具有三维结构的Co(II)配合物二阶非线性光学性质的DFT研究

以实验合成出的Schiff碱配体和Co(II)配合物为母体,设计了Schiff碱配体和具有三维结构的Co(II)配合物.采用密度泛函理论的B3LYP/6-31g(d)-FF方法对具有开壳层电子组态Co(II)配合物及相应配体的二阶非线性光学(NLO)效应进行了计算.结果表明:Schiff碱配体形成配合物后分子的二阶NLO性质没有发生大的改变,这是由于金属Co2 离子在配合物电荷转移(CT)过程中起到了桥的作用,对分子的二阶NLO响应直接贡献不大.结合配合物的前线分子轨道分析发现,在分子内电荷转移过程中,对分子二阶NLO系数的主要贡献是配体内电荷转移(ILCT)跃迁.     

Syntheses and Structures of Blue Luminescent Zinc(Ⅱ) Complexes with 2,6-Bis(imino)pyridyl Ligands

Luminescent coordination compounds with nitrogen-containing ligands have attracted much attention due to their good performance in sensor and electroluminescent device techniques[1-17]. To develop new luminescent materials, a large number of d10 metal complexes, especially zinc complexes, with the nitrogen-containing ligands have been synthesized and their luminescence behaviour have been studied[1-11]. It has been found that for a given complex, the size of the π-conjugated system of the ligand and the electronic effect of substituents at the ligand are important factors for modulating its luminescent properties[5,8,9].     

Manganese(I) tricarbonyl complexes: UV-dependent antioxidant activity,electrochemistry, and DFT/TDDFT calculation

Abstract

As important catalysts, metal carbonyl complexes have received considerable attention in recent years owing to their ability to store and transport carbon monoxide that have been proven to function as antiinflammatory, antiapoptotic, and antiproliferative agents. In addition, imidazole/benzimidazole derivative molecules have been known to be bioactive owing to their antihypertensive, antiinflammatory, and antimicrobial properties. Combining these two bioactive species could be a good idea for possible synergistic effect. In this study, [Mn(CO)₃(bpy)L]X (bpy =2,2-bipyridyl; X?=?PF₆, SO₃CF₃, L?=?imidazole, N-methylimidazole, benzimidazole, N-benzylbenzimidazole, N-4-chlorobenzylbenzimidazole) complexes have been characterized electrochemically and related to CO-releasing properties. The molecules have been theoretically analyzed in terms of electronic transitions and spin-density plot in water, acetonitrile, and gas phase for having insight that promote CO-releasing and electroactivity characteristics. Antioxidant activity of the complexes has also been analyzed in order to gain a possible relationship with CO-releasing properties of the complexes.     

Design and synthesis of 1,10-phenanthroline based Zn(II) complexes bearing 1D push-pull NLO-phores for tunable quadratic nonlinear optical properties

Three Zn(II) complexes bearing 1,10-phenanthroline and one-dimensional (1D) push-pull NLO-phores with various acceptor strength as well as π-conjugation length have been synthesized in high yields for two-dimensional (2D) nonlinear optical response. The quadratic optical nonlinearity of the ligands and the complexes are measured by the HRS technique. The ligands show small second-order optical nonlinearity (β) comparable to the standard, para-nitroaniline (pNA). However, upon complexation with Zn(II), each complex exhibits large β values showing the importance of metal ion in enhancing the optical nonlinear effect.     

Organosilicon(IV) and organotin(IV) complexes as biocides and nematicides: synthetic,spectroscopic and biological studies of N∩N donor sulfonamide imine and its chelates

