Study the cooperative noncovalent interactions in Lithium-1, 10-Phenanthroline complex,its DFT calculations and Hirschfield surface analysis

The new compound [Li(NO₃)(phen)]_n (phen: 1,10-phenanthroline) has been synthesized and characterized by elemental analysis, and single crystal X-ray diffraction. The Li⁺ ion is five coordinated occupied distorted TBP (trigonal bipyramidal) geometry. The Li⁺ ions are bridged by nitrate anions into 1D polymeric chain. The nitrate anions are coordinated to Li⁺ ions through chelating and bridging bidentate mode of binding. There are cooperative noncovalent interactions like strong or weak H-bonding, weak π···π and C?H···π interactions are involved to form 2D network. Thermal properties of this complex have been completely described by thermo gravimetric analysis (TGA). Both molecular and crystal structures of this compound were compared and discussed the intermolecular interactions by using Hirshfeld surface analysis and 2D-fingerprint plots. The optimized molecular geometry by DFT calculations agrees closely with obtained from the crystallographic study. Hirshfeld surface analysis of compound (I) indicates that H···H, π···π and C?H···π contacts can account for 30.9, 15.0 and 7.4% respectively of the total Hirshfeld surface area.     

First Principle Study on Electronic and Transport Properties of Finite-Length Nanoribbons and Nanodiscs for Selected Two-Dimensional Materials

Using the density functional theory, we calculate electronic states of various nanoribbons and nanodiscs formed from selected two-dimensional materials, such as graphene, silicene, and hexagonal boron nitride. The main objective of the analysis is a search for zero-energy states in such systems, which is an important issue as their presence indicates certain topological properties associated with chirality. The analysis is also supported by calculating transport properties.     

Synthesis,characterization, and structure of lanthanide picrate complexes with tetramethylenesulfoxide (TMSO)

A series of complexes with composition M(pic)₃(TMSO)₃ (M=La, Nd, Sm, Eu, Gd, Er, Yb, and Y) were synthesized and characterized. The electronic absorption spectrum of the Nd complex and the emission spectrum of the Eu complex were recorded and assigned. The unique compound, Sm(pic)₃(TMSO)_2.5(EtOH)_0.5, obtained by recrystallizatiori of Sm(pic)₃(TMSO)₃ from ethanol, was characterized by single-crystal X-ray analysis. The complex crystallizes in a monoclinic cell space groupP2₁/n witha=21.809(4)Å,b=15.811(3)Å,c=12.800(3)Å and =99.87(4)°. The coordination polyhedron about the Sm center is a tricapped trigonal prism involving the three picrates, which act as bidentate ligands via the phenoxo oxygen and an oxygen of an adjacent nitro group, as well as the oxygens of two TMSO ligands. The ninth position is statistically (50%) occupied by an oxygen atom of a third TMSO ligand and an oxygen atom of an ethanol molecule.     

确定分子中离域π键πnm的方法

A method for obtaining the delocalized π bonds π_n^m in a molecule has been discussed in this paper, and the delocalized π bonds π_n^m in linear, bent, planar trigonal, single cyclic conjugated, and polycyclic conjugated molecules have been studied. The reasons of π₃⁴ in NO₂ and 2π₃² in C₃ molecules have been proposed. The delocalized π bonds 2π₁₈¹⁸ in cyclo[18] carbon are analyzed.     

A New Dinuclear Cu(Ⅱ) Complex of a Ligand with Benzimidazole Group - Synthesis and Crystal Structure

A new dinuclear copper complex, [Cu(C9H11N3)Cl2]2(C18H22Cl4Cu2N6), has been synthesized and characterized by X-ray structure determination. It crystallizes in the triclinic P-1 space group with a = 7.526(3), b = 9.473(4), c = 9.535(3)(A), α = 117.214(10), β = 108.251(9), γ = 91.560(6)°, V = 562.3(4)(A)3, Z = 1, Mr = 591.30, F(000) = 298, Dc = 1.746 g/cm3, μ(MoKα) = 2.385 mm-1, the final R = 0.0577 and wR = 0.1248 for 2188 unique reflections with 1629 observed ones (Ⅰ＞ 2σ(Ⅰ)). In the title complex, each copper(Ⅱ) atom is located at the center of a distorted trigonal bipyramid of five coordination atoms (two nitrogen and three chlorine atoms). Two copper(Ⅱ) atoms were bridged by two chlorine anions (Cl(2) and Cl(2a)) to form a Cu(Ⅱ)-Cu(Ⅱ) binuclear entity with the distance between two copper(Ⅱ) atoms of 3.398 (A).     

