Shape linear peptides into rigid rings: a sp~3 C–H arylation approach to cyclophane-braced peptide macrocycles

正Peptide-based therapeutics have attracted increasing attention due to their unique properties in comparison to small molecule drugs and recombinant biologics [1]. With moderate size and suitable surface area, peptides possess enormous potential in drug discovery for their promising capabilities of intercepting protein-protein interactions(PPIs), which is extremely difficult to be accomplished using small molecule compounds [2]. However, the biological instability and poor membrane permeability of peptides have significantly compromised their value as drug candidates or therapeutics. Macrocyclization is a widely applied strategy to     

Synthesis, Structure Characterization and Biological Activity of Layered Vanadium Oxides [ NH3 （ CH2 ）2 NH （ CH2 ）2 NH3 ] [ V6 O14 ]

Introduction Over the past decades, polyoxometalates(POMs)have been attracting extensive interestowing to the widerange of their topological properties and potential appli-cations in catalysis, photochemistry, electrochromism,and magnetism[1,2]. Meanwhile, owing to the potentialapplication of polyoxometalaes as anticancer and antivi-ral drugs, their complexes have attracted increasing in-terest of both inorganic chemists and biochemists[3]. Itis well known that polyoxometalates are excellent …     

Synthesis and Structure of [Er4（μ3—OH）4（Hpro）4（Pro）2（H2O）7]（ClO4）6.7H2O

1 INTRODUCTION The design and synthesis of polynuclear com- plexes have attracted chemists?attention in the contemporary chemistry, since their clusters maybe lead to novel materials with magnetic, optical, electronic and catalytic properties of the constituent metals[1～3]. It is also prevalently interesting to synthesize high-nuclearity metal complexes for their nanoscopic dimensions[3, 4]. Spectroscopic properties of the lanthanides are widely used in the study of biological systems. …     

Synthesis and Structure of a New Copper(II) Complex Cu(C_(13)H_9N_3O_2Br)_2.H_2O

1 INTRODUCTION Owing to their biological activities and chemical/industrial versalities, considerable attention has been continually attracted to metal-hydrazine complexes. For instance, Schiff base hydrazine and its analogues have been well studied in order to better understand the action mechanism of Vitamin B6-containing enzymes[1~3]. Six-coordinated copper(Ⅱ) complexes are of considerable interest, mainly due to their coordination geometry and spectroscopic properties[4]. Due to th…     

Synthesis and Crystal Structure of a New Mononuclear Nickel（Ⅱ） Mixed Complex Derived from 2-Aminoethyl-bi（3-bi-aminopropyl）amine with 1,10-Phenanthroline

1 INTRODUCTION The research on organic polyamines is currently of great interest because of their potential applica- tions as useful organic ligands, in which the amine nitrogen atoms have strong coordination ability to the transition metal ions and recognition function[1~4]. Their transition metal complexes play an excellent role in catalysis and mimic studies on dismutase and chlorophyll[5~7]. Therefore much attention has been focused on their syntheses and applications[8~11]. Our group…     

Synthesis and Crystal Structure of a New One-dimensional Zn(II) Nitronyl Nitroxide Complex Bridged by Pyridine-2,4-dicarboxylate Anion

1 INTRODUCTION The synthesis and study of transition metal com- pounds incorporating organic free radicals directly bound to their coordination sphere are a major re- search aim in the field of molecular magnetism[1]. Exceptional stability, ease of chemical modification and versatility in their coordination properties have made nitroxide free radicals one of the most attrac- tive spin carriers for the design of molecular magne- tic materials[2, 3]. The structures and magnetic prope- rties …     

Syntheses and Crystal Structures of Three Novel Amino-acid-containing Polyoxomolybdosilicates

1 INTRODUCTION Polyoxometalates as metal-oxygen cluster ions have received a great deal of research due to their potential applications in catalysis, medicine and ma- terials science[1]. The modification of organic groups to the surface of polyoxoanions gives POMs more interesting character, and many derivatives of poly- oxoanions with organic ligands have been studied[2]. Particularly the potential applications of polyoxo- metalate as drugs in anti-viral and anti-AIDS have attracted t…     

