二苯甲醇类结构异构体的胶束纸色谱法分离及其色谱行为

应用胶束纸色谱法使９种二苯甲醇的结构异构体得到了分离，Ｃｍ对Ｒｆ／（１－Ｒｆ）的曲线不仅偏离了Ａｒｍｓｔｒｏｎｇ理想曲线，而且呈锯齿状，其原因在于二苯甲醇类化合物具有大的立体效应。溶质的分子结构与胶束空穴的形状、大小适配，是色谱分离的主要驱动力。     

酞菁键合硅胶的制备及分离取代酞菁异构体

制备和表征了一种新的酞菁键合硅胶，三-β-(辛巯基)-β-(磺酰胺基)-酞菁铜键合硅胶。研究了该键合酞菁硅胶作为HPLC固定相的基本色谱性能。实验结果表明，该固定相可以分离四-α-(2，2，4-三甲基-3-戊氧基)酞菁(铜、镍)的4种异构体，也可以观察到四-α-(2，2，4-三甲基-3-戊氧基)无金属酞菁的4种异构体，而商业C₁₈(VERTEX Eurospher)却只能观察到两组峰，表明这种酞菁键合硅胶固定相在分析、分离一些取代酞菁异构体方面比商业C₁₈具有更好的分离效果。     

Preparative High-Performance Liquid Chromatographic Separation of Natural Farnesol Isomers (1)

Abstract

Farnesol, 3,7,11-trimethyl-2,6,10-dodecatrien-1-ol, is a naturally occurring sesquiterpenoid that is used in perfumery and synthesis. In synthesis, it is used as a starting material for other terpenoids and insect juvenile hormone derivatives. A preparative high-performance liquid chromatographic separation procedure was developed whereby 2.1 g of 2E,6E-farnesol could be readily isolated from 4.8 g of a 1:1 mixture of the 2E,6E- and 2Z,6E-isomers of farnesol. This rapid one-step procedure simplifies the separation of the mixed isomers on a preparative scale.     

Structural Isomers of Bis(diphenylarsino)methane‐dichloroplatinum(II)

From a range of preparative methods, three geometric isomers of bis(diphenylarsino)methane‐dichloroplatinum(II) have been isolated, viz. cis‐PtCl₂(dpam), trans, trans‐Pt₂Cl₄(dpam)₂ and cis, trans‐Pt₂Cl₄(dpam)₂. Their structures were determined by single‐crystal X‐ray diffraction.     

Synthesis, Structure and Properties of Tetrakis (thiourea) mercury (II) Tetrakis (thiocyanato-N) zinc (II)

Introduction In recent years, much attention has been paid to the research of novel, high-quality nonlinear optical (NLO) crystals, especially those metalorganic complex crystals that can generate high efficient second-harmonic blue-violet light using GaAlAs laser diodes. In order to find this type of crystals, much work has been done in our laboratory on the complex crystals of MM'(SCN)4 and MM'(SCN)·nL, where M = Zn, Cd, Mn; M' = Cd, Hg and L = adduct1-6. A 404.5nm blue-violet lig…     

Unusual Structural Features in the Lysozyme Derivative of the Tetrakis(acetato)chloridodiruthenium(II,III) Complex

The reaction between the paddle‐wheel tetrakis(acetato)chloridodiruthenium(II,III) complex, [Ru₂(μ‐O₂CCH₃)₄Cl] and hen egg‐white lysozyme (HEWL) was investigated through ESI‐MS and UV/Vis spectroscopy and the formation of a stable metal–protein adduct was unambiguously demonstrated. Remarkably, the diruthenium core is conserved in the adduct while two of the four acetate ligands are released. The crystal structure of this diruthenium–protein derivative was subsequently solved through X‐ray diffraction analysis to 2.1 Å resolution. The structural data are in agreement with the solution results. It was found that HEWL binds two diruthenium moieties, at Asp101 and Asp119, respectively, with the concomitant release of two acetate ligands from each diruthenium center.     

