as dynamical changes of the monomer and the polymer.     

Metal-organic frameworks from zinc sulfite clusters, chains, and sheets: 4-connected, (3,4)-connected 3-D frameworks and 2-D arrays of catenane-like interlocking rings

Even though open-framework solids have been made in a variety of compositions such as silicates, phosphates, germanates, borates, and phosphites, few are known that are based on trigonal-pyramidal sulfite anions. We report here the first synthetic and structural studies of metal-organic framework materials in the zinc sulfite composition. It is demonstrated here that Zn2+ and SO32- can form various neutral inorganic subunits that can be 0-D clusters, 1-D chains, or 2-D sheets. These inorganic subunits of different dimensionality can subsequently be connected into extended frameworks of higher dimensionality through bifunctional ligands. In (ZnSO3)2en, infinite corrugated ZnSO3 layers are pillared by ethylenediamine (en) molecules into a 3-D network that can be classified as a (3,4)-connected net based on tetrahedral Zn nodes and trigonal-pyramidal S nodes. In (ZnSO3)pip, infinite ZnSO3 chains are cross-linked with piperazine molecules into a 3-D framework that can be classified as 4-connected net based on tetrahedral Zn nodes only. In (ZnSO3)2(TMDPy)2, (ZnSO3)2 dimers are doubly bridged by trimethylenedipyridine molecules into an infinite chain with a string of circles. Each circle along the chain is interlocked with another circle from a chain in the perpendicular direction, creating a 2-D pattern with an infinite-square array of catenane-like units.     

From crystal engineering to cluster engineering: How to transform cadmium chloride from 2-D to 0-D

The transformation of a 2-D perovskite structure to "expanded" 2-D and finally to a 0-D hexanuclear cadmium chloride cluster by varying the size of substituents on the associated counterions (H vs. methyl vs. ethyl) is described.     

Guest-induced crystal-to-crystal expansion and contraction of a 3-D porous coordination polymer

A silver(I) 3-D porous coordination polymer (PCP, 1) with a sodalite topology undergoes a remarkable reversible crystal-to-crystal expansion and contraction upon exposure to different solvents. Notably, complete desolvation of 1 also facilitates a transformation to a non-porous 2-D coordination polymer (2).     

Two 1-D metal-organic polymers constructed from bis-benzimidazole-based ligands: syntheses,crystal structures,and luminescent properties

By combination of Mn(II) and Hg(II) salts with a flexible building unit 1,1′-(1, 5-pentanediyl)bis-1H-benzimidazole (pbbm), two 1-D chain metal-organic polymers [Mn(SCN)₂(pbbm)₂] _n (1) and {[HgCl₂(pbbm)] · DMF} _n (2) have been prepared. The polymeric 1-D chains in 1 consist of parallel ribbons of rings, whereas 2 possesses a 1-D zig-zag chain framework based on tetrahedral mercury atoms bridged by pbbm molecules and terminally coordinated by two chlorides. The significant differences of these metal-organic frameworks indicate that the flexible pbbm ligand adjusts its conformation to meet the requirement of the coordination preference of the metal center. The photoluminescent properties of these new materials have been studied in the solid state at room temperature.     

Synthesis and Crystal Structure of an Interpentateing 3-D Framework Constructed from Mixed Ligands

A novel organic-inorganic hybrid compound constructed from mixed ligands, Co3（SIP）2（bipy）4（H2O）6·6.5H2O （H3SIP = 5-sulfoisophthalic acid, bipy = 4,4′-bipyridyl）, has been hydrothermally synthesized and characterized by IR, TGA and single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space group P212121 with a = 11.395（2）, b = 19.395（4）, c = 30.675（6） A^°, Mr = 1513.05, V= 6779（2） A^°^3, Dc= 1.482 g/cm^3, F（000） = 3120, μ = 0.873 mm^-1, Z= 4, the final R = 0.0439 and wR = 0.119 for 13421 observed reflections with I〉 2σ（I）. The structure of the compound presents a 3-D framework containing Co-bipy 1-D chain and 2-D bilayer motifs and carboxylate spacers, and the connection of 1-D chain and 2-D bilayer motifs by carboxylate ligand results in the final open framework with twofold interpenetration net. A probe reaction of the oxidation of benzaldehyde with H2O2 using the title compound as catalyst was carded out in a liquid-solid system, showing that the compound has high oxidative catalytic activity to the reaction.     

