Hydrogen Bonds Dictate the Coordination Geometry of Copper: Characterization of a Square‐Planar Copper(I) Complex

Dahl, Eric W.; Szymczak, Nathaniel K.

doi:10.1002/ange.201511527

Cited by 24 publications

(19 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, Cu I centers favor a tetrahedral coordination geometry. 64 This difference in preferred coordination geometry for the +I and +II oxidation states of copper can result in large reorganization barriers during electron transfer. As indicated by the crystal structure of Cu - terpy ( Figure S3 ) and the EPR data of Cu - bmpa (see Section 3 in the Supporting Information ), the Cu II state of these complexes adopts an octahedral geometry and an elongated octahedral, square pyramidal, or square planar geometry, respectively.…”

Section: Resultsmentioning

confidence: 99%

Influence of Ligand Denticity and Flexibility on the Molecular Copper Mediated Oxygen Reduction Reaction

et al. 2020

View full text Add to dashboard Cite

To date, the copper complex with the tris(2-pyridylmethyl)amine ( tmpa ) ligand ( Cu - tmpa ) catalyzes the ORR with the highest reported turnover frequency (TOF) for any molecular copper catalyst. To gain insight into the importance of the tetradentate nature and high flexibility of the tmpa ligand for efficient four-electron ORR catalysis, the redox and electrocatalytic ORR behavior of the copper complexes of 2,2′:6′,2″-terpyridine ( terpy ) and bis(2-pyridylmethyl)amine ( bmpa ) ( Cu - terpy and Cu - bmpa , respectively) were investigated in the present study. With a combination of cyclic voltammetry and rotating ring disk electrode measurements, we demonstrate that the presence of the terpy and bmpa ligands results in a decrease in catalytic ORR activity and an increase in Faradaic efficiency for H 2 O 2 production. The lower catalytic activity is shown to be the result of a stabilization of the Cu I state of the complex compared to the earlier reported Cu - tmpa catalyst. This stabilization is most likely caused by the lower electron donating character of the tridentate terpy and bmpa ligands compared to the tetradentate tmpa ligand. The Laviron plots of the redox behavior of Cu - terpy and Cu - bmpa indicated that the formation of the ORR active catalyst involves relatively slow electron transfer kinetics which is caused by the inability of Cu - terpy and Cu - bmpa to form the preferred tetrahedral coordination geometry for a Cu I complex easily. Our study illustrates that both the tetradentate nature of the tmpa ligand and the ability of Cu - tmpa to form the preferred tetrahedral coordination geometry for a Cu I complex are of utmost importance for ORR catalysis with very high catalytic rates.

show abstract

Section: Resultsmentioning

confidence: 99%

Influence of Ligand Denticity and Flexibility on the Molecular Copper Mediated Oxygen Reduction Reaction

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Very recently, Policar et al developed a sugar-based ligand, which provides a strong preorganisation for Cu(II) coordination in a trigonal bipyramid, but with an unusual stabilisation of its Cu(I) redox state 28 . Szymczak et al synthesised a constrained Cu(I) complex, which is very close to a square-planar coordination 29 . Recently, we reported a series of bis(chelate) Cu(I) and Cu(II) guanidine-quinoline complex cations [Cu II (TMGqu) 2 ] + and [Cu I (TMGqu) 2 ] 2+ (see Figure 1b for overlay of both cations 10 ).…”

Section: Manuscriptmentioning

confidence: 99%

Transferring the entatic-state principle to copper photochemistry

et al. 2018

View full text Add to dashboard Cite

The entatic state denotes a distorted coordination geometry of a complex from its typical arrangement that generates an improvement to its function. The entatic-state principle has been observed to apply to copper electron-transfer proteins and it results in a lowering of the reorganization energy of the electron-transfer process. It is thus crucial for a multitude of biochemical processes, but its importance to photoactive complexes is unexplored. Here we study a copper complex-with a specifically designed constraining ligand geometry-that exhibits metal-to-ligand charge-transfer state lifetimes that are very short. The guanidine-quinoline ligand used here acts on the bis(chelated) copper(I) centre, allowing only small structural changes after photoexcitation that result in very fast structural dynamics. The data were collected using a multimethod approach that featured time-resolved ultraviolet-visible, infrared and X-ray absorption and optical emission spectroscopy. Through supporting density functional calculations, we deliver a detailed picture of the structural dynamics in the picosecond-to-nanosecond time range.

show abstract

“…The precipitates were filtered and washed with cold methanol-water mixture (1:10). Finally, the product was recrystallized from methanol [33].…”

Section: Synthesis Of (2ementioning

confidence: 99%

“…In this work we explored approach (b) by using bulky monodentate ligands derived from chalcones of 4'-(imidazol-1-yl)acetophenone containing peripheral groups allowing formation of non-covalent interactions such as hydrogen or halogen bonding [29,30]. Such interactions can either induce or stabilize distortions of molecular shapes [31] or coordination polyhedrons [32,33]. Here, we report on the first results obtained using the above-mentioned approach.…”

Section: Synthesis and Basic Characterizationsmentioning

confidence: 99%

Halogen Bonding in New Dichloride-Cobalt(II) Complex with Iodo Substituted Chalcone Ligands

et al. 2020

View full text Add to dashboard Cite

The synthesis and properties of new chalcone ligand 4I-L ((2E)-1-[4-(1H-imidazol-1-yl)phenyl]-3-(4-iodophenyl)prop-2-en-1-one) and tetracoordinate Co(II) complex [Co(4I-L)2Cl2], (1a), are reported in this article. Upon recrystallization of 1a, the single crystals of [Co(4I-L)4Cl2]·2DMF·3Et2O (1b) were obtained and crystal structure was determined using X-ray diffraction. The non-covalent interactions in 1b were thoroughly analyzed and special attention was dedicated to interactions formed by the peripheral iodine substituents. The density functional theory (DFT), atoms in molecule (AIM) and noncovalent interaction (NCI) methods and electronic localization function (ELF) calculations were used to investigate halogen bond formed between the iodine functional groups and co-crystallized molecules of diethyl ether.

show abstract

Hydrogen Bonds Dictate the Coordination Geometry of Copper: Characterization of a Square‐Planar Copper(I) Complex

Cited by 24 publications

References 71 publications

Influence of Ligand Denticity and Flexibility on the Molecular Copper Mediated Oxygen Reduction Reaction

Influence of Ligand Denticity and Flexibility on the Molecular Copper Mediated Oxygen Reduction Reaction

Transferring the entatic-state principle to copper photochemistry

Halogen Bonding in New Dichloride-Cobalt(II) Complex with Iodo Substituted Chalcone Ligands

Contact Info

Product

Resources

About