Synthesis and Crystal Structure of Potassium triaqua（ethyleneamin—N,N,N‘,N’—tetraacetate）gadolinium（Ⅲ）pentahydrate

1 INTRODUCTION The chemistry of lanthanide (Ⅲ) complexes has a considerable history. The stereochemistry of the lanthanide (Ⅲ) complexes with ethyleneamine- N, N, N, N-tetraacetate (Edta) has been investigated[1~10]. Up to now, many Ln-Edta complexes with the chemical formulae of M[Ln(Edta)(H2O)m]nH2O (M = Na+, K+, Cs+, NH4+, Guanium; m = 2, 3; n = 0, 1, 3, 5) have been reported and suggested that the coordination modes and crystal systems for the Ln-Edta complexes depend on …     

PRELIMINARY STUDIES ON THE SYNTHESIS AND CHARACTERIZATION OF OXY-AND THIO-DIACETIC ACID HYDRAZITION AND THEIR FIRST-ROW TRANSITION METAL COMPLEXES

It has been made certain that thio-and oxy-diacetic acid hydrazidesare potential anticancer compounds.However,their ability to formcomplexes with transition metals and the properties of the complexes thusformed have not been studied.Employing a new potential anticancer ligand1,2-bis(thioacetic acid hydrazide)ethane prepared in our lab,along withligands oxydiacetic hydrazide and 1,2-bis(oxyacetic acid hydrazide)ethane,a series of 11 new first-row transition metal(M=Zn~(2+),Cu~(2+),Co~(2+),Ni~(2+))complexes with each of the above three ligands have been synthesizedand characterized by means of elemental analyses,IR,TG and X-raypowder diffraction.     

Reaction of Metallocenyl η2-Diyne with Co2(CO)8 and RuCo2(CO)11

Alkyne and alkynyl species bearing a C = C functional group belong to a class of surface species which may play a pivotal role in various catalytic reaction such as CO hydrogenation, and the coordination chemistry of the corresponding ligands has been studied extensively. The interaction of alkynyl compounds with dinuclear species leading to adducts with a tetrahedral C2M2core has been recognized as one of the classical reactions in the field of organometallic chemistry.     

Preparation and Characterization of Heteropoly Octadecamolybdodiphosphates

Heteropoly molybdophosphates with general formula M(?)P2Mo18O62 ·xH2O, where M = H+, K+, NH4+, Ca2+, Co2+, Ni2+, Cu2+, Zn2+ and Ag+, were prepared and characterlzed by elemental analysis, IR and UV spectrometry and thermal analysis. The solubilities of the compounds were examined. The IR spectra show that the countercations and the crystallization water have an influence upon the vibration frequencies of vMo-Oc and vMo-Oc-Mo·In the UV spectra, the charge-transfer bands are assigned to e→e and e→b2 transition. All the compounds decompose at 328-534℃.     

SYNTHESES AND STRUCTURAL STUDIES OF Mo-Fe-S-CLUSTER COMPOUNDS Ⅶ.SPECTROSCOPIC STUDY OF THE [MoFe_3S_4] CUBANE UNIT IN (Bt_4N)4(Mo_2Fe Sa(SR)_12] AND RELATED COMPOUNDS

<正> INTRODUCTION. In the study of nitrogenases, scientists have proposed many models for the active center of MoFe protein and for FeMoco. All of them contain a basic structural unit [FeS_2M] (M=Fe or Mo). We have reported some structural regularities in a series of linear Mo-Fe-S compounds. In order to investigate the electron distribution and the synergism of metal atoms within a Mo-Fe-S cluster with [MoFe_3S_4] cubane unit, we have synthe     

Crystal Structure and Spectroscopic Analysis of Polyphenyl Quinoxaline with Hg(Ⅱ)

