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001-es BibID:	BIBFORM067445
Első szerző:	Nagy Nóra Veronika
Cím:	Copper(II) complexes of some N-substituted bis(aminomethyl)phosphinate ligands : An integrated EPR study of microspeciation and coordination modes by the two-dimensional simulation method / Nóra Veronika Nagy, Terézia Szabó-Plánka, Gyula Tircsó, Róbert Király, Zsuzsanna Árkosi, Antal Rockenbauer, Ernő Brücher
Dátum:	2004
ISSN:	0162-0134
Megjegyzések:	Copper(II) complexes of bis(aminomethyl)phosphinic acid (L1), bis(N-glycino-N-methyl)phosphinic acid (L2), bis(N-benzylglycino-N-methyl)phosphinic acid (L3), bis(l-prolino-N-methyl)phosphinic acid (L4) and bis(iminodicarboxymethyl-N-methyl)phosphinic acid (L5) were studied in aqueous solution by pH-potentiometric and electron paramagnetic resonance (EPR) spectroscopic methods. The EPR spectrum packages recorded at various ligand-to-metal concentration ratios and pH's were analyzed (after matrix rank analysis by the method of residual intensities as a complementary method) by the two-dimensional computer simulation method, which simultaneously determines the formation constants and the EPR parameters of the various (micro)species. L1 forms mono and bis complexes in different protonation states; for the other ligands, the mono complexes are always prevalent. For steric reasons, the formation of CuL is shifted to increasingly higher pH regions in the sequence L2, L3 and L4. CuLH was identified for L3, L4 and L5, and also CuLH2 for L4 and L5. Cu2L2 was found in small amounts for L3 and L4, while it predominates at pH > 4 for L5. For L5, Cu2L2H2 was also detected. For the ligands that form dimeric metal complexes in equimolar solution or at a ligand excess, Cu2L is formed at a metal ion excess. Ligation of the phosphinate O was suggested by indirect proofs in the protonated complexes of L1. For the ligands L2, L3 and L4, the copper(II) coordination in various species in different protonation states is reminiscent of that in the mono and bis complexes of simple amino acids. For the bis(aminomethyl)phosphinates, however, the cis positions of the amino groups in CuL are ensured by the structure of the ligand, and the isomers differ from each other in the (equatorial or axial) position of the second carboxylate group.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban Electron paramagnetic resonance Copper(II) complexes N-Substituted bis(aminomethyl)phosphinic acids Microspeciation Coordination modes
Megjelenés:	Journal of Inorganic Biochemistry 98 : 11 (2004), p. 1655-1666. -
További szerzők:	Szabó-Plánka Terézia Tircsó Gyula (1977-) (vegyész, kémia tanár) Király Róbert Árkosi Zsuzsanna Rockenbauer, Antal Brücher Ernő (1935-) (vegyész)
Pályázati támogatás:	T-032929 OTKA T-038364 OTKA T-046953 OTKA
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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