New partially oxidized 1-D platinum chain complexes consisting of carboxylate-bridged cis-diammineplatinum dimer cations

The first/second examples of partially oxidized 1-D platinum chain compounds consisting of cationic dimer units have been obtained from electro-oxidation of an aqueous solution containing cis-[Pt(NH3)2(OH2)2]2+ and acetate/propionate. The analytical and crystallographic studies reveal the mixed-valency of Pt(2.2+)infinity. The XPS confirms the presence of both Pt(II) and Pt(III). The solid-state physical measurements reveal that they are diamagnetic semiconductors and display a fairly broad, low-energy absorption band in the range of 500-3200 nm.     

Trace LC/MS quantitative analysis of polypeptide biomarkers: impact of 1-D and 2-D chromatography on matrix effects and sensitivity

We investigated the impact of one dimension (single reverse phase (RP) column) and two dimension (two different RP columns) chromatographic methods on SIM (MS) and multiple reaction monitoring (MRM; MS/MS) performance from human plasma. We find that MRM analysis is clearly preferable for 1-D applications; however, implementation of SIM detection in conjunction with 2-D separation technique resulted in an over 60-fold increase in analyte peak area and improved S/N compared to MRM for our analyte, human C-peptide. Implementation of a 2-D RP-RP technique with SIM detection is capable of eliminating matrix effects and greatly increases signal response and data quality. For two large peptides in complex biological samples, we found that a 2-D approach performed better than high quality sample preparation together with 1-D chromatography and MRM, even on a high-end mass spectrometer.     

Selective gas sorption property of an interdigitated 3-D metal-organic framework with 1-D channels

An interdigitated 3-D metal-organic framework, [Cd(3)(OH)(2)L(4)(H(2)O)(2)], with 1-D channels was prepared using 4-aminophenyl-1H-tetrazole (HL) and Cd(II) ions, where the host framework shows selective gas sorption behavior that is based on the different nature of the interactions between the gas and the framework rather than on the size-exclusion effect of the micropores.     

A series of 1-D, 2-D and 3-D coordination polymers self-assembled from a flexible dicarboxylate and mixed N-donor ligands: syntheses,structural diversity,and luminescent properties

We have synthesized a series of metal–organic coordination frameworks under solvothermal conditions, formulated as [Cu(L)(phen)](1), [Co₂(L)₂(bib)]·CH₃OH(2), [Co(L)(btmb)_0.5](3), [Zn(L)(bib)]·2H₂O(4), [Cu(L)(bib)]·DMF(5), and [Mn₄(L)₄(bimb)(CH₃OH)](6) based on a flexible multicarboxylic bridging ligand 4,4′-methylenebis(oxy)-dibenzoic acid (H₂L) and flexible N-donor ligands 1,4-bis (1H-imidazol-1-yl)-butane (bib), 1,4-bis(1H-1,2,4-triazol- 1-ylmethyl)benzene (btmb), and 1,4-bis(1H-imidazol-1-ylmethyl)benzene (bimb). The structures of the frameworks have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric analyses. The crystal structure determinations reveal that 1 has a 1-D Z-shape chain. Compounds 2 and 3 are 2-D twofold parallel interpenetrating 4-connected net with the Schläfli symbol {4⁴·6²}. Compound 4 is a 2-D threefold parallel interpenetrating 4-connected nets with the Schläfli symbol {4⁴·6²}. Compound 5 is 3-D 4-connected net with the Schläfli symbol {6⁵·8}. Compound 6 is characterized by a three-dimensional framework with one-dimensional homogeneous Mn-carboxylate chain. We found that flexible carboxylate ligands have different coordination modes under different synthetic conditions. The flexible skeleton of ligands and the coordination angle between the ligand and the metal ion is described. The luminescence and thermogravimetric properties of these compounds have been investigated.     

Self-assembly of three Cd(II) complexes: 0-D, 1-D,and 3-D structures based on 2-(1H-imidazol-1-methyl)-1 H-benzimidazole

Three new complexes, [Cd(L)I₂]₂ (1), {[Cd(L)I₂]?·?DMF} _n (2), and [Cd₂(L)₄(μ ₂-I)I(H₂O)] _n (3), have been obtained through self-assembly of an unsymmetrical ligand 2-(1H-imidazol-1-methyl)-1H-benzimidazole (L) with Cd(II) salts. Single-crystal X-ray diffraction shows that 1 displays a dimeric structure in which two Cd(II) ions are bridged by two bidentate bridging L. Complex 2 exhibits a 1-D chain structure (···Cd–L–Cd–L···) constructed by L bridging Cd(II) ions. In 3, the Cd(II) ions are five-connected nodes and linked by L and iodide leading to the 3-D network. Complexes 2 and 3 are synthesized maintaining the same solvents and stoichiometric ratio of metal and ligand at different reaction temperature. The different structures of the complexes indicate that the temperature plays a significant role in construction of the complexes. Luminescent properties of 1–3 have been investigated in the solid state at room temperature.     