The interaction of Hg~(2+) with polyphenyl quinoxaline ligand 2,3,6,7,10,11-hexaphenyldipyrazino[2,3-f:2?,3?-h]quinoxaline(HPQ) was investigated, and a new complex(C_(49)H_(32)N_6Br_2Cl_2Hg) has been synthesized and characterized. It exhibits a 0D single-core structure,and adopts triclinic P 1 space group with a = 11.139(2), b = 13.429(3), c = 14.488(3) ?, α =76.10(3), β = 83.16(3), γ = 87.36(3)o, V = 2088.4(7) ?3, Z = 2, S = 1.056, F(000) = 1104, R = 0.0417 and w R = 0.0931(I 2σ(I)). Furthermore, the behavior of HPQ with Hg~(2+) in the solution was also investigated, and the result shows that HPQ was found to have excellent fluorescent selectivity for Hg~(2+) over many other metal ions(Li~+, K~+, Na~+, Sr~+, Ca~(2+), Mg~(2+), Mn~(2+), Fe~(3+), Ni~(2+), Co~(2+), Cu~(2+), Zn~(2+),Cd~(2+), Pb~(2+), Al~(3+) and Cr~(3+)) based on the intermolecular charge-transfer mechanism, which makes HPQ a potential fluorescence sensor or probe for Hg~(2+).     

Ab Initio Study of Mechanism of Forming a Si-heterocyclic Spiro-Sn-heterocyclic Ring Compound by Cycloaddition Reaction of Cl_2Si=Sn: and Ethylene

X_2Si=Sn:(X = H, Me, F, Cl, Br, Ph, Ar…) are new species of chemistry. The cycloaddition reaction of X_2Si=Sn: is a new study field of stannylene chemistry. To explore the rules of cycloaddition reaction between X_2Si=Sn: and the symmetric p-bonded compounds, the cycloaddition reactions of Cl_2Si=Sn: and ethylene were selected as model reactions in this paper.The mechanism of cycloaddition reaction between singlet Cl_2Si=Sn: and ethylene has been first investigated with the MP2/GENECP(C, H, Cl, Si in 6-311++G**; Sn in LanL2dz) method in this paper. From the potential energy profile, it could be predicted that the reaction has one dominant reaction channel. The reaction rule presented is that the 5p unoccupied orbital of Sn in Cl_2Si=Sn: and the π orbital of ethylene forming a p→p donor-acceptor bond, resulting in the formation of an intermediate. Instability of the intermediate makes it isomerize to a four-membered Si-heterocyclic ring stannylene. Because the 5p unoccupied orbital of Sn atom in the four-membered Si-heterocyclic ring stannylene and the π orbital of ethylene form a p→p donor-acceptor bond, the four-membered Si-heterocyclic ring stannylene further combines with ethene to form another intermediate. Because the Sn atom in the intermediate shows sp~3 hybridization after transition state, the intermediate isomerizes to a Si-heterocyclic spiro-Sn-heterocyclic ring compound. The research result indicates the laws of cycloaddition reaction between X_2Si=Sn: and the symmetric π-bonded compounds. The study opens up a new research field for stannylene chemistry.     

Solid-state Syntheses,Crystal Chemistry and Optical Properties of Two Europium Oxide/sulfide Silicates,Eu_2O(SiO_4) and Eu_5S(SiO_4)_3

Two europium oxide/sulfide silicates, Eu_2O(SiO_4)(1) and Eu5S(SiO 4)3(2), have been synthesized using high-temperature solid-state reactions. 1 crystallizes in the monoclinic space group P21/c with a = 9.1459(7), b = 7.1280(5), c = 6.7655(5) ? and b = 107.611(2)°, belonging to the Gd_2O(SiO_4) structure type; 2 crystallizes in space group P63/m of the hexagonal system with a = 9.786(4) and c = 6.789(3) ?, belonging to the apatite Ca_5Cl(PO_4)_3 structure type. The structure chemistry of related RE_2O(SiO_4) and RE_5S(SiO_4)_3 compounds is also discussed. The optical energy gap of 2 is determined to be 2.05 eV.     

