Sterically Shielded Heptamethine Cyanine Dyes for Bioconjugation and High Performance Near-Infrared Fluorescence Imaging was written by Li, Dong-Hao;Schreiber, Cynthia L.;Smith, Bradley D.. And the article was included in Angewandte Chemie, International Edition in 2020.Safety of 2,5-Dibromo-1,3-dimethylbenzene This article mentions the following:
The near-IR window of fluorescent heptamethine cyanine dyes greatly facilitates biol. imaging because there is deep penetration of the light and negligible background fluorescence. However, dye instability, aggregation, and poor pharmacokinetics are current drawbacks that limit performance and the scope of possible applications. All these limitations are simultaneously overcome with a new mol. design strategy that produces a charge balanced and sterically shielded fluorochrome. The key design feature is a meso-aryl group that simultaneously projects two shielding arms directly over each face of a linear heptamethine polyene. Cell and mouse imaging experiments compared a shielded heptamethine cyanine dye (and several peptide and antibody bioconjugates) to benchmark heptamethine dyes and found that the shielded systems possess an unsurpassed combination of photophys., physiochem., and biodistribution properties that greatly enhance bioimaging performance. In the experiment, the researchers used many compounds, for example, 2,5-Dibromo-1,3-dimethylbenzene (cas: 100189-84-2Safety of 2,5-Dibromo-1,3-dimethylbenzene).
2,5-Dibromo-1,3-dimethylbenzene (cas: 100189-84-2) belongs to organobromine compounds. Many of the organo bromine compounds are relatively nonpolar. Bromine is more electronegative than carbon (2.8 vs 2.5) and hence the carbon in a carbon–bromine bond is electrophilic in nature. Many of the alkyl bromine derivatives are excellent alkylating agents since bromides are good leaving groups. Tribromides, like tetrabutylammonium tribromide, are used as a solid source of bromine. N-bromosuccimide (NBS) is used for the selective bromination of allylic bonds.Safety of 2,5-Dibromo-1,3-dimethylbenzene
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary