Ion Mobility Mass Spectrometry Uncovers Guest-Induced Distortions in a Supramolecular Organometallic Metallosquare.

Cristian Vicent,Carlos Larriba‐Andaluz,Eduardo Peris,Viraj Gandhi,Victor Martinez‐Agramunt,Dmitry G Gusev

doi:10.1002/anie.202100914

Abstract

The encapsulation of the tetracationic palladium metallosquare with four pyrene‐bis‐imidazolylidene ligands [1]4+ with a series of organic molecules was studied by Electrospray ionization Travelling Wave Ion‐Mobility Mass Spectrometry (ESI TWIM‐MS). The method allowed to determine the Collision Cross Sections (CCSs), which were used to assess the size changes experienced by the host upon encapsulation of the guest molecules. When fullerenes were used as guests, the host is expanded ΔCCS 13 Å2 and 23 Å2, for C60 or C70, respectively. The metallorectangle [1]4+ was also used for the encapsulation of a series of polycyclic aromatic hydrocarbons (PAHs) and naphthalenetetracarboxylic diimide (NTCDI), to form complexes of formula [(NTCDI)2(PAH)@1]4+. For these host:guest adducts, the ESI IM‐MS studies revealed that [1]4+ is expanded by 47–49 Å2.. The energy‐minimized structures of [1]4+, [C60@1]4+, [C70@1]4+, [(NTCDI)2(corannulene)@1]4+ in the gas phase were obtained by DFT calculations.Introduction

Highlights

The encapsulation of the tetracationic palladium metallosquare with four pyrene-bis-imidazolylidene ligands [1]4+ with a series of organic molecules was studied by Electrospray ionization Travelling Wave Ion-Mobility Mass Spectrometry (ESI TWIM-MS)
We describe the use of Electrospray ionization Travelling wave ion-mobility mass spectrometry (ESI TWIM-MS), combined with Collision Cross Sections (CCSs) numerical calculations from DFT-derived structures, for detecting the expansion/compressions produced in the metallosquare [1](BF4)4 upon the encapsulation of fullerenes (C60 and C70), and three-stacked planar heteroguests
We showed recently that metallosquare [1]4+ is effective for the simultaneous encapsulation of three large p-conjugated heteroguests, enabling the formation of quintuple D-AD-A-D (D = donor, A = acceptor) stacks.[13b]. The supramolecular quaternary [(NTCDI)2(PAH)@1]4+ complexes (NTCDI = naphthalenetetracarboxylic diimide; polycyclic aromatic hydrocarbons (PAHs) = polycyclic aromatic hydrocarbon = pyrene, triphenylene and coronene) were formed by the direct mixing of the components

Summary

Introduction

The encapsulation of the tetracationic palladium metallosquare with four pyrene-bis-imidazolylidene ligands [1]4+ with a series of organic molecules was studied by Electrospray ionization Travelling Wave Ion-Mobility Mass Spectrometry (ESI TWIM-MS). We describe the use of Electrospray ionization Travelling wave ion-mobility mass spectrometry (ESI TWIM-MS), combined with CCS numerical calculations from DFT-derived structures, for detecting the expansion/compressions produced in the metallosquare [1](BF4)4 upon the encapsulation of fullerenes (C60 and C70), and three-stacked planar heteroguests.

Results

Conclusion