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1.

001-es BibID:BIBFORM047932
Első szerző:Baranyai Zsolt (vegyész)
Cím:Equilibrium, Kinetic and Structural Studies of AAZTA Complexes with Ga3+, In3+ and Cu2+ / Zsolt Baranyai, Fulvio Uggeri, Alessandro Maiocchi, Giovanni B. Giovenzana, Camilla Cavallotti, Anett Takács, Imre Tóth, István Bányai, Attila Bényei, Ernő Brücher, Silvio Aime
Dátum:2013
Megjegyzések:A detailed study of the structures, thermodynamic stabilities and kinetics of the dissociation of Ga3+, In3+ and Cu2+ complexes formed with the heptadentate ligand AAZTA is reported. The stability constants (logKML) of the AAZTA complexes of Ga3+, In3+ and Cu2+ are 22.18, 29.58 and 22.27, respectively, which suggests that the seven-membered-ring skeleton is suited to the accommodation of these metal ions. The solid-state structure of Cu(H2AAZTA)]?H2O shows a distorted octahedral coordination. The equatorial coordination sites of Cu2+ are occupied by one of the ring N atoms, a water O atom, one of the carboxylate O atoms and the N atom of the iminodiacetate moiety. The other ring N atom and thecarboxylate O atom of the iminodiacetate moiety coordinate to the Cu2+ in the axial positions. In the pH range 4.5?8.5, Ga3+ is present in the form of the highly stable [Ga(AAZTA)OH]2? (log ?GaLH?1 = 17.69) The exchange reactions of [Ga(AAZTA)OH]2? with Cu2+ and transferrin are very slow and mainly occur through the spontaneous dissociation of the complex close to physiological conditions. The half-life for the dissociation of [Ga(AAZTA)OH]2? is t1/2 = 23 h at pH = 7.5 and 25 ?C in 0.025 M NaHCO3 and 0.15 M NaCl. The high conditional stability, fast formation and sufficiently slow dissociation of [Ga(AAZTA)OH]2? represent promising properties for the complexation and diagnostic applications of radioactive Ga isotopes.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Gallium
Indium
Copper
Complexation
Thermodynamics
Kinetics
Radiopharmaceuticals
Imaging agents
Molekulatudomány
Doktori iskola
Megjelenés:European Journal Of Inorganic Chemistry. - 2013 : 1 (2013), p. 147-162. -
További szerzők:Uggeri, Fulvio Maiocchi, Alessandro (vegyész) Giovenzana, Giovanni Battista Cavallotti, Camilla Takács Anett Tóth Imre (1950-) (vegyész) Bányai István (1953-) (vegyész) Bényei Attila (1962-) (vegyész) Brücher Ernő (1935-) (vegyész) Aime, Silvio
Pályázati támogatás:K-84291
OTKA
TÁMOP-4.2.1/B-09/1/KONV-2010-0007
TÁMOP
Bimodális kontrasztanyagok tervezése, előállítása és komplexeik fizikai-kémiai tulajdonságaik jellemzése
TÁMOP-4.2.2/B-10/1-2010-0024
TÁMOP
Kémiai Tudományok Doktori Iskola
EU COST (TD1004) "Theragnostics Imaging and Therapy" Action Program.
Egyéb
HU11MO2-TET_10-1-2011-0202
Egyéb
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2.

001-es BibID:BIBFORM002545
Első szerző:Baranyai Zsolt (vegyész)
Cím:Kinetics of the Formation of [Ln(DOTAM)]3+ Complexes / Zsolt Baranyai, István Bányai, Ernő Brücher, Róbert Király, Enzo Terreno
Dátum:2007
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Macrocyclic ligands
Lanthanides
Kinetics
Reaction mechanisms
Megjelenés:European Journal Inorganic Chemistry. - 23 (2007), p. 3639-3645. -
További szerzők:Brücher Ernő (1935-) (vegyész) Király Róbert (1947-) (vegyész) Terreno, Enzo Bányai István (1953-) (vegyész)
Internet cím:elektronikus változat
DOI
elektronikus változat
elektronikus változat
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3.

