788094-30-4

Upstream product

• 862772-42-7 C₁₆H₁₆N₂O₈S₂ 
• 18653-98-0 N,N'-bis(2-hydroxybenzyl)ethylenediamine 
• 90-02-8 salicylaldehyde 
• 25149-61-5 5-sulpho-2-hydroxybenzaldehyde 

Relevant academic research and scientific papers

Hydrogenation and redox isomerization of allylic alcohols catalyzed by a new water-soluble Pd-tetrahydrosalen complex

For applications in aqueous media, sulfonated tetrahydrosalen (sulfosalan, HSS) was synthesized by sulfonation of tetrahydrosalen in fuming sulfuric acid. The Pd(II) complex of this ligand, [Pd(HSS)], showed outstanding activity in hydrogenation and redox isomerization of allylic alcohols in homogeneous aqueous solutions or in aqueous-organic biphasic systems (for oct-1-en-3-ol TOF(hydrogenation) = 1580 h-1, TOF(redox isomerization) = 400 h -1). DFT calculations revealed that H2 is activated heterolytically, resulting in a Pd(II)-hydride complex, [Pd(H)(HSS-Hphen)], in which one of the phenolate oxygens is protonated. Both hydrogenation and redox isomerization take place via concerted transfer of a proton and a hydride from the hydrogenated catalyst to the allylic alcohol.

Vanadium(IV and V) complexes of Schiff bases and reduced Schiff bases derived from the reaction of aromatic o-hydroxyaldehydes and diamines: Synthesis, characterisation and solution studies

Several sal2en-type reduced Schiff bases have been prepared from the reaction of 2 equiv. of salicylaldehyde (or derivatives) with ethylenediamine followed by reduction with NaBH4 and subsequently characterised. The water-soluble ligands (SO3-sal)2en and R(SO3-sal)2en (SO3-sal = salicylaldehyde-5- sulphonate) have been studied by pH potentiometry and 1H NMR spectroscopy and the protonation constants of R(SO3-sal) 2en have been determined. The Schiff bases are more susceptible to hydrolysis than the corresponding reduced Schiff bases. The crystal structures of H2(o-van)2en and KH(o-van)2en (o-van = o-vanillin) have been determined by X-ray diffraction. The vanadium(IV) complexes have been prepared and characterised by magnetic measurements and IR, UV/Vis and EPR spectroscopy. The colours, magnetic susceptibilities and IR spectra of the new vanadium(IV) complexes of the reduced Schiff bases now obtained suggest oligomeric/polymeric structures for the compounds while the corresponding VIVO-Schiff-base complexes are monomeric. The complexation of [VIVO]2+ and [VVO 2]+ with R(SO3-sal)2en in aqueous solution has been studied by pH potentiometry, UV/Vis as well as by EPR spectroscopy for the VIVO system and 1H and 51V NMR spectroscopy for the VVO2 system. Complex formation constants have been determined and binding modes have been proposed. N,N′-ethylenebis(pyridoxylaminato) (Rpyr2en) has also been obtained and the structure of Na[VVO2(Rpyr 2en)]·CH3OH·3H2O determined by X-ray diffraction. The Rpyr2en2- ligand coordinates through both the N-amine and O-phenolate moieties in a symmetrical α-cis type coordination mode, i.e. with both O-phenolato donors cis to the O-oxo atoms and trans to each other. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.