Use of Chemically Bonded β‐Cyclodextrin Silica Stationary Phase for Liquid Chromatographic Separation of Structural Isomers

The retention behavior of five disubstituted benzene derivatives and two naphthalene derivatives is examined by using a chemically bonded β‐cyclodextrin silica stationary phase with the moiety containing the s‐triazine. The chromatographic results of five disubstituted benzene derivatives and two naphthalene derivatives show that effective separation is achieved on this stationary phase by high‐performance liquid chromatography. The results of the present investigation indicate that the formation of inclusion complexes plays a dominant role in the separation mechanism. However, the selectivity can be significantly enhanced by the n‐n interactions between the s‐triazine ring of the chemically bonded β‐cyclodextrin silica stationary phase and the aromatic ring of solutes. For example, the effective separation of the o‐, m‐, and p‐toluidine isomers on this stationary phase with the moiety containing the s‐triazine ring was better than on that of some β‐cyclodextrin bonded stationary phases without the moiety containing s‐triazine ring.     

Reversed Phase Extraction Chromatographic Separation of Manganese(II) with Tributyl Phosphate

Abstract

The extraction chromatography of manganese(II) was developed using tributyl phosphate as extractant from thiocyanate media with silica gel as the stationary phase. Manganese was extracted from 1.5 M ammonium thiocyanate, stripped with mineral acids and determined spectrophotometrically at 450 nm. It was separated from alkali metals, Mo(VI), nickel, silver and lead by selective extraction, and from iron(III), zinc, cobalt by selective stripping. The method was extended for the analysis of manganese in samples of soil and minerals.     

(Tetrakis(2-pyridylmethyl)ethylenediamine)iron(II) perchlorate. Study of density functional methods

On the basis of the data obtained by X-ray diffraction, the properties of two independent crystallographic subsystems in the [Fe(tpen)](ClO4)2.2/3H2O complex are studied in detail with the density functional method B3LYP. The energies of singlet, triplet, and quintet states at different temperatures are obtained, the influences of geometry on energy changes are analyzed, the regularity of the spin-state interconversions is investigated, and the effect of the triplet and action of the anion on spin crossover are discussed. This investigation demonstrates that (1) the energy difference between the high-spin state and singlet state decreases as the Fe-N distance and geometric distortion increase, (2) the spin-equilibrium system is predominantly in low-spin form below room temperature and the proportion of high-spin state rapidly increases above room temperature, (3) one of the two cation sites has a greater presence of the high-spin content, (4) the triplet state may be responsible for the fast rate of spin-state interconversions, and (5) the B3LYP method proves to be very adequate to study the spin-state transition of this complex.     

Gold(II) Phthalocyanine Revisited: Synthesis and Spectroscopic Properties of Gold(III) Phthalocyanine and an Unprecedented Ring‐Contracted Phthalocyanine Analogue

In 1965, gold(II) phthalocyanine (AuPc, 1 ) was described to be synthesized from unsubstituted 1,3‐diiminoisoindoline and gold powder or AuBr. Compound 1 has been regarded as a rare example of a paramagnetic gold(II) complex. However, its chemistry, especially the oxidation state of the central gold ion, has not been previously explored due to the inherent insolubility of 1 caused by its unsubstituted structure. In our attempt to synthesize soluble AuPcs by using 5,6‐di‐substituted 1,3‐diiminoisoindolines, gold(III) phthalocyanine chloride ( 3 ) and a gold(III) complex of an unprecedented ring‐contracted phthalocyanine analogue ([18]tribenzo‐pentaaza‐triphyrin(4,1,1), 4 ) were isolated. With this discrepant result from the original literature in hand, a reinvestigation of the original AuPc synthesis by using unsubstituted 1,3‐diiminoisoindoline and various gold salts (including gold powder and AuBr) was performed, finding that only unsubstituted analogues of 3 and 4 or free‐base phthalocyanine were obtained. No gold(II)‐containing species could be isolated.     

Isomers of C(20): an energy profile II

Semi-empirical calculations, at the PM3 level provided within the Winmopac v2.0 software package, are used to geometrically optimize and determine the absolute energies (heats of formation) of a variety of C(20) isomers that are predicted to exist in and around the bowl and cage isomers. Using the optimized Cartesian coordinates for the bowl and the cage isomers, a saddle-point calculation was performed. The output file generated, containing energy, distance, and geometry information, is then organized into a graphical format. The resulting graph, which plots the energy of the 20-atom system as a function of the distance from the geometric midpoint, is a two-dimensional energy profile. This profile illustrates an estimation of the contours on the potential energy surface, showing energy minima and maxima that are encountered as the bowl evolves into the cage structure, or vice-versa. To expand the surface into three dimensions, geometry optimizations were performed on the sets of Cartesian coordinates that correspond to energy minima in the bowl-cage profile. Based on these optimizations, eight additional isomers of C(20) have been identified and are predicted to be energetically stable. These additional isomers were subsequently subjected to saddle-point calculations in order to identify those isomers that lie adjacent to one another on the three-dimensional surface. Two isomers that are adjacent to each other will exhibit an energy profile that progresses smoothly from the potential well of each isomer up to the saddle point separating them. Consequently, these adjacent pairs of isomers establish a step-wise transformation between the bowl and the cage. This process, which extends out over the three-dimensional surface, is predicted to require less energy than that of the direct, two-dimensional transformation predicted in the bowl-cage profile.     

