Antibacterial, spectroscopic and X-ray crystallography of newly prepared heterocyclic thiourea dianion platinum(II) complexes with tertiary phosphine ligands

Polyhedron ◽  
2021 ◽  
pp. 115602
Author(s):  
Ahmed S. Faihan ◽  
Subhi A. Al-Jibori ◽  
Mohammad R. Hatshan ◽  
Ahmed S. Al-Janabi
Keyword(s):  
Phosphine Ligands ◽  
Tertiary Phosphine ◽  
X Ray ◽  
X Ray Crystallography

Preparation and characterization of some ruthenium(II) porphyrins containing tertiary phosphine axial ligands, including the crystal structure of (octaethylporphinato)bis(triphenylphosphine)ruthenium(II)

1984 ◽  
Vol 62 (4) ◽  
pp. 755-762 ◽  
Author(s):  
Sara Ariel ◽  
David Dolphin ◽  
George Domazetis ◽  
Brian R. James ◽  
Tak W. Leung ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phosphine Ligands ◽  
Tertiary Phosphine ◽  
X Ray ◽  
Porphyrin Complex ◽  
H Nmr ◽  
Axial Ligands ◽  
Nmr Data ◽  
Phosphine Complex

The ruthenium(II) porphyrin complex Ru(OEP)(PPh3)2 (OEP = the dianion of octaethylporphyrin) has been prepared from Ru(OEP)(CO)EtOH, and the X-ray crystal structure determined; as expected, the six-coordinate ruthenium is situated in the porphyrin plane and has two axial phosphine ligands. Synthesized also from the carbonyl(ethanol) precursors were the corresponding tris(p-methoxyphenyl)phosphine complex, and the Ru(TPP)L2 (TPP = the dianion of tetraphenylporphyrin, L = PPh3, P(p-CH3OC6H4)3, P″Bu3) and Ru(TPP)(CO)PPh3 complexes. Optical and 1H nmr data are presented for the complexes in solution. In some cases dissociation of a phosphine ligand to generate five-coordinate species occurs and this has been studied quantitatively in toluene at 20 °C for the Ru(OEP)L2 and Ru(TPP)L2 systems.

scholarly journals Peripherally-metallated porphyrins: meso-η1-porphyrinyl-platinum(II) complexes of 5,15-diaryl- and 5,10,15-triarylporphyrins

2002 ◽  
Vol 06 (11) ◽  
pp. 695-707 ◽  
Author(s):  
Regan D. Hartnell ◽  
Alison J. Edwards ◽  
Dennis P. Arnold
Keyword(s):  
Oxidative Addition ◽  
Building Blocks ◽  
Molecular Structures ◽  
Porphyrin Ring ◽  
Tertiary Phosphine ◽  
X Ray ◽  
Ring Carbon ◽  
X Ray Crystallography ◽  
Phosphine Complexes ◽  
Organolithium Reagents

Attempted metathesis reactions of peripherally-metallated meso-η1-porphyrinylplatinum(II) complexes such as trans-[ PtBr ( NiDPP )( PPh 3)2]( H 2 DPP = 5,15- diphenylporphyrin ) with organolithium reagents fail due to competitive addition at the porphyrin ring carbon opposite to the metal substituent. This reaction can be prevented by using 5,10,15-triarylporphyrins, e.g. 5,10,15-triphenylporphyrin ( H 2 TrPP ) and 5-phenyl-10,20-bis(3′,5′-di-t-butylphenyl)porphyrin ( H 2 DAPP ) as substrates. These triarylporphyrins are readily prepared using the method of Senge and co-workers by addition of phenyllithium to the appropriate 5,15-diarylporphyrins, followed by aqueous protolysis and oxidation. They are convenient, soluble building blocks for selective substitutions and subsequent transformations at the remaining free meso carbon. The sequence of bromination, optional central metallation and oxidative addition of Pt (0) tris(phosphine) complexes generates the organoplatinum porphyrins in high overall yields. The bromo ligand on the Pt (II) centre can be substituted by alkynyl nucleophiles, including 5-ethynyl NiDPP , to form the first examples of meso-η1-porphyrinylplatinum(II) complexes with a second Pt - C bond. The range of porphyrinylplatinum(II) bis(tertiary phosphine) complexes was extended to the triethylphosphine analogues, by oxidative addition of H 2 TrPPBr to Pt ( PEt 3)3, and the initially-formed cis adduct is only slowly thermally transformed to trans-[ PtBr ( H 2 TrPP )( PEt 3)2]16. The molecular structures of NiDAPP 9b, trans-[ Pt ( NiDPP )( C 2 NiDPP )( PPh 3)2]14 and 16 were determined by X-ray crystallography.

