Novel Cd (II) Coordination Polymers Afforded with EDTA or Trans-1,2-Cdta Chelators and Imidazole, Adenine, or 9-(2-Hydroxyethyl) Adenine Coligands

We thank the “Centre de Tecnologies de la Informació” (CTI), Universitat de les Illes Balears for computational facilities. We also thank all Projects for financial support.Three mixed-ligands of Cd(II) coordination polymers were unintentionally obtained: {[Cd(µ3-EDTA)(Him)·Cd(Him)(H2O)2]·H2O}n (1), {[Cd(µ4-CDTA)(Hade)·Cd(Hade)2]}n (2), and {[Cd(µ3-EDTA)(H2O)·Cd(H9heade)(H2O)]·2H2O}n (3), having imidazole (Him), adenine (Hade) or 9-(2-hydroxyethyl)adenine (9heade) as the N-heterocyclic coligands. Compounds 2 and 3 were obtained by working with an excess of corresponding N-heterocyclic coligands. The single-crystal X-ray diffraction structures and thermogravimetric analyses are reported. The chelate moieties in all three compounds exhibit hepta-coordinated Cd centers, whereas the non-chelated Cd center is five-coordinated in 1 and six-coordinated in 2 and 3. Him and Hade take part in the seven-coordinated chelate moieties in 1 and 2, respectively. In contrast, 9heade is unable to replace the aqua ligand of the chelate [Cd (EDTA) (H2O)] moiety in 3. The thermogravimetric analysis (TGA) behavior of [Cd (H2EDTA) (H2O)]·2H2O in 1 and 3 leads to a residue of CdO, whereas the N-rich compound 2 yields CdO·Cd(NO3)2 as a residue. Density functional theory (DFT) calculations along with molecular electrostatic potential (MEP) and quantum theory of atoms-in-molecules computations were performed in adenine (compound 2) and (2-hydroxyethyl)adenine (compound 3) to analyze how the strength of the H-bonding and π-stacking interactions, respectively, are affected by their coordination to the Cd-metal center.Excellence Network "Metal Ions in Biological Systems" MetalBio CTQ2017-90802-REDTJunta de Andalucia FQM-283MICIU /AEI of Spain CTQ2017-85821-

Anion–Cation Recognition Pattern, Thermal Stability and DFT-Calculations in the Crystal Structure of H2dap[Cd(HEDTA)(H2O)] Salt (H2dap = H2(N3,N7)-2,6-Diaminopurinium Cation)

We thank the Centre de Tecnologies de la Informació (CTI), Universitat de les Illes Balears for computational facilities. We also thank all projects for financial support.The proton transfer between equimolar amounts of [Cd(H2EDTA)(H2O)] and 2,6-diaminopurine (Hdap) yielded crystals of the out-of-sphere metal complex H2(N3,N7)dap [Cd(HEDTA)(H2O)]·H2O (1) that was studied by single-crystal X-ray diffraction, thermogravimetry, FT-IR spectroscopy, density functional theory (DFT) and quantum theory of “atoms-in-molecules” (QTAIM) methods. The crystal was mainly dominated by H-bonds, favored by the observed tautomer of the 2,6-diaminopurinium(1+) cation. Each chelate anion was H-bonded to three neighboring cations; two of them were also connected by a symmetry-related anti-parallel π,π-staking interaction. Our results are in clear contrast with that previously reported for H2(N1,N9)ade [Cu(HEDTA) (H2O)]·2H2O (EGOWIG in Cambridge Structural Database (CSD), Hade = adenine), in which H-bonds and π,π-stacking played relevant roles in the anion–cation interaction and the recognition between two pairs of ions, respectively. Factors contributing in such remarkable differences are discussed on the basis of the additional presence of the exocyclic 2-amino group in 2,6-diaminopurinium(1+) ion.This research was funded by the Excellence Network ‘Metal Ions in Biological Systems’ MetalBio CTQ2017-90802-REDT, the Research group FQM-283 (Junta de Andalucía) and MICIU/AEI of Spain (project CTQ2017-85821-R FEDER funds)