001-es BibID:BIBFORM084830
Első szerző:Csajbók Éva (vegyész, kémikus)
Cím:Dynamic NMR properties of DOTA ligand: variable pH and temperature 1H NMR study on [K(HxDOTA)](3-x)- species / Éva Csajbók, István Bányai, Ernő Brücher
Dátum:2004
ISSN:1477-9226
Megjegyzések:The (1)H NMR spectra of [H(x)DOTA]((4-x)-) species are reported as a function of pH and temperature in aqueous solution. The spectra show line broadening both in ligand proton signals and also in the water proton signal by titration with KOH solution. The formation of different [K(H(x)DOTA)]((3-x)-) complexes is found to be responsible for this behaviour. At high pH the usual fluxional motions, i.e. the ring inversion and the change in the acetate arms' helicity, which are also characteristic for other but inert metal-DOTA complexes, have been detected. However, because of the kinetic lability of K(+)-O and K(+)-N coordinative bonds a new type of rearrangement appears. This new motion requires breaking of coordinative bonds in the complex and can be described as a certain type of "ring slewing" around the ring C-C bonds. At low temperature (about 270 K) the ring slewing slows down and becomes negligible compared with the ring inversion and the change in the arms' helicity. These two latter processes have the same rate. When the temperature is higher (about 320 K) the ring slewing accelerates and its rate exceeds the rate of ring inversion. At this temperature the change in the acetate arms' helicity has the same rate as the ring slewing. Additionally, in the pH range 4-5 a slow intermolecular proton exchange process has been observed between the water and the dissociable protons of [K(H(x)DOTA)]((3-x)-). A water-assisted proton exchange mechanism is proposed on the basis of the activation parameters. This finding supports the previously suggested slow proton motion hypothesis for the formation of DOTA complexes.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Dalton Transactions. - 2004 : 14 (2004), p. 2152-2156. -
További szerzők:Bányai István (1953-) (vegyész) Brücher Ernő (1935-) (vegyész)
Pályázati támogatás:OTKA T035127
OTKA
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4.

001-es BibID:BIBFORM095293
Első szerző:Jászberényi Zoltán
Cím:Equilibrium and NMR studies on Gd-III, Y-III, Cu-II and Zn-II complexes of various DTPA-N,N"-bis(amide) ligands. Kinetic stabilities of the gadolinium(III) complexes / Zoltán Jászberényi, István Bányai, Ernö Brücher, Róbert Király, Kálmán Hideg, Tamás Kálai
Dátum:2006
ISSN:1477-9226
Megjegyzések:Three DTPA-derivative ligands, the non-substituted DTPA-bis(amide) (L-0), the mono-substituted DTPA-bis(n-butylamide) (L-1) and the di-substituted DTPA-bis[bis(n-butylamide)] (L-2) were synthesized. The stability constants of their Gd3+ complexes (GdL) have been determined by pH-potentiometry with the use of EDTA or DTPA as competing ligands. The endogenous Cu2+ and Zn2+ ions form ML, MHL and M2L species. For the complexes CuL0 and CuL1 the dissociation of the amide hydrogens (CuLH-1) has also been detected. The stability constants of complexes formed with Gd3+, Cu2+ and Zn2+ increase with an increase in the number of butyl substituents in the order ML0 < ML1 < ML2. NMR studies of the diamagnetic YL0 show the presence of four diastereomers formed by changing the chirality of the terminal nitrogens of their enantiomers. At 323 K, the enantiomerization process, involving the racemization of central nitrogen, falls into the fast exchange range. By the assignment and interpretation of H-1 and C-13 NMR spectra, the fractions of the diastereomers were found to be equal at pH = 5.8 for YL0. The kinetic stabilities of GdL0, GdL1 and GdL2 have been characterized by the rates of the exchange reactions occurring between the complexes and Eu3+, Cu2+ or Zn2+. The rates of reaction with Eu3+ are independent of the [Eu2+] and increase with increasing [H+], indicating the rate determining role of the proton assisted dissociation of complexes. The rates of reaction with Cu2+ and Zn2+ increase with rising metal ion concentration, which shows that the exchange can take place with direct attack of Cu2+ or Zn2+ on the complex, via the formation of a dinuclear intermediate. The rates of the proton, Cu2+ and Zn2+ assisted dissociation of Gd3+ complexes decrease with increasing number of the n-butyl substituents, which is presumably the result of steric hindrance hampering the formation or dissociation of the intermediates. The kinetic stabilities of GdL0 and GdL1 at pH = 7.4, [Cu2+] = 1 x 10(-6) M and [Zn2+] = 1 x 10(-5) M are similar to that of Gd(DTPA)(2-), while the complex GdL2 possesses a much higher kinetic stability.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Dalton Transactions. - 2006 : 8 (2006), p. 1082-1091. -
További szerzők:Bányai István (1953-) (vegyész) Brücher Ernő (1935-) (vegyész) Király Róbert (1947-) (vegyész) Hideg Kálmán Kálai Tamás
Pályázati támogatás:T 34307
OTKA
T 038364
OTKA
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5.

