CCL

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001-es BibID:BIBFORM099499
035-os BibID:(WoS)000747265100001 (Scopus)85123424554
Első szerző:Csupász Tibor (1991-)
Cím:A New Oxygen Containing Pyclen-Type Ligand as a Manganese(II) Binder for MRI and 52Mn PET Applications: Equilibrium, Kinetic, Relaxometric, Structural and Radiochemical Studies / Tibor Csupász, Dániel Szücs, Ferenc Krisztián Kálmán, Oldamur Hollóczki, Anikó Fekete, Dezső Szikra, Éva Tóth, Imre Tóth, Gyula Tircsó
Dátum:2022
ISSN:1420-3049
Megjegyzések:A new pyclen-3,9-diacetate derivative ligand (H23,9-OPC2A) is synthesized possessing an etheric O-atom opposite to the pyridine ring, to improve the dissociation kinetics of its Mn(II) complex (pyclen = 3,6,9,15-tetraazabicyclo(9.3.1)pentadeca-1(15),11,13-triene). The new ligand is less basic than the N-containing analogue (H23,9-PC2A) due to the non-protonable O-atom. In spite of its lower basicity, the conditional stability of the (Mn(3,9-OPC2A)) (pMn = ?log(Mn(II)), cL = cMn(II) = 0.01 mM. pH = 7.4) remains unaffected (pMn = 8.69), compared to the (Mn(3,9-PC2A)) (pMn = 8.64). The (Mn(3,9-OPC2A)) possesses one water molecule, having a lower exchange rate with bulk solvents (kex298 = 5.3 ??0.4 ? 107 s?1) than (Mn(3,9-PC2A)) (kex298 = 1.26?108 s?1). These mild dif-ferences are rationalized by the density-functional theory (DFT) calculations. The acid assisted dissociation of (Mn(3,9-OPC2A)) is considerably slower (k1 = 2.81 ??0.07 M?1s?1) than that of the complexes of diacetates or bisamides of various 12-membered macrocycles and the parent H23,9-PC2A. The (Mn(3,9-OPC2A)) is inert in rat/human serum as confirmed by 52Mn labeling (nM range), as well as by relaxometry (mM range). However, a 600-fold excess of EDTA (pH = 7.4) or a mixture of essential metal ions, propagated some transchelation/transmetalation in 7 days. The H23,9-OPC2A is labeled efficiently with 52Mn at elevated temperatures, yet at 37 ?C the parent H23,9-PC2A performs slightly better. Ultimately, the H23,9-OPC2A shows advantageous features for further ligand designs for bifunctional chelators.
A new pyclen-3,9-diacetate derivative ligand (H23,9-OPC2A) is synthesized possessing an etheric O-atom opposite to the pyridine ring to improve the dissociation kinetics of its Mn(II) complex (pyclen = 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene). The new ligand is less basic than the N-containing analogue (H23,9-PC2A) due to the non-protonable O-atom. In spite of its lower basicity, the conditional stability of the [Mn(3,9-OPC2A)] (pMn=-log[Mn(II)], cL=cMn(II)=0.01 mM. pH=7.4) remains unaffected (pMn=8.69) compared to the [Mn(3,9-PC2A)] (pMn=8.64). The [Mn(3,9-OPC2A)] possesses one water molecule, having a lower exchange rate with bulk solvent (kex298=5.3?0.4?107 s-1) than [Mn(3,9-PC2A)] (kex298=1.26?108 s-1). These mild differences are ration-alized by density-functional theory (DFT) calculations. The acid assisted dissociation of [Mn(3,9-OPC2A)] is considerably slower (k1=2.81?0.07 M-1s-1) than that of the complexes of diac-etates or bisamides of various 12-membered macrocycles and the parent H23,9-PC2A. The [Mn(3,9-OPC2A)] is inert in rat/human serum as confirmed by 52Mn labeling (nM range) as well as by relaxometry (mM range). However, 600-fold excess of EDTA (pH=7.4) or a mixture of es-sential metal ions propagated some transchelation/transmetalation in 7 days. The H23,9-OPC2A is labeled efficiently with 52Mn at elevated temperatures, yet at 37 oC the parent H23,9-PC2A per-forms slightly better. Altogether the H23,9-OPC2A shows advantageous features for further lig-and design for bifunctional chelators.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Molecules. - 27 (2022), p. 1-27. -
További szerzők:Szücs Dániel (1994-) (gyógyszerész) Kálmán Ferenc K. (1978-) (vegyész) Hollóczki Oldamur (1983-) (okleveles vegyészmérnök) Fekete Anikó (1973-) (vegyész) Szikra Dezső Péter (1983-) (vegyész) Tóth Éva Tóth Imre (1950-) (vegyész) Tircsó Gyula (1977-) (vegyész, kémia tanár)
Pályázati támogatás:K-120224
OTKA
K-128201
OTKA
K-134694
OTKA
FK-134551
OTKA
University of Debrecen Innovation Fund (POC-012)
Egyéb
the János Bolyai Research Scholarship of the Hungarian Academy of Sciences
MTA
ÚNKP-21-4 new national excellence program of the Ministry of Human Capacities
Egyéb
Doctoral School of Chemistry at the University of Debrecen
Egyéb
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2.