Novel Cd (II) Coordination Polymers Afforded with EDTA or Trans-1,2-Cdta Chelators and Imidazole, Adenine, or 9-(2-Hydroxyethyl) Adenine Coligands

Three mixed-ligands of Cd(II) coordination polymers were unintentionally obtained: {[Cd(µ3-EDTA)(Him)·Cd(Him)(H2O)2]·H2O}n (1), {[Cd(µ4-CDTA)(Hade)·Cd(Hade)2]}n (2), and {[Cd(µ3-EDTA)(H2O)·Cd(H9heade)(H2O)]·2H2O}n (3), having imidazole (Him), adenine (Hade) or 9-(2-hydroxyethyl)adenine (9heade) as the N-heterocyclic coligands. Compounds 2 and 3 were obtained by working with an excess of corresponding N-heterocyclic coligands. The single-crystal X-ray diffraction structures and thermogravimetric analyses are reported. The chelate moieties in all three compounds exhibit hepta-coordinated Cd centers, whereas the non-chelated Cd center is five-coordinated in 1 and six-coordinated in 2 and 3. Him and Hade take part in the seven-coordinated chelate moieties in 1 and 2, respectively. In contrast, 9heade is unable to replace the aqua ligand of the chelate [Cd (EDTA) (H2O)] moiety in 3. The thermogravimetric analysis (TGA) behavior of [Cd (H2EDTA) (H2O)]·2H2O in 1 and 3 leads to a residue of CdO, whereas the N-rich compound 2 yields CdO·Cd(NO3)2 as a residue. Density functional theory (DFT) calculations along with molecular electrostatic potential (MEP) and quantum theory of atoms-in-molecules computations were performed in adenine (compound 2) and (2-hydroxyethyl)adenine (compound 3) to analyze how the strength of the H-bonding and π-stacking interactions, respectively, are affected by their coordination to the Cd-metal centerThis research was funded by the Excellence Network “Metal Ions in Biological Systems” MetalBio CTQ2017-90802-REDT, the Research group FQM-283 (Junta de Andalucía), and MICIU/AEI of Spain (project CTQ2017-85821-R FEDER funds)S

H-Bonds, π-Stacking and (Water)O-H/π Interactions in (µ4-EDTA)Bis(Imidazole) Dicopper(II) Dihydrate

We synthesized and studied the polymeric compound {[Cu2 (µ4 -EDTA)(Him)2 ] 2H2O}n (1). The single-crystal structure is reported along with an in depth characterization of its thermal stability (TGA), spectral properties (FT-IR, Vis-UV and RSE), and magnetic behavior. The crystal consists of infinite 2D-networks built by centrosymmetric dinuclear motifs, constructed by means of a bridging anti,syn-carboxylate group from each asymmetric unit. Each layer guides Him ligands toward their external faces. They are connected by intermolecular (Him)N-H···O(carboxylate) bonds and antiparallel π–π stacking between symmetry related pairs of Him ligands, and then pillared in a 3D-network with parallel channels, where disordered water molecules are guested. About half of the labile water is lost from these channels over a wide temperature range (r.t. to 210 ◦C) before the other one, most strongly retained by the cooperating action of (water)O1-H(1A)···O(carboxylate) and (water) O1-H(1B)···π(Him) interactions. The latter is lost when organic ligands start to burn. ESR spectra and magnetic measurements indicated that symmetry related Cu(II) centers connected by the bridging carboxylate groups behave magnetically not equivalently, enabling an exchange interaction larger than their individual Zeeman energies.MICINN of Spain (project PGC2018-102047-B-I00)MICIU/AEI of Spain (project CTQ2017- 85821-R FEDER)Research groups FQM-283FQM-243 (Junta de Andalucía, Spain

