Dendrimers are highly branched, monodispersed, globular macromolecules with well-defined shape and size. Dendrimers have tree like shape, consist of three main components a central core, branches and surface terminal functional groups.1 These hyper-branched molecules were first discovered by Fritz Vogtle in 1978, by Donald Tomalia and co-worker in early 1980s.2 Dendrimers have gained a broad range of applications in supramolecular chemistry especially in host-guest interactions and self-assembly processes. With increasing in generation the dendritic molecule tends to linearly increasing in diameter and adopt a globular shape.3 Due to their high degree of surface functionality and versatility, the modification in the end groups at periphery resulting in different physiochemical properties and biological application. Dendrimer possessing single type of terminal functional groups are mostly symmetrical and easier to synthesize. But the synthesis of dendrimer, consists of two hemispheres, with eventually different sizes, polarities, functionalization and number of terminal groups is more difficult to carry out than the synthesis of symmetrical dendrimer. Such type of dendrimer is called JANUS dendrimer. For that reason relatively limited number of examples are known for janus dendrimers as compared to classical symmetrical dendrimers. The amphiphilic properties of janus dendrimer is particularly useful in biomedical applications, which includes water solubility, drug carrier and as fluorescent group. The synthesis of dendrimer involves an efficient well known method i.e. convergent process. Right now different efficient methods of synthesis which reduces reaction steps as well as time of reaction with good yield has been focused. Now a days the dendrimer chemistry is gaining attention because of their wide application in both medical and non-medical processes. 4, 5 such as drugs delivery, contrasting agent in diagnosis, sensor, catalyst, organic diode etc. By using ethylenediamine, PEG, adamantane tetra carboxylic acid, benzene derivatives, pentaerythritol, cyclodextrin, etc. as a core initiator different types of dendrimers have been developed till now. In our approach cyclooctatetraene derivatives are used as core initiators. The core is non-aromatic and it adopts a stable, non-planer conformation. In this seminar we focus on various methods of synthesis, shape, and size, involvement of supramolecular chemistry, application and formulation of dendrimer. Furthermore our strategy to synthesize cyclooctatetraene core based dendrimer and some preliminary result will be discussed in this seminar.
References:
1. Frechet. M .J; Grayson. M. S; Chemical Reviews, 2001, 101, 3819-3867.
2. Tomalia, D. A; Frechet, M. J; J Polym Sci A Polym Chem 2002,40, 27192728
3. Svenson, S; Tomalia, D. A; Adv. Drug. Deliv. Rev, 2005, 57, 2106-2129.
4. Glancedo. J. V; et al., App. Bio. Mater, 2020, 3, 369-376.
5. Shaw, P. E; et al., Macromolecules, 2020, 53, 1652-1664.