Synthesis and Characterization of a 1-D Zigzag Catenarian Compound [Sn（edt）2（p-phenylenediamine）]n

1 INTRODUCTION In recent years, the researches on tin sulfide ma- terials have drawn increasing attention of chemists owning to their potential applications as photo-vol- taic materials, holographic recording system[1, 2], so- lar control devices[3] and semiconductor materials. In the last decades, many finite adducts of tin (IV) thio- lates with organic amine ligands have been synthe- sized by self-assembly, such as cis-Sn(SPh)4(2,2?-bi- py)[4], cis-Sn(edt)2(ethyldimiane)[5], trans-Sn(…     

Syntheses and structures of three zinc coordination polymers with 1-D zigzag chain,double chain,and triple chain

Three new coordination polymers [Zn(btp)(NCS)₂] _n (1), {[Zn(btp)₂(dca)₂] _n (2), and {[Zn(btp)₃](BF₄)₂} _n (3) (btp = 1,3-bis(1,2,4-triazol-1-yl)propane, dca = dicyanamide) were synthesized and characterized. In 1, 2, and 3, one-, double-, triple-btp ligands link two Zn(II) atoms and extend to form a 1-D zigzag chain for 1, 1-D double chain for 2, and 1-D triple chain for 3. The conformations of the btp ligands in 1, 2, and 3 are analyzed. 1, 2, and 3 have emission maxima at approximately 405, 407, and 409 nm, respectively, in the solid state at room temperature.     

Two solvent directed zinc(II) coordination polymers with 1-D single-zigzag chain and 1-D double-zigzag chains

Two coordination polymers, {[Zn(NiL)(DMA)(H₂O)₂] (DMA)(H₂O)} _n (1) (DMA?=?N,N-dimethylacetamide) and {[Zn₂(NiL)₂(DMF)(H₂O)₄]?·?3DMF} _n (2) (DMF?=?N,N-dimethylformamide), have been prepared by reactions of Zn(NO₃)₂?·?6H₂O and NiL in CH₂Cl₂-DMA–H₂O and CH₂Cl₂-DMF–H₂O, respectively. H₂L denotes dimethyl 5,6,7,8,15,16-hexahydro-6,7-dioxodibenzo-9,10-benzo-[1,4,8,11]tetraazacyclotetradecine-13,18-dicarboxylate. Single-crystal X-ray diffraction analyses reveal that coordination geometries around Ni(II) are identical with slightly distorted square planar and all Ni–N bonds are very short. Complex 1 shows 1-D zigzag chain structure, while 2 has 1-D double-zigzag chains. The chains, which are packed parallel in 1 and 2, are interconnected by lattice solvent through O–H···O and C–H···O hydrogen bonds to form 3-D supramolecular networks. We discuss solvent effects on assembly of the two coordination polymers. The results reveal that coordinated solvent has influence on the assembly procedure.     

Dinuclear copper(II) complex and 1-D copper(II) complex with taurine Schiff base: synthesis,crystal structure,and properties

A dinuclear copper(II) compound, [Cu(btssb)(H₂O)]₂ · 4(H₂O) (1), and a 1-D chain copper(II) compound, [Cu(ctssb)(H₂O)] _n (2) [where H₂btssb is 2-[(5-bromo-2-hydroxy-benzylidene)-amino]-ethanesulfonic acid and H₂ctssb is 2-[(3,5-dichloro-2-hydroxy-benzylidene)-amino]-ethanesulfonic acid], were prepared and characterized. Compound 1 crystallizes in the monoclinic space group P2₁/c, with a = 10.109(2) Å, b = 20.473(4) Å, c = 6.803(1) Å, β = 100.32(3)°, V = 1385.1(5) ų, and Z = 2; R ₁ for 1796 observed reflections [I > 2σ(I)] was 0.0357. The geometry around each copper(II) can be described as slightly distorted square pyramidal. The Cu^II ··· Cu^II distance is 5.471(1) Å. Compound 1 formed a 1-D network through O–H ··· O hydrogen bonds and 1-D water chains exist. The 1-D chain complex 2 crystallizes in the triclinic space group P 1, with a = 5.030(2) Å, b = 7.725(2) Å, c = 17.011(5) Å, α = 92.706(4)°, β = 97.131(4)°, γ = 102.452(3)°, V = 638.6(3) ų, and Z = 2; R ₁ for 1897 observed reflections [I > 2σ(I)] was 0.0171. In 2, Cu(II) was also a slightly distorted square pyramid formed by two oxygens and one nitrogen from ctssb, one oxygen from another ctssb, and one water molecule. The complex formed a 1-D chain through O–S–O bridge of ctssb ligand. The 1-D chain further constructed a double chain through O?H ··· O hydrogen bonds.