scholarly journals Synthesis and NMR spectroscopic characterization of Si-substituted 1-silacyclobutene derivatives

2011 ◽  
Vol 9 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Ezzat Khan ◽  
Bernd Wrackmeyer
Keyword(s):  
Magnetic Resonance ◽  
Room Temperature ◽  
Spectroscopic Characterization ◽  
The Other ◽  
Resonance Spectroscopy ◽  
29Si Nmr ◽  
Reaction Conditions ◽  
New Compounds ◽  
Substituted 1

AbstractHydroboration of trialkyn-1-yl(organo)silanes with one equivalent and two equivalents of 9-borabicyclo[3.3.1]nonane, 9-BBN afford dialkyn-1-ylsilanes and alkyn-1-ylsilanes, respectively. The alkyn-1-ylsilane derivatives are stable at room temperature and can be store under dry argon for prolong period of time. These compounds are attractive materials for further rearrangements to afford novel 1-silacyclobutene derivatives bearing Si-alkenyl or Si-alkynyl functionalities. The hydroboration reaction is well controlled by the Si-R1 function, i.e., the starting silanes with R1 = Ph selectively afford hydroboration of one Si-C≡C bond with one equivalent of 9-BBN, leaving the other two functionalities untouched. Under mild reaction conditions (25°C), the starting silanes with R1 = Me lead to mixture containing dialkyn-1-ylsilane, alkyn-1-ylsilane and their respective 1-silacyclobutene derivatives. All new compounds are sensitive towards air and moisture and were studied by multinuclear magnetic resonance spectroscopy (1H, 13C, 11B, 29Si NMR) in solution.

scholarly journals Design, Synthesis, Spectroscopic Characterization of New Pyrazole Carbothioamides as Antifungal and Antibacterial Candidates

2021 ◽  
Vol 11 (3) ◽  
pp. 3689-3699
Keyword(s):  
Room Temperature ◽  
Antimicrobial Agents ◽  
Spectroscopic Analysis ◽  
Spectroscopic Characterization ◽  
Efficient Synthesis ◽  
Design Synthesis ◽  
Amberlyst 15 ◽  
New Compounds

In a sustained search for novel antimicrobial agents as weaponry in the war against infectious diseases, resulting in improved survivability for both humans and their domestic animals, the present study demonstrates an efficient synthesis of N,N-dimethylaminophenyl substituted pyrazole carbothioamide derivatives. The synthesis involves (3+2) cycloaddition of chalcones with hydrazinecarbothioamide hydrochloride in the presence of the amberlyst-15 catalyzed at room temperature. The structures of new compounds were characterized by spectroscopic analysis. Furthermore, the synthesized new compounds 5(a-g) were assessed in vitro for their antimicrobial susceptibilities. The results indicate that compounds 5a found potent against tested bacteria species; 5b and 5c show excellent inhibition against the tested fungi and bacteria species. Therefore, these could act as antifungal and antibacterial leads for further investigations.

scholarly journals Synthesis, NMR characterization and reactivity of 1-silacyclohex-2-ene derivatives

2012 ◽  
Vol 10 (5) ◽  
pp. 1633-1639 ◽  
Author(s):  
Ezzat Khan ◽  
Bernd Wrackmeyer
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Functional Groups ◽  
Fractional Distillation ◽  
Pure Form ◽  
Resonance Spectroscopy ◽  
29Si Nmr ◽  
Nmr Characterization ◽  
Moisture Sensitive ◽  
New Compounds

AbstractThe chloro functionality of allyldichlorosilane (HSiCl2(C3H5)) and allyldichloromethylsilane (MeSiCl2(C3H5)) were replaced by alkynyl groups and new compounds, allyldialkynylsilane 1 and allyldialkynylmethylsilane 2, were obtained. These silanes, which served as starting materials for the onward reactions, were purified by fractional distillation. They were further subjected to hydroboration with 9-BBN (9-borabicyclo[3.3.1]nonane) and were converted into 1-silacyclohex-2-ene derivatives 5 and 6. The competition between C≡C and C=C in the reaction was studied. The hydroborating reagent 9-BBN was expected to prefer terminal C=C bonds and to leave C≡C bond untouched. This hypothesis of preferable hydroboration was experimentally proved, and hence, 1-silacyclohex-2-ene derivatives were obtained in reasonably pure form. The reaction of allyldialkynylsilane 2 with one equivalent of 9-BBN affords 1-silacyclohex-2-ene bearing Si-C≡C-function, ready to be hydroborated further with one equivalent of 9-BBN. The obtained compound bears two C-B bonds, which are attractive synthones for further transformations. This study aims to highlight the chemistry of C-B and Si-H functional groups. All new compounds obtained were colorless air and moisture sensitive oils, and they were studied by multinuclear magnetic resonance spectroscopy (1H, 13C, 11B, 29Si NMR) in solution.

Characterization of Copper-Modified ZSM-5 with Sorbed Pyridine Using Nuclear Magnetic Resonance Spectroscopy

2012 ◽  
Vol 43 (3) ◽  
pp. 431-442
Author(s):  
Stanislava Nagyová ◽  
Mária Kovaľaková ◽  
Oľga Fričová ◽  
Viktor Hronský ◽  
Dušan Olčák ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Nuclear Magnetic

On the Chemistry of Tetrabenzyl Thiuram Disulfide and Tetramethyl Thiuram Disulfide with Bis (Triethoxysilylpropyl) Tetrasulfide in Silica Compounds

2003 ◽  
Vol 76 (4) ◽  
pp. 876-891 ◽  
Author(s):  
R. N. Datta ◽  
A. G. Talma ◽  
S. Datta ◽  
P. G. J. Nieuwenhuis ◽  
W. J. Nijenhuis ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Succinic Anhydride ◽  
Dynamic Properties ◽  
The Other ◽  
Resonance Spectroscopy ◽  
Reaction Products ◽  
Negative Effect ◽  
Higher Temperature ◽  
Analytical Tools

Abstract The use of thiurams such as Tetramethyl thiuram disulfide (TMTD) or Tetrabenzyl thiuram disulfide (TBzTD) has been explored to achieve higher cure efficiency. The studies suggest that a clear difference exists between the effect of TMTD versus TBzTD. TMTD reacts with Bis (triethoxysilylpropyl) tetrasulfide (TESPT) and this reaction can take place even at room temperature. On the other hand, the reaction of TBzTD with TESPT is slow and takes place only at higher temperature. High Performance Liquid Chromatography (HPLC) with mass (MS) detection, Nuclear Magnetic Resonance Spectroscopy (NMR) and other analytical tools have been used to understand the differences between the reaction of TMTD and TESPT versus TBzTD and TESPT. The reaction products originating from these reactions are also identified. These studies indicate that unlike TMTD, TBzTD improves the cure efficiency allowing faster cure without significant effect on processing characteristics as well as dynamic properties. The loading of TESPT is reduced in a typical Green tire compound and the negative effect on viscosity is repaired by addition of anhydrides, such as succinic anhydride, maleic anhydride, etc.

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