Studies on the synthesis of heterocyclic compounds. V. Preparation of 1,3,2-benzoxathiaphosphole,arsole and stibole derivatives by exchange methods

A new convenient method for synthesis of heterocyclic compounds of five-membered rings containing an O-M-S (M = P, As, Sb) linkage is described. The compounds IIIa-c, IVa-b, Va-b, Viand VII were prepared starting from 2,2-dimethyl-1,3,2-benzoxathiastannole (II) and derivatives of phosphorus, arsenic and antimony. The structures of newly prepared compounds was determined by elemental analysis, spectroscopic methods (ir, nmr and ms) and comparison with authentic samples obtained via a different manner.     

Studies on the synthesis of heterocyclic compounds. Synthesis of 1,3,2-benzoxathia- and 1,3,2-benzodioxastibole derivatives

The preparation of 1,3,2-benzoxathia- and 1,3,2-benzodioxachlorostiboles (IIa-b) by reaction of antimony trichloride with 2-hydroxythiophenol (Ia) or 1,2-benzodiol (Ib) is described. The halogen was easily removed. Thus a Wurtz-like reaction gave the distibole compounds (IVa-b), which were also produced by organolithium compounds or pyridine. The compounds Va-b were obtained with sodium hydroxide, ethoxide and phenoxide, but spiran derivatives VIIa-b, of antimony, were obtained by treating IIa-b with 2-hydroxythiophenol or 1,2-benzodiol in the presence of triethylamine. The structure of the prepared compounds was determined by spectro-scopic methods.     

Studies on the synthesis of heterocyclic compounds. VIII. Action of acyl halides on 2,2-di-n-butyl-1,3,2-benzoxathiastannole, 2-chloro-1,3,2-benzoxathiaarsole and -stibole

The cleavage reaction of some 1,3,2-benzoxathiastannole, -arsole and -stibole derivatives with acetyl and benzoyl chloride is described. The reactions were carried out refluxing in benzene or at room temperature. In all cases, the reaction occurs through the initial cleavage of the S-M linkage with formation of the respective o-acylthio derivatives. The structure of the prepared compounds was assigned on the basis of their analytical, physical and spectral data.     

Solid state reaction synthesis of filled skutterudite compounds (Ce or Y)yFexCo4-xSb12 and the effect of filling atoms Ce or Y on lattice thermal conductivity

The synthesis of filled skutterudite compounds (Ce or Y)_y(Fe)_x(Co)_(4x)(Sb)_(12), through a solidstate reaction using chloride of Ce or Y,high purity powder of Co, Fe, and Sb as starting materials,was investigated. (Ce or Y)_y(Fe)_x(Co)_(4x)(Sb)_(12) (x=0--1.0, y=0--0.15) compounds were obtained at850--1 123 K. The results of Rietveld analysis demonstrate that (Ce or Y)_y(Fe)_x(Co)_(4x)(Sb)_12synthesized by a solid state reaction possesses a filled skutterudite structure. The filling fraction ofCe or Y obtained by Rietveld analysis agrees well with the composition obtained by chemicalanalysis. The lattice constant of (Ce)_y(Fe)_x(Co)_(4x)(Sb)_(12) increases with increasing substitution of Fe at Cosites, and with an increasing Ce filling fraction in the Sb-dodecahedron voids. The lattice thermalconductivity of (Ce or Y)_y(Fe)_x(Co)_(4x)(Sb)_(12) decreases significantly with an increasing Ce or Y fillingfraction in the voids and with substitution of Fe at Co sites.     

Syntheses, crystal and solution structures, ligand-exchange, and ligand-coupling reactions of mixed pentaarylantimony compounds

All possible combinations of mixed pentaarylantimony compounds bearing p-methylphenyl and p-trifluoromethylphenyl groups were synthesized; ArnTol5-nSb (n=0-5: Ar=p-CF3C6H4, Tol=p-CH3C6H4): Tol5Sb (1), ArTol4Sb (2), Ar2Tol3Sb (3), Ar3Tol2Sb (4), Ar4TolSb (5), and Ar5Sb (6). Compounds 2-5 are the first well-characterized examples of mixed acyclic pentaarylantimony species. The structures of 2-6 were determined by X-ray crystallography to feature trigonal-bipyramidal (TBP) geometry with the more electronegative p-trifluoromethylphenyl substituents selectively occupying the apical positions. Consideration of the chemical shifts of the ipso carbons of the aryl and tolyl groups suggested that the solution structures of 1-6 were also TBP, although their pseudorotation could not be frozen even at -80 degrees C. Ligand-exchange reactions (LERs) took place between 1 and 6 at approximately 60 degrees C in [D6]benzene and all six species 1-6 were found in the equilibrium mixture. The relative stabilities of 1-6 were determined quantitatively by comparison of the observed molar ratios of 1-6 in equilibrium with calculated statistical molar ratios, and Ar2Tol3Sb (3) was found to be the most stable. The ligand-coupling reactions (LCRs) of 2-5 in solution were greatly accelerated by adding Cu(acac)2 or Li+TFPB- (TFPB: [3,5-(CF3)2 C6H3]4 B), whereby the rate becomes comparable to the LER. The use of flash vacuum thermolysis (FVT) allowed the LCR to occur with very little ligand-exchange; the exception ArTol4Sb had very fast ligand-exchange. The selectivities of the LCRs were calculated from the yield of the biaryls synthesized by using FVT. These results were highly consistent with reactions catalyzed in solution, in which bitolyl was not obtained at all. The experimental results suggested that the LCR of pentaarylantimony compounds proceeds in the manner of apical-apical coupling.     

