Long-Range Orientational Self-Assembly, Spatially Controlled Deprotonation, and Off-Centered Metalation of an Expanded Porphyrin

Abstract

Expanded porphyrins are large-cavity macrocycles with enormous potential in coordination chemistry, anion sensing, photodynamic therapy, and optoelectronics. In the last two decades, the surface science community has assessed the physicochemical properties of tetrapyrrolic-like macrocycles. However, to date, the sublimation, self-assembly and atomistic insights of expanded porphyrins on surfaces have remained elusive. Here, we show the self-assembly on Au(111) of an expanded aza-porphyrin, namely, an "expanded hemiporphyrazine", through a unique growth mechanism based on long-range orientational self-assembly. Furthermore, a spatially controlled "writing" protocol on such self-assembled architecture is presented based on the STM tip-induced deprotonation of the inner protons of individual macrocycles. Finally, the capability of these surface-confined macrocycles to host lanthanide elements is assessed, introducing a novel off-centered coordination motif. The presented findings represent a milestone in the fields of porphyrinoid chemistry and surface science, revealing a great potential for novel surface patterning, opening new avenues for molecular level information storage, and boosting the emerging field of surface-confined coordination chemistry involving f-block elements.

Electrostatically Driven Guest Binding in Self-Assembled Molecular Network of Hexagonal Pyridine Macrocycle at the Liquid/Solid Interface: Symmetry Breaking Induced by Coadsorbed Solvent Molecules

“…Over the past decades, co-adsorption of cationic 29,34,[61][62][63][64][65][66][67] and anionic 36,68 guests embedded in the porous space of 2D matrices by electrostatic interactions at the liquid-solid interface has been investigated. We revealed that the tropylium (Tr) cation was immobilized in the pore of square macrocycles of pyridinylene-butadiynylene type via electrostatic interactions.…”

Double‐Decker Paramagnetic {(K)(H3Hhp)2}⋅2− Radical Dianions Comprising Two [30]Trithia‐2,3,5,10,12,13,15,20,22,23,25,30‐Dodecaazahexaphyrins and a Potassium Ion

“…Recently, expanded porphyrins have attracted attention . Among them the ABABAB‐type macrocycles containing three alternating thiadiazole (A) and isoindole (B) sub‐units linked by meso ‐nitrogen atoms attracted much attention for their unique structure and properties . Using gas electron diffraction and X‐ray methods, it was established that both in gas and in solid state the macrocyclic [30]trithia‐2,3,5,10,12,13,15,20,22,23,25,30‐dodecaazahexaphyrin (H 3 Hhp) framework has a highly symmetrical planar shape (Figure ).…”

“…Insoluble macrocycles can be solubilized in the anionic reduced state and, as a result,c rystalline radicala nion salts can be obtained. Although hemihexaphyrazines possess several useful properties, [6,7] the [a] Dr.D.V . Konarev,Prof.…”

Hemihexaphyrazine and Thiadiazole Annulated Hemihexaphyrazine: A Theoretical Insight into Aromaticity and Energetics of Hydrogen Bonding

“…[1][2][3][4][5][6][7] Among a huge number of macrocycles, hemihexaphyrazins of ABABABtype attract a great interest due to their unusually high symmetrical structures, [4][5][6] expanded coordination cavity with enormous potential in coordination chemistry [8][9][10][11] and catalysis, [12] and molecular level information storage. [6] In our recent work [13] a study of tautomeric preference and intramolecular hydrogen bonding was performed for the thiadiazole annulated hemihexaphyrazine (TDAHHp, Scheme 1). According to the results of the DFT calculations, TDAHHp was determined to have the single energetically favourable tautomer of D 3h symmetry, while the other structures were more than 39 kJ·mol -1 higher in energy.…”