Dimethylplatinum(IV) Complexes With Cyanide: Thermal and Photoassisted Substitution Reactions, and Characterization of Products by N.M.R.

1987 ◽  
Vol 40 (9) ◽  
pp. 1565 ◽  
Author(s):  
TG Appleton ◽  
JR Hall ◽  
MA Williams
Keyword(s):  
Ultraviolet Irradiation ◽  
Oxidative Addition ◽  
Reductive Elimination ◽  
Methyl Groups ◽  
Substitution Reactions ◽  
Aqueous Acid ◽  
Cyanide Ligands ◽  
Cis And Trans ◽  
Insoluble Precipitate

Reactions of cyanide with the dimethylplatinum (IV) complexes, [PtMe2(OH) (H20)1.5 n, [PtMe2Br2]n and fac-PtMe2Br(H2O)3+, have been studied, principally by 1H, 13C and 195Pt n.m.r. Cyanide rapidly displaces the ligands trans to the methyl groups. Subsequent reactions cis to the methyl groups occur more slowly with heating, or, for bromo complexes, on ultraviolet irradiation. These substitution reactions compete with reductive elimination of groups from the platinum(IV) compounds to produce platinum(II) products. All attempts to prepare solutions of fac-PtMe2(CN)(H2O)3+ were unsuccessful. Oxidative addition of ICN to cis-PtMe2( py )2 ( py = pyridine) gave PtMe2I(CN)( py )2, from which a solution of fac-PtMe2(CN)( MeOH )3+ in methanol could be obtained. Addition of water or aqueous acid to this solution gave a very insoluble precipitate of [PtMe2(CN)(OH)n. The cis and trans influences on Jpt -C and δC of the cyanide ligands have been evaluated.

Oxidative addition/reductive elimination of aldehydes and ketones at rhodium. Synthesis and characterization of cis-hydrido acyl complexes of rhodium(III)

1987 ◽  
Vol 6 (11) ◽  
pp. 2453-2455 ◽  
Author(s):  
Claudio. Bianchini ◽  
Andrea. Meli ◽  
Maurizio. Peruzzini ◽  
Alberto. Vacca ◽  
Fabrizio. Zanobini
Keyword(s):  
Oxidative Addition ◽  
Reductive Elimination ◽  
Synthesis And Characterization ◽  
Acyl Complexes ◽  
Aldehydes And Ketones

Synthesis and study of platinum silylene complexes of the type (R3P)2Pt=SiMes2 (Mes = 2,4,6-trimethylphenyl)

2003 ◽  
Vol 81 (11) ◽  
pp. 1127-1136 ◽  
Author(s):  
Jay D Feldman ◽  
Gregory P Mitchell ◽  
Jörn-Oliver Nolte ◽  
T Don Tilley
Keyword(s):  
Oxidative Addition ◽  
Reductive Elimination ◽  
Synthesis And Characterization ◽  
Silylene Complexes

The synthesis and characterization of neutral platinum silylene complexes (R3P)2Pt=SiMes2 (R = i-Pr (1) or cyclohexyl (2), Mes = 2,4,6-trimethylphenyl) is reported. The dimesitylsilylene ligand in 2 is displaced by a number of ligands including phosphines, alkenes, alkynes, and O2. Complex 2 reacts with ROH substrates (R = H, Me, Et) to give (Cy3P)2Pt and Mes2Si(OR)(H) and with H2 to give trans-(Cy3P)2Pt(H)SiHMes2 (3). Reaction of H2SiMes2 with (Cy3P)2Pt gave cis-(Cy3P)2Pt(H)SiHMes2 (4). EXSY NMR experiments of 4 reveal that exchange of silicon and platinum hydrides occurs via reductive elimination – oxidative addition and not via a silylene intermediate.Key words: silylene, EXSY, platinum, hydride.

Reversible Oxidative-Addition and Reductive-Elimination of Thiophene from a Titanium Complex and Its Thermally-Induced Hydrodesulfurization Chemistry

2019 ◽  
Author(s):  
Alejandra Gomez-Torres ◽  
J. Rolando Aguilar-Calderón ◽  
Carlos Saucedo ◽  
Aldo Jordan ◽  
Alejandro J. Metta-Magaña ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Ring Opening ◽  
Thiophene Ring ◽  
Oxidative Addition ◽  
Reductive Elimination ◽  
Thermally Induced ◽  
Titanium Complex

<p>The masked Ti(II) synthon (<sup>Ket</sup>guan)(<i>η</i><sup>6</sup>-Im<sup>Dipp</sup>N)Ti (<b>1</b>) oxidatively adds across thiophene to give ring-opened (<sup>Ket</sup>guan)(Im<sup>Dipp</sup>N)Ti[<i>κ</i><sup>2</sup>-<i>S</i>(CH)<sub>3</sub><i>C</i>H] (<b>2</b>). Complex <b>2</b> is photosensitive, and upon exposure to light, reductively eliminates thiophene to regenerate <b>1</b> – a rare example of early-metal mediated oxidative-addition/reductive-elimination chemistry. DFT calculations indicate strong titanium π-backdonation to the thiophene π*-orbitals leads to the observed thiophene ring opening across titanium, while a proposed photoinduced LMCT promotes the reverse thiophene elimination from <b>2</b>. Finally, pressurizing solutions of <b>2 </b>with H<sub>2</sub> (150 psi) at 80 °C leads to the hydrodesulfurization of thiophene to give the Ti(IV) sulfide (<sup>Ket</sup>guan)(Im<sup>Dipp</sup>N)Ti(S) (<b>3</b>) and butane. </p>

SYNTHESIS AND CHARACTERIZATION OF CIS AND TRANS-DICHLOROBIS-(ETHYLENEDIAMINE)-RHODIUM(III) SALTS:1

1960 ◽  
Vol 82 (16) ◽  
pp. 4423-4424 ◽  
Author(s):  
S. Anderson ◽  
Fred Basolo
Keyword(s):  
Synthesis And Characterization ◽  
Cis And Trans

scholarly journals Characterization of a Natural, Stable, Reversible and Colourful Anthocyanidin Network from Sphagnum Moss Based Mainly on the Yellow Trans-Chalcone and Red Flavylium Cation Forms

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 709
Author(s):  
Helge Berland ◽  
Øyvind M. Andersen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Cell Wall ◽  
Peat Moss ◽  
Sphagnum Moss ◽  
Naturally Occurring ◽  
Two Component ◽  
Colour System ◽  
The Common ◽  
Cis And Trans

Anthocyanins with various functions in nature are one of the most important sources of colours in plants. They are based on anthocyanidins or 3-deoxyanthocyanidins having in common a C15-skeleton and are unique in terms of how each anthocyanidin is involved in a network of equilibria between different forms exhibiting their own properties including colour. Sphagnorubin C (1) isolated from the cell wall of peat moss (Sphagnum sp.) was in fairly acidic and neutral dimethyl sulfoxide characterized by nuclear magnetic resonance (NMR) and ultraviolet–visible (UV–vis) absorption techniques. At equilibrium, the network of 1 behaved as a two–component colour system involving the reddish flavylium cationic and the yellow trans–chalcone forms. The additional D- and E-rings connected to the common C15-skeleton extend the π-conjugation within the molecule and provide both bathochromic shifts in the absorption spectra of the various forms as well as a low isomerization barrier between the cis- and trans-chalcone forms. The hemiketal and cis-chalcone forms were thus not observed experimentally by NMR due to their short lives. The stable, reversible network of 1 with good colour contrast between its two components has previously not been reported for other natural anthocyanins and might thus have potential in future photochromic systems. This is the first full structural characterization of any naturally occurring anthocyanin chalcone form.

Interconversion of Quadruply and Quintuply Bonded Molybdenum Complexes by Reductive Elimination and Oxidative Addition of Dihydrogen

2013 ◽  
Vol 125 (11) ◽  
pp. 3309-3313 ◽  
Author(s):  
Mario Carrasco ◽  
Natalia Curado ◽  
Celia Maya ◽  
Riccardo Peloso ◽  
Amor Rodríguez ◽  
...  
Keyword(s):  
Oxidative Addition ◽  
Reductive Elimination ◽  
Molybdenum Complexes
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