Exploring the Limits of Dative Boratrane Bonding: Iron as a Strong Lewis Base in Low-Valent Non-Heme Iron-Nitrosyl Complexes

Dong, Hai T.; Chalkley, Matthew J.; Oyala, Paul H.; Zhao, Jiyong; Ercan, E.; Hu, Michael Y.; Peters, Jonas C.; Lehnert, Nicolai

doi:10.1021/acs.inorgchem.0c01686

Cited by 11 publications

(18 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the ls-{FeNO} 8 and ls-{FeNO} 10 complexes are diamagnetic, the ls-{FeNO} 9 complex is paramagnetic with a total spin of S t = 1/2. Vibrational spectroscopy (IR and NRVS) further showed that these complexes have strong Fe–NO bonds, with Fe–NO and N–O stretching frequencies of 610/583/602 cm –1 and 1745/1667/1568 cm –1 , respectively, along the ls-{FeNO} 8–10 series . Interestingly, a QCC-NCA analysis of the NRVS data revealed force constants for the Fe–B bond of 0.51/0.42/1.56 mdyn/Å for the ls-{FeNO} 8–10 series.…”

Section: Non-heme Iron Centers and Nomentioning

confidence: 99%

“…This result suggests that a Fe–B single bond is formed in the ls-{FeNO} 10 complex, where iron now takes on the role of the Lewis base and donates an electron pair in the d z 2 orbital to the boron Lewis acid. In this sense, the [Fe(TPB)] platform can store two electrons in the Fe–B bond upon reduction of the iron center to the formally Fe(-II) oxidation state, and these electrons can then be utilized for small molecule activation, for example in N 2 activation. ,,, Even though boron is not used in this regard in biology, other Lewis acids can potentially act in such a way to stabilize reactive intermediates of NO chemistry and of other small-molecule activation processes.…”

Section: Non-heme Iron Centers and Nomentioning

confidence: 99%

“…More recently, a unique series of highly reduced ls-{FeNO} 8−10 complexes was reported by Peters and coworkers, making use of their tris(phosphine)borane coligand (see Figure , top) . Here, the presence of the boratrane group helps to stabilize the highly reduced nitrosyl complexes . In addition, Meyer and coworkers used a tripodal triscarbene ligand scaffold to create a series of {FeNO} 6−9 complexes (see Figure , bottom) .…”

Section: Introductionmentioning

confidence: 95%

“…Spin states and N–O stretching frequencies [cm –1 ] of the ls-{FeNO} 8−10 series with the TPB coligand (top) and the hs-{FeNO} 8−10 series with TIMEN MES (bottom) . Adapted with permission from ref . Copyright 2020 American Chemical Society.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The Biologically Relevant Coordination Chemistry of Iron and Nitric Oxide: Electronic Structure and Reactivity

et al. 2021

Self Cite

View full text Add to dashboard Cite

Nitric oxide (NO) is an important signaling molecule that is involved in a wide range of physiological and pathological events in biology. Metal coordination chemistry, especially with iron, is at the heart of many biological transformations involving NO. A series of heme proteins, nitric oxide synthases (NOS), soluble guanylate cyclase (sGC), and nitrophorins, are responsible for the biosynthesis, sensing, and transport of NO. Alternatively, NO can be generated from nitrite by heme- and copper-containing nitrite reductases (NIRs). The NO-bearing small molecules such as nitrosothiols and dinitrosyl iron complexes (DNICs) can serve as an alternative vehicle for NO storage and transport. Once NO is formed, the rich reaction chemistry of NO leads to a wide variety of biological activities including reduction of NO by heme or non-heme iron-containing NO reductases and protein post-translational modifications by DNICs. Much of our understanding of the reactivity of metal sites in biology with NO and the mechanisms of these transformations has come from the elucidation of the geometric and electronic structures and chemical reactivity of synthetic model systems, in synergy with biochemical and biophysical studies on the relevant proteins themselves. This review focuses on recent advancements from studies on proteins and model complexes that not only have improved our understanding of the biological roles of NO but also have provided foundations for biomedical research and for bio-inspired catalyst design in energy science.

show abstract

Section: Non-heme Iron Centers and Nomentioning

confidence: 99%

Section: Non-heme Iron Centers and Nomentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Biologically Relevant Coordination Chemistry of Iron and Nitric Oxide: Electronic Structure and Reactivity

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The bonding and electronic structures of P 3 B Fe–N 2 [0/1−] and (AltraPhos)Fe–N 2 [0/1−] have previously been elucidated through spectroscopic and computational methods. ,− In short, the bonding in these complexes is best described as involving an Fe → X(III) dative interaction where the apical Lewis acidic atom serves to lower the energy of the σ(Fe–X) orbital of Fe d z 2 and X p z parentage below that of the d xy , x 2 – y 2 set in a typical trigonal bipyramidal orbital scheme. Therefore, reduction of 3 to 4a / 5a and 6 to 7 is primarily Fe centered, giving rise to formally Fe(−I) species with electronic configurations (d xz , yz ) 4 (σ(Fe–X)) 2 (d xy , x 2 – y 2 ) 3 and a substantial Fe-to-X backbond …”

Section: Resultsmentioning

confidence: 63%

Tripodal P₃^XFe–N₂ Complexes (X = B, Al, Ga): Effect of the Apical Atom on Bonding, Electronic Structure, and Catalytic N₂-to-NH₃ Conversion

Fajardo

Peters

2021

Inorg. Chem.

