200713-94-6

Upstream product

• 106-46-7 para-dichlorobenzene 
• 200713-92-4 1,4-Dibromo-2,5-di-n-butylbenzene 
• 1571-86-4 1,4-dibutyl-benzene 
• 1373042-26-2 2,2'-(2,5-dibutylbenzene-1,4-diyl)bis(5,5-dimethyl-1,3-dioxane) 

Downstream Products

• 1373042-30-8 3,3'-(2,5-dibutylbenzene-1,4-diyl)dipropanoic acid 
• 1373042-28-4 dibenzyl 3,3'-(2,5-dibutylbenzene-1,4-diyl)bis(2,4,8,15-tetraoxa-12-azadispiro[5.2.5.2]hexadecane-12-carboxylate) 

Relevant academic research and scientific papers

Molecular rods based on oligo-spiro-thioketals

We report on an extension of the previously established concept of oligospiroketal (OSK) rods by replacing a part or all ketal moieties by thioketals leading to oligospirothioketal (OSTK) rods. In this way, some crucial problems arising from the reversible formation of ketals are circumvented. Furthermore, the stability of the rods toward hydrolysis is considerably improved. To successfully implement this concept, we first developed a number of new oligothiol building blocks and improved the synthetic accessibility of known oligothiols, respectively. Another advantage of thioacetals is that terephthalaldehyde (TAA) sleeves, which are too flexible in the case of acetals can be used in OSTK rods. The viability of the OSTK approach was demonstrated by the successful preparation of some OSTK rods with a length of some nanometers.

Building blocks for oligospiroketal (OSK) rods and evaluation of their influence on rod rigidity

We report on the synthesis of three new sleeves and their incorporation in OSK rods. The structures of these sleeves are based on neo-inositol, terephthalaldehyde diacetals, and indacene. To quantify the influence of the sleeves on rod rigidity, we applied the worm-like chain (WLC) model on the new rods and found that this approach is rather disappointing. As the chief cause of this result, we assume that the rigidity of typical molecular rods largely exceeds the rigidity of polymers, which were successfully described by the WLC model. Alternatively, we suggest quantifying the rigidity of molecular rods by fitting an empirical function on the end-to-end distance distribution curve obtained by MD simulations. After checking various function types, the Levy-Martin function proved to be most suitable for this purpose. On the basis of this function, we defined the Levy-Martin parameter and suggest using this parameter for the characterization of the rigidity of molecular rods.