001-es BibID:BIBFORM006198
Első szerző:Kálmán Ferenc K. (vegyész)
Cím:Synthesis, potentiometric, kinetic, and NMR studies of 1,4,7,10-tetraazacyclododecane-1,7-bis(acetic acid)-4,10-bis(methylenephosphonic acid) (DO2A2P) and its complexes with Ca(II), Cu(II), Zn(II) and lanthanide(III) ions / Kalman, F. K., Baranyai, Z., Toth, I., Banyai, I., Kiraly, R., Brucher, E., Aime, S., Sun, X., Sherry, A. D., Kovacs, Z.
Dátum:2008
ISSN:0020-1669
Megjegyzések:A cyclen-based ligand containing trans-acetate and trans-methylenephosphonate pendant groups, H(6)DO2A2P, was synthesized and its protonation constants (12.6, 11.43, 5.95, 6.15, 2.88, and 2.77) were determined by pH-potentiometry and H-1 NMR spectroscopy. The first two protonations were shown to occur at the two macrocyclic ring N-CH2-PO32- nitrogens while the third and fourth protonations occur at the two phosphonate groups. In parallel with protonation of the two -PO32- groups, the protons from the NH+-CH2-PO32- are transferred to the N-CH2-COO- nitrogens. The stability constants of the Ca2+, Cu2+, and Zn2+ (ML, MHL, MH2L, and M2L) complexes were determined by direct pH-potentiometry. Lanthanide(III) ions (Ln(3+)) form similar species, but the formation of complexes is slow; so, "out-of-cell" pH-potentiometry (La3+, Eu3+, Gd3+, Y3+) and competitive spectrophotometry with Cu(II) ion (Lu3+) were used to determine the stability constants. By comparing the log K-ML values with those of the corresponding DOTA (H(4)DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and DOTP (H8DOTP = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylenephosphonic acid) complexes, the order DOTA < DO2A2P < DOTP was found for all the metal ion complexes examined here with the exception of the Ca2+ complexes, for which the order is reversed. The relaxivity of Gd(DO2A2P) decreases between pH 2 and 7 but remains constant in the pH range of 7 < pH < 12 (r(1) = 3.6 mM(-1) s(-1)). The linewiths of the O-17 NMR signals of water in the absence and presence of Gd(DO2A2P) (at pH = 3.45 and 8.5) between 274 and 350 K are practically the same, characteristic of a q = 0 complex. Detailed kinetic studies of the Ce3+ and Gd3+ complexes with DO2A2P showed that complex formation is slow and involves a high stability diprotonated intermediate Ln(H(2)DO2A2P)*. Rearrangement of the diprotonated intermediate into the final complex is an OH- assisted process but, unlike formation of Ln(DOTA) complexes, rearrangement of Ln(H(2)DO2A2P)* also takes place spontaneously likely as a result of transfer of one of the protons from a ring nitrogen to a phosphonate group. The order of the OH- assisted formation rates of complexes is DOTA > DO2A2P > DOTP while the order of the proton assisted dissociation rates of the Gd3+ complexes is reversed, DOTP > DO2A2P > DOTA. H-1 and C-13 NMR spectra of Eu(DO2A2P) and Lu(DO2A2P) were assigned using two-dimensional correlation spectroscopy (2D COSY), heteronuclear multiple quantum coherence (HMQC), heteronuclear chemical shift correlation (HETCOR), and exchange spectroscopy (EXSY) NMR methods. Two sets of H-1 NMR signals were observed for