Ivan Lukeš - Academia.edu (original) (raw)
Papers by Ivan Lukeš
Description of experiments of copper complexes of high thermodynamic selectivity and extraordinar... more Description of experiments of copper complexes of high thermodynamic selectivity and extraordinary kinetic inertness.
Ln(III) complexes of H4dota and its derivatives are utilized in many areas of medicine. The molec... more Ln(III) complexes of H4dota and its derivatives are utilized in many areas of medicine. The molecular spectroscopy in UV/VIS region was employed to investigate chemical features of Eu(III)/Gd(III)/Tb(III) complexes of the title ligand in order to investigate their possible applications as bimodal agents. The stability constants and acid-assisted dissociation of Ln(III) complexes show high thermodynamic stability and kinetic inertness. In the study of formation (pH = 5.0-6.0, t = 25 C, I = 0.1 M KCl) was found that the reactive species is HL 2- and the rate increases with decreasing ionic radius of the metal ions and it follows a trend along the Ln(III) series. The ligand capable of complex formation due show interesting photophysical properties to presence of chromophor/fluorophor group and it enables to determine the low concentration of Eu(III)/Tb(III) ions.
Philosophical Transactions of the Royal Society A, Sep 28, 2010
Core-shell nanoparticles consisting of La 0.75 Sr 0.25 MnO 3 cores covered by silica were synthes... more Core-shell nanoparticles consisting of La 0.75 Sr 0.25 MnO 3 cores covered by silica were synthesized by a procedure consisting of several steps, including the sol-gel method in the presence of citric acid and ethylene glycol, thermal and mechanical treatment, encapsulation employing tetraethoxysilane and final separation by centrifugation in order to get the required size fraction. Morphological studies revealed well-separated particles that form a stable water suspension. Magnetic studies include magnetization measurements and investigation of the ferromagnetic-superparamagnetic-paramagnetic transition. Magnetic heating experiments in 'calorimetric mode' were used to determine the heating efficiency of the particles in water suspension and further employed for biological studies of extracellular and intracellular effects analysed by tests of viability.
![Research paper thumbnail of Densely packed Gd(<scp>iii</scp>)-chelates with fast water exchange on a calix[4]arene scaffold: a potential MRI contrast agent](https://attachments.academia-assets.com/120206600/thumbnails/1.jpg)
](Dalton Transactions, 2010
A pyridine-N-oxide functionalized DOTA analogue has been conjugated to a calix[4]arene and the co... more A pyridine-N-oxide functionalized DOTA analogue has been conjugated to a calix[4]arene and the corresponding Gd-complex was characterized with respect to its suitability as MRI contrast agent. The compound forms spherical micelles in water with a cmc of 35 mM and a radius of 8.2 nm. The relaxivity of these aggregates is 31.2 s-1 mM-1 at 25 • C and 20 MHz, which corresponds to a molecular relaxivity of 125 s-1 mM-1. The high relaxivity mainly originates from the short t M (72.7 ns) and the size of the micelles. The interaction with bovine serum albumin (BSA) was studied and an observed relaxivity of up to 40.8 s-1 mM-1 (163.2 s-1 mM-1 per binding place) at 20 MHz and 37 • C was found in the presence of 2.0 mM protein.
European Journal of Nuclear Medicine and Molecular Imaging, Jan 13, 2010
Investigation on a novel bifunctional derivative of H4dota containing three acetate and one phosp... more Investigation on a novel bifunctional derivative of H4dota containing three acetate and one phosphinate pendant arms and propionic acid substituent on phosphorus atom was presented.
Chemicke Listy, 2010
Magnetic resonance imaging (MRI) and positron emission tomography (PET) have gained a great impor... more Magnetic resonance imaging (MRI) and positron emission tomography (PET) have gained a great importance in the last thirty years in medicinal diagnostics as imaging techniques with a superior spatial resolution and contrast. MRI has assumed a critical role in medicinal diagnosis and applications of contrast agents (CAs), mostly based on Gd(III) complexes. For this purpose, specific CAs have been developed, changing relaxivity after cleavage of some bonds sensitive to the presence of specific ions or metabolites. For PET applications, a new isotope 68Ga(III) has been proposed. In view of utilization of toxic ions, the crucial condition for their applications in vivo is their complexation in stable species. In this review, the ligand types and structures of their complexes as well as their physicochemical parameters are discussed.
