MonodentateN coordination of 1aza4oxo1,3butadienes [R1NC(R2)C(R3)O] to platinum(II). X-ray structure of trans-[PtCl2(PEt3){σ-N-(t-BuNCHC(Me)O)}]
| Autor: | Johannus A. M. van Beek, Kees Vrieze, M.Robert P. Van Vliet, Caspar H. Stam, Gerard van Koten, F. Muller |
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| Rok vydání: | 1986 |
| Předmět: |
chemistry.chemical_classification
Denticity Schiff base Chemistry Ligand Stereochemistry Imine Crystal structure Nuclear magnetic resonance spectroscopy Inorganic Chemistry chemistry.chemical_compound Crystallography Materials Chemistry Orthorhombic crystal system Physical and Theoretical Chemistry Alkyl |
| Zdroj: | Inorganica Chimica Acta. 112:77-85 |
| ISSN: | 0020-1693 |
| Popis: | Reaction of dimeric trans-[PtCl,(PR3)] 2 with 1-aza-4-oxo-1,3-butadienes [R’N=C(R’)C(R’)=O, R3 = Me, Ph, OMe, NEtz] in a 1:2 molar ratio results in almost quantitative formation of mononuclear complexes WLWZS- [PtC12(PR3){u-N-(R’N=C(R’)C(R3)=O)}]. The ligands are bonded in the monodentate u-N bonding mode to the platinum(I1) centre. This has been established by an X-ray structure determination of trans-[PtCl,(PEt,)(o-N-(tBuN=CHC(Me)=O)}]. Crystals of the latter compound are orthorhombic with space group Pc2,n; cell constants are II = 14.712(3), b = 15.053(2), c = 9.025(5) A, Z= 4 and R, = 0.056 for 3281 reflections. The 1-aza-4-oxo-l,3-butadiene (Gminoketone for R3 is alkyl or aryl) has the E-configuration about the imine bond (C=N 1.34(4) A), with a C(5)-C(6) distance of 1.44(5) 8, and a N=C(5)/ C(6)=0 torsion angle of 89(4)‘. As a result of this ligand conformation, the acetyl hydrogen atoms are positioned (on average) into the neighbourhood of the Pt-atom above the Pt-coordination plane. Infrared and NMR (‘H, 13C, 31P) data show that these structural features are also predominant in solution. organometallic reagent used, i.e. organo-zinc or -aluminum, a variety of products could be made in a chemoselective way. Examples of selective transfer of alkyl groups from alkyl-aluminum or -zinc reagents to each of the four atoms of the 1,3-butadiene system have now been established [3,4]. In order to understand the mechanistic details of these transfer reactions, more information on the coordination properties of the a-iminoketones is required than is available in the literature. |
| Databáze: | OpenAIRE |
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