Converting Thiophene in Simulated Coking Crude Benzene to N,N-Dimethyl-2-thiophenecarboxamide by Dimethylcarbamyl Chloride Under Mild Conditions

Since the content of thiophene in coking crude benzene is high, it is necessary to remove it from coking crude benzene for efficient utilization. In this study, an important intermediate, N,N-dimethyl-2-thiophenecarboxamide, was synthesized from thiophene and dimethylcarbamyl chloride. The influences of the dosages of dimethylcarbamyl chloride and ZnCl2 catalyst, reaction temperature and time on the removal rate were further explored based on the reaction kinetics.The structure of the target product was characterized by means of MS,NMR and 13C NMR.The removal rate of thiophene was 98.14% after the reaction for 2 h and thiophene was almost removed after the reaction for 3 h under the optimal reaction conditions [a molar ratio of n(thiophene):n(dimethylcarbamyl chioride):w(ZnCl2)=1:12:10,300 r/min, 318 K and 101.325 kPa].The acylation of thiophene with dimethylcarbamyl chloride was approximately in accord with the first order kinetic equation at 303-323K.The activation energy was 53.9850 kJ/mol and the pre-exponential factor was 1.4521×10^9 h^-1.     

C CP MAS NMR, FTIR, X-ray diffraction and PM3 studies of some N-(ω-carboxyalkyl)morpholine hydrohalides

N-(ω-carboxyalkyl)morpholine hydrochlorides, OC₄H₈N(CH₂)_nCOOH·HCl, n=1–5, were obtained and analyzed by ¹³C cross polarization (CP) magic angle spinning (MAS) NMR, FTIR and PM3 calculations. The structure of N-(3-carboxypropyl)morpholine hydrochloride (n=3) has been solved by X-ray diffraction method at 100 K and refined to the R=0.031. The crystals are monoclinic, space group P2₁/c, a=14.307(3), b=9.879(2), c=7.166(1) Å, β=93.20(3)°, V=1011.3(3) ų, Z=4. In this compound the nitrogen atom is protonated and two molecules form a centrosymmetric dimer, connected by two N⁺–HCl⁻ (3.095(1) Å) and two O–HCl⁻ (3.003(1) Å) hydrogen bonds. ¹³C CP MAS NMR spectra, contrary to the solution, showed non-equivalence of the ring carbon atoms. The PM3 calculations predict a molecular dimer without proton transfer for an HCl complex, while for an HBr complex an ion pairs with proton transfer, and reproduces correctly the conformation of both dimers but overestimates H-bond distances. Shielding constants calculated from the PM3 geometry of ion pairs gave a linear correlation with the ¹³C chemical shifts in solids.     

Molecular motion and phase transition in perovskite-type (CH3)nNH4−nSnCl3 (n=1–4) studied by proton NMR spin–lattice relaxation

Powder X-ray diffraction, ¹¹⁹Sn NMR spectra, and ¹H NMR spin–lattice relaxation times, T₁, were measured for (CH₃)_nNH_4−nSnCl₃ (n=1–4). From the Rietveld analysis, it is shown that all four compounds crystallize into deformed perovskite-type structures at room temperature. The temperature dependence of ¹H T₁ was analyzed in terms of the CH₃ reorientation and other motions of the whole cation. Except for the phase transition in CH₃NH₃SnCl₃, which is from monoclinic to rhombohedral at 331 K, ¹H T₁ was continuously changed at other phase transitions in this compound as well as in the n=2–4 compounds, suggesting that the transitions are not caused by the change of the motional state of the cation but by an instability of the [SnCl₃]_nⁿ⁻ perovskite lattice.     

