The formula of triazines is C3H3N3 with three isomeric forms (Fig.1). Triazine derivatives consist of a six-membered aromatic ring containing three nitrogen atoms. Isomeric forms include 1,2,3-; 1,2,4-; and 1,3,5-triazine. Tri-substituted 1,3,5-triazines are one of the oldest classes of organic compounds that continue to be used as important core structures in many chemotherapeutic agents due to their interesting pharmacological properties, including anticancer, anti-angiogenesis, anti-HIV, antimalarial, antibacterial, and antimicrobial activities. These compounds have also been used as subunits in the formation of supramolecular structures because they possess good optical and electronic properties and are able to form multiple hydrogen bonds. Triazine derivatives have also been found to be PI3K and mTOR inhibitors, as well as efficient corrosion inhibitors for mild steel in acidic solutions.
Fig. 1 The three isomers of triazine with ring numbering
(cited from Wikipedia)
Besides, 1,3,5-triazine derivatives have been employed as, agrochemicals, dyes, and so on. 1,3,5-Triazin-2-one derivatives include well-known anticancer drugs. For example, 5-azacytidine-(4- amino-1-b-D-ribofuranosyl-1,3,5-triazin-2(1H)-one), a synthetic analogue of the natural pyrimidine nucleoside cytidine, has strong antileukemic activity. Trichloromethyl-1,3,5-triazines constitutes also an important class of photoinitiators for free-radical initiated photo imaging systems. Many chromophore-substituted triazines have been reported in the patent literature, even if it has not been disclosed which of these compounds have important commercial applications. However, a number of chromophore-substituted triazines with a group that absorbs ultraviolet or visible radiation have been reported .
Drug delivery applications of triazine-based dendrimers were investigated. Pegylated G3 dendrimers with molecular weights of 18 and 34 kDa with 9% and 17% iodine content by weight, respectively, were synthesized as potential macromolecular contrast agents. The development of macromolecular contrast agents is of great interest to counteract the drawbacks associated with currently used, small molecule contrast media, including toxicity, extravasation into the extracellular space, and rapid clearance from the bloodstream. Dendrimers are well suited for use as macromolecular media due to the unique properties of these molecules, including monodispersity and multivalency
Among herbicides, the chloro-s-triazine derivatives, and atrazine in particular, are the most heavily used worldwide, and are often therefore, detected in rivers, lakes and groundwater. The main representants of the triazine herbicides are shown in Figure 2. Triazine herbicides belong to a category classified as persistent organic compounds since they resist biological and chemical degradation.
Fig.2 Four main triazine herbicides.
Thomas group in 2008 synthesized a series of polymers with triazine linkage and firstly presented the concept of “covalent triazine frameworks” (CTFs), which is becoming a promising new class of high performance organic materials (POPs). CTFs have a series of unique characteristics, aromatic C=N linkage, the absence of weak bonds except for the aromatic group, which endow themselves with high chemical stability, rich nitrogen contents and bring great value for their practical applications and amazing heteroatom effect(HAE). These special properties endow CTFs with many unique advantages in various applications such as separation and storage, energy storage, photocatalysis and heterogeneous catalysis.