Paolo Tecilla | Università degli Studi di Trieste (original) (raw)
Papers by Paolo Tecilla
Chemistry-a European Journal, 2007
Inorganic Chemistry, 2003
The catalytic effects of the Zn(II) complexes of a series of poliaminic ligands in the hydrolysis... more The catalytic effects of the Zn(II) complexes of a series of poliaminic ligands in the hydrolysis of the activated phosphodiesters bis-p-nitrophenyl phosphate (BNP) and 2-hydroxypropyl-p-nitrophenyl phosphate (HPNP) have been investigated. The reactions show first-order rate dependency on both substrate and metal ion complex and a pH dependence which is diagnostic of the acid dissociation of the reactive species. The mechanism of the metal catalyzed transesterification of HPNP has been assessed by solvent isotopic kinetic effect studies and involves the intramolecular nucleophilic attack of the substrate alcoholic group, activated by metal ion coordination. The intrinsic reactivity of the different complexes is controlled by the nature and structure of the ligand: complexes of tridentate ligands, particularly if characterized by a facial coordination mode, are more reactive than those of tetradentate ligands which can hardly allow binding sites for the substrate. In the case of tridentate ligands that form complexes with a facial coordination mode, a linear Brønsted correlation between the reaction rate (log k) and the pK(a) of the active nucleophile is obtained. The beta(nuc) values are 0.75 for the HPNP transesterification and 0.20 for the BNP hydrolysis. These values are indicated as the result of the combination of two opposite Lewis acid effects of the Zn(II) ion: the activation of the substrate and the efficiency of the metal coordinated nucleophile. The latter factor apparently prevails in determining the intrinsic reactivity of the Zn(II) complexes.
Chemical Communications, 2003
A fluorescence nanosensor for Cu2+ ions has been obtained by surface functionalization of silica ... more A fluorescence nanosensor for Cu2+ ions has been obtained by surface functionalization of silica particles with trialkoxysilane derivatized ligand and fluorescent dye.
Journal of The American Chemical Society, 1990
Page 1. 9408 J. Am. Chem. SOC. 1990, 112, 9408-9410 2.5r 2.0. 1.5. Diff. in Fluor. Emiss. I .o. H... more Page 1. 9408 J. Am. Chem. SOC. 1990, 112, 9408-9410 2.5r 2.0. 1.5. Diff. in Fluor. Emiss. I .o. Hydrogen-Bonding Self-Assembly of Multichromophore Structures Paolo Tecilla,' Robert P. Dixon, Gregory Slobodkin, David S. Alavi ...
Journal of Materials Chemistry, 2005
The homopolymer poly(methyl methacrylate) (PMMA) shells were grafted onto the silica nanoparticle... more The homopolymer poly(methyl methacrylate) (PMMA) shells were grafted onto the silica nanoparticle surfaces by iron(Z)-mediated atom transfer radical polymerisation with activators regenerated by electron transfer (ARGET ATRP). The grafting process was carried out in two steps. First, the halogen-functional ATRP initiators were immobilised on the silica nanoparticle surfaces. Secondly, the polymerisation of methyl methacrylate was conducted on the surfaces of silica using FeCl 3 as the catalyst and ascorbic acid (VC) as the reducing agent in the presence of a limited amount of air. Well-defined polymer was grown from the silica surfaces to yield nanospheres composed of a silica core and a densely grafted outer PMMA shell.
New Journal of Chemistry, 2007
ABSTRACT The development of synthetic agents able to hydrolytically cleave phosphate diester bond... more ABSTRACT The development of synthetic agents able to hydrolytically cleave phosphate diester bonds with high efficiency is a fascinating challenge, which will ultimately open the way to artificial nucleases able to compete with the natural enzymes. This Perspective highlights the progress reported in the realization of hydrolytic catalysts based on the Zn2+ ion, a metal ion which, due to its peculiar properties, is a very promising candidate. The review critically examines the reactivity of such catalysts toward model substrates and nucleic acids, paying particular attention to the strategies that can be pursued to improve efficiency and sequence selectivity.
Chemistry-a European Journal, 2006
Molecular Recognition and Inclusion, 1998
Journal of the Chemical Society, Chemical Communications, 1990
... Paolo Tecilla and Andrew D. Hamilton* Department of Chemistry, University of Pittsburgh, Pitt... more ... Paolo Tecilla and Andrew D. Hamilton* Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA ... B. S. Green, Y. Ashari, and D. Chipman, Elsevier, Amsterdam, 1982; H. Dugas, 'Bioorganic Chemistry,' Springer Verlag, New York, 1989, p. 172. ...