La-NMR-spektroskopie an allyllanthan(III)-komplexen

¹³⁹La-NMR chemical shifts were measured for several anionic complexes of formulae Li(C₄H₈O₂)_3/2 [La(ν³-C₃H₅)₄], [Li(C₄H₈O₂)₂][Cp′_nLa(ν³-C₃]H₅)_4−n] (Cp′ = Cp(ν⁵-C₅H₅); n = 1, 2 and Cp′ = Cp * (ν⁵-C₅Me₅); N = 1) and Li[R_nLa(ν³-C₃H₄)₄−n] (R = N(SiMe₃)₂; n = 1, 2 and R = CCsIMe₃; n = 4), as well as for neutral compounds for formulae La(ν³-C₃H₅)₃L_n (L = (C₄H₈O₂)_1.5, (HMPT)₂, TMED), Cp′_nLa(ν³-C₃H₅)_3−n (Cp′= Cp(ν⁵-Cp₅H₅), Cp *(ν⁵-C₅Me₅); n = 1, 2) and La(ν³-C₃H₂)₂X(THF)₂ X = Cl, Br, I). Typical ranges of the ¹³⁹La-NMR chemical shifts were found for the different types of complex independent of number and kind of organyl groups directly bonded to lanthanum.

Zusammenfassung

¹³⁹La-NMR-Spektroskopie wurde an einer Reihe anionischer Allyllanthanat(III)-Komplexe der Zusammensetzung ]- [La)ν³-C₃H₅)₄, [Li(C₄H₈)₂][Cp′_nLa(ν³-C₃H₅)_4−n(Cp′ = Cp(ν⁵-C₅H₅); n = 1, 2 und Cp′ = Cp * (ν⁵-C₅Me₅); N = 1) und Li[R_nLa(ν³-C₃H₅)_4−n (R = B(SiMe₃)₂; n = 1, 2 und R = CCSiMe₃; n = 4 sowie neutraler Allyllanthan(III)-Komplexe der Zusammensetzung La(ν³-C₃H₅)₃L_n (L_n = (C₄H₈O₂)_1.5, (HMPT)₂, TMED), Cp′_n, La(ν³-C₃H₅)_3−n (Cp′ = Cp(ν⁵-C₅H₅), Cp * (ν⁵- Cp₅Me₅); n = 1, 2) und La(ν³-Cp₃H₅)₂X(THF)₂ (X = Cl, Br, I) durchgefürt. In Abhängikeit von der Anzahl und der Art der am Lanthan gebundenen Gruppen wurden für die verschieden Komplextypen charakteristische Resonanzbereiche ermittelt.     

Iron carbonyl complexes from 2-[2,3-diaza-4-(2-thienyl)buta-1,3-dienyl]thiophene: N---N bond cleavage and cyclometalation

When thienyl Schiff base 1, derived from 2-formylthiophene and hydrazine, reacted with Fe₂(CO)₉ in n-hexane, three major complexes were obtained: (1) a diironhexacarbonyl complex with two 2-thienylmethylideneamido bridging ligands 2, which resulted from the =N---N= bond cleavage of ligand 1; (2) a doubly cyclometalated di-μ-di-(η¹:η²-thienyl; η¹:η¹(N))bis(hexacarbonyldiiron) complex (3); and (3) a cyclometalated (μ-η¹:η²-thienyl; η¹:η¹(N))hexacarbonyldiiron complex (4). Molecular structures of compounds 1a, 1c, and 2a have been determined by single-crystal X-ray diffraction.     

Investigation on lanthanide binuclear complexes of 1,5-bis-(1′-phenyl-3′-methyl-5′-pyrazolone-4′)-1,5-pentanedione and 2,2′-bipyridine

The coordination of 1,5-bis-(1′-phenyl-3′-methyl-5′-pyrazolone-4′)-1,5-pentanedione (BPMPPD) and 2,2′-bipyridine (bipy) with lanthanide ions in water-alcohol solution has been studied. Binuclear complexes of the types : Ln₂(BPMPPD)₃(bipy)₂·nH₂O (n = 2 for Y, n = 4 for Eu, Gd, Dy, Ho, Er, Tm and Yb); Ln₂(BPMPPD)₃bipy·nH₂O (n = 10 for La, n = 3 for Pr, Nd, Sm and Tb) were formed. The compounds were characterized by elemental analysis, molar conductance, IR, UV, ¹H NMR spectroscopy, thermogravimetric analysis and fluorescence spectra.     