Studies on the synthesis of heterocyclic compounds. XI. Cleavage of 1,3-benzodioxoles by magnesium bromide-acetic anhydride

The cleavage reaction of some 1,3-benzodioxole derivatives with magnesium bromide and acetic anhydride has been studied. The reactions have been carried out in acetonitrile solution at room temperature. In all of the 1,3-benzodioxoles studied, the opening of the heterocyclic ring with formation of bromides, alkenes and their corresponding products of hydrolysis have been observed. The competitive electrophilic substitution on the benzene ring was very limited and was insignificant when a large excess of the cleavage reagent was used. The structures of newly prepared compounds have been determined by elemental analysis, spectroscopic data and comparison with authentic samples.     

Potentiometric determination of antimony in metal(II) hexafluoroantimonates(V)

The purpose of this study was to develop an accurate and precise analytical procedure for the determination of the content of antimony in coordination compounds of metal(II) hexafluoroantimonates(V) (M(SbF(6))(2) compounds, where M=Mg, Ca, Sr or Ba) synthesized in our laboratory. The major problem was to find an appropriate reagent for reductive decomposition of SbF(6)(-) to Sb(3+) required for the determination of antimony by redox titration. Effective reduction of Sb(5+) regardless of the metal M bound to SbF(6)(-) species was achieved using metallic aluminium powder in acidic medium. Precipitated Sb(0) was quantitatively reoxidized to Sb(3+) and determined potentiometrically with KBrO(3) or KMnO(4). Other metals were determined complexometrically with disodium ethylenediaminetetraacetic acid (EDTA). Highly accurate and reproducible results were obtained in the concentration range 5-25 mg Sb with an RSD smaller than 0.6%. Antimony-fluoro-hydroxo species and fluoride did not interfere with the complexometric determinations of other metals with EDTA. The developed method enabled, for the first time, complete elemental chemical analysis of M(SbF(6))(2) compounds in the bulk form.     

Studies on the synthesis of heterocyclic compounds. XIV. Cleavage of 1,3-benzoxathioles by magnesium bromide-acetic anhydride

The cleavage reaction of some 1,3-benzoxathioles with magnesium bromide and acetic anhydride has been studied. In all the 1,3-benzoxathioles studied, the opening of the heterocyclic ring occurs first with cleavage of the C O bond and formation of bromides and their corresponding products of hydrolysis. Successively also the cleavage of the C S bond can occur. The competitive electrophilic substitution on the benzene ring becomes appreciable only in the 1,3-benzoxathioles-2,2-disubstituted with sterically demanding groups. The structure of newly prepared compounds has been determined by analytical and spectroscopic data and when possible by comparison with authentic samples.     

半水榴石型化合物Sr_6Sb_4M_3O_(14)(OH)_(10)(M=Co,Mn)的合成、结构与性质

在强碱性水热条件下合成了两种新化合物Sr6Sb4Co3O14(OH)10(SSC)与Sr6Sb4Mn3O14(OH)10(SSM).采用粉末X射线衍射数据,通过Rietveld方法进行了结构分析,讨论了金属离子的拓扑结构.两种化合物均为石榴石-水榴石相关结构,空间群I43d,晶胞参数a分别为1.30634(2)nm(SSC)和1.31367(1)nm(SSM).结构中,SbO6八面体与MO4(M=Co,Mn)四面体共顶点连接,Sb5+-M2+(M=Co,Mn)离子表现为ctn即C3N4型的拓扑结构.拓扑结构中,Sb5+为三连接,过渡金属离子M2+(M=Co,Mn)为四连接.Sb5+离子的拓扑结构为体心立方,而M2+(M=Co,Mn)分布呈类风扇状,相互连接形成thp型拓扑结构(即Th3P4中Th原子之间连接关系).过渡金属离子的分布与化合物表现出的磁性质密切相关,Co2+(Mn2+)间存在反铁磁相互作用.Sr6Sb4Co3O14(OH)10在低温下表现出反铁磁倾斜有序.Sr6Sb4Co3O14(OH)10和Sr6Sb4Mn3O14(OH)10在高温下发生分解,产物主相为双钙钛矿Sr2(Sb,M)2O6(M=Co,Mn).     