Journal of the Chemical Society, Perkin Transactions 2, 1996
Source of catalysis of dephosphorylation of p-nitrophenyldiphenylphosphate by metallomicelles. Re... more Source of catalysis of dephosphorylation of p-nitrophenyldiphenylphosphate by metallomicelles. References. 1, (a) J. Chin and V. Jubian, J. Chem. Soc., Chem. Commun., 1989, 839 RSC Article ; (b) J. Chin and M. Banaszczyk, J. Am. Chem. ...
Tetrahedron Letters, 1994
ABSTRACT
Coordination Chemistry Reviews, 2009
Tetrahedron Letters, 2003
1,3,5-Triazacyclononane macrocycle has been linked to the soluble polymer monomethoxy poly(ethyle... more 1,3,5-Triazacyclononane macrocycle has been linked to the soluble polymer monomethoxy poly(ethyleneglycol) and its copper(II) complex efficiently catalyzes the hydrolysis of a model phosphodiester. The catalyst, easily recovered from the water solution, shows no appreciable loss of activity when recycled up to three times.
A new chemosensor for the Cu(II) ion has been realized by connecting via an amido bond an anthrac... more A new chemosensor for the Cu(II) ion has been realized by connecting via an amido bond an anthracenyl residue to the all cis 2,4,6-triamino-1,3,5-trihydroxycyclohexane ligand (TACI). This sensor is able to detect micromolar concentrations of Cu(II) ions in water at pH 7 without interference with many other divalent transition metal ions.
The self-organization of fluorescent dyes and receptors on a proper template to form an organized... more The self-organization of fluorescent dyes and receptors on a proper template to form an organized assembly is a new strategy for the realization of fluorescence chemosensors. In the assembly, the two subunits do not interact directly and the communication between the bound substrate and the dye is only determined by their spatial closeness ensured by the template. The method is simple and the main advantages are related to the minimization of the synthetic work, the ease of modification and optimization of the sensor, the possibility to tune its properties by the simple adjustment of the components ratio. Self-organizing methodologies can open new perspectives to fluorescence chemosensors, both by allowing a simplified preparation and by opening the way to new and more complex functions. This article deals with this new approach and discusses its evolution, applications, and limitations.
Chemistry-a European Journal, 2007
Inorganic Chemistry, 2003
The catalytic effects of the Zn(II) complexes of a series of poliaminic ligands in the hydrolysis... more The catalytic effects of the Zn(II) complexes of a series of poliaminic ligands in the hydrolysis of the activated phosphodiesters bis-p-nitrophenyl phosphate (BNP) and 2-hydroxypropyl-p-nitrophenyl phosphate (HPNP) have been investigated. The reactions show first-order rate dependency on both substrate and metal ion complex and a pH dependence which is diagnostic of the acid dissociation of the reactive species. The mechanism of the metal catalyzed transesterification of HPNP has been assessed by solvent isotopic kinetic effect studies and involves the intramolecular nucleophilic attack of the substrate alcoholic group, activated by metal ion coordination. The intrinsic reactivity of the different complexes is controlled by the nature and structure of the ligand: complexes of tridentate ligands, particularly if characterized by a facial coordination mode, are more reactive than those of tetradentate ligands which can hardly allow binding sites for the substrate. In the case of tridentate ligands that form complexes with a facial coordination mode, a linear Brønsted correlation between the reaction rate (log k) and the pK(a) of the active nucleophile is obtained. The beta(nuc) values are 0.75 for the HPNP transesterification and 0.20 for the BNP hydrolysis. These values are indicated as the result of the combination of two opposite Lewis acid effects of the Zn(II) ion: the activation of the substrate and the efficiency of the metal coordinated nucleophile. The latter factor apparently prevails in determining the intrinsic reactivity of the Zn(II) complexes.
Chemical Communications, 2003
A fluorescence nanosensor for Cu2+ ions has been obtained by surface functionalization of silica ... more A fluorescence nanosensor for Cu2+ ions has been obtained by surface functionalization of silica particles with trialkoxysilane derivatized ligand and fluorescent dye.
Journal of The American Chemical Society, 1990
Page 1. 9408 J. Am. Chem. SOC. 1990, 112, 9408-9410 2.5r 2.0. 1.5. Diff. in Fluor. Emiss. I .o. H... more Page 1. 9408 J. Am. Chem. SOC. 1990, 112, 9408-9410 2.5r 2.0. 1.5. Diff. in Fluor. Emiss. I .o. Hydrogen-Bonding Self-Assembly of Multichromophore Structures Paolo Tecilla,' Robert P. Dixon, Gregory Slobodkin, David S. Alavi ...
