Cobalt(II) complexes of o-hydroxyaryl aldehydes and ketones

1968 ◽  
Vol 21 (6) ◽  
pp. 1487 ◽  
Author(s):  
DP Graddon ◽  
GM Mockler
Keyword(s):  
Double Bond ◽  
High Spin ◽  
Metal Atom ◽  
Spectroscopic Properties ◽  
Planar Structure ◽  
Square Planar ◽  
Aldehydes And Ketones ◽  
Solid Complexes

Cobalt(11) complexes of the types CoL2, CoL2B2 have been prepared, where LH is an o-hydroxyaryl aldehyde or ketone and B = water or 4-methylpyridine. The compounds CoL2B2 have magnetic and spectroscopic properties typical of octahedral cobalt(11) complexes. The solid complexes CoL2 have μeff 4.7-5.0 and spectra typical of octahedral cobalt(11). They are soluble and monomeric in toluene, and these solutions also have spectra typical of octahedral cobalt(11) and quite distinct from those of tetrahedral cobalt(11) complexes. It is concluded that these monomeric, 4-coordinate species are probably examples of high-spin square-planar cobalt(11) complexes, the planar structure being stabilized by dπ� → pπ back-coordination from the metal atom to the anti-bonding orbitals of a localized C=O double bond.

Nickel(II) complexes of some o-hydroxyarylcarbonyl compounds. II. Some 5-substituted 2-hydroxyaryl ketones

1968 ◽  
Vol 21 (4) ◽  
pp. 907 ◽  
Author(s):  
DP Graddon ◽  
GM Mockler
Keyword(s):  
High Spin ◽  
Planar Structure ◽  
Monomeric Form ◽  
Equilibrium Studies ◽  
Molecular Weights ◽  
Square Planar ◽  
Two Stages

Nickel(11) complexes of the type NiL2Bn have been prepared where L = 2-hydroxy-5-methylacetophenone, 2-hydroxy-5-methylbenzophenone, or 5-chloro-2-hydroxybenzophenone; B = H2O or 4-methylpyridine; n = 2 or 0. The properties of these compounds closely resemble those of the unsubstituted compounds described in Part I. Molecular weights of the anhydrous compounds NiL, indicate a monomer-polymer equilibrium in non-donor solvents, the solute being almost wholly monomeric at concentrations below 10-2M. Equilibrium studies in 2.5M 10-8M solution show that NiL2 reacts with 4-methylpyridine in two stages with a five-coordinate intermediate NiL2B, analogous to corresponding copper(11) complexes. The properties of the monomeric form of NiL, are consistent with a high-spin square-planar structure.

scholarly journals Cathodic hydrodimerization of nitroolefins

2015 ◽  
Vol 11 ◽  
pp. 1163-1174 ◽  
Author(s):  
Michael Weßling ◽  
Hans J Schäfer
Keyword(s):  
Double Bond ◽  
Nitro Group ◽  
Bond Formation ◽  
Cathodic Reduction ◽  
High Yield ◽  
Easy Access ◽  
Electrolysis Cell ◽  
Aldehydes And Ketones ◽  
Nef Reaction

Nitroalkenes are easily accessible in high variety by condensation of aldehydes with aliphatic nitroalkanes. They belong to the group of activated alkenes that can be hydrodimerized by cathodic reduction. There are many olefins with different electron withdrawing groups used for cathodic hydrodimerization, but not much is known about the behaviour of the nitro group. Synthetic applications of this group could profit from the easy access to nitroolefins in large variety, the C–C bond formation with the introduction of two nitro groups in a 1,4-distance and the conversions of the nitro group by reduction to oximes and amines, the conversion into aldehydes and ketones via the Nef reaction and base catalyzed condensations at the acidic CH bond. Eight 1-aryl-2-nitro-1-propenes have been electrolyzed in an undivided electrolysis cell to afford 2,5-dinitro-3,4-diaryl hexanes in high yield. The 4-methoxy-, 4-trifluoromethyl-, 2-chloro- and 2,6-difluorophenyl group and furthermore the 2-furyl and 2-pyrrolyl group have been applied. The reaction is chemoselective as only the double bond but not the nitro group undergoes reaction, is regioselective as a ß,ß-coupling with regard to the nitro group and forms preferentially two out of six possible diastereomers as major products.

