A re-investigation the electronic spectra of chromium(III) picolinate complexes and high yield synthesis and characterization of Cr2(μ-OH)2(pic)4·5H2O (Hpic=picolinic acid)

Polyhedron ◽  
1999 ◽  
Vol 18 (22) ◽  
pp. 2891-2897 ◽  
Author(s):  
Nicole E Chakov ◽  
Rachel A Collins ◽  
John B Vincent
2005 ◽  
Vol 19 (12) ◽  
pp. 1215-1219 ◽  
Author(s):  
G. M. Mizanur Rahman ◽  
H. M. ‘Skip’ Kingston ◽  
Matt Pamukcu

2008 ◽  
Vol 62 (6-7) ◽  
pp. 914-917 ◽  
Author(s):  
Ping Ou ◽  
Gang Xu ◽  
Zhaohui Ren ◽  
Xiaohong Hou ◽  
Gaorong Han

Author(s):  
Anca EMANDI

A new series of oxovanadium(IV) chelates containing bi-and tridentate pyrazol-5-one azo derivatives ligands of the type (I) [VO(L)2] and (2) [VO(L)(H2O)] have been prepared and characterized by elementary analysis, IR, electronic spectra, conductance measurements, and molecular weights. The ligands coordinate through (O-N) donor system as monobasic and bidentate (HL) for the first type and through (0-N-O) donor system as dibasic and tridentate (H2L) for the second type of complexes. The molecular weights, the presence of the (V=O) stretching band around 950 cm -1, and the visible spectra suggest a monomeric penta-coordinated structure for these complexes.


1987 ◽  
Vol 42 (9) ◽  
pp. 1088-1096 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Cornelia Dörzbach

Preparative methods have been explored for the synthesis of small, volatile polysilaalkanes, which could serve as starting materials for the production of amorphous silicon a-SiC:H. High yield pathways have been developed for H3SiCH2CH2SiH3 and H3SiCH2CH2CH2SiH3. These compounds can be converted into symmetrically halogen-functional derivatives through the reac­tions with SnCl4 or Br2. The homologous H3SiCH2CH2SiH2CH3 has also been prepared and halogenated, starting from the corresponding vinylsilane via the hydrosilylation route. Allylsilanes were the source of the synthesis of H3SiCH2CH=CH2, CH3SiH2CH2CH=CH, SiH2(CH2CH = CH2)2, SiH2(CH2CH2CH2SiH3)2, or HSi(CH2CH2CH2SiH3)3. Methylated deriva­tives are also available. - Some physical and spectroscopic properties of the new compounds have been investigated. In particular. NMR data were collected and used for an assessment of structure and isomerism.


2016 ◽  
Vol 71 (11) ◽  
pp. 1135-1140 ◽  
Author(s):  
Javad Safaei-Ghomi ◽  
Mehrnoosh Asgari-Kheirabadi ◽  
Hossein Shahbazi-Alavi

AbstractIn this work, we report the synthesis and characterization of CeO2 nanoparticles as an efficient catalyst for the preparation of methyl 6-amino-5-cyano-4-aryl-2,4-dihydropyrano[2,3-c]pyrazole-3-carboxylates via one-pot four-component condensation reaction of dimethyl acetylenedicarboxylate, hydrazine hydrate, malononitrile, and aldehydes in aqueous medium. The use of a non-hazardous organic solvent, easy recovery of the catalyst, compatibility with various functional groups, and high yield of the products make the protocol attractive, greener, and economic.


2014 ◽  
Vol 33 (2) ◽  
pp. 189 ◽  
Author(s):  
Mustafa Er ◽  
Ayşe Şahin ◽  
Hakan Tahtacı

<p>Thiosemicarbazone derivatives <strong>3a–e</strong> were synthesized by the reaction of various aldehydes<strong> 1a–e</strong> with 4-methyl thiosemicarbazide <strong>2</strong> in 78% to 90% yield. Then, the thiazole moieties of the target materials <strong>5a–e</strong> were obtained in high yields (71–93%) using the Hantzsch reaction utilizing thiosemicarbazone derivatives <strong>3a–e</strong> with ethyl-2-chloroacetoacetic ester. The substituted nitrile derivatives <strong>7a–e</strong> were obtained in moderate to high yield (58–84%) from the reaction of compounds <strong>5a–e</strong> with chloroacetonitrile by the nucleophilic aliphatic substitution reaction in the presence of anhydrous potassium carbonate. Finally, substituted 2-amino-1,3,4-thiadiazole compounds <strong>9a–e</strong> were obtained in moderate to good yields (51–62%) from the reaction of thiosemicarbazide with substituted nitrile derivatives <strong>7a–e</strong>. As a result, compounds that all share a high disposition for biological activities were obtained. The structures of the newly synthesized compounds were confirmed by IR, <sup>1</sup>H NMR, <sup>13</sup>C NMR, elemental analysis, and mass spectrometric techniques.</p>


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