5603-18-9Relevant academic research and scientific papers
Synthesis and crystal structure determination of Mn(II) Schiff base complexes and their performance in ethene polymerization
Sood, Anjali,R?is?nen, Minna T.,Aitola, Erkki,Sibaouih, Ahlam,Colacio, Enrique,Ahlgren, Markku,Nieger, Martin,Repo, Timo,Leskel?, Markku
, p. 221 - 229 (2013/07/19)
Mn(II) complexes 1-10, of which eight are novel, were prepared in high yields by reacting MnCl2 with bidentate N,N′-imine-pyridine and N,N′-imine-quinoline-type donor ligands having different kinds of chemical modifications. The complexes were fully characterized by elemental analysis, mass spectrometry and IR spectroscopy. Crystal structures of 6, 7 and 9 were determined by X-ray crystallography and the results showed that 6 has a dimeric square-pyramidal geometry, whereas 7 and 9 have distorted octahedral structures. Magnetic studies on the high spin complexes 6 and 9 showed that the former exhibits a weak intramolecular antiferromagnetic interaction through the chloride-bridging ligands with a magnetic exchange coupling J = -0.46(6) cm -1, whereas the latter, as expected for its mononuclear structure, only shows very weak intermolecular interactions and/or zero-field splitting effects. All the complexes were activated with methylaluminoxane and investigated under low pressure (5 bar) for ethene polymerization at 60 C. Complexes 1 and 6-10 showed catalytic activity. The prepared polyethenes exhibited high molar masses (296 000-399 000 g/mol) and high melting temperatures (133-140 C). The low molar mass distribution values of 2.15-2.55 indicated single-site polymerization behavior.
New quinoline-2, -3, and 4-yl-(amino) methylphosphonates: Synthesis and study on the C-P bond cleavage in quinoline-2 and -4 derivatives under acidic conditions
Michalska, Joanna,Boduszek, Bogdan,Olszewski, Tomasz K.
experimental part, p. 617 - 624 (2011/12/04)
Synthesis of new quinoline-(amino)methylphosphonic acids, their phosphonate esters, and phosphine oxides is presented. The desired new compounds were efficiently obtained by nucleophilic addition of phosphorous species to quinoline-derived Schiff bases. In addition, it was discovered that heating of quinolin-2 and quinolin-4-yl-(amino)-methylphosphonates with aqueous HCl leads to their decomposition resulting in a rupture of the C-P bond, rejecting of the phosphorus containing fragment, and formation of the corresponding secondary quinoline-2 and quinoline-4-alkylamines. Two alternative mechanistic pathways for this cleavage are postulated. Copyright
Allosteric functional switch of neurokinin A-mediated signaling at the neurokinin NK2 receptor: Structural exploration
Valant, Céline,Maillet, Emeline,Bourguignon, Jean-Jacques,Bucher, Bernard,Utard, Valérie,Galzi, Jean-Luc,Hibert, Marcel
experimental part, p. 5999 - 6011 (2010/03/24)
The neurokinin NK2 receptor is known to pre-exist in equilibrium between at least three states: restinginactive, calcium-triggering, and cAMP-producing. Its endogeneous ligand, NKA, mainly induces the calcium response. Using a FRET-based assay, we have previously discovered an allosteric modulator of the NK2 receptor that has the unique ability to discriminate among the two signaling pathways: calcium-signaling is not affected while cAMP signaling is significantly decreased. A series of compounds have been prepared and studied in order to better understand the structural determinants of this allosteric functional switch of a GPCR. Most of them display the same allosteric profile, with smooth pharmacomodulation. One compound however exhibits significantly improved modulatory properties of NKA induced signaling when compared to the original modulator. 2009 American Chemical Society.
