Iron(III) Complexes with Cross‐Bridged Cyclams: Synthesis and Use in Alcohol and Water Oxidation Catalysis

Annunziata, Alfonso; Esposito, Roberto; Gatto, Giordano; Cucciolito, Maria Elena; Tuzi, Angela; Macchioni, Alceo; Ruffo, Francesco

doi:10.1002/ejic.201800451

Cited by 45 publications

(33 citation statements)

References 57 publications

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“…Based on molecule 12,t he development of macrocyclic ligand based WOCs hasb ecomea na ttractive topic ( Figure 7). Af amilyo fs tructural analogues (27)(28)(29)(30)(31)o fc omplex 8,w ith variouse lectron-donating or -withdrawing substituents in the ortho and para positions of the pyridine ligand, were synthesized by Costas et al in 2013t oe valuate the electronic effects on single-site iron catalysts for water oxidation. [27] With modification on the ortho position of the pyridine moiety,c omplex 30 showeda ctivity with aT ON of only 25 AE 3a nd aT OF of 80 AE 1h À1 ;t hese values are much lower than those of the mother complex 12,a nd complex 31 displayed no activityf or water oxidation.…”

Section: Is Water Oxidation Catalysis With Nonheme Iron Complexes Undmentioning

confidence: 99%

“…[30] Ruffo et al also reported ac lass of iron complexes (35-39)c ontaining crossbridged cyclam ligandsw ith diverse substituents for NaIO 4driven water oxidation. [31] Thep resence of at least one methyl substituent is necessary to have reasonable activity:w ith two methyl groups (35)t he highest TOF is observed, while one methyl ando ne ethyl (36)p roduce the highest TON. In the last case, the best compromiseb etween accessibility to the metal centera nd its steric protection is obtained.…”

Section: Is Water Oxidation Catalysis With Nonheme Iron Complexes Undmentioning

confidence: 99%

“…Asian J. 2019,14,[31][32][33][34][35][36][37][38][39][40][41][42][43] www.chemasianj.org reported as WOCs. For example, Thummel and co-workersr eported a m-oxo-bridgedd inuclear complex (53), with a 2-(pyrid-2'-yl)-8-(1'',10''-phenanthrolin-2''-yl)quinoline (ppq) ligand,a nd am ononuclear counterpart( 52), with ab is-phenanthroline amine (dpa) ligand,s haring similars quare-planar arrangement of the quaterpyridine-like backbone (Figure 11).…”

Section: Othersmentioning

confidence: 99%

“…TON TOF Cat. TON TOF 1 [9,21] -0.081 [a] 35 [30,31] 1030 [c] 101 AE10 [c] 0.028 0.025 2 [9] 2.5 [b] -36 [31] 111 AE10 [c] 0.023 3 [9] 5.8 [b] -37 [31] 16 AE 2 [c] 0.0005 4 [9] 7.5 [b] -38 [31] 81 AE 8 [c] 0.013 5 [9] 17 [b] < 6 [c] > 1.3 -40 [28] < 10 [b] < 0.01 6 [18] 220 AE 10 [d] 0.76 41 [33] 14 [b] 0.18 11 [18] 60 AE 4 [d] 0.21 42 [33] < 2 [b] 0.002 12 [11] 82 AE 8 [b] 0.062 43 [34] 3.9 [b] 0.163 13 [11,25] 360 AE 20 [b] > 1050 [c] 194 [d] 0.233 0.062 -49 [36] < 1 [b] 0.08 14 [11] 320 AE 15 [b] 0.143 50 [37] 2380 [f] 2.2 15 [11] 63 AE 7 [b] 0.046 51 [38] --16 [11] 145 AE 5 [b] 0.14 52 [12] 220 [b] 0.023 17 [11] 40 AE 4 [...…”

Section: Catmentioning

confidence: 99%

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Iron‐Based Molecular Water Oxidation Catalysts: Abundant, Cheap, and Promising

Liu

Zhang

Sun

2018

Chemistry An Asian Journal

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An efficient and robustw ater oxidation catalyst based on abundant and cheap materials is the key to converting solar energy into fuels through artificial photosynthesis for the future of humans. The development of molecular water oxidation catalysts (MWOCs) is as mart way to achieve promising catalytic activity,t hanks to the clear structures and catalytic mechanisms of molecular catalysts. Effi-cient MWOCs based on noble-metalc omplexes, for example, ruthenium and iridium,h ave been well developed over the last 30 years;h owever, the developmento fe arth-abundant metal-based MWOCs is very limited and still challenging. Herein,t he promising prospecto fi ron-based MWOCs is highlighted, with ac omprehensive summary of previously reporteds tudiesa nd future research focus in this area. Iron-Based MWOC with TAMLsBy employing tetraamido macrocyclic ligands (TAMLs), which are composed of at ypical framework to hold high-valent metal ions, [16] Bernharde tal.,i n2 010, reported the first series [a] T.