Journal of Materials Chemistry, 2005
The homopolymer poly(methyl methacrylate) (PMMA) shells were grafted onto the silica nanoparticle... more The homopolymer poly(methyl methacrylate) (PMMA) shells were grafted onto the silica nanoparticle surfaces by iron(Z)-mediated atom transfer radical polymerisation with activators regenerated by electron transfer (ARGET ATRP). The grafting process was carried out in two steps. First, the halogen-functional ATRP initiators were immobilised on the silica nanoparticle surfaces. Secondly, the polymerisation of methyl methacrylate was conducted on the surfaces of silica using FeCl 3 as the catalyst and ascorbic acid (VC) as the reducing agent in the presence of a limited amount of air. Well-defined polymer was grown from the silica surfaces to yield nanospheres composed of a silica core and a densely grafted outer PMMA shell.
New Journal of Chemistry, 2007
ABSTRACT The development of synthetic agents able to hydrolytically cleave phosphate diester bond... more ABSTRACT The development of synthetic agents able to hydrolytically cleave phosphate diester bonds with high efficiency is a fascinating challenge, which will ultimately open the way to artificial nucleases able to compete with the natural enzymes. This Perspective highlights the progress reported in the realization of hydrolytic catalysts based on the Zn2+ ion, a metal ion which, due to its peculiar properties, is a very promising candidate. The review critically examines the reactivity of such catalysts toward model substrates and nucleic acids, paying particular attention to the strategies that can be pursued to improve efficiency and sequence selectivity.
Chemistry-a European Journal, 2006
Molecular Recognition and Inclusion, 1998
Journal of the Chemical Society, Chemical Communications, 1990
... Paolo Tecilla and Andrew D. Hamilton* Department of Chemistry, University of Pittsburgh, Pitt... more ... Paolo Tecilla and Andrew D. Hamilton* Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA ... B. S. Green, Y. Ashari, and D. Chipman, Elsevier, Amsterdam, 1982; H. Dugas, 'Bioorganic Chemistry,' Springer Verlag, New York, 1989, p. 172. ...
Journal of the Chemical Society, Perkin Transactions 2, 1996
Source of catalysis of dephosphorylation of p-nitrophenyldiphenylphosphate by metallomicelles. Re... more Source of catalysis of dephosphorylation of p-nitrophenyldiphenylphosphate by metallomicelles. References. 1, (a) J. Chin and V. Jubian, J. Chem. Soc., Chem. Commun., 1989, 839 RSC Article ; (b) J. Chin and M. Banaszczyk, J. Am. Chem. ...
Tetrahedron Letters, 1994
ABSTRACT
Coordination Chemistry Reviews, 2009
Tetrahedron Letters, 2003
1,3,5-Triazacyclononane macrocycle has been linked to the soluble polymer monomethoxy poly(ethyle... more 1,3,5-Triazacyclononane macrocycle has been linked to the soluble polymer monomethoxy poly(ethyleneglycol) and its copper(II) complex efficiently catalyzes the hydrolysis of a model phosphodiester. The catalyst, easily recovered from the water solution, shows no appreciable loss of activity when recycled up to three times.
A new chemosensor for the Cu(II) ion has been realized by connecting via an amido bond an anthrac... more A new chemosensor for the Cu(II) ion has been realized by connecting via an amido bond an anthracenyl residue to the all cis 2,4,6-triamino-1,3,5-trihydroxycyclohexane ligand (TACI). This sensor is able to detect micromolar concentrations of Cu(II) ions in water at pH 7 without interference with many other divalent transition metal ions.
The self-organization of fluorescent dyes and receptors on a proper template to form an organized... more The self-organization of fluorescent dyes and receptors on a proper template to form an organized assembly is a new strategy for the realization of fluorescence chemosensors. In the assembly, the two subunits do not interact directly and the communication between the bound substrate and the dye is only determined by their spatial closeness ensured by the template. The method is simple and the main advantages are related to the minimization of the synthetic work, the ease of modification and optimization of the sensor, the possibility to tune its properties by the simple adjustment of the components ratio. Self-organizing methodologies can open new perspectives to fluorescence chemosensors, both by allowing a simplified preparation and by opening the way to new and more complex functions. This article deals with this new approach and discusses its evolution, applications, and limitations.