Building-block synthesis of porphyrin light-harvesting arrays

Prathapan, Sreedharan; Johnson, Thomas E.; Lindsey, Jonathan S.

doi:10.1021/ja00069a068

Cited by 270 publications

(210 citation statements)

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“…Porphyrins tethered to solid surfaces have potential uses in a wide range of applications 1, 2, 3 including light-harvesting arrays, 4,5,6 optical switches and photonic wires. 2,3,7 Supramolecular arrays are of interest with respect to the study of energy transfer and photosynthetic mechanisms 7,8 while two-dimensional porphyrin assemblies have attracted attention for possible application as chemical sensors, in molecular electronics, or as chemically switchable 2D rotors.…”

Section: Introductionmentioning

confidence: 99%

Deprotection, Tethering, and Activation of a One-Legged Metalloporphyrin on a Chemically Active Metal Surface: NEXAFS, Synchrotron XPS, and STM Study of [SAc]P−Mn(III)Cl on Ag(100)

et al. 2009

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The structural and reactive properties of the acetyl-protected "one-legged" manganese porphyrin[SAc]P-Mn(III)Cl on Ag(100) have been studied by NEXAFS, synchrotron XPS and STM.Spontaneous surface-mediated de-protection occurs at 300 K accompanied by spreading of the resulting thio-tethered porphyrin across the metal surface. Loss of the axial chlorine ligand occurs at 498 K, without any de-metallation of the macrocycle, leaving the Mn center in a low co-ordination state. At low coverages the macrocycle is markedly tilted towards the silver surface, as is the phenyl group that forms part of the tethering "leg". In the monolayer region a striking transition occurs whereby the molecule rolls over, preserving the tilt angle of the phenyl group, strongly increasing that of the 2 macrocycle, decreasing the apparent height of the molecule and decreasing its footprint, thus enabling closer packing. These findings are in marked contrast with those previously reported for the corresponding more rigidly bound four-legged porphyrin [JACS 2009[JACS , 126, 1910 suggesting that the physico-chemical properties and potential applications of these versatile systems should be strongly dependent on the mode of tethering to the surface.

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Section: Introductionmentioning

confidence: 99%

Deprotection, Tethering, and Activation of a One-Legged Metalloporphyrin on a Chemically Active Metal Surface: NEXAFS, Synchrotron XPS, and STM Study of [SAc]P−Mn(III)Cl on Ag(100)

et al. 2009

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“…In the context of solar energy, many multiporphyrin light-harvesting designs have been developed ranging from organic polymers, metalorganic frameworks, and supramolecular ensembles. Porphyrins are remarkable precursors for incorporation into supramolecular designs due to their established syntheses that facilitate welldefined functionalization, the commercial availability of simple variants, and their ability to accommodate a wide range of metal ions, thus unlocking suites of complexes for a given design (40,41). The absorption spectra of porphyrin molecules are dominated by so-called Soret bands in the 380-to 500-nm range, accompanied by a set of weaker, but still considerably intense Q bands in the 500-to 700-nm range.…”

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confidence: 99%

Synthesis and photophysical studies of self-assembled multicomponent supramolecular coordination prisms bearing porphyrin faces