A brief account is given of the synthesis and stereochemistry and the antibacterial, antifungal, nematicidal and insecticidal behaviour of organosilicon(IV) and organotin(IV) complexes of a biologically potent ligand, 2‐acetylfuransulfaguanidine. The unimolar and bimolar substitution products have been characterized by elemental analyses, conductance measurements, molecular weight determinations, and spectral studies, viz. IR, ¹H NMR, ¹³C NMR, UV, ²⁹Si NMR and ¹¹⁹Sn NMR spectra. The data support the binding of the nitrogen atom to the metal atom in R₃M(N^∩N), [R₂M(N^∩N)₂ and R₂M(N^∩N)Cl [(R = Me/Ph and M = Si(IV) and Sn(IV)] types of complex. Based on these studies, with coordination number five and six a trigonal bipyramidal and an octahedral geometry have been proposed for the resulting derivatives. The free ligand (N^∩NH) and its respective metal complexes were tested in vitro against a number of microorganisms to assess their antimicrobial properties. The results are indeed positive. In addition to these studies, the complexes also show good nematicidal and insecticidal properties. The results of these findings have been discussed in detail. Copyright © 2004 John Wiley & Sons, Ltd.     

Luminescent metal alkynyls - from simple molecules to molecular rods and materials

This review describes the design and synthesis of a number of luminescent transition metal alkynyls by this laboratory. The luminescence properties of the complexes have been studied and their emission origin elucidated. Some of these complexes have been shown to be ideal building blocks for the design and construction of luminescent molecular rods and materials, in which the luminescence properties can be readily tuned by changing the alkynyl ligands. Some of them also exhibited luminescence switching behaviour with the “ON-OFF” luminescence states modulated by redox processes, metal ion-binding or solvent composition.     

Magnetism of metal-nitroxide compounds involving bis-chelating imidazole and benzimidazole substituted nitronyl nitroxide free radicals

Coordination compounds based on imidazole and benzimidazole substituted nitronyl nitroxide radicals with transition metal ions and trivalent lanthanide ions are described from the perspective of their magnetic properties.For the transition metal compounds the crystal structures show various metal-nitroxide dimensionalities including mononuclear (0D), one-dimensional (1D) and two-dimensional (2D) complexes. The mononuclear complexes were isolated with most metal ions of the first transition series. One copper(II) complex shows a copper(II)-radical ferromagnetic coupling (J = +75 cm⁻¹) while for the other mononuclear compounds, mainly with manganese(II), the metal-radical interactions are antiferromagnetic. The one-dimensional and two-dimensional complexes are manganese(II) compounds which show canting effects leading to weak ferromagnetism.For the trivalent lanthanide ions [La(III), Gd(III) and Eu(III)], three series of mononuclear complexes were obtained in which the metal center is bound to four, two or one nitroxide radicals depending on the counter ions and ancillary ligands. Unexpectedly, in most gadolinium(III) complexes, the Gd(III)-radical interactions were found to be antiferromagnetic in contradiction with other foundings and previous theoretical models. In support to the magnetic studies, the optical properties of the lantanide complexes have also been investigated and are briefly described.     

New heterocyclic metallomesogens: synthesis,mesomorphic and thermal behaviours of Cu(II) complexes with 1,2,3-triazole-based Schiff bases ligands

Two series of new Cu(II) complexes derived from the reaction of copper acetate with the non-linear 1,2,3-triazole-based Schiff bases have successfully been synthesised. The structures of the ligands and its complexes were elucidated by elemental analysis, FT-IR, ¹H-NMR and UV–visible spectroscopic techniques. The differential scanning calorimetry and polarizing optical microscopy supported the anisotropic properties of uncoordinated ligands in which the focal conic fan-shaped texture and/or broken fan-shaped texture characteristics of respective SmA and SmC phases were recorded. However, not all of their corresponding Cu(II) complexes are mesogenic. Although the iodo-substituted ligands with even parity C₁₀H₂₉ to C₁₄H₃₃ are non-stable and exhibit SmA phase which is not reproducible, the ultimate Cu(II) complexes show exclusively stable SmA phase. This observation can be ascribed to the enhanced colinearity and molecular anisotropic by the presence of Cu-N and Cu-O coordination modes. On the other hand, the comparison studies show that different positions of ortho-hydroxyl group affect the mesomorphic and thermal behaviour of ligands and Cu(II) complexes.     