scholarly journals Bis(μ-diisopropylphosphanido-κ2 P:P)bis[hydrido(triisopropylphosphane-κP)platinum(II)]

2012 ◽  
Vol 68 (6) ◽  
pp. m808-m808
Author(s):  
Nicole Arnold ◽  
Holger Braunschweig ◽  
Alexander Damme
Keyword(s):  
Molecular Structure ◽  
Title Compound ◽  
The Other ◽  
Planar Structure ◽  
Square Planar

In the centrosymmetric molecular structure of the title compound [Pt2(C6H14P)2H2(C9H21P)2], each PtII atom is bound on one side to a phosphane ligand (PiPr3) and a hydrido ligand. On the other side, it is bound to two phosphanide ligands (μ-PiPr2), which engage a bridging position between the two PtII atoms, forming a distorted square-planar structure motif. The Pt...Pt distance is 3.6755 (2) Å. A comparable molecular structure was observed for bis(μ-di-tert-butylphosphanido)bis[hydrido(triethylphosphane)platinum(II)] [Itazaki et al. (2004). Organometallics, 23, 1610–1621].

A Dinuclear Molecular Iron(II) Silicate with Two High-Spin Square-Planar FeO4Units

2013 ◽  
Vol 52 (19) ◽  
pp. 5155-5158 ◽  
Author(s):  
Denise Pinkert ◽  
Serhiy Demeshko ◽  
Fabian Schax ◽  
Beatrice Braun ◽  
Franc Meyer ◽  
...  
Keyword(s):  
High Spin ◽  
Square Planar

Synthesis and Electronic Structure of Neutral Square-Planar High-Spin Iron(II) Complexes Supported by a Dianionic Pincer Ligand

2019 ◽  
Vol 58 (2) ◽  
pp. 1252-1266 ◽  
Author(s):  
Brett M. Hakey ◽  
Jonathan M. Darmon ◽  
Yu Zhang ◽  
Jeffrey L. Petersen ◽  
Carsten Milsmann
Keyword(s):  
Electronic Structure ◽  
High Spin ◽  
Pincer Ligand ◽  
Square Planar ◽  
High Spin Iron

Synthesis, crystal structure, and cytotoxic activity of novel cyclic systems in [1,2,4]thiadiazolo[2,3-a]pyridine benzamide derivatives and their copper(ii) complexes

2014 ◽  
Vol 43 (21) ◽  
pp. 7945-7957 ◽  
Author(s):  
Forogh Adhami ◽  
Maliheh Safavi ◽  
Maryam Ehsani ◽  
Sussan K. Ardestani ◽  
Franziska Emmerling ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Cytotoxic Activity ◽  
Cell Lines ◽  
Cancer Cell ◽  
Human Cancer ◽  
Planar Structure ◽  
Human Cancer Cell ◽  
Human Cancer Cell Lines ◽  
Square Planar ◽  
Benzamide Derivatives

Novel Cu2+complexes with a square planar structure synthesized from benzamide derivatives showed cytotoxic activity against different human cancer cell lines.