New J. Chem., 2017
The interaction of aminomethylphosphonic acid with the Zn(ii)–cyclen complex was evaluated by an ... more The interaction of aminomethylphosphonic acid with the Zn(ii)–cyclen complex was evaluated by an original combination of potentiometry and multinuclear NMR.
Inorganica Chimica Acta, 2018
J. Chem. Soc., Dalton Trans., 1996
ABSTRACT
Polyhedron, 1995
The synthesis of compounds of piperazine-l,4-diylbis(methylene)bis(phosphinic) acid (H2L) (1) wit... more The synthesis of compounds of piperazine-l,4-diylbis(methylene)bis(phosphinic) acid (H2L) (1) with Co 11 is described and the X-ray structures of the isolated complexes [Co(H2L)3](C104)2 • 2H20 (2) and [Co(H20)6]L (3), have been determined. Compound 2 forms a three-dimensional polymeric network of cobalt atoms bridged by 1, which is monodentately coordinated to cobalt through the phosphinate groups. The nitrogen atoms are protonated and non-coordinated. In 3, 1 is deprotonated and forms non-coordinated anions and the octahedral coordination sphere of the cobalt atoms consists of water molecules.
ChemInform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Polyhedron, 1986
Substances of the types MH,ntmp, Wd3Wntmph, M2H2ntmp and Mg[M,(Hntmp)],, where M = Co, Ni, Cu, Zn... more Substances of the types MH,ntmp, Wd3Wntmph, M2H2ntmp and Mg[M,(Hntmp)],, where M = Co, Ni, Cu, Zn and H6ntmp = N[CH,PO(OH)d, were prepared. The sodium and cesium salts of the [Co(Hntmp)13-complexes were also prepared. The IR and electronic spectra and the experimental magnetic susceptibilities indicate that these are high-spin complexes. The coordination surroundings of the central atom consist of a highly distorted octahedron of the ligand oxygen atoms. The nitrogen atom is not coordinated to the central atom.
Journal of Radioanalytical and Nuclear Chemistry, 2007
The complex formation of the bifunctional monophosphinic acid DOTA analogue DO3APABn (1,4,7,10-te... more The complex formation of the bifunctional monophosphinic acid DOTA analogue DO3APABn (1,4,7,10-tetraazacyclododecane-4,7,10-triacetic-1-{methyl[(4-aminophenyl)methyl] phosphinic acid}) with 111In at a tracer level was analyzed. Formation of a complex between 111In and DO3APABn was very rapid even at room temperature and high radiolabeling yields were achieved. As introducing the methylphosphinic acid arm to the DOTA structure generated a chiral centre, more than one peak (probably corresponding to various diastereoisomers) of 111In-DO3APABn were separated on HPLC. Four peaks were separated by HPLC, they probably correspond to four diastereoisomers of 111In-DO3APABn originating from combination of chirality of complexes of DOTA-like ligands with chirality of coordinated phosphorus atom. Studies in rats showed rapid elimination of radioactivity from the blood and other organs and tissues. The results indicate that DO3APABn represents a promising ligand for radiolabeling of target-specific biomolecules with radiometals.
Inorganic Chemistry, 2009
European Journal of Nuclear Medicine and Molecular Imaging, 2010
European Journal of Inorganic Chemistry, 2007
Two new tetraamine ligands, bis[N‐(2‐aminoethyl)aminomethyl]phosphinic acid (Hen2p) and bis[N‐(3‐... more Two new tetraamine ligands, bis[N‐(2‐aminoethyl)aminomethyl]phosphinic acid (Hen2p) and bis[N‐(3‐aminopropyl)aminomethyl]phosphinic acid (Hpn2p), were synthesized from the corresponding diaminoalkanes and bis(chloromethyl)phosphinic acid. Their acid–base properties and complexation with Cu2+, Ni2+, and Zn2+ ions were studied by potentiometric titrations. Different chain lengths of the ligands result in significantly different coordination abilities. The five‐membered chelate ring of Hen2p leads to a higher stability of its complexes. In comparison with tetraamines having the same number of the bridging atoms separating the amino groups, the presence of the phosphinic acid moiety decreases the basicity of the amine groups, and consequently, the stability of their complexes. Several solid‐state structures were determined by X‐ray diffraction analysis. Four nitrogen atoms coordinate the Cu2+ or Zn2+ ion in a square‐planar fashion, whereas the phosphinic acid group is not coordinated or...