scholarly journals Substituent effects in phosphine ligands

2011 ◽  
Vol 30 (1) ◽  
Author(s):  
C. Alicia Renison ◽  
D. Bradley G. Williams ◽  
Alfred J. Muller
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
Molecular Modelling ◽  
31P Nmr ◽  
Substituent Effects ◽  
Phosphine Ligands ◽  
31P Nmr Spectroscopy ◽  
Electronic Effects ◽  
X Ray ◽  
X Ray Crystallography

The study illustrates the use of the P-atom to evaluate steric and electronic effects in P-containing organic compounds. The work involves the synthesis of substituted triarylphosphines and their corresponding Rh Vaska complexes. High resolution X-ray crystallography, molecular modelling, 31P NMR spectroscopy and IR will be used to quantify substituent effects.

Synthesis and organic group transfer of organodiplatinum complex with a 1,2-bis(diphenylphosphino)ethane ligand

2009 ◽  
Vol 87 (1) ◽  
pp. 176-182 ◽  
Author(s):  
Nobuyuki Komine ◽  
Tomoko Ishiwata ◽  
Jun-ya Kasahara ◽  
Erino Matsumoto ◽  
Masafumi Hirano ◽  
...  
Keyword(s):  
Platinum Complex ◽  
Phosphine Ligands ◽  
Transfer Reactions ◽  
Tertiary Phosphine ◽  
X Ray ◽  
Group Transfer ◽  
Organic Group ◽  
Square Planar ◽  
Complex Organic ◽  
Coordination Plane

A series of homometallic alkyl- and phenyldinuclear complexes containing one platinum–platinum bond, (dppe)RPt–Pt(η5-Cp)(CO) (R = Me, Et, CH2CMe3, Ph), have been prepared by oxidative addition of the Pt–C bond of PtR(η5-Cp) to Pt(styrene)(dppe), and were characterized by spectroscopic methods and (or) X-ray structure analysis. The geometry at Pt with a dppe ligand is square planar, and the carbonyl and Cp ligand of the Pt(η5-Cp)(CO) moiety lie orthogonal to the coordination plane of former platinum. Competitive organic group transfer reactions along the Pt–Pt bond in these complexes took place to give PtR(η5-Cp)(CO) and PtR(η1-Cp)(dppe) on thermolysis. Alkyl or aryl transfer from Pt with a dppe ligand were enhanced by addition of olefin, whereas treatment with CO and tertiary phosphine ligands causes Cp transfer from Pt(η5-Cp)(CO).Key words: organoplatinum–platinum complex, organic group transfer.

Cyclopalladation of trimesitylarsine. The X-ray crystal structure for

1988 ◽  
Vol 66 (12) ◽  
pp. 3162-3165 ◽  
Author(s):  
Elmer C. Alyea ◽  
George Ferguson ◽  
John Malito ◽  
Barbara L. Ruhl
Keyword(s):  
Crystal Structure ◽  
Cleavage Product ◽  
Phosphine Ligands ◽  
Monoclinic Space Group ◽  
Dimeric Complex ◽  
Tertiary Phosphine ◽  
X Ray ◽  
H Nmr ◽  
Square Planar ◽  
Cleavage Reactions

The bulky trimesitylarsine ligand, As(mes)3, undergoes facile cyclopalladation to yield the dimeric complex, [Formula: see text], characterized by microanalysis, IR and 1H NMR spectroscopy. This complex is very stable but readily undergoes bridge-cleavage reactions with tertiary phosphine ligands having ligand cone angles less than 170°. The crystal structure for the PPh3 bridge-cleavage product is reported. This complex, [Formula: see text] is monoclinic, space group P21/c with a = 20.469(2), b = 12.702(2), c = 15.401(4) Å, β = 98.46(1)°, V = 3961 Å3Z = 4, R = 0.0284 and Rw = 0.0305. The Pd geometry is distorted square-planar with principal dimensions, Pd—Cl 2.395(1), Pd—P 2.318(1), Pd—C 2.056(3), and Pd—As 2.437(1) Å; As—Pd—Cl 96.5(1), Cl—Pd—P 90.9(1), P—Pd—C 93.7(1), As—Pd—C 78.9(1), As—Pd—P 172.6(1), and Cl—Pd—C 171.7(1)°. The average C—P—C angle (104.3(1)°) is smaller than expected and is rationalized on the basis of steric effects operative within the complex.

