0000000001301058
AUTHOR
Carla Bazzicalupi
Structural and magnetic properties of polynuclear oximate copper complexes with different topologies
Abstract Two new copper(II) complexes containing the methyl(2-pyridyl)ketone oxime ligand (mpkoH) [Cu3(OH)(ClO4)2(mpko)3]·CH3OH (1) and [Cu(ClO4)(mpko)(mpkoH)]n (2) have been prepared from Cu(ClO4)2 and mpkoH in different metal-to-ligand molar ratios. In addition, the compound [Cu{(mpko)2BF2}(H2O)](BF4) (3) [(mpko)2BF2 is the fluoroboration product of the oxime] has been obtained when replacing Cu(ClO4)2 by Cu(BF4)2. Compound 1 is an isolated triangle with a {Cu3(µ3-OH)}5+ core, whereas 2 is a chain of CuII ions linked by anionic mpko− bridges. 1 exhibits strong antiferromagnetic competing interactions, as well as antisymmetric exchange. On the other hand, very weak ferromagnetic interactio…
Proton and metal binding by cyclen-based highly rigid cryptands.
The basicity properties of the two cryptands L1 and L2, featuring, respectively, a dibenzofuran or a diphenyl ether moiety bridging the 1,7 positions of a 1,4,7,10-tetraazacyclododecane macrocycle (cyclen) have been studied by means of potentiometric, UV-vis and fluorescence emission measurements. Both ligands show a high basicity in the first protonation step, the first basicity constant of L1 being too high to be measured in aqueous solution. The crystal structure of {[HL1]L1}(+) shows that the NH(2)(+) group is involved in an intramolecular hydrogen bonding network, which justifies the observed high basicity in solution. (1)H, (13)C NMR, UV-vis and fluorescence emission measurements show…
Determinants for Tight and Selective Binding of a Medicinal Dicarbene Gold(I) Complex to a Telomeric DNA G-Quadruplex: a Joint ESI MS and XRD Investigation
International audience; The dicarbene gold(I) complex [Au(9-methylcaffein-8-ylidene)(2)]BF4 is an exceptional organometallic compound of profound interest as a prospective anticancer agent. This gold(I) complex was previously reported to be highly cytotoxic toward various cancer cell lines invitro and behaves as a selective G-quadruplex stabilizer. Interactions of the gold complex with various telomeric DNA models have been analyzed by a combined ESI MS and X-ray diffraction (XRD) approach. ESI MS measurements confirmed formation of stable adducts between the intact gold(I) complex and Tel 23 DNA sequence. The crystal structure of the adduct formed between [Au(9-methylcaffein-8-ylidene)(2)]…
Polyfunctional Tetraaza-Macrocyclic Ligands: Zn(II), Cu(II) Binding and Formation of Hybrid Materials with Multiwalled Carbon Nanotubes
The binding properties of HL1, HL2, and HL3 ligands toward Cu(II) and Zn(II) ions, constituted by tetraaza-macrocyclic rings decorated with pyrimidine pendants, were investigated by means of potentiometric and UV spectrophotometric measurements in aqueous solution, with the objective of using the related HL-M(II) (HL = HL1–HL3; M = Cu, Zn) complexes for the preparation of hybrid MWCNT-HL-M(II) materials based on multiwalled carbon nanotubes (MWCNTs), through an environmentally friendly noncovalent procedure. As shown by the crystal structure of [Cu(HL1)](ClO4)2, metal coordination takes place in the macrocyclic ring, whereas the pyrimidine residue remains available for attachment onto the s…
Exchange coupling in a thiocyanato-bridged copper(II) chain: Computational approach to magnetostructural correlations
Abstract In this article we report the synthesis and magneto-structural characterization of two new copper(II) compounds with thiocyanato and methyl(2-pyridil) ketone oxime (mpkOH), namely [Cu(NCS)(mpkO)(mpkOH)] (1) and [Cu(µ-NCS)(NCS)(mpkOH)]n (2). Compound 1 is a mononuclear complex that crystallizes as discrete units. Conversely, compound 2 is a single equatorial-axial end-to-end thiocyanato bridged polymeric chain of Cu(II) with the oxime as a co-ligand. The coordination geometry around the Cu(II) centers is distorted square pyramidal for 1 and 2. The magnetic susceptibility data for 2 reveal weak intrachain antiferromagnetic coupling, with J value −0.74(3) cm−1 and g = 2.10(1). The ap…
Structural Studies on Polyaza[n]paracyclophanes. A Molecular Mechanics and Crystallographic Study
Abstract Structural analysis of polyaza[n]paracyclophanes 1-5 has been carried out by the use of molecular mechanics and other techniques. NMR data and molecular mechanics calculations show that conformations in which the polyamine chain is arching above the aromatic ring are prevalent in solution. The crystal structure of triprotonated durene derivative 2b agrees with those studies. Crystals of 3H+.2b are triclinic, space group P1, with a = 11.758(4) A, b = 13.870(5) A, c = 17.181(3) A, α = 96.66(2)°, β = 106.02(2)°, γ = 104.87(3)°, Z = 4, R1 = 0.072, wR2 = 0.18. Three different conformations are present in the crystal. Good agreement between the crystal structures and calculated conformat…
Addressing selectivity criteria in binding equilibria
Abstract Chemical systems, in particular those involving biological and environmental backgrounds, develop through selective processes which are determined by multiple equilibria. Several methods that have been developed to assess thermodynamic selectivity in binding equilibria, including the analysis of selectivity coefficients, the use of calculated species distribution diagrams, selectivity diagrams, and conditional stability constants, are reviewed in this paper with reference to examples mainly related to chemical systems of biological and/or environmental concern. Also the concept of binding affinity has been dealt with, since binding selectivity in equilibrium systems relates to the …
Metals in supramolecular chemistry
Abstract Metals have played a fundamental role in the development of supramolecular chemistry. The main steps taken from the pre-supramolecular age to the present time are retraced with a brief description of salient examples from the unconscious use of gold nanoparticle in the preparation of the Lycurgus cup (5th or 4th century B.C.) to the modern use of metals as templates, for the preparation of large self-assembled structures, of molecular sensors, switches, motors and machines, for mimicking biological processes, for tissue and organ imaging or for the application of the Boolean logic at the molecular level.
