scholarly journals Combining Metal-Metal Cooperativity, Metal-Ligand Cooperativity and Chemical Non-Innocence in Diiron Carbonyl Complexes

2021 ◽  
Author(s):  
Cody Bernard Beek ◽  
Nicolaas P. van Leest ◽  
Martin Lutz ◽  
Robertus J. M. Klein Gebbink ◽  
Bas de Bruin ◽  
...  
Keyword(s):  
Bond Activation ◽  
Binding Mode ◽  
Carbonyl Complexes ◽  
Bimetallic Systems ◽  
Metal Atoms ◽  
Metal Metal ◽  
Close Proximity ◽  
Catalytic Reactivity ◽  
Unstable Intermediate ◽  
Metal Ligand

Several metalloenzymes, including [FeFe]-hydrogenase, employ cofactors wherein multiple metal atoms work together with surrounding ligands that mediate heterolytic and concerted proton-electron transfer (CPET) bond activation steps. Herein, we report a new dinucleating PNNP expanded pincer ligand, which can bind two low-valent iron atoms in close proximity to enable metal-metal cooperativity (MMC). In addition, reversible partial dearomatization of the ligand’s naphthyridine core enables both heterolytic metal-ligand cooperativity (MLC) and chemical non-innocence through CPET steps. Thermochemical and computational studies show how a change in ligand binding mode can lower the bond dissociation free energy of ligand C(sp3)–H bonds by ~25 kcal mol-1. H-atom abstraction enabled trapping of an unstable intermediate, which undergoes facile loss of two carbonyl ligands to form an unusual paramagnetic (S = 1/2) complex containing a mixed-valent iron(0)-iron(I) core bound within a partially dearomatized PNNP ligand. Finally, cyclic voltammetry experiments showed that these diiron complexes show catalytic activity for the electrochemical hydrogen evolution reaction. This work presents the first example of a ligand system that enables MMC, heterolytic MLC and chemical non-innocence, thereby providing important insights and opportunities for the development of bimetallic systems that exploit these features to enable new (catalytic) reactivity.

scholarly journals Metal–Metal and Metal–Ligand Bonding in Trinuclear Vinylidene Rhenium-Iron-Platinum Complex Studied by Topological Analysis of Electron Density

2020 ◽  
pp. 553-564
Author(s):  
Aleksey M. Shor ◽  
Svetlana S. Laletina ◽  
Anatoly I. Rubaylo ◽  
Elena A. Ivanova-Shor
Keyword(s):  
Electron Density ◽  
Density Functional ◽  
Topological Analysis ◽  
Density Functional Method ◽  
Platinum Complex ◽  
Functional Method ◽  
Iron Platinum ◽  
Metal Atoms ◽  
Metal Metal ◽  
Metal Ligand

Metal–metal and metal–ligand bonding in vinylidene ReFePt complex was studied by density functional method and topological analysis of electron density. Topological analysis did not found direct bonding between the metal atoms pointing to indirect metal–metal interaction mediated via the bridging vinylidene ligand. At the same time, the delocalization index δ(Fe,Pt) reveals the strong Fe–Pt interaction that allows for supposing a chemical bonding between these atoms

Structural aspects of heterotrinuclear Pt2M, PtM2, and PtMM′ complexes – distortion isomers

2018 ◽  
Vol 38 (4) ◽  
pp. 151-162 ◽  
Author(s):  
Milan Melnik ◽  
Peter Mikus ◽  
Andrea Forgacsova ◽  
Maria Bodnar Mikulova
Keyword(s):  
Structural Parameters ◽  
Bond Angles ◽  
Metal Atoms ◽  
Metal Metal ◽  
Coordination Spheres ◽  
Independent Molecules ◽  
Structural Aspects ◽  
Metal Ligand ◽  
Ligand Bond