001-es BibID:BIBFORM113302
035-os BibID:(cikkazonosító)2574 (Scopus)85151110163 (WoS)000958431900001
Első szerző:Fickenscher, Zeno B. G.
Cím:Synergistic Catalysis in Heterobimetallic Complexes for Homogeneous Carbon Dioxide Hydrogenation / Zeno B. G. Fickenscher, Peter Lönnecke, Anna K. Müller, Oldamur Hollóczki, Barbara Kirchner, Evamarie Hey-Hawkins
Dátum:2023
ISSN:1420-3049
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
bimetallic complex
carbon dioxide
hydrogenation
synergistic catalysis
Megjelenés:Molecules. - 28 : 6 (2023), p. 1-8 (cikkazonosító)2574. -
További szerzők:Lönnecke, Peter Mueller, Anna-Kristin Hollóczki Oldamur (1983-) (okleveles vegyészmérnök) Kirchner, Barbara Hey-Hawkins, Evamarie
Pályázati támogatás:OTKA-FK 138823
OTKA
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3.

001-es BibID:BIBFORM116391
035-os BibID:(cikkazonosító)7163 (Scopus)85175048981 (WoS)001095206200001
Első szerző:Ramazanova, Kyzgaldak
Cím:Ring-Opening Reaction of 1-Phospha-2-Azanorbornenes via P-N Bond Cleavage and Reversibility Studies / Kyzgaldak Ramazanova, Anna Karina Müller, Peter Lönnecke, Oldamur Hollóczki, Barbara Kirchner, Evamarie Hey-Hawkins
Dátum:2023
ISSN:1420-3049
Megjegyzések:The reactive P-N bond in 1-phospha-2-azanorbornenes is readily cleaved by simple alcohols to afford P-chiral 2,3-dihydrophosphole derivatives as a racemic mixture. The isolation of the products was not possible due to the reversibility of the reaction, which could, however, be stopped by sulfurization of the phosphorus atom, thus efficiently blocking the lone pair of electrons, as exemplified for 6b yielding structurally characterized 8b. Additionally, the influence of the substituent in the ? position to the phosphorus atom (H, Ph, 2-py, CN) on the reversibility of the reaction was studied. Extensive theoretical calculations for understanding the ring-closing mechanism suggested that a multi-step reaction with one or more intermediates was most probable.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
chirality
phospholes
racemates
reversibility
ring-opening reaction
Megjelenés:Molecules. - 28 : 20 (2023), p. 1-10. -
További szerzők:Müller, Anna Karina Lönnecke, Peter Hollóczki Oldamur (1983-) (okleveles vegyészmérnök) Kirchner, Barbara Hey-Hawkins, Evamarie
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