双核钼/钨金属键有机化合物的反应化学研究

着重总结了我们研究组近几年来对M-M(M=Mo,W)金属单键化合物(η^5-RC5H4)2M2(CO)6,M=M金属双键化合物(η^5-RC5H4)2M2(CO)2(μ-EPh)2(E=S,Se,Te)及M≡M金属三键化合物(η^5-RC5H4)2M2(CO)4的反应化学所取得的系列成果。该系列成果清楚地表明这三类典型的金属键有机化合物可分别同多种无机、有机以及金属有机试剂发生涉及金属键加成、金属键断裂以及金属键上配体的消除和环戊二烯基配体上有机官能团的转化等一系列有趣反应。这些反应不仅有重要理论意义而且被广泛地用在新型金属有机和原子簇化合物的合成上。     

Reaction of 1-formyladamantane with heterocyclic compounds. Mass spectra,antibacterial and antifungal activity

1-Formyladamantane reacts with some amino derivatives to give I, II, III and IV. 3-Substiluted 2-adamantyl-4-thiazolidinones (V), (VI) and (VII) were obtained by reacting the above compounds with mercaptoacetic acid. Their structure was established by ir, pmr and mass spectroscopy. All compounds synthesized inhibit the growth of gram-negative and gram-positive bacteria and fungi.     

Studies on the synthesis of heterocyclic compounds. XVI. Cleavage of 1,3-benzodioxoles and -benzoxathioles by sodium iodide-acyl chloride

The cleavage reaction of ethereal and thioethereal bonds with sodium iodide and acyl chloride has been studied. In all the 1,3-benzodioxoles and -benzoxathioles studied, the opening of the heterocyclic ring with formation of 1,2-diacetoxybenzene or 2-hydroxythiophenol diacetic ester and gem-diiodoalkanes and iodoalkenes has been observed. The structure of newly prepared compounds has been determined by analytical and spectroscopic data or comparison with authentic samples.     

Effect of the electronic structure of the heteroatom on the basicities of heterocyclic compounds

The proton-acceptor capacities of heterocyclic nitrogen compounds (pyridine, pyrazine, pyrimidine, and some of their derivatives) were subjected to a theoretical study by means of the molecular electrostatic-potential method. The wave functions of the examined compounds were obtained by the INDO method. It was found that the difference in the proton-acceptor capacities of the examined compounds is due to the difference in the electronic structures of the unshared pairs of the most basic atoms in these compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1079–1083, August, 1981.     

Studies on the synthesis of heterocyclic compounds. Part IX. Action of N,N-dimethylformamide dimethylacetal on some oximino-β-dicarbonyl compounds

3-Oximino-2,4-pentanedione ( 1 ) and ethyl 2-oximino-3-oxobutanoate ( 6 ) reacted with N,N-dimethylformamide dimethylacetal (DFDA) to give 1,7-bisdimethylamino-3,5-dioxo-4-methoximinohepta-1,6-diene ( 4 ) and ethyl 5-dimethylamino-2-methoximino-3-oxo-4-pentenoate ( 8 ), respectively. When compounds 4 and 8 were treated with hydrazine hydrate, they gave O-methyldipyrazol-3(5)-ylketoxime ( 5 ) and ethyl 2-methoximino-3(5)-pyrazolylethanoate ( 9 ) together with its corresponding hydrazide 10 , respectively. Upon action of DFDA on 3-oximino-2,4-pentanedione ( 1 ) at -20° an explosive crystalline product was obtained. On the other hand, the reaction of 3-acetoximino-2,4-pentanedione ( 11 ) with DFDA at -20° afforded a product which in ethanol solution, spontaneously deacetylated to give 1-dimethylamino-3,5-dioxo-4-oximinohexa-1-ene ( 13 ). The structures of all the new compounds were assigned on the basis of satisfactory analytical and spectroscopic data.     

Mass spectra of heterocyclic compounds. II-Hexahydro-1,3,5,-triazines

The twelve tri-N-sulphonylhexahydro-1,3,5-triazines (R = alkyl or aryl) exhibit a common fragmentation pattern; most of the fragments are directly or indirectly generated from the [M ? RSO₂]⁺ ion. Tri-N-Benzylsulphonylhexahydro-1,3,5-triazine (R = PhCH₂) departs from the others mainly because the key ion [M ? RSO₂]⁺ suffers a skeletal rearrangement with loss of SO₂. The rationalizations presented are supported by metastable evidence, accurate mass measurements and deuterium labelling.     

