A convenient access to N-phosphonio-substituted NHC metal complexes [M = Ag(i), Rh(i), Pd(ii)]

2017 ◽  
Vol 46 (36) ◽  
pp. 12293-12305 ◽  
Author(s):  
Idir Benaissa ◽  
Rachid Taakili ◽  
Noël Lugan ◽  
Yves Canac
Keyword(s):  
Metal Complexes ◽  
Metal Center ◽  
Convenient Access

NHC Pd(ii) complexes featuring a propyl bridge were ionized by the introduction of a phosphonium moiety, which may coordinate to the metal center or remain pendant.

Übergangsmetallkomplexe mit Schwefelliganden, LXV. Diastereospezifische Alkylierung von [Mo(NO)2(′S2′)2]2- zu chiralen [Mo(NO)2(′RS4')]-Komplexen mit chirotopen und prostereogenen Mo-Zentren / Transition Metal Complexes with Sulfur Ligands, LXV. Diastereospecific Alkylation of [Mo(NO)2(′S2')2]2- to Chiral [Mo(NO)2(′RS4')] Complexes with Chirotopic and Prostereogenic Mo-Centers

1991 ◽  
Vol 46 (10) ◽  
pp. 1343-1348 ◽  
Author(s):  
Dieter Sellmann ◽  
Franz Grasser ◽  
Falk Knoch ◽  
Matthias Moll
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Parent Compound ◽  
Metal Center ◽  
Chiral Complexes ◽  
Metal Centers ◽  
Electronic Character

In order to investigate how chirotopicity and stereogenicity of metal centers influence the enantioselectivity of metal centered reactions the stereogenic properties of metal centers in chiral complexes have to be varied without changing their electronic character. Diastereospecific alkylation of [Mo(NO)2(′S2′ )2]2- by racemic 1,2-dibromopropane and 1,2-dibromobutane yields the title complexes [Mo(NO)2(′MeS4′ )] and [Mo(NO)2(′EtS4′)] that differ from the parent compound [Mo(NO)2('S4′)] with respect to the stereogenicity of the metal center and allow future investigations of the question raised above.

Ultrastructural features of cells following incubation with metal complexes using phenanthroline-based ligands: The influence of the metal center

2017 ◽  
Vol 41 (1) ◽  
pp. 128-129 ◽  
Author(s):  
Fernanda Marques ◽  
António Pedro Matos ◽  
Cristina P. Matos ◽  
Isabel Correia ◽  
João Costa Pessoa ◽  
...  
Keyword(s):  
Metal Complexes ◽  
Metal Center

α-Pyridinyl Alcohols, α,α’-Pyridine Diols, α-Bipyridinyl Alcohols, and α,α’-Bipyridine Diols as Structure Motifs Towards Important Organic Molecules and Transition Metal Complexes

2020 ◽  
Vol 17 (5) ◽  
pp. 344-366
Author(s):  
Tegene T. Tole ◽  
Johannes H.L. Jordaan ◽  
Hermanus C.M. Vosloo
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Single Molecule ◽  
Organic Molecules ◽  
Metal Cluster ◽  
Metal Center ◽  
Phosphine Ligands ◽  
High Ability ◽  
Metal Centers

Background: The preparation and use of pyridinyl alcohols as ligands showed incredible increment in the past three decades. Important property of pyridinyl alcoholato ligands is their strong basicity, which is mainly due to the lack of resonance stabilization of the corresponding anion. This strongly basic anionic nature gives them high ability to make bridges between metal centers rather than to bind to only one metal center in a terminal fashion. They are needed as ligands due to their ability to interact with transition metals both covalently (with oxygen) and hemilabile coordination (through nitrogen). Objective: The review focuses on the wide application of α-pyridinyl alcohols, α,α’-pyridine diols, α- bipyridinyl alcohols, and α,α’-bipyridine diols as structure motifs in the preparation of important organic molecules which is due to their strongly basic anionic nature. Conclusion: It is clear from the review that in addition to their synthetic utility in the homogeneous and asymmetric catalytic reactions, the preparation of the crown ethers, cyclic and acyclic ethers, coordinated borates (boronic esters), pyridinyl-phosphine ligands, pyridinyl-phosphite ligands, and pyridinyl-phosphinite ligands is the other broad area of application of pyridinyl alcohols. In addition to the aforementioned applications they are used for modeling mode of action of enzymes and some therapeutic agents. Their strongly basic anionic nature gives them high ability to make bridges between metal centers rather than to bind to only one metal center in a terminal fashion in the synthesis of transition metal cluster complexes. Not least numbers of single molecule magnets that can be used as storage of high density information were the result of transition metal complexes of pyridinyl alcoholato ligands.

Synergy of DNA intercalation and catalytic activity of a copper complex towards improved polymerase inhibition and cancer cell cytotoxicity

2021 ◽  
Author(s):  
Adolfo Ignacio Barros Romo ◽  
Marta SP Carepo ◽  
Pedro Levin ◽  
Otaciro Nascimento ◽  
Daniel E Diaz ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Metal Complexes ◽  
Cancer Cell ◽  
Copper Complex ◽  
Chemical Properties ◽  
Metal Center ◽  
Fine Tuning ◽  
Dna Intercalation ◽  
Cell Cytotoxicity ◽  
And Chemical Properties

Improving the binding of metal complexes to DNA to boost cancer cell cytotoxicity requires fine tuning of their structural and chemical properties. Copper has been used as metal center in...

