In order to explore the potential propensity of the 1,1′‐methylenedipyridinium dication to form organic–inorganic hybrid ionic compounds by reaction with the appropriate halide metal salt, the organic–inorganic hybrid salts 1,1′‐methylenedipyridinium tetrachloridocuprate(II), (C11H12N2)[CuCl4], (I), and 1,1′‐methylenedipyridinium bis[tetrachloridoaurate(III)], (C11H12N2)[AuCl4]2, (II), were obtained by treatment of 1,1′‐methylenedipyridinium dichloride with CuCl2 and Na[AuCl4], respectively. Both hybrid salts were isolated as pure compounds, fully characterized by multinuclear NMR spectroscopy and their molecular structures confirmed by powder X‐ray diffraction studies. The crystal structures consist of discrete 1,1′‐methylenedipyridinium dications and [CuCl4]2− and [AuCl4]− anions for (I) and (II), respectively. As expected, the dications form a butterfly shape; the CuII centre of [CuCl4]2− has a distorted tetrahedral configuration and the AuIII centre of [AuCl4]− shows a square‐planar coordination. The ionic species of (I) and the dication of (II) each have twofold axial symmetry, while the two [AuCl4]− anions are located on a mirror‐plane site. Both crystal structures are stabilized by intermolecular C—H...Cl hydrogen bonds and also by Cl...π interactions. It is noteworthy that, while the average intermolecular centroid–centroid pyridinium ring distance in (I) is 3.643 (8) Å, giving strong evidence for noncovalent π–π ring interactions, for (II), the shortest centroid–centroid distance between pyridinium rings of 5.502 (9) Å is too long for any significant π–π ring interactions, which might be due to the bulk of the two [AuCl4]− anions. 相似文献
A new environmentally benign, convenient, and facile methodology for the N-formylation of amines is reported using ultrasound irradiation under solvent- and catalyst-free conditions at room temperature. Compared with conventional methods, the main advantages of the present procedure are milder, cleaner and greener conditions, shorter reaction time, higher purity and yields, simpler work-up, and lower generation of waste or pollutions. 相似文献
A simple Pd2+ ligand exchanger was prepared and applied for isolation of aromatic heterocyclic sulfur compounds (S-PAHs) from petroleum condensate oil. The ligand exhibited excellent isolation efficiency and selectivity towards S-PAHs. The chromatograms of pre-isolated S-PAHs recorded by universal flame ionization (FID) and mass spectrum (MS) detections are similar to selective sulfur atomic emission detector chromatograms, indicated from traces or absence of hydrocarbons in FID and MS chromatograms. Nitrogen adsorption, electronic microscope, and X-ray diffraction techniques were employed to confirm the formation of capped Pd2+ nanoparticle dispersion within the silica framework. The results obtained revealed that Pd2+ ions exist as dispersed capped nanoparticles sized between 69 and 79 nm that can be rationalized for their enhanced isolation selectivity towards the S-PAH fraction of petroleum condensate oil.
The action of 2-mercaptoacetic acid, thiosemicarbazide and hydrazine hydrate on the titled compound 1 is studied. On the other hand, the behaviour of the titled compound towards thiourea, ethyl acetoacetate and malononitrile under Michael's conditions is reported. The structure of the new heterocycles 2 - 8 is discussed in the light of IR and 1HNMR spectra. 相似文献
Stable crystalline phosphorus ylides were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, in the presence of strong NH-acids, such as imidazole, 2-methylimidazole, 4-methylimidazole, 2-ethylimidazole, benzimidazole, and 5,6-dimethylbezimidazole. These stable ylides exist in solution as a mixture of two geometrical isomers as a result of restricted rotation around the carbon–carbon partial double bond resulting from the conjugation of the ylide moiety with the adjacent carbonyl group. 相似文献
Stable crystalline phosphorus ylides were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine and dialkyl acetylenedicarboxylates in the presence of strong NH acids, such as indole and 2-methyl indole, 3-methyl indole, and 5-boromo indole. These stable ylides exist in a solution as a mixture of two geometrical isomers as a result of the restricted rotation around the carbon–carbon partial double bond resulting from the conjugation of the ylide moiety with the adjacent carbonyl group. 相似文献
Abstract UV-irradiation (λ > 313 nm) of o,o-diethyl-o-(3-chloro-4-methyl-coumarin-7-yl)-thiophosphate (Coumaphos; 1) in chloroform results in an regioselective dimerization reaction to afford the head-to-tail anti-dimer 2. The structure of 2 is established by single crystal x-ray diffraction. Singlet oxygen does not affect the formation of 2. 相似文献