Bibracchial diazatetralactams. Structure and molecular modeling of calcium complexes

Doubly-armed diazatetralactams constitute a new series of easily synthesized tetralactams. The structural study of the calcium complexes of their N,N′-dimethyl acetamido and (2-pyridylmethyl) derivatives was performed by IR, ¹H, ¹³C NMR spectroscopies and molecular modeling. These complexes showed a C₂ symmetry and a high number (8–9) of coordination around the calcium atom.     

N-vinyl-2-pyrrolidone and methacrylonitrile copolymers: nuclear magnetic resonance characterization

The copolymers of N-vinyl-2-pyrrolidone and methacrylonitrile (V/N) were prepared by free radical bulk polymerisation. The copolymer composition was determined from the quantitative ¹³C{¹H} NMR spectrum. The reactivity ratios for N-vinyl-2-pyrrolidone (V) and methacrylonitrile (N) were found to be r_V=0.04, r_N=1.56. The complete spectral assignment of the overlapped and complex carbon and proton NMR spectra were done with the help of two dimensional ¹³C–¹H Heteronuclear Single Quantum Correlation Spectroscopy (HSQC) and Total Correlation Spectroscopy (TOCSY). Distortionless Enhancement by Polarization Transfer (DEPT) was used to differentiate between the methylene, the methine and the methyl carbon resonance signals of the copolymers.     

New phosphabenzenes by [4 + 2] cycloaddition of stannoles to 1-phospha-1-alkynes — determination of signs of coupling constants [J(P, C), J(P, H), J(P, Si), J(Sn, P)]

Stannoles bearing dialkylboryl groups in 3-position react with 1-phospha-1-alkynes P≡C---^tBu (1) and P≡C---CH₂^tBu (2) by [4 + 2] cycloaddition and elimination of stannylene to give phosphabenzenes in high yield. The stannylenes oligomerise to give [R¹₂Sn]_n with n ≥ 7 (R --- Me, Et, -(CH₂)₅₋ or, in the case of R¹ = ^tBu, react with the stannole itself. All phosphabenzenes are characterized by their consistent sets of NMR data. The absolute signs of the coupling constants ⁿJ(³¹P, ¹H), ⁿJ(³¹P, ¹³C), ²J(³¹P, ²⁹Si) and ²J(¹¹⁹Sn, ³¹P) were determined by appropriate ID and 2D NMR experiments.     

Novel rearrangements of fused zwitterionic heterocyclic systems

(E)-2-Chlorodimethylstannyl-3-diethylboryl-2-pentene (1) reacts with the C-lithiated azoles 2 (derived from thiazole (2a), 4-methylthiazole (2b), 1,4-dimethylimidazole (2c), benzoxazole (2d) and benzthiazole (2e)) to eliminate LiCl, giving first mixtures containing compounds with either a coordinative N--- bond (3) or the zwitterionic isomer with an Sn---N bond (4), or both, and in some cases a rearranged product (5) with a 1,2,5-azastannaborole unit is also present. The zwitterionic compounds 4 tend to rearrange into the heterocycles 5 in which the heteroaromatic system is no longer present and two new C---C bonds, a new B---C and a new B---N bond are formed. The reactions were monitored by multinuclear NMR (¹H, ¹¹B, ¹³C, ¹⁴N and ¹¹⁹Sn NMR) which also served for the characterization of the final products. In the case of 5e, the molecular structure was determined by single-crystal X-ray analysis (monoclinic; space group P2₁/n; A=11.691(2), B=12.396(2), C=13.149(2) Å; β=93.41(2)°).     