A Tetranuclear Ni(II)-Cubane Cluster Molecule Build by Four µ3-O-Methanolate (MeO) Ligands, Externally Cohesive by Four Unprecedented Bridging µ2-N7,O6-Acyclovirate (acv-H) Anions

Metal ion interactions with nuclei acids and their constituents represent a multi-faceted and growing research field. This contribution deals with molecular recognition between synthetic purine 17 nucleosides and first-row transition metal complexes, with O- and/or N-amino chelators which are able to 18 engage in intra-molecular N-H···(N or O) and O-H···(N or O) interligand interactions. Crystals of these complexes can also display inter-molecular aromatic π-stacking and/or other non-conventional interactions. In this manuscript, we used 2-(2-aminoethoxy)ethanol (2aee) as a potential N,O(e),O(ol)-chelator for nickel(II). However, unexpectedly, the reaction between NiCl, acyclovir (acv), and 2aee in methanol afforded parallelepiped apple-green crystals of [Ni(acv-H)(MeO)(HO)]·8HO, (1) a tetranuclear molecule with an equimolar Ni(II):µ-methanolate(1-):µ-N7,O6-acyclovirate(1-) (acv-H) ratio. The µ-N7,O6-(acv-H) metal-binding pattern (MBP) is unprecedented in terms of both its anionic and bridging roles. The single-crystal X-ray diffraction structure as well as thermogravimetric analysis and the (FT-IR +Vis-UV) spectra of 1 are reported. Theoretical density functional theory (DFT) calculations are used to analyse the antiparallel π-stacking interactions that govern the formation of self-assembled dimers in the solid state.his research was funded by MICINN of Spain (project PGC2018-102047-B-I00), MICIU/AEI of Spain (project PID2020-115637GB-I00, FEDER), Project B-FQM-478-UGR20 (FEDER-Universidad de Granada, Spain) and the Research groups FQM-283 and FQM-243 (Junta de Andalucía, Spain)

A Tetranuclear Ni(II)-Cubane Cluster Molecule Build by Four µ3-O-Methanolate (MeO) Ligands, Externally Cohesive by Four Unprecedented Bridging µ2-N7,O6-Acyclovirate (acv-H) Anions

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/cryst13010007/s1, Figure S1: Crystals of compound [Ni(μ2-N7,O6-acv-H)(μ3-MeO)(H2O)]4·8H2O (1).; Structural parameters, TGA curves and IR information.Acknowledgments: We thank the Centre de Tecnologies de la Informació (CTI) at the University of the Balearic Islands (UIB) for the use of their computational facilities.Metal ion interactions with nuclei acids and their constituents represent a multi-faceted and growing research field. This contribution deals with molecular recognition between synthetic purine 17 nucleosides and first-row transition metal complexes, with O- and/or N-amino chelators which are able to 18 engage in intra-molecular N-H···(N or O) and O-H···(N or O) interligand interactions. Crystals of these complexes can also display inter-molecular aromatic π-stacking and/or other non-conventional interactions. In this manuscript, we used 2-(2-aminoethoxy)ethanol (2aee) as a potential N,O(e),O(ol)-chelator for nickel(II). However, unexpectedly, the reaction between NiCl2, acyclovir (acv), and 2aee in methanol afforded parallelepiped apple-green crystals of [Ni(acv-H)(MeO)(H2O)]4·8H2O, (1) a tetranuclear molecule with an equimolar Ni(II):µ3-methanolate(1-):µ2-N7,O6-acyclovirate(1-) (acv-H) ratio. The µ2-N7,O6-(acv-H) metal-binding pattern (MBP) is unprecedented in terms of both its anionic and bridging roles. The single-crystal X-ray diffraction structure as well as thermogravimetric analysis and the (FT-IR +Vis-UV) spectra of 1 are reported. Theoretical density functional theory (DFT) calculations are used to analyse the antiparallel π-stacking interactions that govern the formation of self-assembled dimers in the solid state.MICINN of Spain (project PGC2018-102047-B-I00), MICIU/AEI of Spain (project PID2020-115637GB-I00, FEDER)Project B-FQM-478-UGR20 (FEDER-Universidad de Granada, Spain)Research groups FQM-283 and FQM-243 (Junta de Andalucía, Spain