澄清溶液中NaA型分子筛膜的合成及气体渗透性能

The use of zeolite membranes in separation or combined reaction and separation processes is very attractive. Advantages of using such a type of membranes include their ability to discriminate molecules based on the molecular size and their stability[1]. In the past ten years, most efforts were involved in the synthesis and permeation studies of MFI zeolite membrane[2, 3]. Recently, NaA zeolite membrane has attracted much attention because of its high potential in the dehydration of organic liquids[4]. However, few gas permeation results were reported[5]. Furthermore, most of the NaA zeolite membrane was synthesized from gel[4]. In this letter, the synthesis of NaA zeolite membrane from clear solution and its gas permeation properties are reported.     

Syntheses and Crystal Structures of Two Cyano-bridged Bimetallic Complexes [Ce(DMSO)_4(H_2O)_3Fe(CN)_6]·H_2O and [La(DMSO)_4(H_2O)_3Co(CN)_6]·H_2O(DMSO = Dimethylsulfoxide)

1INTRODUCTION Recently,cyano-bridged lanthanide-transition me-tal complexes have been extensively investigateddue to their potential applications as precursors in the preparation of rare earth orthoferrites,fluores-cent and magnetic materials[1].Various complexes of this system have been obtained in order to ex-plore the relations between structures and pro-perties by using different ligands,such as DMF,4,4?-bipy,and so on,to fill the coordination sites of lanthanide ions[2～9].But up to…     

A Co(II) 3,5-Diaminobenzoate Coordination Polymer

1 INTRODUCTION The researches in design and construction of novel inorganic-organic hybrid coordination poly- mers based on covalent interactions have drawn great attention in recent years and developed rapidly not only due to their fascinating structures[1, 2] but also to their potential applications in functional ma- terials[3, 4]. The design of coordination polymers is greatly influenced by the coordination nature of metal ions, structural characteristics of the polyden- tate organic li…     

Synthesis and Crystal Structure of a [Cu(HTren)Cl_2]ClO_4·H_2O Complex (Tren = Tris(2-aminoethyl)amine)

1INTRODUCTION Investigation of the coordination chemistry of copper(II)continues to be stimulated by interest in developing modes for copper proteins and in under-standing the factors which give rise to the seemingly infinite variety of distortions from regular stereo-chemistry observed in Cu(II)complexes[1,2].For more than decades,due to the unique coordination polyhedra and their easy preparation,tripodal copper complexes have attracted much attention in addition to their special chemi…     

A Mixed-valent Hexanuclear Cu^Ⅱ-Cu^Ⅰ Complex with Unusual Tridentate pbi Ligand （pbi = 2-（2-Pyridyl）-benzimidazole）

1INTRODUCTION Imidazole(Him)or pyrazole(Hpz)and its deriva-tives in their deprotonated forms have been exten-sively employed in building a large variety of po-lynuclear complexes and polymeric systems[1].A number of metal imidazolates have been studied owing to their fascinating properties and great poten-tial applications,such as high thermal stability[2],magnetic hysteresis[3],luminescence[4]as well as anticorrosive[5]and microbial activities[6].As an im-portant branch,copper imidazolat…     

Synthesis and Crystal Structure of 4-Azido-2,2,6,6-Tetramethylpiperidine-1-oxyl Free Radical

1 INTRODUCTION Stable nitroxyl radicals are widely used in mole- cular biology, molecular pharmacology and phar- macy for noninvasive characterization of enzymes, receptors and drug delivery systems[1, 2]. They are al- so applied to examine the active center topography, the penetration of water, microviscosity, micropolo- rity, PH and oxygen concentration of their surroun- ding as well as spin carriers due to their exceptional stability and ease of chemical modification[3, 4]. However, th…     