Synthesis and characterisation of the methylene-inserted mixed-chalcogenide compounds Fe2(CO)6(μ-SeCH2Te) and Fe2(CO)6(μ-SCH2Te)

The methylene-bridged, mixed-chalogen compounds Fe₂(CO)₆(μ-SeCH₂Te) (1) and Fe₂(CO)₆(μ-SCH₂Te) (3) have been synthesised from the room temperature reaction of diazomethane with Fe₂(CO)₆(μ-SeTe) and Fe₂(CO)₆(μ-STe), respectively. Compounds 1 and 3 have been characterised by IR, ¹H, ¹³C, ⁷⁷Se and ¹²⁵Te NMR spectroscopy. The structure of 1 has been elucidated by X-ray crystallography. The crystalsare monoclinic,space group P2₁/n, A = 6.695(2), B = 13.993(5), C = 14.007(4)Å, β = 103.03(2)°, V = 1278(7) ų, Z = 4, D_c = 2.599 g cm⁻³ and R = 0.030 (R_w = 0.047).     

1,2,7,9-四取代去氢骆驼蓬碱衍生物的合成及体外抗肿瘤活性

为了寻找高效低毒的抗肿瘤候选化合物, 以去氢骆驼蓬碱为原料, 对β-咔啉环的2-,7-和9-位3个结构位点进行了结构改造, 合成了11个去氢骆驼蓬碱衍生物, 化合物的结构经核磁共振、 红外光谱、 质谱及元素分析确证. 采用四甲基偶氮唑盐(MTT)法初步测试了目标化合物体外抗肿瘤(Bel-7402, 786-0, BGC-823, A375, 769-P和MCF7)活性, 结果表明化合物4a, 4b, 8a和8b具有显著的体外抗肿瘤活性.     

Zr-TUD-1: A novel heterogeneous catalyst for the Meerwein–Ponndorf–Verley reaction

A series of Schiff-base complexes has been synthesized by the condensation of 1,2-diaminocyclohexane with salicylaldehyde, 2-pyridinecarboxaldehyde, and 2-hydroxy-1-naphthaldehyde, followed by the metallation with manganese (1, 2, 3a), cobalt (3b), copper (3c) and iron (3d) salts. These Schiff-base ligands L₁–L₃ and complexes 1, 2, 3a–d were then characterized by IR, ¹H NMR, ¹³C NMR, UV–vis spectra, and DSC measurement. Schiff-base Mn complex (3a) resulting from N,N′-bis(2-hydroxy-1-naphthalidene)cyclohexanediamine (L₃) ligand was considerably active for the catalytic epoxidation of styrene under mild conditions, in which the highest yield of styrene oxide reached 91.2 mol%, notably higher than those achieved from simple salt catalysts Mn(Ac)₂·4H₂O and MnSO₄·H₂O. However, another two salen–Mn complexes 1 and 2 derived from ligands N,N′-bis(salicylidene)cyclohexanediamine (L₁) and N,N′-bis(2-pyridine carboxalidene)cyclohexanediamine (L₂) exhibited relatively poor activity under identical experimental conditions.     

Phosphorus–nitrogen compounds. Part VI. Aminolysis of octachlorocyclotetraphosphazatetraene and the crystal structure of 2-trans-6-bis(n-propylamino)-2,4,4,6,8,8-hexakis-tert-butylaminocyclo-2λ, 4λ, 6λ, 8λ-tetraphosphazatetraene

The reactions of 2-trans-6-N₄P₄(NHPrⁿ)₂Cl₆ (2), which was obtained from N₄P₄Cl₈ (1) and n-propylamine, with pyrrolidine and t-butylamine in different solvents have been studied. Compound (2) gave two different products, namely monocyclic (3 and 5) and bicyclic (4 and 6) phosphazenes. Compounds (2–6) have been characterized by elemental analysis, IR, ¹H-, ¹³C-, ³¹P NMR, HETCOR and MS and the structure of compound (5) has been examined crystallographically. The bicyclic phosphazene (6) is the first exciting example of bicyclic phosphazenes containing chlorine atoms, in the literature. The formation mechanisms of bicyclic phosphazenes are re-considered by taking into account the synthesis of compound (6), which contains three stereogenic phosphorus atoms. Compound (5) crystallizes in the monocyclic space group P2₁/n with a=13.974(2), b=17.836(5), and c=18.683(4) Å, β=98.50(1)°, V=4605.4(2) Å³, Z=4 and D_x=1.051 g cm^−3. It consists of a non-centrosymmetric, non-planar phosphazene ring in a saddle conformation, with two n-propylamino (in 2-trans-6 positions) and six bulky t-butylamino side groups. The bulky substituents are instrumental in determining the molecular geometry.     

The synthesis and x-ray structure of (N,N-dimethyldithiocarbamato)(n-butyl)diphenyltin(IV)

(N,N-Dimethyldithiocarbamato)(n-butyl)diphenyltin(IV), n-BuPh₂SnS₂NMe₂, crystallizes in the monoclinic space group P2₁/n with a 9.772(5), b 9.895(4), c 21.418(9) Å, β 95.81(3)⁰, V 2060 ų Z = 4, μ 14.4 cm⁻¹ The structure was determined by the heavy-atom technique from 3103 independent reflections measured at room temperature on an Enraf-Nonius four-circle CAD-4 diffractometer using monochromatized Mo-K radiation and refined to a final R value of 5.8%. The tin atom is essentially four-coordinated with a weak fifth tin-sulphur bond (Sn---S(2) 3.079(1) Å) considerably longer than the other (Sn---S(1) 2.466(1) Å). A comparison with the complex n-BuPhSn(C1)S₂CNEt₂ (Sn---S(1) 2.454(1) Å; Sn---S(2) 2.764(1) Å) suggests that enhanced steric factors are responsible for the preferential monodentate behaviour of the dithiocarbamate ligand in the title complex.     

X-ray studies of the layer thickness in smectic phases

X-ray investigations of nine smectogenic substances exhibiting the smectic A_d, A₁ and crystalline E phases were performed at various temperatures. X-ray patterns yielded the layer thickness d (A_d, A₁ phases) and orthorhombic unit cell parameters (E phase). The layer thickness of the A_d phase in 4'-n-alkyl-4-cyanobiphenyls (nCBs) has different temperature coefficients for shorter (n = 8-10) and longer (n = 12-14) members, which is explained as resulting from two competing effects: a weakening with temperature of the intermolecular association energy that favours an increase in d, and the increasing number of conformers which reduces the molecular length. A small anisotropy of the thermal expansivity in the smectic phases was found by comparing the linear quantity d(T) with the linearized bulk characteristic of the system, V^-3(T), where V = 1/ρ is the specific volume, ρ is the density. Differences between the slopes of the two quantities are less in the case of the A₁ phase of two nDBTs (5-n-alkyl-2-(4'-isothiocyanatophenyl)-1,3-dioxanes). The present X-ray data and recent results of studies of the low frequency relaxation process in these compounds (under atmospheric as well as elevated pressures) give a consistent picture of molecular reorientations around the short axes in the smectic phases.     

Si-Kernresonanzspektren und synthese von bromdisilanen und ioddisilanen

The syntheses of Bromodisilanes Br_nSi₂H_6−n and Iododisilanes I_nSi₂H_6−n (n = 1, 2, 3, 4, 5), starting from caryldisilanes Ar_nSi₂H_6−n (Ar = phenyl, -naphthyl, mesityl) are reported. The ²⁹Si-NMR-spectra of all compounds, including ²⁹Si²⁹Si-coupling constants, have been measured.

