Substitution Reactions by Azide and Thiocyanide Anions in Room Temperature Ionic Liquids

Conducted in the ionic liquids, activated and inactivated halides, acyl chlorides, tosylate, and bezotriazolyl acylates were converted to corresponding azide and thiocyanide compounds in high yields under mild conditions.

α-Oxoketene Cyclic S, S-cetals Chemistry-Substitution Reaction of α,α'-Dicinnamoyl Ketene Cyclic S, S-Acetals with Ethylenediamine

α,α'-Dicinnamoyl ketene cyclic S, S-acetals 4 were reacted with ethylenediamine to afford α,α'-dicinnamoyl ketene cyclic N,N-acetals 5. This process provides a new method for thesynthesis of 5 in high yield under mild conditions.

THE RADICAL NUCLEOPHILIC SUBSTITUTION REACTION OF HETEROCYCLIC KETENE AMINALS WITH 2,4-DINITROHALOBENZENES

The anion of heterocyclic ketene aminals reacted with 2,4-dini- tro-halobenzenes to give an arylated product through the radical nucleo- philic substitution confirmed by ESR spectroscopy,ESR-spin trapping techni- que,and depression of the reaction rate by the addition of inhibitor.

Kinetic Studies on Ligand Substitution Reactions of Metallothioneins with DTPA and EDTA

Cd, Zn-thionelns were isolated from the rat liver by improved Winge method and purified further. The composition was determined. The mobilization of Cd ions from the Cd, Zn-metallothioneins was studied with spectrophotometric method. The results show that the reaction of DTP A or EDTA with Cd, Zn-thioneins occurs through three steps. The first step follows pseudo-first order reaction with association mechanism. The formation constants and the dissociation rate constants of the relevant intermediate ternary complexes and apparent rate constants, Kapp were determined. The properties and structure of Cd, Zn-thioneins and ligands with low molecular weights affect the values of Kapp.

SYNTHESIS AND APPLICATIONS OF CROSS-LINKED POLY(DIALLYLDIMETHYL AMMONIUM CHLORIDE) AND ITS DERIVATIVE COPOLYMERS AS EFFICIENT PHASE TRANSFER CATALYST FOR NUCLEOPHILIC SUBSTITUTION REACTIONS

Cross-linked poly（diallyldimethylammonium chloride） and its derivative copolymers were synthesized and used as phase transfer catalyst in the nucleophilic substitution reaction especially halogen exchange reactions.In addition,the effect of hydrophilic-hydrophobic character of the polymers in the nucleophilic reactions was investigated.

SUBSTITUTION REACTIONS OF ALKANES (Ⅴ)——PHOTONITROSATION OF SOME ALKANES

A rather satisfactory method of synthesis of aldoximes and ketoximes by direct nitrosation of alkanes and an adequate technique of separating the mixtures and identifying the components from the reactions were worked out.By these procedures, the nitrosation of pentane, hexane and heptane gave different results from those reported in literature, and the study on octane was new.

A new class of rhodium complexes containing free donor atoms and their intramolecular substitution reaction

A new class of rhodium complexes with high catalytic activity as well as excellent stability, which was used as catalyst for carbonylation of methanol to acetic acid, is reported. It contains free donor (namely un-coordinated donor) atoms which enable to improve its stability by intramolecular substitution reaction. Its synthesis, characteristic and catalytic reaction were discussed here.

Rationalization of regioselectivity of electrophilic substitution reaction for cyclic compounds in terms of D_(pb) values

Accepted theories predict that substitution reactions are controlled by the electronic nature of the attacked site for electrophilic aromatic substitution. Here it is shown that in addition the bond strength of the broken bond may also influence the regioselectivity of the substitution reaction, and that the Dpb is a good indicator of the strength of a chemical bond. The Dpb denotes the depth of the potential acting on one electron in a molecule at the bond center （bc）. In this letter, the values of Dpb along the C-H and N-H bonds have been investigated, and it is demonstrated that for aromatic compounds, the regioselectivity of the electrophilic substitution can well be rationalized in terms of Dpb values.

An unusual substitution reaction of an aromatic sulfonic group based on 3-carbonyl-4-phenolsulfonic acid

An unusual substitution reaction of an aromatic sulfonic group based on 3-carbonyl-4-phenolsulfonic acid was discovered in a diazo-coupling process. The reaction occurred under mild reaction conditions （pH 8.0-9.0, 0-5 ℃, solvent： water） within a short reaction time （1 h）. A plausible substitution reaction mechanism by phenol-ketone resonance was proposed.