Molecular assemblies based on strong axial coordination in metal complexes of saddle-distorted dodecaphenylporphyrins

2015 ◽  
Vol 19 (01-03) ◽  
pp. 32-44 ◽  
Author(s):  
Tomoya Ishizuka ◽  
Shunichi Fukuzumi ◽  
Takahiko Kojima
Keyword(s):  
Electron Transfer ◽  
Metal Ions ◽  
Metal Complexes ◽  
Photoinduced Electron Transfer ◽  
Oxidation Potential ◽  
Metal Center ◽  
Lewis Acidity ◽  
Central Metal ◽  
Axial Coordination ◽  
Keggin Type

In this mini-review, we have highlighted our works on metal complexes having saddle-distorted dodecaphenylporphyrin (DPP) and its derivative as ligands in the light of enhancement of the Lewis acidity of a metal center coordinated by the porphyrin. The important point through this mini-review is ill-overlap of the out-of-plane lone pairs of pyrrole nitrogen atoms with σ-orbitals of the metal center bound to the saddle-distorted porphyrin core. The enhanced Lewis acidity of the central metal ions enabled us to construct stable molecular complexes through axial coordination using metal–DPP (M(DPP)) moieties ( M = Mo V or Sn IV ) and molecular or ionic entities with Lewis-basic coordination sites, including Keggin-type polyoxometallates (POM), which are known to have weak Lewis basicity and thus hard to coordinate to metal ions. A discrete 1:2 complex with a Ru -substituted POM performs catalytic substrate oxidation reactions in organic solvents. A 1:1 complex between Sn IV ( DPP ) and a Keggin-type POM exhibited photoinduced electron transfer, in which the Sn IV ( DPP ) moiety acts as an electron donor and the POM as an electron acceptor. Besides POM, other electron acceptors, including μ3-oxo trinuclear Ru III clusters and anthraquinone, having carboxyl groups as a linker unit also formed stable complexes with DPP-metal complexes as axial ligands to perform photoinduced electron transfer. Successful photoreactions of the M(DPP)-acceptor complexes are mainly enabled by the enhanced Lewis acidity of the DPP-metal complexes for the stabilization of the assemblies and also by lowering the oxidation potential of the porphyrin ligand to gain larger driving force of electron transfer to form an electron-transfer state with avoiding intersystem crossing. The stability and photochemical behavior are in sharp contrast to those for metal complexes with planar porphyrins as ligands.

Gas-phase reactivity of Cp* group IX metal complexes bearing aromatic N,N′-chelating ligands

2017 ◽  
Vol 41 (15) ◽  
pp. 6995-7006 ◽  
Author(s):  
Christian Kerner ◽  
Jens P. Neu ◽  
Maximilian Gaffga ◽  
Johannes Lang ◽  
Benjamin Oelkers ◽  
...  
Keyword(s):  
Metal Complexes ◽  
Gas Phase ◽  
Metal Center ◽  
Chelating Ligands ◽  
Chelate Ligand

Compounds of the type [(η5-Cp*)M(Cl)(N,N′)]+ bearing N,N′-coordinating ligands show different modes of HCl cleavage depending on the nature of the N,N′-chelate ligand and the metal center.

New metal complexes of NNO tridentate ligands: Effect of metal center and co-ligand on biological activity

2014 ◽  
Vol 420 ◽  
pp. 39-46 ◽  
Author(s):  
I. Machado ◽  
M. Fernández ◽  
L. Becco ◽  
B. Garat ◽  
R.F. Brissos ◽  
...  
Keyword(s):  
Biological Activity ◽  
Metal Complexes ◽  
Metal Center ◽  
Tridentate Ligands

Redox-Coupled Complexation of 23-Phospha-21-thiaporphyrin with Group 10 Metals: A Convenient Access to Stable Core-Modified Isophlorin−Metal Complexes

2008 ◽  
Vol 130 (49) ◽  
pp. 16446-16447 ◽  
Author(s):  
Yoshihiro Matano ◽  
Takashi Nakabuchi ◽  
Shinya Fujishige ◽  
Haruyuki Nakano ◽  
Hiroshi Imahori
Keyword(s):  
Metal Complexes ◽  
Stable Core ◽  
Group 10 ◽  
Group 10 Metals ◽  
Convenient Access

scholarly journals Dimerisation of Dipiperidinoacetylene: Convenient Access to Tetraamino‐1,3‐Cyclobutadiene and Tetraamino‐1,2‐Cyclobutadiene Metal Complexes

2019 ◽  
Vol 25 (70) ◽  
pp. 16148-16155
Author(s):  
Ludwig Hackl ◽  
Alex R. Petrov ◽  
Thomas Bannenberg ◽  
Matthias Freytag ◽  
Peter G. Jones ◽  
...  
Keyword(s):  
Metal Complexes ◽  
Convenient Access
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