A Tetranuclear Ni(II)-Cubane Cluster Molecule Build by Four µ₃-O-Methanolate (MeO) Ligands, Externally Cohesive by Four Unprecedented Bridging µ₂-N7,O6-Acyclovirate (acv-H) Anions

Metal ion interactions with nuclei acids and their constituents represent a multi-faceted and growing research field. This contribution deals with molecular recognition between synthetic purine 17 nucleosides and first-row transition metal complexes, with O- and/or N-amino chelators which are able to 18 engage in intra-molecular N-H···(N or O) and O-H···(N or O) interligand interactions. Crystals of these complexes can also display inter-molecular aromatic π-stacking and/or other non-conventional interactions. In this manuscript, we used 2-(2-aminoethoxy)ethanol (2aee) as a potential N,O(e),O(ol)-chelator for nickel(II). However, unexpectedly, the reaction between NiCl2, acyclovir (acv), and 2aee in methanol afforded parallelepiped apple-green crystals of [Ni(acv-H)(MeO)(H2O)]4·8H2O, (1) a tetranuclear molecule with an equimolar Ni(II):µ3-methanolate(1-):µ2-N7,O6-acyclovirate(1-) (acv-H) ratio. The µ2-N7,O6-(acv-H) metal-binding pattern (MBP) is unprecedented in terms of both its anionic and bridging roles. The single-crystal X-ray diffraction structure as well as thermogravimetric analysis and the (FT-IR +Vis-UV) spectra of 1 are reported. Theoretical density functional theory (DFT) calculations are used to analyse the antiparallel π-stacking interactions that govern the formation of self-assembled dimers in the solid state

Supramolecular Nature of Multicomponent Crystals Formed from 2,2′-Thiodiacetic Acid with 2,6-Diaminopurine or N9-(2-Hydroxyethyl)adenine

The synthesis and characterization of the multicomponent crystals formed by 2,2′-thiodiacetic acid (Htda) and 2,6-diaminopurine (Hdap) or N9-(2-hydroxyethyl)adenine (9heade) are detailed in this report. These crystals exist in a salt rather than a co-crystal form, as confirmed by single crystal X-ray diffractometry, which reflects their ionic nature. This analysis confirmed proton transfer from the 2,2′-thiodiacetic acid to the basic groups of the coformers. The new multicomponent crystals have molecular formulas [(H9heade)(Htda)] 1 and [(Hdap)(tda)]·2HO 2. These were also characterized using FTIR, H and C NMR and mass spectroscopies, elemental analysis, and thermogravimetric/differential scanning calorimetry (TG/DSC) analyses. In the crystal packing the ions interact with each other via O–H⋯N, O–H⋯O, N–H⋯O, and N–H⋯N hydrogen bonds, generating cyclic hydrogen-bonded motifs with graph-set notation of (Formula presented.) (16), (Formula presented.) (10), (Formula presented.) (10), (Formula presented.) (10), (Formula presented.) (9), (Formula presented.) (8), and (Formula presented.) (8), to form different supramolecular homo- and hetero-synthons. In addition, in the crystal packing of 2, pairs of diaminopurinium ions display a strong anti-parallel π,π-stacking interaction, characterized by short inter-centroids and interplanar distances (3.39 and 3.24 Å, respectively) and a fairly tight angle (17.5°). These assemblies were further analyzed energetically using DFT calculations, MEP surface analysis, and QTAIM characterization.This research was funded in part by MICIU/AEI, Spain (project PID2020-115637GB-I00 FEDER funds) and Universidad de Granada, Spain (project B-FQM-478-UGR20 FEDER funds)

Reasons to be cheerful? Reflections on GPs' responses to depression

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes