Synthesis and Crystal Structure of Dissymmetrical Double Schiff Base Cu（Ⅱ） Homobinuclear and Cu（Ⅱ）-Mg（Ⅱ）-Cu（Ⅱ） Heterotrinuclear Complexes

Homobinuclear complex （HCuL）2 （1） （H3L： N-3-carboxylsalicylidene-N＇-salicylaldehyde-1,2-diaminoethane） was obtained from self-organization of the reported complex HCuL, and its crystal structure was determined through X-ray diffraction at room temperature. The crystal of complex 1 belongs to monolinic system, the space group Cc, a=2.5326（5） nm, b=0.88861（18） nm, c=1.3738（3） nm, β=96.95（3）°, Z=4, R1=0.0520, wR2=0.1185. （HCuL）2 is a dimeric molecule and has extended phenolic oxygen-bridged structure. In addition, using mononuclear complex HCuL as building blocks, Cu（Ⅱ）-Mg（Ⅱ）-Cu（Ⅱ） heterotrinuclear complex 2 was synthesized, and its crystal structure also has been determined by X-ray analysis. The crystal of complex 2 is of monoclinic system, space group Pc, a=1.1816（2） nm, b=1.5599（3） nm, c=1.9642 （4） nm, β=98.22°, Z=2, R1=0.0701, wR2=0.1498. Each dissymmetricai cell unit of complex 2 contains two heterotrinucler neutral molecules： {[CuL（H2O）]Mg[CuL（CH3OH）]} and {[CuL]Mg[CuL（H2O）]}.

Guest-Mediated Hierarchical Self-Assembly of Dissymmetric Organic Cages to Form Supramolecular Ferroelectrics Guest-Mediated Hierarchical Self-Assembly of Dissymmetric Organic Cages to Form Supramolecular Ferroelectrics

Herein,we report on the guest-responsive hierarchical self-assembly of dissymmetric cage DC-1 with an intrinsic dipole along its C_(3)-symmetric axis.DC-1 molecules self-assemble into supramolecular columns with themolecular dipoles aligned along the columnar axis.Mediated by different host-guest interactions of ethyl acetate(EtOAc)and chloroform(CHCl_(3)),the columns are arranged in an antiparallel and parallel fashion,respectively,leading to a switch of the centrosym metric and noncentrosymmetric superstructures.The symmetry of themolecular packing of DC-1 molecules of the noncentrosymmetric crystalline phase is therefore broken,producing a supramolecular ferroelectric with second-harmonic generation and piezoelectric responses.We demonstrate that cages can serve as promising building blocks for the discovery of supramolecular materials with emergent functions and properties,including but not limited to,organic ferroelectrics and nonlinear optics.

Axially Dissymmetric Chiral (R)-N,N′-Bis(2-hydroxy-3,5-di-tert-butyl-arylmethyl)-1,1′-binaphthalene-2,2′-diamine as Chiral Ligands in the Reaction of Diethylzinc to Aldehydes

Chiral ligand (R)-N, N'-Bis(2-hydroxy-3,5-di- tert-butyl-aryl-methyl)-1, 1'-binaphthalene-2,2'-diamine derived from the reduction of Schiff base (R)-2,2'-bis (3,5-di-tert-butyl-2-hy-droxybenzylideneamino)-1, 1'-binaphthyl with LiAIH(4) is fairly effective in the asymmetric addition reaction of diethylzinc to aldehydes by which good yields (46%-94%) of the corresponding sec-alcohols can be obtained in moderate ee (51%-79%) with R configuration for a variety of aldehydes.

Research on Knowledge Creation in Software Requirement Development

After field survey and literature review, we found that software requirement development (SRD) is a knowledge creation process, and knowledge creation theory of Nonaka is appropriate for analyzing knowledge creating of SRD. The characteristics of knowledge in requirement elicitation process are analyzed, and dissymmetric knowledge of SRD is discussed. Experts on requirement are introduced into SRD process as a third knowledge entity. In addition, a knowledge creation model of SRD is put forward and the knowledge flow and the relationship of entities of this model are illustrated. Case study findings are illustrated in the following: 1) The necessary diversity of the project team can facilitate the implementation of the SRD. 2) The introduction of experts on requirement can achieve the transformation of knowledge effectively, thus helping to carry out the SRD. 3) Methodology and related technologies are important for carrying out the SRD.

Planar Chiral[2.2]Paracyclophane-Based Zr(IV)Metal-Organic Frameworks

Self-assembly has been widely explored to improve the circularly polarized_(lum)inescence(CPL)activities of molecular chromophores,but it is hard to amplify CPL while maintaining strong emissions.Optically pure,planar-chiral[2.2]paracyclophane(pCp)is one of the most important sources of chirality for electronic and optoelectronic materials,but the photo_(lum)inescence of its derivatives is significantly quenched after forming aggregates.Here we demonstrate that reticulation of pCp chromophores into highly stable Zr(IV)metal-organic frameworks(MOFs)can simultaneously boost the dissymmetry factor(|g_(lum)|)and_(lum)inescence efficiency(Φ_(PL)).Functionalization of pCp enables the synthesis of two tetracarboxylate linkers with different side arms,which are assembled into two highly stable Zr-MOFswith different topological structures.Geometrical constraints and segregated arrangements of the pCp chromophores imposed by the framework inhibit the aggregation-caused quenching effect and boost their CPL behaviors.Both Zr-MOFs display strong CPL emissions,affording|g_(lum)|andΦ_(PL)values of up to 8.3×10^(-3)and 87%,respectively,which are amplified by∼18-and 52-fold compared to the corresponding free ligands.This work highlights the potential of optimizing CPL performances of chiral chromophores by using MOFs as support structures.