Dendron‐Functionalized Bis(terpyridine)–Iron(II) or –Cadmium(II) Metallomacrocycles: Synthesis, Traveling‐Wave Ion‐Mobility Mass Spectrometry, and Photophysical Properties

Abstract

The synthesis, purification, structural analysis, and photophysical properties of a series of five-, six-, and seven-sided Fe(II) macrocycles and the corresponding hexameric Cd(II) macrocycle, all prepared by self-assembly of a 120° bis(terpyridine) ligand modified with first- and second-generation 1→3 C-branched dendrons, are reported. All metallomacrocycles were fully characterized by (1)H and (13)C NMR spectroscopy, traveling-wave ion-mobility mass spectrometry (TWIM MS), molecular modeling, UV/Vis absorption spectroscopy, photoluminescence, and cyclic voltammetry. A gradual increase of the collision cross sections of the Fe(II) metallomacrocycles was observed with a successive increase of the number and molecular size of the ligands. The combination of ion-mobility mass spectrometry and NMR techniques unveils structural features that agree well with calculations. Extinction coefficients and emission are significantly modulated by increasing the ring size and changing the metal ion center from Fe(II) to Cd(II) .

Dondorff Rings: Synthesis, Isolation, and Properties of 60°‐Directed Bisterpyridine‐Based Folded Tetramers

“…Herein, we report the utilization of a 60°‐directed bisligand and its transformation to a corresponding Ru II ‐based dimer, which was used for self‐assembly of novel hetero ‐ and homo‐metallotetramers possessing folded shapes that resemble manta rays of the family Mobulidae, specifically of genus Manta . These Dondorff‐shaped tetramers, aptly named after the first to describe the manta ray,31 were characterized by 1 H and 13 C NMR spectroscopy as well as electrospray ionization traveling wave ion mobility mass spectrometry (ESI TWIM‐MS);32–34 their photophysical and electrochemical properties were also studied.…”

Interfacing Multistage Mass Spectrometry with Liquid Chromatography or Ion Mobility Separation for Synthetic Polymer Analysis

“…IM-MS applications have also been reported about organic polymers, [34][35][36]51,52,[94][95][96][97][98][99][100][101][102][103][104] organometallic macromolecules 37,38,[43][44][45][46][47][48][49][50] as well as polymer-biomolecule complexes. 47,104 These studies examined the gas-phase structures of metal-cationized polymers, 34,35,[96][97][98][99][100][101][102][103] macromolecular architectures 37,38,[43][44][45][46][47][48][49][50] and complex stoichiometries, 47,104 respectively.…”

“…37,38,49,50,[58][59][60][61] With the IM-MS variant used (traveling wave IM-MS), calibration of the drift time scale is required in order to convert the measured drift times to experimental collision cross-sections. 44,45,48,49,68,69 Unfortunately, this could not be performed because of the lack of anion calibrants in the m/z range 400-1000. • losses; moieties with n = 0-1 are eliminated from the 5mer, and moieties with n = 0-3 from the 7mer (spectrum not shown), to yield fragment ions carrying a P-Ocharge at the site of the cleaved P-N bond.…”

“…Studies reported in the last years have demonstrated that ion mobility separations can resolve complicated polymer and material distributions arising from different end groups, varied structural arrangements, unpredicted byproducts or degradation products. [34][35][36][37][38][43][44][45][46][47][48][49][50][51][52] A further advantage of IM-MS is that it deconvolutes, overlapping charge distributions generated by ESI, facilitating stoichiometric and compositional analyses by this ionization method. 43,46,50 Moreover, IM-MS separations are completed within a short time, typically within tens of milli seconds.…”

Stepwise Self‐Assembly and Dynamic Exchange of Supramolecular Snowflakes

“…Recently, in order to facilitate the ligand design with precise bond angle and proper arm length, and to prevent unpredicted structures, two shape‐persistent snowflake‐like supramolecules ( S1 and S2 ) with all rigid backbone were constructed through stepwise coordination‐driven self‐assembly strategy using 2,2′ : 6′,2′′‐terpyridine (tpy) ligand, a widely used building block in supramolecular and macromolecular chemistry . They were quite different from the pioneering works of Stang and Newkome on assembling snowflake‐like structures via exo‐functionalizing supramolecular hexagons with dendrimers ,. To further explore the robustness of our designed super snowflake structure and to enlarge the scope of the possible ligands for future potential functionality, it is extremely intriguing to construct new super snowflake based on longer version of ligands.…”