AbstractIn this review, the structural parameters of 18 heterotrinuclear Pt2M (M=Hg, Zn, Cd, Au, Mn, Ag, Pd), PtM2 (M=Al, Ga, Sb, In, Mo, Fe), PtFeMn, PtHgMn, and PtFeOs types are summarized and analyzed. The Pt atoms are four-, five-, and even six-coordinated, among which the four-coordinated ones are the most common. The M atoms are found to be two- (Hg), three- (Hg), four- (Hg, Sb, In, Ag, Au), and six- (Ga, In, Al, Mo, Mn, Fe, Pd) coordinated and even sandwiched (FeC10). There is a wide variety of donor atoms (ligands) (O+NL, N+CL, NL, CO, CN, CL, Cl, SL, PL, I), which build up the respective inner coordination spheres about the metal atoms. The 17 complexes contain two crystallographically independent molecules within the same crystal, and 1 complex contains four such molecules. In each complex, the respective molecules are differing mostly by the degree of distortion in metal-metal and metal-ligand bond distances and ligand-metal-ligand bond angles, and are examples of distortion isomerism.

Catalytic Reactions by Heterobimetallic Carbonyl Complexes with Polar Metal-Metal Interactions

Synthesis ◽  
2020 ◽  
Author(s):  
Hsien-Cheng Yu ◽  
Neal P Mankad
Keyword(s):  
Precious Metal ◽  
Bond Activation ◽  
Alternative Pathway ◽  
Metal Catalysts ◽  
Catalytic Reactions ◽  
Carbonyl Complexes ◽  
Metal Interactions ◽  
Recent Advances ◽  
Precious Metal Catalysts ◽  
Metal Metal

Heterobinuclear catalysts capable of bimetallic cooperative bond activation provide an alternative pathway to approach discovery of novel and unique reactivity and selectivity in catalytic transformations, complementing more traditional mononuclear precious metal catalysts. This review summarizes recent advances in homogenous catalysis using heterobimetallic carbonyl catalysts with polar metal-metal interactions.

Metal-Metal Cooperative Bond Activation by Heterobimetallic Alkyl, Aryl, and Acetylide PtII/CuI Complexes

2020 ◽  
Author(s):  
Shubham Deolka ◽  
Orestes Rivada Wheelaghan ◽  
Sandra Aristizábal ◽  
Robert Fayzullin ◽  
Shrinwantu Pal ◽  
...  
Keyword(s):  
Alkyl Group ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Terminal Alkyne ◽  
Alkyl Aryl ◽  
Metal Metal ◽  
The Stability ◽  
Selective Formation ◽  
Organoplatinum Compounds

We report selective formation of heterobimetallic PtII/CuI complexes that demonstrate how facile bond activation processes can be achieved by altering reactivity of common organoplatinum compounds through their interaction with another metal center. The interaction of the Cu center with Pt center and with a Pt-bound alkyl group increases the stability of PtMe2 towards undesired rollover cyclometalation. The presence of the CuI center also enables facile transmetalation from electron-deficient tetraarylborate [B(ArF)4]- anion and mild C-H bond cleavage of a terminal alkyne, which was not observed in the absence of an electrophilic Cu center. The DFT study indicates that the role of Cu center acts as a binding site for alkyne substrate, while activating its terminal C-H bond.

scholarly journals Solvent Controlled Colorimetric And Fluorometric Detection of Fe2+ and Cu2+ Ions By Naphthaldimine-Glucofuranose Conjugate

2021 ◽  
Author(s):  
Mini Loya ◽  
Bholanath Dolai ◽  
Ananta Kumar Atta
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Binding Mode ◽  
Fluorometric Detection ◽  
Nmr Titration ◽  
Fluorescence Studies ◽  
Color Changes ◽  
H Nmr ◽  
Absorption And Emission Spectroscopy ◽  
Absorbance Data ◽  
Metal Ligand

Abstract The sensing properties of naphthaldimine-glucofuranose conjugates 1 and 2 towards metal ions were investigated by 1H NMR titration, FTIR, absorbance, and fluorescence spectroscopic methods. The absorbance and fluorescence studies indicated that compound 1 formed coordination with Fe2+ and Cu2+ ions in DMSO through color changes yellow to brown and colorless, respectively. The Job's plots using absorbance data showed metal-ligand binding ratio is 1:1 for both cases. The formation of 1-Fe2+ and 1-Cu2+ complexes have been analyzed by absorption and emission spectroscopy, high-resolution mass spectrometry (HRMS) data, FTIR, 1H NMR titration experiment, and DFT calculations. The detection limits of naphthaldimine sugar conjugate 1 towards Fe2+/Cu2+ were calculated from UV-vis and fluorescence data according to the standard method. The sugar-naphthaldimine conjugate 2 has been used to establish the binding mode of 1 with Fe2+ or Cu2+ ions in DMSO.

