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.

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.

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

scholarly journals Sedimentation-equilibrium studies on the heterogeneity of two β-lactamases

1970 ◽  
Vol 118 (3) ◽  
pp. 467-474 ◽  
Author(s):  
P. H. Lloyd ◽  
A. R. Peacocke
Keyword(s):  
Molecular Weight ◽  
Diffusion Coefficients ◽  
Minor Component ◽  
Theoretical Solution ◽  
Sedimentation Equilibrium ◽  
Equilibrium Studies ◽  
Molecular Weights ◽  
A Minor

Solutions of crystalline β-lactamase I and β-lactamase II, prepared by Kuwabara (1970), were examined in the ultracentrifuge and their sedimentation coefficients, diffusion coefficients, molecular weights and heterogeneity determined. Each sample was shown to consist of a major component comprising at least 97% of the material and a minor component of much higher molecular weight. The molecular weights of the major components were 27800 for β-lactamase I and 35600 for β-lactamase II. Emphasis is placed on a straightforward practical way of analysing the sedimentation-equilibrium results on mixtures of two macromolecular components rather than on a strict theoretical solution. Appendices describe the theory of systems at both chemical and sedimentation equilibrium and the procedure for calculating the combined distribution of two components.

Thermodynamics of metal-ligand bond formation. XXIX. Nickel(II) dialkylmonothiocarbamate complexes

1977 ◽  
Vol 30 (10) ◽  
pp. 2133 ◽  
Author(s):  
DP Graddon ◽  
IA Siddiqi
Keyword(s):  
Absorption Spectra ◽  
High Spin ◽  
Benzene Solution ◽  
Bond Formation ◽  
Molecular Weights ◽  
Metal Ligand ◽  
Ligand Bond

In benzene solution at concentrations below 10-2 M, measurements of molecular weights, absorption spectra and the enthalpies of reaction with bases are all consistent with Ni(SOCNR2)2 (R = Pr or Bu) existing as an equilibrium between low-spin monomeric and high-spin dimeric, probably five-coordinate, species. Enthalpies of dimerization are about -55 kJ (g-atom Ni)-1 and dimerization constants increase from 250 l. mol-1 at about 5�C to 1000 l. mol-1 at 30�C, which shows that the entropy of dimerization is not temperature-invariant. Addition of bidentate bases to the monomer is quantitative with ΔH� about -100 kJ mol-1. Addition of pyridine, 4-methylpyridine or piperidine occurs in two steps, giving high-spin adducts, first five-coordinate NiL2B then six-coordinate NiL2B2 with K1 ≈ K2, ΔH1� ≈ -100 and ΔH2� near zero. Comparisons are made with other low-spin nickel(II) complexes which form high-spin polymers or adducts.

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

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 A high-spin square-planar Fe(ii) complex stabilized by a trianionic pincer-type ligand and conclusive evidence for retention of geometry and spin state in solution

2015 ◽  
Vol 6 (1) ◽  
pp. 608-612 ◽  
Author(s):  
M. E. Pascualini ◽  
N. V. Di Russo ◽  
A. E. Thuijs ◽  
A. Ozarowski ◽  
S. A. Stoian ◽  
...  
Keyword(s):  
High Spin ◽  
Spin State ◽  
Conclusive Evidence ◽  
Planar Geometry ◽  
Square Planar

Extensive spectroscopic evaluation of a novel ONO3− trianionic pincer Fe(ii) complex indicates the rare square-planar geometry and S = 2 spin state are retained in solution.

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