title: A new class of organogelators based on triphenylmethyl derivatives of primary alcohols: hydrophobic interactions alone can mediate gelation.
abstract: In the present work, we have explored the use of the triphenylmethyl group, a commonly used protecting group for primary alcohols as a gelling structural component in the design of molecular gelators. We synthesized a small library of triphenylmethyl derivatives of simple primary alcohols and studied their gelation properties in different solvents. Gelation efficiency for some of the derivatives was moderate to excellent with a minimum gelation concentration ranging between 0.5-4.0% w/v and a gel-sol transition temperature range of 31-75 °C. 1,8-Bis(trityloxy)octane, the ditrityl derivative of 1,8-octanediol was the most efficient organogelator. Detailed characterizations of the gel were carried out using scanning electron microscopy, FTIR spectroscopy, rheology and powder XRD techniques. This gel also showed a good absorption profile for a water soluble dye. Given the non-polar nature of this molecule, gel formation is likely to be mediated by hydrophobic interactions between the triphenylmethyl moieties and alkyl chains. Possible self-assembled packing arrangements in the gel state for 1,8-bis(trityloxy)octane and (hexadecyloxymethanetriyl)tribenzene are presented. Results from this study strongly indicate that triphenylmethyl group is a promising gelling structural unit which may be further exploited in the design of small molecule based gelators.
authors.affiliation: Organic Materials Research Laboratory, Department of Basic Sciences & Social Sciences, North-Eastern Hill University, Shillong-793022, Meghalaya, India.
authors.forename: Wangkhem P
authors.initials: WP
authors.lastname: Singh
authors.affiliation: Organic Materials Research Laboratory, Department of Basic Sciences & Social Sciences, North-Eastern Hill University, Shillong-793022, Meghalaya, India.
authors.forename: Rajkumar S
authors.initials: RS
authors.lastname: Singh
keywords: SEM; hydrophobic interactions; organogelator; triphenylmethyl group; xerogel