Synthesis and Crystal Structure of Co(DMSO)2(H2O)2(SCN)2 with One-dimensional Hydrogen-bonded Structure (DMSO = Dimethylsulfoxide)

1 INTRODUCTION The development of supramolecular complexes has recently attracted considerable attention due to the fundamental interest in self-assembly processes of transition-metal complexes, supramolecular che- mistry and crystal engineering[1]. The ultimate goal is to gain control in order to direct their function[2]. Self-assembly through coordination and nonco- valent interactions such as hydrogen bonds, aromatic π···π stacking, steric repulsion and Van der Waals forces leads …     

Synthesis and Structural Characterization of Mono-and Di-nuclear Zinc（ Ⅱ ） Coordination Compounds of Triphenylphosphoniopropionate

IntroductionThe coordination chemistry of zinc(Ⅱ)has beensubjected to extensive study in the past decades owingto its importance in life science[1].It has been foundthat zinc(Ⅱ)ions are crucially involved in the activesites of over300metalloenzymes and their role is notonly confined to catalysis and gene expression.Further-more,the presence of zinc(Ⅱ)helps to stabilize thetertiary and quaternary structures of proteins and nucle-ic acids[2—4].Like cadmium(Ⅱ),zinc(Ⅱ)is clearly amongthose m…     

Conjugated polymer crystals via topochemical polymerization

<正>The discovery and development of conductive polymers in the 1970 s by Alan J. Heeger, Alan G. Mac Diarmid and Hideki Shirakawa opens the new research field of organic electronics. Over the past decades, conjugated polymers and their applications in various electronic and optoelectronic devices have received considerable attention and studies due to their unique advantages of low cost fabrication methods and mechanical flexibility [1]. With the development of new conjugated polymer materials(to date, maybe hundreds of semiconducting polymers have been synthesized [2,3]) sig-     

Synthesis and Crystal Structure of a Novel Zinc Complex [Zn(OH_2)(HDPA)_2]·3H_2O

1INTRODUCTION In recent years,dicarboxylic acids have been wide-ly used as poly-dentate ligands involved in various metal chelation reactions to form transition or rare earth metal complexes with interesting properties in material science[1~3]and biological systems[4~7].For example,Kim,Y.and his coworkers focus on the syn-theses of copper(II)complexes containing ligands of malonate and pyrazine to study their electronic con-ductivity and magnetic property[8].The importance of Tr(II)/dic…     

Synthesis and Structure of a Novel Macrocyclic Complex [Cd_2(phen)_4(phth)_2]·4H_2O

1 INTRODUCTION In recent years, extensively attention has been fo- cused on the design and synthesis of d10 metal- based complexes[1, 2]. A series of d10 metal-organic frame- works have been described not only because of their intriguing structures but also due to their ptential ap- plications in photoluminescent fields[3～7]. Although phthalate ligand was successfully used to design and synthesize a wide variety of metal complexes, those containing Cd(II) complex are less considered[8～…     

Crystal Structure of a Nickel(II) Complex with Asymmetric _L-Histidine Ligand

1 INTRODUCTION Metal-amino acid complexes are involved in the process of some important metal transport in humans. These complexes and their derivatives are important due to their biochemical and pharmacological pro- perties[1～5]. Nickel(II), as a Jahn-Teller center, when complexed with amino acids, adopts a variety of coordination geometries from distorted square plane, flattened tetrahedron and distorted square pyramid to distorted octahedron as observed in structures reported[6, 7], …     

Synthesis and Crystal Structure of an Indenylnickel(II) NHC Complex (Ind)NiBr(1,3-bisbenzylimidazol-2-ylidene)

1 INTRODUCTION During the past few decades, indene and its substituted derivatives (Ind) are of special interest in Group IVB complexes owing to their easy coordina- tion modification by substitution[1～7]. The Ind li- gands can be tuned spontaneously to coordinate to the center metal from η1 to η5 via relatively facile “ring slippage”, thus leading to better stabilization of transition states or reaction intermediates[8]. How- ever, their applications in Group 10 metal complexes ha…