Shi

Sánchez‐Molina

Cao

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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Multicomponent self-assembly, wherein two unique donor precursors are combined with a single metal acceptor instead of the more common two-component assembly, can be achieved by selecting Lewis-basic sites and metal nodes that select for heteroligated coordination spheres. Platinum(II) ions show a thermodynamic preference for mixed pyridyl/carboxylate coordination environments and are thus suitable for such designs. The use of three or more unique building blocks increases the structural complexity of supramolecules. Herein, we describe the synthesis and characterization of rectangular prismatic supramolecular coordination complexes (SCCs) with two faces occupied by porphyrin molecules, motivated by the search for new multichromophore complexes with promising light-harvesting properties. These prisms are obtained from the self-assembly of a 90°Pt(II) acceptor with a meso-substituted tetrapyridylporphyrin (TPyP) and dicarboxylate ligands. The generality of this self-assembly reaction is demonstrated using five dicarboxylate ligands, two based on a rigid central phenyl ring and three alkyl-spaced variants, to form a total of five free-base and five Zn-metallated porphyrin prisms. All 10 SCCs are characterized by 31 P and 1 H multinuclear NMR spectroscopy and electrospray ionization mass spectrometry, confirming the structure of each self-assembly and the stoichiometry of formation. The photophysical properties of the resulting SCCs were investigated revealing that the absorption and emission properties of the free-base and metallated porphyrin prisms preserve the spectral features associated with free TPyP. supramolecular chemistry | metallacages T he use of sunlight is ubiquitous as the input for carbonneutral, renewable energy schemes (1). Every strategy that relies on solar energy conversion, ranging from direct conversion to electricity in photovoltaics (2) to the generation of fuels via electrocatalysis (3), photoanode (4, 5), or photocathode devices (6), or photocatalysis (7) requires that photons be absorbed by a molecule or material as the first step in providing the driving force for subsequent transformation. Natural systems have evolved light-harvesting complexes, comprising multiprotein ensembles embedded with pigment molecules to enhance photon absorption for photosynthesis (8). These pigment-rich sites are arranged such that excitation of a distal chromophore will ultimately result in energy transfer to a reaction center via a series of migration and transfer processes (9). Strategies to replicate natural light-harvesting complexes necessarily demand the organization of multiple chromophores (10), a requirement that makes self-assembly and supramolecular chemistry particularly well suited for such efforts (11-13). As such, a variety of approaches have been applied toward the development of new materials that exhibit broadband absorption and efficient energy transfer (14-16). The subsequent studies of such materials span investigations of the fundamental science behind energy migration and transfer, t...

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“…The porphyrins bore peripheral iodo or ethynyl groups and were facially encumbered to suppress aggregation. The free base or metalloporphyrins were then joined via homogeneous Pd: mediated coupling reactions under basic conditions to yield the desired assembly (34). This building block approach would provide an ideal pathway to larger arrays resembling those found in the natural photosynthetic system.…”

Section: Fig 6 Molecular Photonic Wire Porphyrin Light-harvesting Amentioning

confidence: 99%

Metalloporphyrins—Applications and clinical significance

Chandra

Tiwari

Kaur

et al. 2000

Indian J Clin Biochem

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The fascinating structures of naturally occurring porphyrins and metalloporphyrins have been perfected by nature to give functional dyes par excellence. The important roles these tetrapyrrolic macrocycles play in vital biological processes, in particular photosynthesis (chlorophyll), oxygen transport (hemoglobin), oxygen activation (cytochrome), have led to their characterization as 'pigments of life'. Because porphyrins possess extended n-electron systems and exhibit stability, they are finding use, to an increasing extent, in advanced materials, as components in organic metals, molecular wires, and other devices. In medicine, porphyrins are experiencing a renaissance due to the acivent of photodynamic therapy of great promise in the treatment of cancer and dermatological diseases. The interdisciplinary interest porphyrins thus generate has provided the impetus to develop Novel-porphyrin like molecules anticipated to exhibit special properties, by structural variation of the tetrapyrrolic macrocycle, while maintaining a (4n+2)~ main conjugation pathway.In addition to their esoteric application in science, porphyrins have been shown to have profound implications for therapeutic purposes. Their photosensitizing properties have led to their utilization in photodynamic therapy. Certain metalloporphyrins such as SnPP are being tested as drugs for the treatment of neonatal jaundice. Metailoporphyrins are serving as SOD mimetics to combat oxidative stress and a range of metalloporphyrin complexes have been proposed as contrast agents for magnetic resonance imaging

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Building-block synthesis of porphyrin light-harvesting arrays

Cited by 270 publications

References 0 publications

Deprotection, Tethering, and Activation of a One-Legged Metalloporphyrin on a Chemically Active Metal Surface: NEXAFS, Synchrotron XPS, and STM Study of [SAc]P−Mn(III)Cl on Ag(100)

Deprotection, Tethering, and Activation of a One-Legged Metalloporphyrin on a Chemically Active Metal Surface: NEXAFS, Synchrotron XPS, and STM Study of [SAc]P−Mn(III)Cl on Ag(100)

Synthesis and photophysical studies of self-assembled multicomponent supramolecular coordination prisms bearing porphyrin faces

Metalloporphyrins—Applications and clinical significance

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