A molecular probe for recognizing the size of hydrophobic cavities based on near-infrared absorbing diradical–PtII complexes

Abstract

A diradical-platinum(II) complex was able to recognize the subtle difference in cavity size between β- and γ-cyclodextrin with on-off switching of intense near-infrared absorption. This provides a new probe for identifying the size of hydrophobic cavities, which has been successfully applied here to differentiate human serum albumin from α-chymotrypsin.

A diquinone–imidazole ensemble for selective colorimetric sensing of cyanide in aqueous medium via anion induced NIR absorption

“…Molecular receptors with NIR-absorption are very rare in literature [21][22][23] and gaining importance due to many advantages of NIR-absorption over visible absorption. [23][24][25][26]…”

Crystal Structure of the <i>cis</i>-Bis(3-<i>tert</i>-butyl-<i>o</i>-diiminobenzosemiquinonato)platinum(II) Complex

“…3 Generally, in order to acquire images with high signal-to-noise ratio, it is desired that the contrast agents show signals only when they are taken up to the target tissues. 4 In previous papers, [5][6][7] we reported that the platinum(II) complex had an attractive feature to use them as a signal-switching contrast agent: the NIR absorption was switched on and off, depending upon the pH or the hydrophobic microenvironment. Toward a goal of designing NIR-absorbing contrast-agents with appropriate signal-switching ability, it is needed to obtain further insights into how the properties of the substituents, such as electron-donating/accepting ability and hydrophobicity/ hydrophilicity, affect the physicochemical properties of the platinum(II) complexes.…”