A thermodynamic insight into the recognition of hydrophilic and hydrophobic amino acids in pure water by aza-scorpiand type receptors.
Interactions of different hydrophilic (His, Asp, Glu,) and hydrophobic (Ala, Phe, Tyr, Trp) amino acids in water with a scorpiand aza-macrocycle (L1) containing a pyridine group in the ring and its derivative (L2) bearing a naphthalene group in the tail have been analysed by potentiometric and calorimetric measurements. Theoretical calculations corroborate that major attractive forces that hold the adduct together are hydrogen bonds and salt-bridges, even though other interactions such as π-stacking or NH(+)⋯π may contribute in the case of hydrophobic amino acids and L2. Calorimetric measurements indicate that the interactions between L1 and the different amino acids are principally driven …
Assembly of Polyiodide Networks with Cu(II) Complexes of Pyridinol-Based Tetraaza Macrocycles
Polyiodide networks are currently of great practical interest for the preparation of new electronic materials. The participation of metals in the formation of these networks is believed to improve their mechanical performance and thermal stability. Here we report the results on the construction of polyiodide networks obtained using Cu(II) complexes of a series of pyridinol-based tetraazacyclophanes as countercations. The assembly of these crystalline polyiodides takes place from aqueous solutions on the basis of similar structural elements, the [CuL]2+ and [Cu(H–1L)]+ (L = L2, L2-Me, L2-Me3) complex cations, so that the peculiarities induced by the increase of N-methylation of ligands, the …
[Au(9-methylcaffein-8-ylidene) 2 ] + /DNA Tel23 System: Solution, Computational, and Biological Studies
International audience; Physicochemical methods have been used to investigate interactions occurring in solution between the dicarbene gold(I) complex [Au(9‐methylcaffein‐8‐ylidene)2]BF4 (AuNHC) and a human telomeric DNA sequence, namely Tel23. Circular dichroism measurements allow identification of the conformational changes experienced by Tel23 upon interaction with AuNHC, and the respective binding stoichiometries and constants were determined. Computational studies provide a good link between previous crystallographic results of the same system and the present solution data, offering an exhaustive description of the inherent noncovalent metallodrug–DNA interactions. Remarkably, we found…
Construction of green nanostructured heterogeneous catalysts via non-covalent surface decoration of multi-walled carbon nanotubes with Pd(II) complexes of azamacrocycles
Abstract Green nanostructured heterogeneous catalysts were prepared via a bottom-up strategy. Designed ligands were synthesized joining covalently an electrondeficient pyrimidine residue and a scorpiand azamacrocycle. The desired molecular properties were easily transferred to nanostructured materials in two steps: first, exploiting their spontaneous chemisorption onto multi-walled carbon nanotubes (MWCNTs) via the pyrimidinic moiety in water at room temperature, then, taking advantage of the easy coordination of Pd(II) to the azamacrocycle in the same conditions. An evenly distribution of catalytic centres was obtained on the MWCNTs surface. Catalytic properties of these materials were ass…
Stabilisation of Exotic Tribromide (Br3−) Anions via Supramolecular Interaction with A Tosylated Macrocyclic Pyridinophane. A Serendipitous Case.
Tetraaza-macrocyclic pyridinophane L-Ts, decorated with a p-toluenesulfonyl (tosyl
Stabilization of polyiodide networks with Cu(ii) complexes of small methylated polyazacyclophanes: shifting directional control from H-bonds to I⋯I interactions
Ordered polyiodide networks have recently gathered considerable attention as electronic materials, a topic historically dominated by metals. Could we incorporate metal cations into polyiodide frameworks in a controlled manner to simultaneously boost electronic properties and robustness of these materials? Herein we present a first principles study featuring three analogous polyazacyclophanes (L, L-Me, L-Me3), differing only in the extent of N-methylation. We demonstrate (potentiometry, ITC) how they all form the same CuL2+ (L = L, L-Me, L-Me3) complex as prevalent species in solution, so that a level playing field exists where only N-methylation distinguishes them. Then we use them as count…
Polyfunctional recognition of pyridinedicarboxylate anions with macrocyclic polyamine receptors containing heteroaromatic groups.
The interaction of the biologically relevant anions deriving from the six pyridinedicarboxylic acids (H2PDC) with two macrocyclic receptors containing a pentamine chain and a bipyridine (1) or a phenanthroline (2) moiety, as well as with the aliphatic analogue [21]aneN7 (3), was studied by means of spectroscopic methods (UV-vis, NMR) and potentiometric titrations affording the stability constants of the adducts formed. All three receptors form stable complexes with the substrates thanks to the formation of several salt bridges and hydrogen bond contacts, as observed in the crystal structure of the H8[3(2,6-PDC)4] x H2O x 0.5 EtOH solid compound. Additional pi-stacking interactions between t…
CCDC 2062422: Experimental Crystal Structure Determination
Related Article: Álvaro Martínez-Camarena, Matteo Savastano, Salvador Blasco, Estefanía Delgado-Pinar, Claudia Giorgi, Antonio Bianchi, Enrique García-España, Carla Bazzicalupi|2022|Inorg.Chem.|61|368|doi:10.1021/acs.inorgchem.1c02967
CCDC 2094998: Experimental Crystal Structure Determination
Related Article: Álvaro Martínez-Camarena, Matteo Savastano, Salvador Blasco, Estefanía Delgado-Pinar, Claudia Giorgi, Antonio Bianchi, Enrique García-España, Carla Bazzicalupi|2022|Inorg.Chem.|61|368|doi:10.1021/acs.inorgchem.1c02967
CCDC 864757: Experimental Crystal Structure Determination
Related Article: Lorena Martínez, Carla Bazzicalupi, Antonio Bianchi, Francesc Lloret, Ricardo González, Carlos Kremer, Raúl Chiozzone|2017|Polyhedron|138|125|doi:10.1016/j.poly.2017.09.017
CCDC 1538260: Experimental Crystal Structure Determination
Related Article: Lorena Martínez, Carla Bazzicalupi, Antonio Bianchi, Francesc Lloret, Ricardo González, Carlos Kremer, Raúl Chiozzone|2017|Polyhedron|138|125|doi:10.1016/j.poly.2017.09.017
CCDC 2017310: Experimental Crystal Structure Determination
Related Article: Álvaro Martínez-Camarena, Matteo Savastano, José M. Llinares, Begoña Verdejo, Antonio Bianchi, Enrique García-España, Carla Bazzicalupi|2020|Inorg.Chem.Front.|7|4239|doi:10.1039/D0QI00912A
CCDC 2010176: Experimental Crystal Structure Determination
Related Article: ��lvaro Mart��nez-Camarena, Matteo Savastano, Carla Bazzicalupi, Antonio Bianchi, Enrique Garc��a-Espa��a|2020|Molecules|25|3155|doi:10.3390/molecules25143155
CCDC 864758: Experimental Crystal Structure Determination
Related Article: Lorena Martínez, Nicolás Veiga, Carla Bazzicalupi, Antonio Bianchi, Francesc Lloret, Carlos Kremer, Raúl Chiozzone|2021|Polyhedron|208|115406|doi:10.1016/j.poly.2021.115406
CCDC 2094997: Experimental Crystal Structure Determination
Related Article: Álvaro Martínez-Camarena, Matteo Savastano, Salvador Blasco, Estefanía Delgado-Pinar, Claudia Giorgi, Antonio Bianchi, Enrique García-España, Carla Bazzicalupi|2022|Inorg.Chem.|61|368|doi:10.1021/acs.inorgchem.1c02967
CCDC 2017311: Experimental Crystal Structure Determination
Related Article: Álvaro Martínez-Camarena, Matteo Savastano, José M. Llinares, Begoña Verdejo, Antonio Bianchi, Enrique García-España, Carla Bazzicalupi|2020|Inorg.Chem.Front.|7|4239|doi:10.1039/D0QI00912A
CCDC 2017309: Experimental Crystal Structure Determination
Related Article: Álvaro Martínez-Camarena, Matteo Savastano, José M. Llinares, Begoña Verdejo, Antonio Bianchi, Enrique García-España, Carla Bazzicalupi|2020|Inorg.Chem.Front.|7|4239|doi:10.1039/D0QI00912A
CCDC 2073463: Experimental Crystal Structure Determination
Related Article: Lorena Martínez, Nicolás Veiga, Carla Bazzicalupi, Antonio Bianchi, Francesc Lloret, Carlos Kremer, Raúl Chiozzone|2021|Polyhedron|208|115406|doi:10.1016/j.poly.2021.115406
CCDC 2062421: Experimental Crystal Structure Determination
Related Article: Álvaro Martínez-Camarena, Matteo Savastano, Salvador Blasco, Estefanía Delgado-Pinar, Claudia Giorgi, Antonio Bianchi, Enrique García-España, Carla Bazzicalupi|2022|Inorg.Chem.|61|368|doi:10.1021/acs.inorgchem.1c02967