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Section: Is Water Oxidation Catalysis With Nonheme Iron Complexes Undmentioning

confidence: 99%

Section: Is Water Oxidation Catalysis With Nonheme Iron Complexes Undmentioning

confidence: 99%

Section: Othersmentioning

confidence: 99%

Section: Catmentioning

confidence: 99%

See 2 more Smart Citations

Iron‐Based Molecular Water Oxidation Catalysts: Abundant, Cheap, and Promising

Liu

Zhang

Sun

2018

Chemistry An Asian Journal

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“…We now have focused our attention on diiron compounds. Iron offers access to a wider range of oxidation states, and Fe‐PDI and ‐cyclam complexes are uniquely suited for a variety of redox and organometallic reactions, including several of the aforementioned biologically relevant reactions . We envisioned that the combined scope of reactions facilitated by the two types of Fe compounds might give rise to unique activities.…”

Section: Introductionmentioning

confidence: 99%

Structural Differences and Redox Properties of Unsymmetric Diiron PDIxCy Complexes

2020

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We present two bimetallic iron complexes, [Fe 2 (PDIeCy)(OTf ) 4 ] (1) and [Fe 2 (PDIpCy)(THF)(OTf ) 4 ] (2) coordinated by an unsymmetric ligand. The new ligand, PDIeCy (PDI = pyridyldiimine; e = ethyl; Cy = cyclam), is a variant of the previously reported PDIpCy (p = propyl) ligand, featuring a shorter linker between the two metal coordination sites. The structural and electronic properties of 1 and 2, both in the solid and solution state, were analyzed by means of X-ray crystallography, and spectroscopic methods, including 19 F-NMR. The two ligand platforms yield markedly different diiron structures: the PDIeCy ligand permits formation of a bridged, μ-OTf complex, while the [a] 499 two iron centers of the PDIpCy-based 2 remain unconnected, directly, under all conditions examined. Both compounds contain electronically non-coupled high-spin (S = 2) ferrous centers, as established by Mössbauer spectroscopy and magnetic susceptibility studies. Cyclic voltammetry demonstrates the rich redox chemistry of the compounds, involving both ligand and metal-centered redox processes. Moreover, we synthesized the two-electron reduced [Fe 2 (PDIeCy)] 2+ form of 1, which contains the dianionic PDI 2ligand, and represents a two-electron charge localized complex.group, to support dinuclear complexes thereof (Scheme 1). [29] We reported the synthesis of non-coupled homo-and heterobimetallic Ni-and Zn-containing PDIpCy complexes. We now have focused our attention on diiron compounds. Iron offers Scheme 1. Synthesis of 1 and 2.

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Homogeneous Molecular Iron Catalysts for Direct Photocatalytic Conversion of Formic Acid to Syngas (CO+H₂)

2020

Angewandte Chemie

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The catalytic decomposition of formic acid to generate syngas (a mixture of H2 and CO) is a highly valuable strategy for energy conversion. Syngas can be used directly in internal combustion engines or can be converted to liquid fuels, meeting future energy challenges in a sustainable manner. Herein, we report the use of homogeneous molecular iron catalysts combined with a CdS nanorods (NRs) semiconductor to construct a highly efficient photocatalytic system for direct conversion of formic acid to syngas at room temperature and atmospheric pressure. Under optimal conditions, the photocatalytic system presents an activity of 150 mmol gcatalyst−1 h−1 towards H2, and an apparent quantum yield (AQY) of 16.8 %, making it among the most active noble‐metal‐free photocatalytic systems for H2 evolution from formic acid under visible light. Meanwhile, these iron‐based molecular catalysts also demonstrate remarkable enhancement in CO evolution with robust stability. The mechanistic role of the molecular catalyst is further investigated by using cyclic voltammetry, which suggests the formation of FeI species as the key step in the catalytic conversion of formic acid to syngas.

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Iron(III) Complexes with Cross‐Bridged Cyclams: Synthesis and Use in Alcohol and Water Oxidation Catalysis

Cited by 45 publications

References 57 publications

Iron‐Based Molecular Water Oxidation Catalysts: Abundant, Cheap, and Promising

Iron‐Based Molecular Water Oxidation Catalysts: Abundant, Cheap, and Promising

Structural Differences and Redox Properties of Unsymmetric Diiron PDIxCy Complexes

Homogeneous Molecular Iron Catalysts for Direct Photocatalytic Conversion of Formic Acid to Syngas (CO+H₂)

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Iron(III) Complexes with Cross‐Bridged Cyclams: Synthesis and Use in Alcohol and Water Oxidation Catalysis

Cited by 45 publications

References 57 publications

Iron‐Based Molecular Water Oxidation Catalysts: Abundant, Cheap, and Promising

Iron‐Based Molecular Water Oxidation Catalysts: Abundant, Cheap, and Promising

Structural Differences and Redox Properties of Unsymmetric Diiron PDIxCy Complexes

Homogeneous Molecular Iron Catalysts for Direct Photocatalytic Conversion of Formic Acid to Syngas (CO+H2)

Contact Info

Product

Resources

About

Homogeneous Molecular Iron Catalysts for Direct Photocatalytic Conversion of Formic Acid to Syngas (CO+H₂)