X-ray structural studies on metal complexes with nucleotides and pyridoxal-amino acid Schiff bases. Models for platinum binding to DNA and pyridoxal catalyzed reactions

X-ray structural studies on metal complexes with nucleotides and with pyridoxalamino acid Schiff bases are briefly reviewed. The results with ternary metal nucleotide complexes show that the oxopurine nucleotides coordinate to the metal ion through the N(7) atoms of the bases incis position. The relevance of this mode of binding is discussed in terms of the possible mechanism of action of the novel platinum drugs. On the basis of the studies on metal pyridoxal-amino acid Schiff base complexes, the variations in stereochemistry of the ligands in different metal complexes have been related to the catalytic activity of various metal ions in pyridoxal-catalyzed nonenzymatic reactions.     

Ruthenium, osmium and rhodium complexes of polypyridyl ligands: Metal-promoted activities, stereochemical aspects and electrochemical properties

This article presents a brief overview of the reactions of2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) in presence of rhodium(III), ruthenium(II) and osmium(II) under various experimental conditions. Under certain experimental conditions tptz exhibits metal-assisted hydrolysis/hydroxylation at the triazine ring. However, synthetic methods have also been developed to prepare complexes with intact tptz. Molecular structures of some of the complexes, especially stereoisomers of the hydroxylated products, are established by single crystal X-ray studies. A critical analysis of all data suggests that the electron-withdrawing effect of the metal ion (L→Mσ donation) is the predominant factor, rather than angular strain, that is responsible for metal-promoted reactivities. Electrochemical properties of all of these complexes have been investigated, Rh(III) complexes are excellent catalysts for electrocatalytic reduction of CO₂, and dinuclear Ru(II) and Os(II) complexes exhibit strong electronic communication between the metal centres.     

Recent developments in the field of metal complexes containing photochromic ligands: Modulation of linear and nonlinear optical properties

Organic photochromic molecules are important for the design of photoresponsive functional materials, as switches and memories. Over the past 10 years, research efforts have been directed towards the incorporation of photoresponsive molecules into metal systems, in order either to modulate the photochromic properties, or to photoregulate the redox, optical and magnetic properties of the organometallic moieties. This review article focuses on some of the recent work reported within the last few years in the area of organometallic and coordination complexes containing photochromic ligands for the photoregulation of optical and nonlinear optical properties. The first part is related to photochromic 1,2-diarylethene (DAE)-containing metal complexes, examples of mono- and multi-DAE metal-based will be discussed. The second part deals with metal complexes incorporating spiropyran and spirooxazine derivatives.     

Pesticidal and antifertility activities of triorganogermanium(IV) complexes synthesized using a green chemical approach

Microwave chemistry is a green chemical method that improves reaction conditions and product yields while reducing solvent amounts and reaction times. This paper deals with the synthesis, spectral and biological studies of germanium(IV) complexes with chelating hydrazones derived from 1‐(pyridine‐2‐yl)ethanone (F₁) and 1‐(furan‐2‐yl)ethanone (F₂) with isonicotinohydrazide (INH). The complexes have been synthesized under a microwave–green chemical approach and investigated using a combination of microanalytical analysis, melting point, IR spectra, ¹H NMR spectra and ¹³C NMR spectra. Trimethylgermanium(IV)chloride and triphenylgermanium(IV)chloride interact with the hydrazones in a 1:1 molar ratio (metal:ligand), resulting in the formation of coloured products. On the basis of conductance and spectral evidence, a pentacoordinated structure for germanium(IV) complexes has been assigned for these products. The ligand is coordinated to the germanium(IV) via the azomethine nitrogen atom and the enolic oxygen atom. The free ligands and their metal complexes have been tested in male rats in order to assess their antifertility properties. Ligands and their metal complexes have also been tested in vitro against a number of pathogenic microorganisms in order to assess their antimicrobial and pesticidal properties. Both the ligands and their complexes were found to possess appreciable antifertility activity and other activities, which have been discussed in brief. Copyright © 2013 John Wiley & Sons, Ltd.     

Electronic, EPR, magnetic and mass spectral studies of mono and homo-binuclear Co(II) and Cu(II) complexes with a novel macrocyclic ligand

A series of 20-memebered macro-cyclic metal(II) complexes have been synthesized by a macro-cyclic ligand, i.e. 1,5,11,15-tetraaza-6,10,16,20-tetraoxo-8,18-dithia-cyclocosane, it was prepared by the condensation reaction of 1,3-diaminopropane with thiodiglycolic acid. The bonding and stereochemistry of the complexes have been characterized by elemental analysis, magnetic moment, molar conductance, mass, 1H NMR, IR, electronic and EPR spectral studies. The mononuclear complexes of the type [ML]X2 have been found to have distorted octahedral geometry and the binuclear complexes [M2LX2]X2 were found to possess square planar configuration around the central metal ion.     

Synthesis and Structural Studies of 2,2′-[(2E,5E)-hexane-2,5-diylidenedi-nitrilo]-dibenzenethiol and 2-Hydroxybenzaldehyde (2E,5E)-hexane-2,5-diylidenehydrazone ligands and their Mononuclear Cu(II) and Ni(II) Complexes

Monomeric copper(II) and nickel(II) complexes with tetradentate two new ligands, 2,2′-[(2E,5E)-hexane-2,5-diylidenedi- nitrilo]dibenzenethiol(H₂L) and 2-hydroxybenzaldehyde (2E,5E)-hexane-2,5-diylidenehydrazone(H₂L¹) have been synthesized and characterized by elemental analyses, magnetic moments, molar conductance, ¹H-NMR and ¹³C-NMR, IR, mass spectral studies, theoretical calculations (MM2 and AM1) molecular methods. The mononuclear metal complexes of H₂L and (H₂L¹) were found to have a 1:1 metal:ligand ratio. Elemental analyses, stoichiometric and spectroscopic data of metal complexes indicated that the metal ions were coordinated to the sulphur (-SH) and/or (-OH) oxygen and imine nitrogen atoms (C = N). All of the data obtained from spectral, and molecular mechanics (MM2) or semi empirical calculations (AM1) studies support the structural properties of ligands and its Cu(II) and Ni(II) metal complexes.     

Luminescent Ionic Transition‐Metal Complexes for Light‐Emitting Electrochemical Cells

Higher efficiency in the end‐use of energy requires substantial progress in lighting concepts. All the technologies under development are based on solid‐state electroluminescent materials and belong to the general area of solid‐state lighting (SSL). The two main technologies being developed in SSL are light‐emitting diodes (LEDs) and organic light‐emitting diodes (OLEDs), but in recent years, light‐emitting electrochemical cells (LECs) have emerged as an alternative option. The luminescent materials in LECs are either luminescent polymers together with ionic salts or ionic species, such as ionic transition‐metal complexes (iTMCs). Cyclometalated complexes of Ir^III are by far the most utilized class of iTMCs in LECs. Herein, we show how these complexes can be prepared and discuss their unique electronic, photophysical, and photochemical properties. Finally, the progress in the performance of iTMCs based LECs, in terms of turn‐on time, stability, efficiency, and color is presented.     

Effect of salt concentrations on the displacement adsorption enthalpies of denatured protein folding at a moderately hydrophobic surface

Lead(II) complexes of reduced glutathione (GSH) of general composition [Pb(L)(X)]·H₂O (where L=GSH; X=Cl, NO₃, CH₃COO, NCS) have been synthesized and characterized by elemental analyses, infrared spectra and electronic spectra. Thermogravimetric (TG) and differential thermal analytical (DTA) studies have been carried out for these complexes. Infrared spectra indicate deprotonation and coordination of cysteinyl sulphur with metal ion. It indicates the presence of water molecule in the complexes that has been supported by TG/DTA. The thermal behaviour of complexes shows that water molecule is removed in first step-followed removal of anions and then decomposition of the ligand molecule in the subsequent steps. Thermal decomposition of all the complexes proceeds via first order kinetics. The thermodynamic activation parameters, such as E*, A, ΔH*, ΔS* and ΔG* have been calculated. The geometry of the metal complexes has been studied with the help of molecular modeling for energy minimization calculation.     