Self Cite

View full text Add to dashboard Cite

Terminal dinitrogen complexes of iron ligated by tripodal, tetradentate P 3 X ligands (X = B, C, Si)have previously been shown to mediate catalytic N 2 -to-NH 3 conversion (N 2 RR) with external proton and electron sources. From this set of compounds, the tris(phosphino)borane (P 3 B ) system is most active under all conditions canvassed thus far. To further probe the effects of the apical Lewis acidic atom on structure, bonding, and N 2 RR activity, Fe-N 2 complexes supported by analogous group 13 tris(phosphino)alane (P 3 Al ) and tris(phosphino)gallane (P 3 Ga ) ligands are synthesized. The series of P 3 X Fe-N 2 [0/1−] compounds (X = B, Al, Ga) possess similar electronic structures, degrees of N 2 activation, and geometric flexibility as determined from spectroscopic, structural, electrochemical, and computational (DFT) studies. However, treatment of [Na(12crown-4) 2 ][P 3 X Fe-N 2 ] (X = Al, Ga) with excess acid/reductant in the form of HBAr F 4 /KC 8 generates only 2.5 ± 0.1 and 2.7 ± 0.2 equiv of NH 3 per Fe, respectively. Similarly, the use of [H 2 NPh 2 ][OTf]/Cp* 2 Co leads to the production of 4.1 ± 0.9 (X = Al) and 3.6 ± 0.3 (X = Ga) equiv of NH 3 . Preliminary reactivity studies confirming P 3 X Fe framework stability under pseudocatalytic conditions suggest that a greater selectivity for hydrogen evolution versus N 2 RR may be responsible for the attenuated yields of NH 3 observed for P 3 Al Fe and P 3 Ga Fe relative to P 3 B Fe.

show abstract

Well‐defined Nickel P₃C Complexes as Hydrogenation Catalysts of N‐Heteroarenes Under Mild Conditions

et al. 2022

View full text Add to dashboard Cite

The reactivity of metal complexes can be primarily controlled by their coordinating ligands. Electronic effects and geometric restrictions imposed by ligands, prototypically modify their reactivity, but are not always straightforward accessible. In the course of the study, we explored new C3‐symmetric organometallic nickel (II) complexes ((P3C)Ni)) with the particularity of having a metalated apical carbon trans to a labile coordination site readily available as a catalytic site. The synthetic methodology allowed to tune the electronic properties by introducing substituents on the phosphines. We studied the nature of the C−Ni bond by X‐ray absorption spectroscopy (XAS) and DFT and applied them to the catalytic hydrogenation of quinolines with a good chemical scope and group tolerance. 1H‐NMR monitoring, isotopic labelling, and computational studies are consistent with a heterolytic activation of the dihydrogen molecule after forming a σ‐H2 adduct trans to the metalated carbon.

show abstract

Exploring the Limits of Dative Boratrane Bonding: Iron as a Strong Lewis Base in Low-Valent Non-Heme Iron-Nitrosyl Complexes

Cited by 11 publications

References 89 publications

The Biologically Relevant Coordination Chemistry of Iron and Nitric Oxide: Electronic Structure and Reactivity

The Biologically Relevant Coordination Chemistry of Iron and Nitric Oxide: Electronic Structure and Reactivity

Tripodal P₃^XFe–N₂ Complexes (X = B, Al, Ga): Effect of the Apical Atom on Bonding, Electronic Structure, and Catalytic N₂-to-NH₃ Conversion

Well‐defined Nickel P₃C Complexes as Hydrogenation Catalysts of N‐Heteroarenes Under Mild Conditions

Contact Info

Product

Resources

About

Exploring the Limits of Dative Boratrane Bonding: Iron as a Strong Lewis Base in Low-Valent Non-Heme Iron-Nitrosyl Complexes

Cited by 11 publications

References 89 publications

The Biologically Relevant Coordination Chemistry of Iron and Nitric Oxide: Electronic Structure and Reactivity

The Biologically Relevant Coordination Chemistry of Iron and Nitric Oxide: Electronic Structure and Reactivity

Tripodal P3XFe–N2 Complexes (X = B, Al, Ga): Effect of the Apical Atom on Bonding, Electronic Structure, and Catalytic N2-to-NH3 Conversion

Well‐defined Nickel P3C Complexes as Hydrogenation Catalysts of N‐Heteroarenes Under Mild Conditions

Contact Info

Product

Resources

About

Tripodal P₃^XFe–N₂ Complexes (X = B, Al, Ga): Effect of the Apical Atom on Bonding, Electronic Structure, and Catalytic N₂-to-NH₃ Conversion

Well‐defined Nickel P₃C Complexes as Hydrogenation Catalysts of N‐Heteroarenes Under Mild Conditions