Thiophene groups

The zinc chloride complex of l-(2-pyridyl)-2-(2-thienyl)ethyne has been structurally characterized by single crystal X-ray diffraction showing the ligand is a monodentate nitrogen donor. The N2Q2 tetrahedral coordination geometry reveals little apparent influence of the acetylene or thiophene groups.110... 

Fig. 6 A view down the c-axis of the (BEDT-TTFlFe BgHjoC SE salt, illustrating the very thick anionic layers which result from the thiophene derivatized iron carborane anions. Hydrogen atoms and disordered thiophene groups have been omitted for clarity...

Formulas 53 and 54 depict two redox systems with a central thiophene group. For reasons already discussed they are isolated as 5Jqx and In spite of a longer... 

Prior art reference 2 A thiophene group is a common bioisostere for a phenyl group and may often be used interchangeably in the search for alternative analogues with similar activity."... 

Guglielmetti et al.21 also reported the synthesis of a series of thiophenes (e.g., 25) and terthiophenes (e.g., 26) substituted with spironaphthoxazine photochromic groups. It has been shown that electropolymerization of the thiophene group in 25 that occurs at 1.7 V [vs. saturated calomel electrode (SCE)] is blocked by the... 

Electron-rich dithieno(thiophene) groups are also effective in increasing the value of the closed-ring form (Scheme 4). 

Articaine is an aminoamide that also contains an ester group, which is rapidly hydrolysed by plasma esterases. It is 4-methyl-3([2-(propylamino)propion-amido)]-2-thiophenecarboxylic acid, methyl ester hydrochloride. The thiophene group increases its lipid solubility while the ester group enables it to undergo plasma esterase hydrolysis as well as hepatic enzyme metabolism. Articaine is formulated as a 4% solution with adrenaline. It is the most widely used local anesthetic agent in dentistry in some parts of Europe. 

It is conceivable that the interior of large coal particles can condense and form graphitized compounds that are less susceptible to reduction. The strong reducing agent used can penetrate into smaller coal particles and inhibit the rate of condensation. While aliphatic thiols and sulfides are reduced at low temperature, before condensation commences, the reduction of thiophenes occurs simultaneously with the condensation, and, therefore, in large particles thiophenic groups could form condensed thiophenes, which are less amenable to reduction. 

Figure 11 Croup 3 complexes bearing bis(naphtholate) and bis(phenolate) ligands bridged by pyridine or thiophene groups...

This inhibitory effect on mitosis has been studied further and has led to two semisynthetic derivatives Etoposide and Teniposide, where a methylgroup in Etoposide is changed to a thiophene-group in Teniposide. The semisynthetic derivatives have a premitotic effect, and stop the inclusion of thymidine and uridine in the DNA and RNA in cell and protein synthesis. 

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