Synthesis and Crystal Structure of Tetrakis（1- vinylimidazole-kN^3）diisothiocyanatomanganese（II）

The title compound I （C22H24MnN10S2, Mr = 547.57） has been synthesized and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group P2 1/c with a = 8.6010（17）, b = 9.0180（18）, c = 17.773（4）A, β = 101.79（3）°, V = 1349.5（5）A^3, Z = 2, Dc = 1.348 g/cm^3,/1 = 0.674 mm^-1, F（000） = 566, the final R = 0.0488 and wR = 0.1289. In the structure, each Mn atom is coordinated by four Vim （Vim = 1-vinylimidazole） ligands and a pair of monodentate isothioeyanic groups, affording a compressed oetahedral MnN6 core.     

Synthesis and Crystal Structure of Tetrakis(dimethyl sulfoxide)copper(II) Hexafluorosilicate

A new complex of composition [Cu(DMSO)₄SiF₆] (I), where DMSO is dimethyl sulfoxide (CH₃)₂SO, has been prepared and characterized by X-ray diffraction. Crystals I are triclinic, space group P\(\bar 1\), Z = 2, a = 10.1772(4) Å, b = 10.3061(5) Å, c = 10.6071(5) Å, V = 1003.94 Å3, ρ_calc = 1.714 g/cm³.     

Photophysics of Zinc (II) Phthalocyanine Polymer and Gel Formulation

The photophysical properties of lipophilic phthalocyanines encapsulated into a polymer and two different gels were studied in order to predict their photosensitizing efficacy in vivo. Photophysical techniques for solid phase were adapted for light dispersing samples. Gel formulation of two tetrasubstituted phthalocyanines, tetra-t-butylphthalocyaninato zinc(II) ( 1 ), tetrakis(1,1-dimethyl-2-phthalimido)ethylphtalocyaninatozinc(II) ( 2 ) and two octasubstituted phthalocyanines, 2,3,9,10,16,17,23,24-octakis(decyloxy)phthalocyaninatozinc(II) ( 3 ) and 2,3,9,10,16,17,23,24-octakis[(N,N-dimethylamino)ethylsulfanyl]phthalocyaninatozinc(II) ( 4 ) were investigated for their possible use in photodynamic therapy for topical purposes. Supporting the fact that gel formulation improves the photophysical properties of phthalocyanines, singlet molecular oxygen quantum yield (Φ_Δ) values for 1 – 4 zinc(II) phthalocyaninates in Lutrol^® F 127-Cremophor^® RH 40 were 0.60, 0.60, 0.20 and 0.26, respectively. Permeation studies showed that no release of phthalocyanines occurs, thus indicating there should be no risk of generalized skin photosensitivity in areas other than the dye-deposition site.     

Tetrakis(2-quinolinylmethyl)ethylenediamine (TQEN) as a new fluorescent sensor for zinc

A new fluorescent sensor for zinc that binds 1 equivalent of zinc ion, N,N,N',N'-tetrakis(2-quinolylmethyl)ethylenediamine (TQEN), has been prepared and characterized. Zinc-bound TQEN exhibits fluorescence around 383 nm upon excitation at 317 nm, while free TQEN emits very weak fluorescence. UV-Vis and 1H NMR spectral changes also detected the binding of TQEN with zinc ion. The crystal structure of zinc complex with TQEN was determined by X-ray crystallography and compared with that of the TPEN-Zn complex (TPEN =N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine). The binding affinity of TQEN with zinc ion is very high (Kd < 1 microM in aqueous dmf solution). Competition experiments reveal that the zinc-binding affinity of TQEN is lower than the parent, strong metal ion chelator TPEN, and comparable to EGTA (EGTA = ethylene glycol-bis(2-aminomethyl)-N,N,N',N'-tetraacetic acid).