Dalton Trans., 2003
Bis(aminomethyl)phosphinic acid, (NH2CH2)2PO2H (HL), was synthesized using a new procedure. Its c... more Bis(aminomethyl)phosphinic acid, (NH2CH2)2PO2H (HL), was synthesized using a new procedure. Its coordination ability towards Co(II)/(III), Ni(II), Cu(II) and Zn(II) was studied both in solution and in the solid state. Because of the presence of two nitrogen atoms the ligand exhibits a higher overall basicity than common (aminoalkyl)phosphinic acids. Consequently, the values of the determined stability constants are comparable with those found for (aminoalkyl)phosphonic acids. NMR titrations of Zn(II) point to the interaction of phosphinate with the metal ion in a strong acid solution. The X-ray structures show several coordination modes in the solid state. All-trans-[MCl2(H2L-O)2(H2O)2]Cl2, where M(II) are Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Ca(II), and Cd(II), crystallized from acid solutions. The central ion is octahedrally coordinated with two phosphinate oxygen atoms, two molecules of water and two chlorides in all-trans arrangement. Amine groups are protonated and non-coordinated. Participation of the donor groups in crystals isolated from neutral solutions depends on the metal ion. All donor atoms are coordinated in monomeric fac-N,N,O-trans-O,O′-[Co(L-N,N,O)2]+. On the other hand, in the zinc(II) complex, two phosphinate oxygen atoms and two amine nitrogen atoms (trans to each other) of two different ligand molecules are coordinated in an equatorial plane and two amino groups of the two other ligand molecules are bound in axial positions. Thus, each molecule of the amino acid forms a five-membered N,O-chelate to one zinc(II) ion and the other amino group is bound to the neighbouring ion creating an infinite chain. Nickel(II) forms a trans-O,O′-[Ni(H2O)2(L-N,N)2] complex in which the metal ion is chelated by four amine nitrogen atoms forming two six-membered chelates in an equatorial plane and the octahedron is completed with two water molecules at the apical positions. The phosphinate group is not coordinated. The above results point to a relatively low coordination ability of the phosphinate group; however, due to its low pKA, it is able to bind metal ions at lower pH than other coordinating groups do.
Description of experiments of copper complexes of high thermodynamic selectivity and extraordinar... more Description of experiments of copper complexes of high thermodynamic selectivity and extraordinary kinetic inertness.
Ln(III) complexes of H4dota and its derivatives are utilized in many areas of medicine. The molec... more Ln(III) complexes of H4dota and its derivatives are utilized in many areas of medicine. The molecular spectroscopy in UV/VIS region was employed to investigate chemical features of Eu(III)/Gd(III)/Tb(III) complexes of the title ligand in order to investigate their possible applications as bimodal agents. The stability constants and acid-assisted dissociation of Ln(III) complexes show high thermodynamic stability and kinetic inertness. In the study of formation (pH = 5.0-6.0, t = 25 C, I = 0.1 M KCl) was found that the reactive species is HL 2- and the rate increases with decreasing ionic radius of the metal ions and it follows a trend along the Ln(III) series. The ligand capable of complex formation due show interesting photophysical properties to presence of chromophor/fluorophor group and it enables to determine the low concentration of Eu(III)/Tb(III) ions.
Philosophical Transactions of the Royal Society A, Sep 28, 2010
Core-shell nanoparticles consisting of La 0.75 Sr 0.25 MnO 3 cores covered by silica were synthes... more Core-shell nanoparticles consisting of La 0.75 Sr 0.25 MnO 3 cores covered by silica were synthesized by a procedure consisting of several steps, including the sol-gel method in the presence of citric acid and ethylene glycol, thermal and mechanical treatment, encapsulation employing tetraethoxysilane and final separation by centrifugation in order to get the required size fraction. Morphological studies revealed well-separated particles that form a stable water suspension. Magnetic studies include magnetization measurements and investigation of the ferromagnetic-superparamagnetic-paramagnetic transition. Magnetic heating experiments in 'calorimetric mode' were used to determine the heating efficiency of the particles in water suspension and further employed for biological studies of extracellular and intracellular effects analysed by tests of viability.
