Emission Control by Molecular Manipulation of Double‐Paddled Binuclear Pt^II Complexes at the Air‐Water Interface

Abstract

Molecular functions depend on conformations and motions of the corresponding molecular species. An airwater interfacei sasuitablea symmetricf ield for the control of molecular conformationsa nd motions under as mall applied force. In this work, double-paddled binuclear Pt II complexes containing pyrazole rings linked by alkyl spacers were synthesized and their orientations and emission properties dynamically manipulateda tt he air-water interface. The complexese merge from water with concurrent variation of interfaceo rientation of the planes of the Pt II complexes from perpendicular to parallel during mechanical compression suggesting au nique 'submarine emission'. Phosphorescence of the complexes is quenched at the air-water interface prior to monolayer formation with intensities subsequently rapidly increasing during monolayer compression. These results indicate that asymmetricr eactions andm otionsm ight be controlled by applying mechanical force at the air-water interface.

Nanoarchitectonics for Coordination Asymmetry and Related Chemistry

“…Molecular orientations can be also tuned by macroscopic mechanical motions of Langmuir monolayers at the air-water interface. Recently, Mori, Naota, and coworkers proposed, submarine emission, 96 as a novel mechanism for controls of optical properties. This mechanism was first demonstrated through orientational and positional controls of chromophore coordination complex upon mechanical compression of the its monolayer at the air-water interface (Figure 16).…”

The evolution of molecular machines through interfacial nanoarchitectonics: from toys to tools

“…14). 85 In the submarine emission process, the oating-up motion of submarine molecules from the water phase into the air phase across a sub-nanometer level interfacial region induces a drastic increase of uorescence emission. The submarine molecules employed are double paddle-type platinum dinuclear complexes, consisting of two mononuclear pyrazolato Pt(II) Fig.…”

Nanoarchitectonics Revolution and Evolution: From Small Science to Big Technology

“…Subtle changes of molecular disposition at the air–water interface resulted in exposure of chromophore part to low‐dielectric phase accompanied with enhancement of fluorescence emission. This submarine emission mechanism [ 91 ] is supported by nano–macro connections upon interfacial nanoarchitectonics ( Figure ). Mechanical photo‐property controls of functional molecules embedded at dynamic interface were similarly reported as mechanical mechanically controlled indicator displacement assay.…”