Zusammenfassung

Ausgehend von Aryldisilanen ArS₂H_6−n, (Ar = Phenyl, -Naphthyl, Mesityl) wurden die Bromdisilane Br_nSi₂H_6−n, und Ioddisilane I_nSi₂H_6−n, (n = 1, 2, 3, 4, 5) synthetisiert. Die ²⁹Si-NMR-Spektren aller Verbindungen, (eingeschlossen ²⁹Si²⁹Si-Kopplungskonstanten) wurden vermessen.     

"一锅法"N-(2-苯甲酰胺苯基)-水杨醛亚胺/TiCl4·2THF催化乙烯聚合

报道了4个含苯甲酰胺取代的水杨醛亚胺配体: N-(2-苯甲酰胺苯基)-水杨醛亚胺(L1)、 N-(2-苯甲酰胺苯基)-3-甲基水杨醛亚胺(L2)、 N-(2-苯甲酰胺苯基)-3-叔丁基水杨醛亚胺(L3)和N-(2-苯甲酰胺苯基)-3,5-二溴水杨醛亚胺(L4)的合成, 采用 ¹H NMR和HRMS对其结构进行了表征. 在助催化剂甲基铝氧烷(MAO)作用下, 以L3与TiCl₄·2THF为模型催化体系, 在最佳陈化条件(陈化温度为25 ℃, 陈化时间为30 min, 配体与TiCl₄·2THF的摩尔比3∶1)下, 考察了L1~L4/TiCl₄·2THF催化体系Al/Ti摩尔比、 反应时间、 反应温度和聚合压力, 以及配体结构等对乙烯聚合的影响. 结果表明, 随着在水杨醛骨架上氧原子邻位取代基位阻的增大, 催化体系的活性及所得聚乙烯的分子量均有增加, 其中以L3的催化活性最高, 达到224 kg PE/(mol Ti?h). 采用高温 ¹H NMR, ¹³C NMR, GPC-IR和DSC等对由不同配体L1~L4/TiCl₄·2THF得到的聚乙烯样品的微观结构与热性能进行了分析与表征, 结果显示样品为线性高密度聚乙烯, M_n=5.9×10 ⁴~11.9×10 ⁴, 分子量分布(PDI)为21.9~72.1.     

The crystal and molecular structure of bis(indazol-1-yl)pyridin-2′-ylmethane (BIPM) and [Rh(BIPM)(NBD)]PF6

The syntheses of a new tripodal ligand bis(indazol-1-yl)pyridin-2′-ylmethane (BIPM) and of a cationic complex (Rh(BIPM)(NBD)]PF₆, (NBD = 2,5-norbornadiene) are reported. Both compounds were characterized by infrared, ¹H, and ¹³C NMR spectroscopy and by single crystal X-ray analysis. BIPM crystallizes in the monoclinic system in space group P2₁/n with an β helical conformation. The [Rh(BIPM)(NBD)]PF₆ complex crystallizes in the monoclinic space group C/2c, the rhodium atom being pentacoordinate with a distorted trigonal bipyramidal geometry.     

Synthesis, characterization and antitumor activity of some arylantimony triphenylgermanylpropionates and crystal structures of Ph3GeCH(Ph)CH2CO2SbPh4 and [Ph3GeCH2CH(CH3)CO2]2Sb(4-ClC6H4)3

A series of novel arylantimony(V) triphenylgermanylpropionates with the formula (Ph₃GeCHR¹CHR²CO₂)_nSbAr_(5−n) (R¹=H, Ph; R²=H, CH₃; n=1, 2) were synthesized and characterized by elemental analysis, IR, ¹H-NMR, ¹³C-NMR and mass spectroscopy. The crystal structures of Ph₃GeCH(Ph)CH₂CO₂SbPh₄ and [Ph₃GeCH₂CH(CH₃)CO₂]₂Sb(4-ClC₆H₄)₃ were determined by X-ray diffraction. The in vitro antitumor activities of some selected compounds against five cancer cells are reported.