Synthesis of Some Novel Phenyl Substituted Oxothiazolidin- 1’’,3’’,4’’-thiadiazolo-[3’,4’-b]thiazoline of 3β-Substituted Cholestane

Three title compounds 4a—4c have been synthesized by the cyclodehydration of 1’-benzylidine-4’-(3β-substituted-5α-cholestane-6-yl)thiosemicarbazones 2a—2c with thioglycolic acid followed by the treatment with cold conc. H2SO4 in dioxane. The compounds 2a—2c were prepared by condensation of 3β-substituted-5α-cholestan- 6-one-thiosemicarbazones 1a—1c with benzaldehyde. These thiosemicarbazones 1a—1c were obtained by the reaction of corresponding 3β-substituted-5α-cholestan-6-ones with thiosemicarbazide in the presence of few drops of conc. HCl in methanol. The structures of the products have been established on the basis of their elemental, analytical and spectral data.     

Structure of Nb/Ta layered ternary tellurides containing first row transition metal atoms

A summary of research on the structure of Nb/Ta layered tellurides in the past period is reported. 14 compounds, which have been structurally characterized by X-ray diffraction work, are presented according to their structural features. The first two compounds, Nb2CrTe4 and Nb2Cu1.48Te4, are characterized in that the ternary atoms are inserted in the different layers from the Nb atoms. While in the other compounds, both kinds of metal atoms are inserted in the same layer. The six compounds with formula M2M'2Te4(M = Nb/Ta; M' = Ni, Co, Fe) are characterized in that their structure can be described as construction by using cluster units "M2M'2Te10" as building blocks. in the two metal-rich compounds, TaCo2Te2 and TaNi2Te2, Ta atom has a distorted mono-capped pentagonal prism configuration. The structure of TaFeTe3, TaNTe3 and NbNi2.34Te3 can be described as building by the arrangement of double octahedral chains (DOC), in this con-nection, a selenide Ta2Ni2Se5 is also included by using the second type of     

Half-sandwich 1,3-Di-t-butylcyclopentadienyl Rhodium Complexes Containing Sulfido Ligands

Interest in the coordination chemistry of organo-transition metal complexescontaining sulfur ligands is continuing because they are involved in important catalyticprocesses[1 ,2 ] ,particularly hydrodesulfurization and hydrogenation reactions[3] and theyundergo a variety of reaction with metal species[4～ 6] . Although half-sandwichpentamethylcyclopentadienyl complexes with sulfido ligands are well known,only threetypes of half-sandwich compounds with chelating oligosulfido ligands have beendes…     

Preface to Special Issue on Catalysis in Organic Synthesis

<正>Organic synthesis plays a central role in chemistry. The cre-ation of compounds with new properties and functions both distinguishes synthetic chemistry from other sciences and also emphasizes chemistry’s central place in science. In principle, the possibilities for atomic and molecular manipulation are unlimited, which provides a firm molecular basis for biosci-ence, materials science and medical science. Man-made chemi-cals have entered many research fields where they play im-portant roles. Synthesis is changing all aspects of human socie-ty and improving the quality of our life. Catalysts are the     

Special Issue of "Organofluorine Chemistry"

Organofluorine chemistry is a coherent sub-discipline of organic chemistry,which concerns both the fundamental knowledge and technological application of organofluorine compounds that contain C-F bond(s).Given their unique properties and wide applications,organofluorine compounds touch all of our everyday lives,ranging from refrigerants,Teflon tapes,medicines,to coatings of our buildings and textiles.The past decade has witnessed the renaissance of organofluorine chemistry,and in particular,the transition metal-involved fluorination and fluoroalkylation chemistry have nowadays become a "hot" research topic in chemistry.     