Difference Fourier Analysis of Glucose Embedded and Frozen Hydrated Purple Membrane

1982 ◽  
Vol 40 ◽  
pp. 74-75
Author(s):  
Jules S. Jaffe ◽  
Robert M. Glaeser
Keyword(s):  
Purple Membrane ◽  
Data Set ◽  
High Resolution Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Fourier Techniques ◽  
Versus Protein ◽  
The Difference ◽  
Difference Fourier ◽  
Ideal Method

Although difference Fourier techniques are standard in X-ray crystallography it has only been very recently that electron crystallographers have been able to take advantage of this method. We have combined a high resolution data set for frozen glucose embedded Purple Membrane (PM) with a data set collected from PM prepared in the frozen hydrated state in order to visualize any differences in structure due to the different methods of preparation. The increased contrast between protein-ice versus protein-glucose may prove to be an advantage of the frozen hydrated technique for visualizing those parts of bacteriorhodopsin that are embedded in glucose. In addition, surface groups of the protein may be disordered in glucose and ordered in the frozen state. The sensitivity of the difference Fourier technique to small changes in structure provides an ideal method for testing this hypothesis.

3-D reconstruction of molecular shape from microcrystal thin sections

1983 ◽  
Vol 41 ◽  
pp. 748-749
Author(s):  
S. Cusack ◽  
J.-C. Jésior
Keyword(s):  
Three Dimensional ◽  
Molecular Shape ◽  
Biological Molecules ◽  
Fourier Space ◽  
Single Particles ◽  
Thin Sections ◽  
Standard Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimensional Reconstruction

Three-dimensional reconstruction techniques using electron microscopy have been principally developed for application to 2-D arrays (i.e. monolayers) of biological molecules and symmetrical single particles (e.g. helical viruses). However many biological molecules that crystallise form multilayered microcrystals which are unsuitable for study by either the standard methods of 3-D reconstruction or, because of their size, by X-ray crystallography. The grid sectioning technique enables a number of different projections of such microcrystals to be obtained in well defined directions (e.g. parallel to crystal axes) and poses the problem of how best these projections can be used to reconstruct the packing and shape of the molecules forming the microcrystal.Given sufficient projections there may be enough information to do a crystallographic reconstruction in Fourier space. We however have considered the situation where only a limited number of projections are available, as for example in the case of catalase platelets where three orthogonal and two diagonal projections have been obtained (Fig. 1).

Electron microscopy of rabbit FC crystals

1983 ◽  
Vol 41 ◽  
pp. 730-731
Author(s):  
Robert A. Grant ◽  
Laura L. Degn ◽  
Wah Chiu ◽  
John Robinson
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Molecular Replacement ◽  
X Ray ◽  
X Ray Crystallography ◽  
Resolution Electron ◽  
Replacement Technique ◽  
Hydrated Crystal ◽  
Molecular Structure Analysis

Proteolytic digestion of the immunoglobulin IgG with papain cleaves the molecule into an antigen binding fragment, Fab, and a compliment binding fragment, Fc. Structures of intact immunoglobulin, Fab and Fc from various sources have been solved by X-ray crystallography. Rabbit Fc can be crystallized as thin platelets suitable for high resolution electron microscopy. The structure of rabbit Fc can be expected to be similar to the known structure of human Fc, making it an ideal specimen for comparing the X-ray and electron crystallographic techniques and for the application of the molecular replacement technique to electron crystallography. Thin protein crystals embedded in ice diffract to high resolution. A low resolution image of a frozen, hydrated crystal can be expected to have a better contrast than a glucose embedded crystal due to the larger density difference between protein and ice compared to protein and glucose. For these reasons we are using an ice embedding technique to prepare the rabbit Fc crystals for molecular structure analysis by electron microscopy.

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