Eu(DO2A2P) characteristic of the presence of two coordination isomers in solution, a twisted square antiprism (TSAP) and a square antiprism (SAP), in the ratio of 93% and 7%, respectively. Line shape analysis of the H-1 NMR spectra of Lu(DO2A2P) gave lower activation parameters compared to La(DOTP) for interconversion between coordination isomers. This indicates that the Ln(DO2A2P) complexes are less rigid probably due to the different size and spatial requireents of the carboxylate and phosphonate groups.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Inorganic Chemistry. - 47 : 9 (2008), p. 3851-3862. -
További szerzők:Baranyai Zsolt (1977-) (vegyész) Tóth Imre (1950-) (vegyész) Bányai István (1953-) (vegyész) Király Róbert Brücher Ernő (1935-) (vegyész) Aime, Silvio Sun, Xiankai Sherry, A. Dean Kovács Zoltán
Internet cím:elektronikus változat
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6.

001-es BibID:BIBFORM089116
Első szerző:Sarka Lajos
Cím:Synthesis, equilibrium and NMR studies of lanthanide(III) complexes of the N-mono(methylamide) and N'-mono(methylamide) derivatives of diethylenetriamine-N,N,N',N'',N''-pentaacetic acid / Lajos Sarka, István Bányai, Ernő Brücher, Róbert Király, Johannes Platzek, Bernd Radüchel, Heribert Schmitt-Willich
Dátum:2000
ISSN:0300-9246 1364-5447
Megjegyzések:Two derivative ligands of diethylenetriamine-N,N,N',N ",N "-pentaacetic acid (H(5)DTPA; H5L1) were synthesized: the symmetric and asymmetric mono(methylamides) DTPA-N'-MA (H4L3) and DTPA-N-MA (H4L4). The protonation constants (log K-i(H)) of L-3 and L-4 were obtained by pH-potentiometric titration: 10.04, 8.41, 2.73, 1.94 and 10.18, 6.19, 3.55, 2.0, respectively. The protonation constants and the sites of protonation were interpreted on the basis of the pH dependence of the chemical shifts of the non-labile protons. The stability constants (K-LnL) of the complexes of these ligands with lanthanide(III) ions were determined by direct pH-potentiometry and competition titration. The stability constants decrease in the sequence LnL(1) > LnL(3) > LnL(4). The log K-LnL values of the complexes LnL(3) and LnL(4) increase with increasing atomic number of Ln(3+) from La to Gd, then remain roughly unchanged up to Er and subsequently decrease slightly to Lu. The H-1 and C-13 NMR spectra reveal the presence of 2 isomers for the complexes LnL(3) and 4 isomers for LnL(4) at around 0 degrees C. The AB multiplets of the acetate methylene protons demonstrate the long lifetime of the Ln(3+)-N bonds. The coupling observed between the methyl and methylene protons of the methylamide group in the 2-D COSY spectra indicates partial double bond character of the C-NMe bond.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Journal of the Chemical Society. Dalton Transactions. - 2000 : 20 (2000), p. 3699-3703. -
További szerzők:Bányai István (1953-) (vegyész) Brücher Ernő (1935-) (vegyész) Király Róbert (1947-) (vegyész) Platzek, Johannes Radüchel, Bernd Schmitt-Willich, Heribert
Pályázati támogatás:OTKA 23810
OTKA
OTKA T 026115
OTKA
FKFP 0448/1997
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7.