Chirality in the Torsion of Cylinders with Trigonal Symmetry

Solutions are obtained for a class of torsion problems for cylinders of a material with trigonal material symmetry. In particular, the solutions for elliptical, circular and equilateral triangular cross-sections are presented. These solutions show that the stress distributions are non-chiral and the same as they would be if the material were isotropic; however the in-plane displacements are chiral and different from the isotropic case. The results show that there will be transverse, in-plane stress interactions between the layers of a composite cylinder composed of concentric cylinders of different trigonal materials in torsional loading. Such composite cylinders are structural designs used by nature and by man. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis and structural characterization of a tetracopper(I) complex of 2,6-(bis(3- dimethylamino)-propyliminomethyl)-4- methylthiophenolate

The compound 2,6-diformyl-4-methylphenyl (1) has been made by hydrolysis of S-(2,6- diformyl-4-methylphenyl)dimethylthiocarbamate followed by oxidation with I₂. Condensation of 1 with 4 equiv. of 3-dimethylaminopropylamine and subsequent reduction with Na/benzophenone results in the sodium salt of the Schiff base binucleating ligand 2,6-(bis(3-dimethylamino)-propyliminomethyl)-4-methyl-thiophenolate (2, NaL). The ligand (L) binds 2 eq of Cu(I) and crystallizes from MeCN solution to give an air sensitive tetracopper(I) complex with the formula [Cu₄L₂(MeCN)](PF₆)₂ (3)·0.5 MeCN·0.25 MeOH as determined by X-ray crystallography. The complex contains three distorted trigonal planar and one distorted tetrahedral Cu¹ centers with Cu---S bond lengths short for their respective coordination geometries. In DMSO solution, ¹H NMR spectra of 3 reflect free ligand symmetry suggesting dissociation into dimers. Cyclic voltammetry of 3 in MeCN reveals one irreversible oxidation at 110 mV (vs SCE).     

Comparison of Si_n~+ and Ge_n~+(n=2―15) Cationic Structures

We designed and optimized a large number of the isomers of Si12+ at the level of density functional theory (DFT)-B3LYP/6-311++G(d) using the Gaussian 03 software package. An unambiguous structure of the Si12+ cluster is presented, whose IR spectrum agrees well with the experiment result. The most stable geometric structures of Gen+(n=2―15) clusters were determined by the all-electron PBE/DND method in DMol3 of the Material Studio Package, and compared with those of the corresponding Sin+ geometries. Most st...     

Transition metal complexes of 1,2‐dihydroquinazolinone derivative,an emerging class of analgesic and anti‐inflammatory agents

A new 1,2‐dihydroquinazolinone, 2‐(2‐hydroxy‐phenyl)‐3‐[1‐(2‐oxo‐2H‐chromen‐3‐yl)‐ethylideneamino]‐2,3‐dihydro‐1H‐quinazolin‐4‐one (L) and its Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been prepared. These were characterized by elemental, spectral [UV–visible, IR, NMR (¹H, ¹³C and 2D heteronuclear correlation) and mass], conductance, magnetic susceptibility and thermal studies. The physicochemical data indicate that the ligand behaves as tridentate with ONO donor sequence towards the metal ions, and trigonal bipyramidal geometry was assigned for complexes. The ligand and its metal complexes were evaluated for their in vivo anti‐inflammatory and analgesic activity. The tested compounds have shown excellent activity, which are almost equipotent to the standard used in the study. Copyright © 2011 John Wiley & Sons, Ltd.