Features of Mechanism of Cycloaddition Reaction between Me_2Ge=Sn: and Ethylene

X_2Ge=Sn:(X = H, Me, F, Cl, Br, Ph, Ar···) are new species of chemistry. The cycloaddition reaction of X_2Ge=Sn: is a new study field of stannylene chemistry. To explore the rules of cycloaddition reaction between X_2Ge=Sn: and the symmetric p-bonded compounds, the cycloaddition reactions of Me_2Ge=Sn: and ethylene were selected as model reactions in this paper, and the mechanism was investigated for the first time here using the MP2 theory together with the 6-311++G** basis set for C, H and Ge atoms and the LanL2dzbasis set for Sn atoms. From the potential energy profile, it could be predicted that the reaction has one dominant reaction channel. The reaction rule present is that the 5p unoccupied orbital of Sn in Me_2Ge=Sn: and the π orbital of ethylene form a p → p donor–acceptor bond, resulting in an intermediate which, due to its instability, makes itself isomerize into a four-membered Ge-heterocyclic ring stannylene. Because the 5p unoccupied orbital of Sn atom in the four-membered Ge-heterocyclic ring stannylene and the π orbital of ethylene form a p → p donor-acceptor bond, the four-membered Ge-heterocyclic ring stannylene further combines with ethylene to get another intermediate. Because the Sn atom in this intermediate exhibits sp3 hybridization after transition state, the intermediate isomerizes to a Ge-heterocyclic spiro-Sn-heterocyclic ring compound. The research result indicates the laws of cycloaddition reaction between X_2Ge=Sn: and the symmetric π-bonded compounds. This study opens up a new research field for stannylene chemistry.     

CAN catalyzed one-pot synthesis and docking study of some novel substituted imidazole coupled 1,2,4-triazole-5-carboxylic acids as antifungal agents

The present work describes a facile,one-pot three component synthesis of a series of 3-[(4,5-diphenyl-2-substituted aryl/heteryl)-1H-imidazol-1-yl]-1H-1,2,4-triazole-5-carboxylic acid derivatives M(1-15).Benzil,aromatic aldehydes and 3-amino-l,2,4-triazole-5-carboxylic acid was refluxed in ethanol using cerric ammonium nitrate(CAN) as a catalyst to give the title compounds in good yields.The compounds were evaluated for their in vitro antifungal and antibacterial activity.Compounds M1,M9,and M15 were found to be equipotent against Candida albicans when compared with fluconazole.Compounds M2.M5,and M14 showed higher activity against Streptococcus pneumoniae.Escherichia coli and Streptococcus pyogenes,respectively,compared with ampicillin.Docking study of the newly synthesized compounds was performed,and the results showed good binding mode in the active sites of C albicans enzyme cytochrome P450 lanosterol 14α-demethylase.The results of in vitro antifungal activity and docking study showed that synthesized compounds had potential antifungal activity and can be further optimized and developed as a lead compound.     

A Mild Oxidant for the Regeneration of Carbonyl Compounds from Oximes in Nonaqueous Condition

Since oximes have been empolyed as ketone or aldehyde functional group equivalents in synthetic organic chemistry, the conversion of oximes into their corresponding carbonyl compounds has received considerable attention. The classical method for the cleavage of oximes to parent aldehydes and ketones is hydrolysis in acid, which is not suitable for acid sensitive compounds1-2. In recent years, cleavage of oximes with ozone3, nitrogen tetraoxide4, copper chloride5 and bromine6 have been develope…     

Synthesis and Crystal Structure of 2-Amino-1, 1-diferrocenylethanol

2-Aminoalcohols are useful intermediates in organic chemistry, for example, they serve for the synthesis of various heterocycles1, chelate complexes2, and for the ring expansion of cycloalkanones3. 2-Aminoalcohols containing ferrocene as bidentate ligand may be converted into multinuclear compounds. Several methods for the preparation of 2-aminoalcohols have been developed including reduction of the trimethylsilyl cyanohydrins4 or β-nitromethyl alcohols5 and treatment of the epoxides with a…     