Dalton Transactions, 2010
A pyridine-N-oxide functionalized DOTA analogue has been conjugated to a calix[4]arene and the co... more A pyridine-N-oxide functionalized DOTA analogue has been conjugated to a calix[4]arene and the corresponding Gd-complex was characterized with respect to its suitability as MRI contrast agent. The compound forms spherical micelles in water with a cmc of 35 mM and a radius of 8.2 nm. The relaxivity of these aggregates is 31.2 s-1 mM-1 at 25 • C and 20 MHz, which corresponds to a molecular relaxivity of 125 s-1 mM-1. The high relaxivity mainly originates from the short t M (72.7 ns) and the size of the micelles. The interaction with bovine serum albumin (BSA) was studied and an observed relaxivity of up to 40.8 s-1 mM-1 (163.2 s-1 mM-1 per binding place) at 20 MHz and 37 • C was found in the presence of 2.0 mM protein.
European Journal of Nuclear Medicine and Molecular Imaging, Jan 13, 2010
Investigation on a novel bifunctional derivative of H4dota containing three acetate and one phosp... more Investigation on a novel bifunctional derivative of H4dota containing three acetate and one phosphinate pendant arms and propionic acid substituent on phosphorus atom was presented.
Chemicke Listy, 2010
Magnetic resonance imaging (MRI) and positron emission tomography (PET) have gained a great impor... more Magnetic resonance imaging (MRI) and positron emission tomography (PET) have gained a great importance in the last thirty years in medicinal diagnostics as imaging techniques with a superior spatial resolution and contrast. MRI has assumed a critical role in medicinal diagnosis and applications of contrast agents (CAs), mostly based on Gd(III) complexes. For this purpose, specific CAs have been developed, changing relaxivity after cleavage of some bonds sensitive to the presence of specific ions or metabolites. For PET applications, a new isotope 68Ga(III) has been proposed. In view of utilization of toxic ions, the crucial condition for their applications in vivo is their complexation in stable species. In this review, the ligand types and structures of their complexes as well as their physicochemical parameters are discussed.
New J. Chem., 2017
The interaction of aminomethylphosphonic acid with the Zn(ii)–cyclen complex was evaluated by an ... more The interaction of aminomethylphosphonic acid with the Zn(ii)–cyclen complex was evaluated by an original combination of potentiometry and multinuclear NMR.
Inorganica Chimica Acta, 2018
J. Chem. Soc., Dalton Trans., 1996
ABSTRACT
Polyhedron, 1995
The synthesis of compounds of piperazine-l,4-diylbis(methylene)bis(phosphinic) acid (H2L) (1) wit... more The synthesis of compounds of piperazine-l,4-diylbis(methylene)bis(phosphinic) acid (H2L) (1) with Co 11 is described and the X-ray structures of the isolated complexes [Co(H2L)3](C104)2 • 2H20 (2) and [Co(H20)6]L (3), have been determined. Compound 2 forms a three-dimensional polymeric network of cobalt atoms bridged by 1, which is monodentately coordinated to cobalt through the phosphinate groups. The nitrogen atoms are protonated and non-coordinated. In 3, 1 is deprotonated and forms non-coordinated anions and the octahedral coordination sphere of the cobalt atoms consists of water molecules.
ChemInform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Polyhedron, 1986
Substances of the types MH,ntmp, Wd3Wntmph, M2H2ntmp and Mg[M,(Hntmp)],, where M = Co, Ni, Cu, Zn... more Substances of the types MH,ntmp, Wd3Wntmph, M2H2ntmp and Mg[M,(Hntmp)],, where M = Co, Ni, Cu, Zn and H6ntmp = N[CH,PO(OH)d, were prepared. The sodium and cesium salts of the [Co(Hntmp)13-complexes were also prepared. The IR and electronic spectra and the experimental magnetic susceptibilities indicate that these are high-spin complexes. The coordination surroundings of the central atom consist of a highly distorted octahedron of the ligand oxygen atoms. The nitrogen atom is not coordinated to the central atom.
