Deprotection, Tethering, and Activation of a Catalytically Active Metalloporphyrin to a Chemically Active Metal Surface: [SAc]₄P−Mn(III)Cl on Ag(100)

Abstract

The adsorption and subsequent thermal chemistry of the acetyl-protected manganese porphyrin,[SAc] 4 P-Mn(III)Cl on Ag(100) have been studied by high resolution XPS and temperature programmed desorption. The de-protection event, leading to formation of the covalently bound thio-porphyrin, has been characterized and the conditions necessary for removal of the axial chlorine ligand have been determined, thus establishing a methodology for creating tethered activated species that could serve as catalytic sites for delicate oxidation reactions. Surface-mediated acetyl deprotection occurs at 298 K, at which temperature porphyrin diffusion is limited. At temperatures above ~ 425 K porphyrin desorption, diffusion and deprotection occur and at > 470 K axial chlorine ligand is removed.

A positively charged silver nanowire membrane for rapid on-site swabbing extraction and detection of trace inorganic explosives using a portable Raman spectrometer

“…S4(b) in the ESM). Hence, we can conclude that the DDTC is modified on the surface of the Ag nanowire membrane via S-binding with Ag [40,41].…”

Surface chemistry of porphyrins and phthalocyanines

“…Covalent tethering of porphyrins to metal surfaces through reactive anchoring groups at the periphery of the molecules was performed with protoporphyrin IX (2HPPIX, Fig. 4c) [443,444] and with various other porphyrins using anchor groups on the basis of thiols [445], disulfides [446], acetylthiols [447][448][449][450][451], and others [452,453]. In some cases, electronic decoupling from the (metal) substrate was desired, for example to avoid quenching of excited states by substrate influences in the context of photochemistry.…”

“…1.4) [447]. Related studies where performed using a similar complex equipped with four instead of one anchoring group [448].…”

Detection of different oxidation states of individual manganese porphyrins during their reaction with oxygen at a solid/liquid interface

“…The majority of these studies use ensemble techniques in solution, such as electrochemistry and absorption, electron paramagnetic resonance and nuclear magnetic resonance spectroscopy. The scanning tunneling microscope (STM) has proven to be a promising tool to study reactions at the molecular level [8][9][10][11][12] , and initial experiments have been reported in which the reactive properties of metal porphyrins were studied on a surface at the single molecule level by STM in ultrahigh vacuum (UHV) [13][14][15][16][17] and under ambient conditions 18,19 .Here we report detailed STM studies of the complex redox chemistry of reactions between 10,15,R,R,porphyrin manganese(III) chloride (Mn1Cl, Fig. 2a) and different oxygen donors at a solid/liquid interface.…”