An Alkyne-Appended, Click-Ready PtII Complex with an Unusual Arrangement in the Solid State

To better understand the range of cellular interactions of PtII‐based chemotherapeutics, robust and efficient methods to track and analyze Pt targets are needed. A powerful approach is to functionalize PtII compounds with alkyne or azide moieties for post‐treatment conjugation through the azide–alkyne cycloaddition (click) reaction. Herein, we report an alkyne‐appended cis‐diamine PtII compound, cis‐[Pt(2‐(5‐hexynyl)amido‐1,3‐propanediamine)Cl2] (1), the X‐ray crystal structure of which exhibits a combination of unusual radially distributed CH/π(CC) interactions, PtPt bonding, and NH:O/NH:Cl hydrogen bonds. In solution, 1 exhibits no Ptalkyne interactions and binds readily to DNA. Subsequent click reactivity with nonfluorescent dansyl azide results in a 70‐fold fluorescence increase. This result demonstrates the potential for this new class of alkyne‐modified Pt compound for the comprehensive detection and isolation of Pt‐bound biomolecules. Poised for click: The alkyne‐functionalized probe Scorpio‐Pt, developed to investigate the cellular interactions of Pt‐based therapeutics, exhibits no Ptalkyne interactions and binds readily to DNA. Subsequent click reactivity with fluorogenic dansyl azide results in a 70‐fold fluorescence increase. The PtII compound exhibits an unusual solid‐state arrangement, with CH/π(CC) interactions, PtPt bonding, and NH:O/NH:Cl hydrogen bonds.