Lanthanide DO3A-tropone complexes: efficient dual MR/NIR imaging probes in aqueous medium

Eur J Inorg Chem. 2017 Nov 23;2017(43):4965-4968. doi: 10.1002/ejic.201701003. Epub 2017 Aug 24.


In this work, we describe a novel DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) based ligand with a chromophoric tropone coordinating sidearm (1). Ln3+ complexes of 1 have one inner sphere water molecule. The r1 relaxivity of Gd1 is similar to that of the commercial Gd-based MRI agents. The neutral O-donor atom of the tropone moiety slows down the water exchange rate by a factor of 3 compared to GdDOTA. In addition, Nd1 and Yb1 complexes exhibit significant NIR emission in aqueous solutions indicating that the tropone unit is an efficient sensitizer for these Ln3+-ions. Therefore, this new ligand is a promising platform for the design of Ln3+ based dual MR/optical imaging probes.

Keywords: Lanthanide; MRI; Near-infrared; imaging; tropone.