Molecular Complexes of Phthalocyanine with Organic Solvents

It was established that in crystal solvates and solutions zinc(II)tetra-tert-butylphthalocyanine formed stable molecular complexes with benzene and pyridine. The characteristics of the corresponding molecular complexes were estimated. Molecules of electron-donor and aromatic solvents do not break down the zinc(II)tetra-tert-butylphthalocyanine associates and do not facilitate intraphase polymorphic transition. A comparative analysis was carried out for the coordinative properties of zinc(II)tetra-tert-butylphthalocyanine and its structural analog, zinc(II)tetrabenzoporphyrin, with respect to pyridine in benzene solutions.     

Organometallic Polymers of the Transition Metals

This article provides a comprehensive review of the synthesis, properties and applications of organometallic polymers of the transition metals. The different classes of organometallic polymers are described according to their structural make‐up, as well as by their methods of synthesis. A number of examples of each class are given to emphasize the richness and diversity in these areas of research. In addition to linear polymers, hyperbranched, crosslinked, star and dendritic polymers are also described. The properties that transition metal‐containing organometallic polymers possess, as well as the applications that these materials have found in various domains are highlighted.

     

Methyl Complexes of the Transition Metals

Organometallic chemistry can be considered as a wide area of knowledge that combines concepts of classic organic chemistry, that is, based essentially on carbon, with molecular inorganic chemistry, especially with coordination compounds. Transition‐metal methyl complexes probably represent the simplest and most fundamental way to view how these two major areas of chemistry combine and merge into novel species with intriguing features in terms of reactivity, structure, and bonding. Citing more than 500 bibliographic references, this review aims to offer a concise view of recent advances in the field of transition‐metal complexes containing M?CH₃ fragments. Taking into account the impressive amount of data that are continuously provided by organometallic chemists in this area, this review is mainly focused on results of the last five years. After a panoramic overview on M?CH₃ compounds of Groups 3 to 11, which includes the most recent landmark findings in this area, two further sections are dedicated to methyl‐bridged complexes and reactivity.     

Thermodynamics of Formation of Molecular Complexes of Metalloporphyrins with Pyridine in Organic Solvents at 298.15 K

Microcalorimetric titration was used to obtain a full set of thermodynamic characteristics of the axial coordination of pyridine by metal complexes of synthetic (ZnTPP, NiTPP, CuTPP, (Cl)FeTPP, (Ac)FeTPP, (Cl)MnTPP, (Ac)MnTPP) and biological (ZnHP, ZnDP, ZnMP, ZnPP) porphyrins in benzene and chloroform at 298.15 K. It was established that the involved character of the processes under study is determined both by the structure of the metalloporphyrins and by the specific features of the solvation interactions of metalloporphyrin and pyridine with solvent molecules.     

Supramolecular Complexes of Multivalent Cholesterol‐Containing Polymers to Solubilize Carbon Nanotubes in Apolar Organic Solvents

Copolymers of 2‐ethylhexyl acrylate (EHA) and cholesteryloxycarbonyl‐2‐hydroxymethacrylate (CEM) were prepared by reversible addition–fragmentation chain‐transfer (RAFT) polymerization. Supramolecular complexes of these copolymers with carbon nanotubes (CNTs) were soluble in THF, toluene, and isooctane. The colloidal solutions remained stable for months without aggregation. The rationale for the choice of CEM was based on the high adsorption energy of cholesterol on the CNT surface, as computed by DFT calculations. Adsorption isotherms were experimentally measured for copolymers of various architectures (statistical, diblock, and star copolymers), thereby demonstrating that 2–5 cholesterol groups were adsorbed per polymer chain. Once the supramolecular complex had dried, the CNTs could be easily resolubilized in isooctane without the need for high‐power sonication and in the absence of added polymer. Analysis by atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) indicated that the CNTs were devoid of bundles. The supramolecular complexes could also be employed in an inverse emulsion polymerization of 2‐hydroxyethylmethacrylate (HEMA) in isooctane and dodecane, thereby leading to the formation of a continuous polymeric sheath around the CNTs. Thus, this technique leads to the formation of very stable dispersions in non‐polar organic solvents, without altering the fundamental properties of the CNTs.     

A Solution State Study of the Complexation and Thermodynamic Parameters of Binary Complexes of the Inner Transition Metals with Piracetam in Aqueous and Mixed Solvents

An equilibrium study on complexation behavior of the inner transition metals, where M = {Y(III), La(III, Ce(III, Pr(III), Nd(III), Sm(III), Gd(III), Dy(III), Th(IV)} and L = piracetam, has been carried out using the Irving–Rossotti titration technique in aqueous media at different temperatures and ionic strengths. The protonation constant and stability constants (log₁₀ β _n ) of the resulting inner metal–ligand complexes have been calculated with the Fortran IV program BEST using the method of least squares and considering the BESTFIT model. Thermodynamic parameters were also evaluated, yielding negative ΔG°, ΔH° and positive ΔS° values that indicate complex formation is favorable at ordinary temperatures. Species distribution curves of complexes have been plotted as function of pH using the SPEPLOT FORTRAN IV program to visualize the presence of various species in equilibrium in the pH range 2–6. To understand more about these equilibria, the stability of these complexes was studied at different percentages of solvent (10–30 % v/v) in different aqua-organic solvent mixtures with methanol, ethanol, 1-butanol and dimethylformamide.     

