138164-36-0Relevant academic research and scientific papers
Synthesis and structure of a μ-(E)-vinylene-bis[dimethylglyoximato(1-)-dimethylglyoximato(2-)-(triphenylphosphine) rhodate] complex: A vinylene-bridged dinuclear rhodium complex
Steinborn, Dirk,Aisa, A.M. Ahmed,Heinemann, Frank W.,Lehmann, Silke
, p. 239 - 245 (2007/10/03)
[Rh(dmgH)2(PPh3)]-(dmgH2 = dimethylglyoxime), prepared by reduction of [Rh(dmgH)2(PPh3)Cl] with NaBH4 in methanolic KOH, reacts with (E)-1,2-dichloro ethylene to give the (E)-vinylene-bridged dinuclear rhodium complex [{K(MeOH)2}2-{(PPh3)(dmg)(dmgH)Rh-CH=CH-Rh(dmg)(dmgH)(PPh3)}] (1). Furthermore, 1 is formed in a mixture with [Rh(dmgH)2(PPh3)(Z)-CH=CHCl] (2) and [Rh(dmgH)2(PPh3)CH=CH2] (3) in the reaction of [Rh(dmgH)2(PPh3)]- with (Z)-ClCH=CHCl and in a mixture with 3 in the reaction of [Rh(dmgH)2(PPh3)]- with acetylene. 1 crystallizes in the monoclinic space group C2/c with: a = 22.711(5), b = 10.465(2), c = 27.910(6) A, β = 101.71(3)°, Z = 4. The structure was refined up to R1 = 0.0373 for 4903 reflections. The molecule consists of two [Rh(dmg)(dmgH)(PPh3)] subunits linked by an (E)-CH=CH bridge. The oxygen atoms of the dimethylglyoximato ligands and the solvent molecules (MeOH) are coordinated at the potassium ions. 1H, 13C and 31P NMR spectra of 1 agree definitely with the molecular structure in solid state, as was shown by comparison of the experimental spectra with the computer simulated spectra on the basis of AA′MM′XX′, AMM′XX′ and AA′XX′ spin systems for the vinylene protons, the carbon atoms and the phosphorus atoms respectively. In CDCl3/CD3COOD the neutral complex [(PPh3)(dmgH)2Rh-CH=CH-Rh(dmgH)2(PPh3)] (1′) is formed, as was shown by 1H, 13C and 31P NMR spectroscopy.
Studies on the electronic influence of organoligands. XIII. Synthesis and characterization of 2-functionalized vinyl rhodoximes
Aisa, A. M. Ahmed,Heinemann, Frank W.,Steinborn, Dirk
, p. 1946 - 1952 (2008/10/09)
2-Functionalized vinyl rhodoximes [Rh(dmgH)2 (PPh3)cis/trans-CH=CHZ] ([Rh]-CH=CHZ)1) (1) can be prepared with a wide variation of the substituent Z (cis: OEt (1 a), OPh (1 b), Cl (1 c), Me (1 j), Ph (1 k), SMe (1 l), SPh (1 m); trans: SPh (1 d), Me (1 e), Ph (1 f), CMe3 (1 g), SiMe3 (1 h)) by oxidative addition of XCH=CHZ and/or by nucleophilic addition of HC≡CZ and Me3SiC=CZ, respectively, to [Rh]-. 1 a is converted to [Rh]-CH2CHO (2) already in a weakly acid medium. 1 l is isomerized to trans-[Rh]-CH=CHSMe (1 n) in the presence of acids. The complexes 1 are characterized by microanalysis and by 1H, 31C and 31P NMR spectroscopy. The magnitude of the coupling constants 1J(103Rh,31P) reveals only a small effect of Z on the (NMR) trans influence of the vinyl ligands CH=CHZ. The molecular structures of cis-[Rh]-CH=CHSPh (1 m) and trans-[Rh]-CH=CHSPh (1 d) show a distorted octahedral coordination of Rh with a mutual trans position of triphenylphosphine and the 2-phenylmercaptovinyl ligands. Van der Waals interactions exist between the sulfur and the equatorial dimethylglyoximato ligands in the cis complex 1 m. Johann Ambrosius Barth 1996.