Coordination compounds of biological interest: Thermal properties of some compounds of saccharin (o-benzoic sulphimide) with nickel(II) and zinc(II)

The thermal properties of nickel(II) and zinc(II) complexes of saccharin (sacc) (o-benzoic sulphimide) have been studied and compared both with those of cobalt(II) and copper(II) previously studied and with those of ternary complexes of nickel(II) and zinc(II) having both saccharin and pyridine as ligands. The thermal behaviour is discussed in terms of the interaction between metal and ligands, interaction studied by IR spectroscopy, and by reflectance spectroscopy.The classical thermal stability scale Co(II) > Ni(II) > Cu(II) > Zn(II) is always obtained.     

Complete assignments of NMR data of salens and their cobalt (III) complexes

Salens, derived from 1,2‐ethylenediamine and salicylaldehydes, have been widely used as ligands for metal complexes which have been showing enormous potential in chemical properties of asymmetric catalysts as well as biological properties such as anticancer agents. Almost all of the salen–metal complexes with their corresponding metal (II)‐complexes show the evidences of chelation of two oxygens in salens. However, several metal (II) complexes, especially cobalt (II) complexes, could not show NMR spectra due to their paramagnetism. Recently, it has been reported that one of the cobalt (III) complexes was used for NMR spectroscopy to evaluate its stereoselectivity as a catalyst. Even though many salen ligands are known, their NMR data are not assigned completely. It was possible that modification in northern part of salen with 2‐hydroxyphenyl group afforded another oxygen chelation site in salen ligand. Here we report that synthesis and full NMR assignment of new salen ligands, which form meso 1,2‐bis(2‐hydroxyphenyl)ethylenediamine) and their cobalt (III) complexes. The assignments of ¹H and ¹³C NMR data obtained in this experiment can help us to predict the NMR data of other salen ligands. Copyright © 2008 John Wiley & Sons, Ltd.     

Synthesis,spectroscopic and electrochemical studies of copper(II) and cobalt(II) complexes of three unsymmetrical vic -dioximes ligands

Cobalt(II) and copper(II) complexes with three dioxime ligands cyclohexylamine-p-tolylglyoxime (L₁H₂), tert-butyl amine-p-tolylglioxime (L₂H₂) and sec-butylamine-p-tolylglyoxime (L₃H₂), have been prepared. The metal to ligand ratios of the complexes were found to be 1?:?2. The Cu(II) complexes of these ligands are proposed to be square planar; the Co(II) complexes are proposed to be octahedral with water molecules as axial ligands. Ligands and complexes are soluble in common solvents such as DMSO, DMF, CHCl₃ and C₂H₅OH. The ligands have been characterized by elemental analysis, IR, UV-VIS, ¹H?NMR, ¹³C?NMR and thermogravimetric analysis (TGA). The complexes were characterized by elemental analysis, IR, UV-VIS, magnetic susceptibility measurements, thermogravimetric analysis (TGA) and electrochemistry. Electrochemical properties of metal complexes show quasi-reversible one-electron redox processes. However, Co(L₁H)₂ and Cu(L₁H)₂ complexes show another oxidation peak in the positive region. This single irreversible oxidation peak is caused by the cyclic ring of the ligand. Data also revealed that the electron transfer rates of metal complexes with L₁H₂ are higher than the other complexes.     

8-羟基喹啉过渡金属配合物电子光谱和二阶非线性光学性质的 DFT研究

使用含时密度泛函理论(TDDFT)B3LYP方法计算了IB, IIB, VIIIB过渡金属与8-羟基喹啉络合(MQ)后, 配合物的电子光谱以及二阶非线性光学性质. 结果表明, 掺杂过渡金属后, 形成络合物的能隙值减小100～150 kJ/mol, 最大吸收波长红移150～200 nm左右. 电子从基态到激发态的跃迁主要为p→p*, n→p*跃迁, 属于LLCT, MLCT过程. IB的络合物MQ以及VIIIB的络合物MQ3表现出良好的非线性光学性质.