The reactivities of Mo cluster——A selective substitution reaction of the bridging(dtp)ligand and the crystal structure of{Mo_3S_4(μ-O_2CR)(dtp)_3(Py)}

The reaction of trinuclear molybdenum cluster{Mo_3S_4(μ-dtp)(dtp)_3(H_2O)}1[dtp= S_2P(OEt)_2]with RCO_2Na(R=H,CH_3)in the presence of Py gave the black compounds{Mo_3S_4(μ- O_2CR)(dtp)_3(Py)}(2,R=H,3,R=CH_3).Both compounds are characterized by X-ray crystallo- graphy.It is shown that crystals 2 and 3 belong to space group P with Z=2 and a=10.519(2),b= 12.121(2),c=15.757(2),α=93.27(1),β=94.63(1),γ=105.22(1)°,V=1925~3 for crystal 2,whereas a=9.556(2),b=14.067(7),c=15.914(9),α=101.41(4),β=101.44(4),γ=74.26(3)°,V=1994~3 for crystal 3.The final R factors are 0.041 and 0.048 for crystal 2 and 3 respectively.The structure analysis indicates that(O_2CR)^- ligand selectively substitutes the bridging(dtp)ligand.This type of Mo_3 cluster molecule where structure contains two species of bidentate ligand is for the first time to be obtained by us.

THE REACTION OF BENZOYL SUBSTITUTED HETEROCYCLIC KETENE AMINALS WITH ARYL AZIDES.A FACILE APPROACH TO SYNTHSIZE 1,5-DIARYL-4-(2-IMIDAZOLINYL)-1,2,3-TRIAZOLES

Heterocyclic ketene aminals 1 react with aryl azides 2 to give the titled compounds 3,and in some cases also with the formation of fused heterocycles 4.

STUDIES ON THE WITTIG REACTION(XIII): KINETICS OF THE PTC-WITTIG REACTIONS OF 2-BUTENYL METHYL-DIPHENYLPHOSPHONIUM SALT WITH SUBSTITUTED BEN2ALDEHYDES

The kinetics of PTC-Wittig reaction between substituted aromatic aldehydes and 2-butenyl methyldiphenylphosphonium salt has been studied. The low reaction constant (ρ=0. 30) implies that these PTC-Wittig reactions take place through low polar intermediate.

THE REACTION OF SUBSTITUTED PHENOXY ACETYL CHLORIDE WITH TRIMETHYL PHOSPHITE

Substituted phenoxy acetyl chloride reacted with trimethyl phosphite to form an unexpected substituted phenoxy acetic acid ester, confirmed by;HNMR, IR and MS. The mechanism suggested is different from that of Arbuzov reaction.

SYNTHESIS OF POLYSUBSTITUTED AROMATIC COMPOUNDS:Ⅰ.THE DIELS-ALDER REACTION OF SELENO SUBSTITUTED 3-SULFOLENES WITH DIMETHYL ACETYLENEDICARBOXYLATE

The seleno substituted aromatic compounds were prepared via the Diels-Alder reaction of seleno substituted 3-sulfolenes with dimethyl acetylenedicarboxylate followed by DDQ dehydrogenation.

INVESTIGATION ON THE NEW SYNTHETIC REACTIONS AND MECHANISMS OF SUBSTITUTED DIPHENYL ETHEPS

In the presence of alkali nitrite and carbonate,some nitrobenzenes subs- tituted by strongly electron withdrawing group undergo a self condensation in an aprotic polar sotvent to give symmetrical disubstituted diphenyl ethers in good yields.A possible mechanism is discussed,the nucteophilic aromatic substitution S_NAr and S_(Ru)Ar may occur simultaneously.

MHEORETICAL STUDIES ON THE REACTION MECHANISMS OF CYCLOADDITION REACTIONS BETWEEN KETENE OR SUBSTITUTED KETENES AND CYCLOPENTADIENE

The cycloaddition reactions between ketene or substituted ketenes and cyelopentadiene have been studied theoretically by means of the semiempirical AMI method.Three different substituted ketenes have been selected and ten transition states,corresponding to different approach geometries have been located and characterized,The regioselectivity and stereoselectivity of the reactions are correctly predicted by the calculations and the reaction mechanisms are analyzed in terms of electronic and steric effects of the substitutents on the reacting ketene and cyc-lopentadiene.