Cocrystallization of N-donor type compounds with 5-sulfosalicylic acid: The effect of hydrogen-bonding supramolecular architectures

Benzotriazole,N,N’-dimethylpiperazine and N-methylpiperazine were applied to crystallize with 5-sulfosalicylic acid(5-H2SSA),affording three new binary molecular cocrystals [(C6H6N3+).(C7H5O6S-)].H2O(1),[(C6H16N22+)1/2.(C7H5O6S-)].H2O(2) and [(C5H14N22+).(C7H5O6S-)2].3H2O(3) under general conditions.Proton-transferring occurs from acid to nitrogen of N-donor compounds in all compounds 1,2 and 3.Analysis of the hydrogen-bonding synthons and their effects on crystal packing were also presented in the context of crystal engineering and host-guest chemistry.In compound 1,1-D infinite chains are extended to a 2-D layered architecture via strong O-H...O hydrogen bonds and then to a 3-D network by N-H...O interactions.Compound 2 and 3 both have the 1-D chain which is formed by O-H...O bonds and weak C-H...O hydrogen bonds.A common intramolecular S(6) [synthon I] ring is formed by the hydroxyl with the carboxyl group in all three compounds.     

BrΦnsted acid-promoted ‘on-water’ C(sp^3)-H functionalization fot the synthesis of isoindolinone/[1,2,4]triazolo[1,5-a]pyrimidine derivatives targeting the SKP2-CKS1 interaction

The isoindolinone and biaryl scaffolds are prevalent in natural products and drug molecules,which have showed broad and interesting biological activities.The efficient construction of such hybridized molecules and biological evaluation are of great interest to medicinal chemistry community.In this communication,we report an efficient BrΦnsted acid-promoted C(sp^3)-H functionalization approach that enables the rapid construction of biologically important isoindolinone/[1,2,4]triazolo[1,5-a]pyrimidine hybrids from 5-methyl-7-(2,4,6-trimethoxyphenyl)-[1,2,4]triazolo[1,5-a]pyrimidine,2-formylbenzoic acid and various anilines.The title compounds were generated in high to excellent yields(up to 96%)regardless of the electronic nature and steric effects of the substituents.In this reaction,an isoindolinone scaffold,one C-C single bond,and two C-N bonds were formed simultaneously with high atom economy.In this work,we have envisioned that the methyl group linked to the electron-deficient Nheterocycles could be used as a new synthetic handle for late-state diversification and may have broad applications in the field of organic and medicinal chemistry.Besides,the title compounds have exhibited promising activity against the SKP2-CKS1 interaction.     

Crescent aromatic oligothioamides as highly selective receptors for copper(Ⅱ) ion

A series of crescent aromatic oligothioamides(4, 6, 8, 15, and 18) bearing different number of sulfur atoms were designed and synthesized via thionation of their corresponding aromatic oligoamides(3, 5, and 7) using Lawesson's reagent. The X-ray structure of a trimeric analogue(13) revealed the presence of intramolecular three-center hydrogen bonds that are responsible for the rigidification of the molecular backbone. The extraction by these novel receptors toward some representative heavy metal cations(Zn2+, Cd2+, Co2+, Ni2+, Pb2+, and Cu2+) and alkali and alkaline earth metal cations(Li+, Na+, K+, Rb+, Cs+, Ca2+, and Sr2+) demonstrated high efficiency(83.5%–96.4%) and superior selectivity for Cu2+ over other selected metal cations. Particularly, the extractability was correlated to both the number of sulfur atoms and orientation of thiocarbonyl groups as revealed in the order: 6 4 18 15. This is in stark contrast to the oligoamides that only gave much lower extractability(5.9%–16.4%), suggestive of the importance of replacement of carbonyl oxygen atoms with sulfur atoms in the extraction of Cu2+. The complexation behavior of 4, 6, and 8 with Cu2+ was also examined by UV-Vis and NMR techniques.