scholarly journals Confining the spin between two metal atoms within the carbon cage: redox-active metal–metal bonds in dimetallofullerenes and their stable cation radicals

Nanoscale ◽  
2017 ◽  
Vol 9 (23) ◽  
pp. 7977-7990 ◽  
Author(s):  
Nataliya A. Samoylova ◽  
Stanislav M. Avdoshenko ◽  
Denis S. Krylov ◽  
Hannah R. Thompson ◽  
Amelia C. Kirkhorn ◽  
...  
Keyword(s):  
Carbon Cage ◽  
Cation Radicals ◽  
Metal Atoms ◽  
Redox Active ◽  
Active Metal ◽  
Metal Metal ◽  
Metal Metal Bonds ◽  
Metal Bonds ◽  
Redox Active Metal

Characterizations of Novel Binuclear Transition Metal Polynitrogen Compounds: M2(N5)4 (M=Co, Rh and Ir)

2014 ◽  
Vol 924 ◽  
pp. 233-252 ◽  
Author(s):  
Li Hong Tang ◽  
Hui Bin Guo ◽  
Qian Shu Li ◽  
Jin Hui Peng ◽  
Jun Jie Gu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Nbo Analysis ◽  
High Order ◽  
Multiple Bonds ◽  
Dissociation Energies ◽  
Nucleus Independent Chemical Shift ◽  
Metal Atoms ◽  
Metal Metal ◽  
Natural Bonding Orbital ◽  
Polynitrogen Compounds

Theoretical studies on a series of binuclear transition metal pentazolides M2(N5)4(M=Co, Rh and Ir) predict Paddlewheel-type structures with very short metal-metal distances suggesting high-order metal-metal multiple bonds. Natural Bonding Orbital (NBO) analysis have indicated that the bonding between the metal atom and the five-membered ring is predominantly ionic for each M2(N5)4species, and a high-order metal-metal multiple bonding exists between the two metal atoms, in addition, the presence of the delocalized π orbital plays an important role in the stabilization of this metal-polynitrogen species. Nucleus independent chemical shift (NICS) values confirm that the planar N5exhibits aromaticity in these M2(N5)4species. The values of NICS(0.0), NICS(0.5) and NICS(1.0) for Co2(N5)4are larger than those of the other two M2(N5)4species (M=Rh and Ir), with the order of Co2(N5)4>Rh2(N5)4>Ir2(N5)4. The dissociation energies into Mononuclear Fragments for M2(N5)4(M=Co, Rh and Ir) are predicted to be 82.9 (85.7), 139.9 (113.2), and 155.1 (149.7) kcal/mol, respectively. However, the dissociation energies for the loss of one pentazolato group from the M2(N5)4analysis have indicated that the Co2(N5)4is relatively higher at ~40 kcal/mol. Thermochemistry suggests Co2(N5)4to be a viable species.

Novel routes to heteronuclear metal clusters containing rhodium

1982 ◽  
Vol 308 (1501) ◽  
pp. 87-93 ◽  
Keyword(s):  
Similar Pattern ◽  
Metal Clusters ◽  
Frontier Orbitals ◽  
Metal Metal ◽  
Metal Metal Bonds ◽  
Metal Bonds ◽  
Metal Ligand

Logical methods for preparing small metal clusters with heteronuclear metal-metal bonds can be devised by appreciating the isolobal relationships that exist between certain metal ligand combinations and organic fragments. Thus the group W(CO) 2 (r|-C 5 H 5 ) has frontier orbitals of similar pattern to those of CH, while those of Rh(CO) (r|-C 5 Me 5 ) and CH 2 are also similar. This paper shows how such ideas have been employed to generate compounds with bonds between rhodium and other metals.

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