Design and Structure Analysis of Artificial Metalloproteins:  Selective Coordination of His64 to Copper Complexes with Square-Planar Structure in theapo-Myoglobin Scaffold

2007 ◽  
Vol 46 (13) ◽  
pp. 5137-5139 ◽  
Author(s):  
Satoshi Abe ◽  
Takafumi Ueno ◽  
Pattubala A. N. Reddy ◽  
Seiji Okazaki ◽  
Tatsuo Hikage ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Copper Complexes ◽  
Planar Structure ◽  
Square Planar

Two complexes of PtIVand AuIIIwith 2,2′-dipyridylamine and 2,2′-dipyridylaminide ligands

2014 ◽  
Vol 70 (12) ◽  
pp. 1133-1137
Author(s):  
Alexander N. Chernyshev ◽  
Vadim Yu. Kukushkin ◽  
Matti Haukka
Keyword(s):  
Metal Atom ◽  
Weak Interactions ◽  
Structural Features ◽  
Coordination Environment ◽  
One Dimensional ◽  
Square Planar ◽  
Distorted Octahedral ◽  
Chloride Ligands ◽  
The Difference ◽  
Distorted Octahedral Coordination Environment

Two noble metal complexes involving ancillary chloride ligands and chelating 2,2′-bipyridylamine (Hdpa) or its deprotonated derivative (dpa), namely [bis(pyridin-2-yl-κN)amine]tetrachloridoplatinum(IV), [PtCl4(C10H9N3)], and [bis(pyridin-2-yl-κN)aminido]dichloridogold(III), [AuCl2(C10H8N3)], are presented and structurally characterized. The metal atom in the former has a slightly distorted octahedral coordination environment, formed by four chloride ligands and two pyridyl N atoms of Hdpa, while the metal atom in the latter has a slightly distorted square-planar coordination environment, formed by two chloride ligands and two pyridyl N atoms of dpa. The difference in conjugation between the pyridine rings in normal and deprotonated 2,2′-dipyridylamine is discussed on the basis of the structural features of these complexes. The influence of weak interactions on the supramolecular structures of the complexes, providing one-dimensional chains of [PtCl4(C10H9N3)] and dimers of [AuCl2(C10H8N3)], are discussed.

A high-spin square planar iron(ii)-siloxide and its tetrahedral allogon – structural and spectroscopic models of Fe-zeolite sites

2017 ◽  
Vol 53 (57) ◽  
pp. 8081-8084 ◽  
Author(s):  
D. Pinkert ◽  
M. Keck ◽  
S. Ghassemi Tabrizi ◽  
C. Herwig ◽  
F. Beckmann ◽  
...  
Keyword(s):  
High Spin ◽  
Molecular Model ◽  
Unique Structure ◽  
Square Planar ◽  
Fe Sites

The so far closest molecular model for the α-Fe sites in Fe-zeolites faithfully mimics the unique structure and spectroscopic features.

scholarly journals Computational studies of Ni(II) photosensitizers complexes containing 1,1′-bis(diphenylphosphino)ferrocene and dithio ligands

2020 ◽  
Vol 98 (4) ◽  
pp. 194-203 ◽  
Author(s):  
Sefia Brahim ◽  
Houari Brahim ◽  
Stéphane Humbel ◽  
Ali Rahmouni
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Dye Sensitized Solar Cells ◽  
Substituent Effects ◽  
Spectroscopic Properties ◽  
Basis Sets ◽  
Functional Theory ◽  
Square Planar ◽  
Td Dft ◽  
Sensitized Solar Cells

Detailed theoretical studies of Ni(II) complexes in a distorted square planar form and containing dithio and (P, P) chelating ligands were performed. These Ni(II) complexes are investigated for their use in dye-sensitized solar cells (DSSC). Structures and UV–vis spectra are calculated at density functional theory (DFT) and time-dependent density functional theory (TD-DFT) theories using B3LYP and CAM-B3LYP functionals and 6-31G(d,p) and 6-31G+(d) basis sets. Geometry optimizations result in excellent agreement with the experimental results. Moreover, the analysis of the frontier molecular orbitals (FMOs) allowed a detailed assignment and a clear analysis of the electronic transitions. The TD-DFT calculations reproduce the main spectroscopic properties observed and substituent effects. The results reveal that all absorption spectra are characterized by mixed character mainly dominated by metal to ligand and ligand to ligand charge transfers (MLCT and LLCT). We unveil how the substituent variations affect the DSSCs features of the complexes.

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