Synthesis and Crystal Structure of an Incomplete Cubane-type Mo_3S_4 Cluster with the N-N-O Type Tridentate Ligand: {Mo_3S_4[NH_2CH_2CH(O)CH_2NH_2]_3}(DTP)·(H_2O)_2·(DMF)

A new cluster {Mo3S4[NH2CH2CH(O)CH2NH2]3}(DTP)?(H2O)2?(DMF) (DTP = diethyldithiophosphate) has been synthesized via ligand substitution reaction of Mo3S4(DTP)4(H2O) with an alkaline ligand 1,3-diamino-2-propanol(DAPROH) in a mixed organic solvent, and its crys- tal structure was determined with the following data: Mo3S6PC16H48O8N7, Mr = 977.76, triclinic, space group P1, Z = 2, a = 10.319(2), b = 12.843(3), c = 15.335(3) ?, α = 65.26(3), β = 82.18(3), γ = 70.67(3)o, V = 1741.7(6) ?3, Dc = 1.864 g/cm3, μ = 1.517 mm-1, F(000) = 988, the final R = 0.0794 and wR = 0.2111 for 6318 observed reflections (I>2σ(I)). The structure analysis indicates that all DTP ligands of Mo3S4(DTP)4(H2O) are replaced and each DAPRO molecule acts as a tri- dentate ligand chelating to each Mo atom of the Mo3S4 core. Different from the precursor, the clus- ter symmetry is elevated to C3. In addition, the UV-spectrum of the title compound was measured.

STRUCTURE AND PROPERTIES OF PHOSPHROUS-CONTAINING POLY(ARYLETHER KETONE)WITH BISPHENOL-A MOIETY

A phosphrous-containing poly（aryl ether ketone） was synthesized derived from bisphenol-A and bis[4-（4- fluorobenzoyl）phenyl] phenyl phosphine oxide （FPPPO） by nucleophilic substitution reaction. The structure of the polymer was characterized by FT-IR, ^1H-NMR and ^31p-NMR. The thermal property of the PAEK was measured by DSC and TGA. The glass transition temperature （Tg） of the polymer was 205℃, and the 5% weight loss temperature under nitrogen was 475℃. Good solubility of the polymer in organic solvents, such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide and chloroalkanes was observed, flexible film was obtained from the polymer＇s CH2Cl2 solution. The limiting oxygen index （LOI） of the PAEK was 40, which indicated that organic phosphorus moiety can offer good flame retardant property to the polymer.

Synthesis and Crystal Structure of FeCo_2(CO)_8(μ_3-S)〔P(OCH_2Ph)_3〕

The title compound FeCo2 (CO)8 (μ3-S) [P (OCH2Ph )3] was synthe-sized by the reaction of P (OCH2Ph)3 with FeCo2 (CO)9 (μ3-S) at room temperature.Crystal data: C29H21 O11 PSCo2Fe, Mr=782. 23, monoclinic, space group P21/n(14), a= l5. 123(4), b=14. 580(4), c=15. 942(3)A, g=115. 66(1), V=3168293K, final R= 0. 032, R= 0. 037 for 3010 observed reflections with I>3. 00(I).The monosubstituted ligand P (OCH2Ph )3 in FeCo2 (CO)8 (μ3-S ) [P (OCH2Ph )3] islinked to one cobalt atom of the tetrahedron FeCo2S framework.

Reconfiguring perovskite interface via R4NBr addition reaction toward efficient and stable FAPbI3-based solar cells

Defect states in perovskite films restrict the interfacial stability and open-circuit voltage of perovskite solar cells.Here,aiming at superior interfacial passivation,we investigate the reconfiguration of perovskite interface by the interaction between a series of quaternary ammonium bromides(QAB)and lead—halide(Pb—X)octahedrons.Bromide—iodide substitution reaction or R4NBr addition reaction may occur on the perovskite surface,which is related to the steric hindrance of quaternary ammonium cations.On this basis,the perovskite surface morphology,band structure,growth orientation and defect states are reconstructed via the R4NBr addition reaction.This ordered lead—halide adduct could effectively repair the imperfect perovskite/hole transportation layer interface to suppress non-radiative recombination and ion migration toward ultralong carrier lifetime surpassing 10µs.The resulting perovskite solar cells yield the efficiency of 23.89%with steady-state efficiency of 23.70%.The passivated cells can sustain 86%of initial efficiency after 200-h operation,which is attributed to the passivation effect and hydrophobic characteristics.This work provides an avenue for reconfiguring perovskite surface by QABs.