主链含过渡金属和大π体系的金属有机聚合物研究进展

综述了主链含过渡金属物大π体系的金属有机聚合物的研究进展。这类聚合类中比较典型的是聚茂金属。主要介绍了主链含短时隔基、长间隔基、共轭间隔基的聚茂金属的合成方法和主要特性。在聚茂金属合成方法中，着重描述了开环聚合反应方法。     

Modern Methods for Studying Polymer Complexes in Aqueous and Organic Solutions

This review summarizes published data concerning modern physicochemical methods used to study complexation processes of polymers in solutions. Some of them—dynamic light scattering, nanoparticle tracking analysis, transmission electron microscopy, cryotransmission electron microscopy, atomic force microscopy, small-angle neutron scattering, analytical-velocity sedimentation, and luminescence methods—make it possible to gain insight into the structure of polymer complexes, while the other methods, such as isothermal titration calorimetry and surface plasmon resonance, provide an opportunity to assess the intensity of specific interactions between complex components.     

Luminescence of Novel Neodymium Sulfonylaminate Complexes in Organic Media

Luminescence of Nd(III) in an organic solvent having C-H bonds was achieved for the first time by complexing Nd(III) with long-chain perfluoroalkylated ligands such as bis(perfluorooctylsulfonyl)aminate (pos). The complex [Nd(pos)(3)] gave an emission quantum yield of 3.0+/-0.5 % in undeuterated acetone. The bulky pos ligands suppress the excitation of C-H vibrations, energy migration at diffusional collision, and the coordination of acetone molecules (see picture) to the Nd(III) center, which otherwise quench the luminescence.     

Aldehyde Oxidase Activity and Stability in Water-Miscible Organic Solvents

In this study, the catalytic activity of aldehyde oxidase was investigated in various water-miscible organic solvents for the first time. The enzyme was partially purified from rabbit liver, and its activity was determined in the absence/presence of nine hydro-organic mixtures. The effects of pH and temperature on the enzyme activity were also investigated. The activity was reduced in the presence of all nine organic solvents. However, in some cases, the residual activity remained almost unchanged throughout the incubation of enzyme at 35 °C for 24 h. Considering potential advantages of doing reactions in the presence of organic solvents, these results could be of value. The enzyme showed different behavior in the reaction solutions making it difficult to formulate results in a single comprehensive model. The results indicated that binding and cleavage of the substrate are influenced in the presence of organic solvents.     

过渡金属-稀土异核配合物发光研究进展

借助于d-f能量传递,利用在可见区有很强电荷跃迁吸收的过渡金属有机发色团(d-block chromophore)作为稀土离子光捕获剂是本世纪初发展起来的获得高效敏化稀土发光的一条有效途径。为此,本文简要介绍稀土离子的相关电子特征和有机配体与稀土离子之间的能量传递简易模式;系统介绍了目前获得敏化稀土离子(近红外)发光的研究方法;重点介绍了d-f能量传递方面的研究成果及其在相关领域的应用。本文最后系统地介绍了本研究组近年来利用某些功能化的炔基桥联配体设计合成系列d-f异金属化合物在稀土发光材料方面的研究进展,并对该领域的研究热点和发展趋势作了初步展望。     

第一过渡系金属硅烯配合物的理论研究

以HF/6-311+G^*基组研究了硅烯SiH₂同第一过渡系金属的配合物MSiH₂的分子轨道特征及键解离能.MSiH₂为共平面构型.其中基态的3TiSiH₂和4CoSiH₂带有明显的双键特征.M-Si键具有共价性质.M-Si的键解离能,从Sc到Cu呈现周期性变化,这种变化趋势同M的金属离子激发能之间存在近似的线性关系.     

Sandwich Complexes of the As42-Aromatic Ring with Some Transition Metals

The equilibrium geometries, energies, harmonic vibrational frequencies, and nuc- leus independent chemical shifts (NICS) of the new type sandwich structures [As4MAs4]n- (M = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt; n = 0, 1 or 2) are investigated at the B3LYP level.All the [As4MAs4]n- species adopt staggered (D4d) conformations as their stable structures and eclipsed (D4h) conformations as their transition states, and once the sandwich complexes are formed, the As42- square properties remain unchanged.The NICS calculation confirms that the complexes of Fe, Co, and Ni are aromatic with negative NICS values, and those of Ru, Rh, and Ir exhibit slight aromaticity, while those of Pd, Os, and Pt show slight antiaromaticity.     

Metal-Metal Cooperation in Dinucleating Complexes Involving Late Transition Metals Directed towards Organic Catalysis

Cooperatively bimetallic organic catalysis,coupling actions of two metal centers in a catalytic organic transformation via co-activation of a single molecule or synergistic activation of two molecules,has witnessed rapid development in the last decades.