001-es BibID:BIBFORM038091
Első szerző:Tircsó Gyula (vegyész, kémia tanár)
Cím:Lanthanide Complexes Formed with the Tri- and Tetraacetate Derivatives of Bis(aminomethyl)phosphinic Acid : Equilibrium, Kinetic and NMR Spectroscopic Studies / Gyula Tircsó, Ferenc K. Kálmán, Róbert Pál, István Bányai, Tamás R. Varga, Róbert Király, István Lázár, Laurent Québatte, André E. Merbach, Éva Tóth, Ernő Brücher
Dátum:2012
ISSN:1434-1948
Megjegyzések:The lanthanide(III) complexes formed with the tri- and tetraacetate derivatives of bis(aminomethyl)phosphinic acid, L1 and L2, respectively, have been studied by pH potentiometry, spectrophotometry and 1H and 17O NMR spectroscopy. L1 forms [Ln(L1)]?, [Ln(L1)2]4?, protonated [Ln(HL1)] and Ln(H2L1)]+, and [Ln(L1)(OH)]2? hydroxido complexes. Heptadentate L2 forms [Ln(L2)]2? and protonated [Ln(HL2)]? and [Ln(H2L2)] complexes in solution and it shows a strong propensity to form [Ln2(L2)]+ dinuclear complexes, which has not been observed previously. The stability constants (log?KLnL) of the complexes increase in the order [Ln(L1)]? < [Ln(L2)]2? following the order of increasing number of acetate pendants attached to the bis(aminomethyl)phosphinic acid (BAP) backbone. Within the LnIII series, the log?KLnL values increase from La3+ to Gd3+ and remain practically constant for the heavier lanthanides. Despite the lower basicity, the ligands that contain a phosphinate group generally form similar (L1) or more stable (L2) Ln3+ complexes than the structurally similar N-benzylethylenediamine-N,N·,N·-triacetic acid (L3) and propylenediamine-N,N,N·,N·-tetraacetic acid (L4), respectively. This indicates that the hard phosphinate group may be coordinated to the Ln3+ ions in the complexes, whereas the larger negative charge of the BAP derivatives may also have an extra stabilizing effect. The kinetic inertness of [Ln(L1)] and [Ln(L2)] is lower than that of similar [Ln(EDTA)]? (EDTA = ethylenediamine-N,N,N·,N·-tetraacetic acid), but the rate constants that characterize the dissociation of [Ln(L2)]2? are at least two orders of magnitude lower than those obtained for [Ln(L4)]?. Variable-temperature 17O transverse and longitudinal relaxation rates and NMR spectroscopic chemical shifts have been measured to assess the water exchange and rotational dynamics of [Gd(L2)]. The chemical shifts evidenced monohydration of the complex. The water exchange rate, kex298 = (2.7???0.4)???107 s?1 is about ten times higher than that of [Ln(DTPA)]2? (DTPA = diethylenetriamine-N,N,N·,Nı,Nı-pentaacetic acid). The rotational correlation time, ?RO298 = 270???30 ps, is long considering the small size of the chelate, which points to aggregation in aqueous solution, in accordance with the high value of the proton relaxivity measured.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Lanthanides
Imaging agents
Kinetics
Protonation constants
Stability constants
Water exchange rate
Molekulatudomány
Megjelenés:European Journal Of Inorganic Chemistry. - 12 (2012), p. 2062-2073. -
További szerzők:Kálmán Ferenc K. (1978-) (vegyész) Pál Róbert Bányai István (1953-) (vegyész) Varga Tamás Róbert (1967-) (kémia tanár) Király Róbert (1947-) (vegyész) Lázár István (1959-) (vegyész) Québatte, Laurent Merbach, André E. Tóth Éva (1967-) (koordinációs kémia) Brücher Ernő (1935-) (vegyész)
Pályázati támogatás:TÁMOP-4.2.1/B-09/1/KONV-2010-0007
TÁMOP
Bimodális kontrasztanyagok tervezése, előállítása és komplexeik fizikai-kémiai tulajdonságaik jellemzése
TÁMOP-4.2.2./B-10/1-2010-0024
TÁMOP
K84291
OTKA
PD83253
OTKA
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Intézményi repozitóriumban (DEA) tárolt változat
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