Half-chair conformations of unsaturated heterocyclic compounds

The vicinal proton coupling constants were obtained for some 6-membered ring unsaturated heterocyclic compounds. The R values and ring dihedral angles were determined and found to be consistent with half-chair conformations. Relative to saturated heterocyclic compounds, the effect of the sulfur atom on ring puckering was attenuated. However, an increase in ring puckering resulted from the sulfone group and was attributed to torsional energy.     

Organo group VB chemistry: Part IV: on the NQR spectra of tertiary aryl group VB compounds (35Cl, 75As, 121Sb, 209Bi)

The NQR spectra for the nuclei ³⁵Cl, ⁷⁵As, ¹²¹Sb/¹²³Sb and ²⁰⁹Bi at 300°K in the series of compounds (4-XC₆H₄)₃M and (3-XC₆H₄)₃M (M = P, As, Sb, Bi; X = H, F, Cl) are measured. Hammet sigma constants are calculated. The bonding in these molecules is discussed.     

Solid state reaction synthesis of filled skutterudite compounds (Ce or Y)yFexCo4-xSb12 and the effect of filling atoms Ce or Y on lattice thermal conductivity

The synthesis of filled skutterudite compounds (Ce or Y)yFexCo₄-xSb12, through a solid state reaction using chloride of Ce or Y, high purity powder of Co, Fe, and Sb as starting materials, was investigated. (Ce or Y)yFexCo₄-xSb12 (x = 0 1.0,y = 0 0.15) compounds were obtained at 850 1 123 K. The results of Rietveld analysis demonstrate that (Ce or Y)yFexCo₄-xSb12 synthesized by a solid state reaction possesses a filled skutterudite structure. The filling fraction of Ce or Y obtained by Rietveld analysis agrees well with the composition obtained by chemical analysis. The lattice constant of CeyFexCo₄-xSb12 increases with increasing substitution of Fe at Co sites, and with an increasing Ce filling fraction in the Sb-dodecahedron voids. The lattice thermal conductivity of (Ce or Y)yFexCo₄-xSb12 decreases significantly with an increasing Ce or Y filling fraction in the voids and with substitution of Fe at Co sites.     

N-Alkoxymethylation of heterocyclic compounds with diethyl phosphite via cleavage of P-O bond

N-Alkoxymethylation of heterocyclic compounds with diethyl phosphite via cleavage of P-O bond was investigated and a series of N3-ethoxymethylated heterocyclic compounds were synthesized. A mechanism in which diethyl phosphite acts as an efficient surrogate of ethanol was proposed and supported by several evidences.     

Mixed-valent selenidoantimonates(III,V) with transition-metal complexes as counterions: solvothermal syntheses and characterization of [M(dien)2]2Sb4Se9 (M = Mn, Fe), [Co(dien)2]2Sb2Se6, and [Ni(dien)2]2Sb2Se5

Novel selenidoantimonate compounds [M(dien)2]2Sb4Se9 [M = Mn (1), Fe (2)], [Co(dien)2]2Sb2Se6 (3), and [Ni(dien)2]2Sb2Se5 (4) (dien = diethylenetriamine) were solvothermally synthesized and characterized. The unique features of compounds 1-3 are the mixed-valent anionic structures constructed by the Sb(III)Se3 trigonal pyramid and Sb(V)Se4 tetrahedron. Three Sb(III)Se3 pyramids share common corners, forming a heterocyclic Sb3Se6 moiety, and the Sb3Se6 moieties are further connected with Sb(V)Se4 tetrahedra to form the novel one-dimensional [Sb4Se9(4-)]n anionic chain in 1 and 2. The discrete [Sb2Se6]4- anion in 3 is formed by an Sb(III)Se3 trigonal pyramid and an Sb(V)Se4 tetrahedron sharing a common corner. The [Sb2Se5]4- anion in 4 is composed of two Sb(III)Se3 trigonal pyramids connected in the same manner as the [Sb2Se6]4- anion. The mixed-valent [Sb4Se9(4-)]n and [Sb2Se6]4- anions were not observed before. The synthesis and solid-state structural studies of the title compounds show that the transition-metal complexes exhibit different structure-directing effects on the formation of selenidoantimonates in dien. Extensive N-H...Se hydrogen bonds are observed between cations and anions in compounds 1-4, resulting in three-dimensional network structures. Optical and thermal properties of the compounds are reported.