Journal of Radioanalytical and Nuclear Chemistry, 2007
The complex formation of the bifunctional monophosphinic acid DOTA analogue DO3APABn (1,4,7,10-te... more The complex formation of the bifunctional monophosphinic acid DOTA analogue DO3APABn (1,4,7,10-tetraazacyclododecane-4,7,10-triacetic-1-{methyl[(4-aminophenyl)methyl] phosphinic acid}) with 111In at a tracer level was analyzed. Formation of a complex between 111In and DO3APABn was very rapid even at room temperature and high radiolabeling yields were achieved. As introducing the methylphosphinic acid arm to the DOTA structure generated a chiral centre, more than one peak (probably corresponding to various diastereoisomers) of 111In-DO3APABn were separated on HPLC. Four peaks were separated by HPLC, they probably correspond to four diastereoisomers of 111In-DO3APABn originating from combination of chirality of complexes of DOTA-like ligands with chirality of coordinated phosphorus atom. Studies in rats showed rapid elimination of radioactivity from the blood and other organs and tissues. The results indicate that DO3APABn represents a promising ligand for radiolabeling of target-specific biomolecules with radiometals.
Inorganic Chemistry, 2009
European Journal of Nuclear Medicine and Molecular Imaging, 2010
European Journal of Inorganic Chemistry, 2007
Two new tetraamine ligands, bis[N‐(2‐aminoethyl)aminomethyl]phosphinic acid (Hen2p) and bis[N‐(3‐... more Two new tetraamine ligands, bis[N‐(2‐aminoethyl)aminomethyl]phosphinic acid (Hen2p) and bis[N‐(3‐aminopropyl)aminomethyl]phosphinic acid (Hpn2p), were synthesized from the corresponding diaminoalkanes and bis(chloromethyl)phosphinic acid. Their acid–base properties and complexation with Cu2+, Ni2+, and Zn2+ ions were studied by potentiometric titrations. Different chain lengths of the ligands result in significantly different coordination abilities. The five‐membered chelate ring of Hen2p leads to a higher stability of its complexes. In comparison with tetraamines having the same number of the bridging atoms separating the amino groups, the presence of the phosphinic acid moiety decreases the basicity of the amine groups, and consequently, the stability of their complexes. Several solid‐state structures were determined by X‐ray diffraction analysis. Four nitrogen atoms coordinate the Cu2+ or Zn2+ ion in a square‐planar fashion, whereas the phosphinic acid group is not coordinated or...
Dalton Trans., 2003
Bis(aminomethyl)phosphinic acid, (NH2CH2)2PO2H (HL), was synthesized using a new procedure. Its c... more Bis(aminomethyl)phosphinic acid, (NH2CH2)2PO2H (HL), was synthesized using a new procedure. Its coordination ability towards Co(II)/(III), Ni(II), Cu(II) and Zn(II) was studied both in solution and in the solid state. Because of the presence of two nitrogen atoms the ligand exhibits a higher overall basicity than common (aminoalkyl)phosphinic acids. Consequently, the values of the determined stability constants are comparable with those found for (aminoalkyl)phosphonic acids. NMR titrations of Zn(II) point to the interaction of phosphinate with the metal ion in a strong acid solution. The X-ray structures show several coordination modes in the solid state. All-trans-[MCl2(H2L-O)2(H2O)2]Cl2, where M(II) are Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Ca(II), and Cd(II), crystallized from acid solutions. The central ion is octahedrally coordinated with two phosphinate oxygen atoms, two molecules of water and two chlorides in all-trans arrangement. Amine groups are protonated and non-coordinated. Participation of the donor groups in crystals isolated from neutral solutions depends on the metal ion. All donor atoms are coordinated in monomeric fac-N,N,O-trans-O,O′-[Co(L-N,N,O)2]+. On the other hand, in the zinc(II) complex, two phosphinate oxygen atoms and two amine nitrogen atoms (trans to each other) of two different ligand molecules are coordinated in an equatorial plane and two amino groups of the two other ligand molecules are bound in axial positions. Thus, each molecule of the amino acid forms a five-membered N,O-chelate to one zinc(II) ion and the other amino group is bound to the neighbouring ion creating an infinite chain. Nickel(II) forms a trans-O,O′-[Ni(H2O)2(L-N,N)2] complex in which the metal ion is chelated by four amine nitrogen atoms forming two six-membered chelates in an equatorial plane and the octahedron is completed with two water molecules at the apical positions. The phosphinate group is not coordinated. The above results point to a relatively low coordination ability of the phosphinate group; however, due to its low pKA, it is able to bind metal ions at lower pH than other coordinating groups do.