Unprecedented layered coordination polymers of dithiolene group 10 metals: Magnetic and electrical properties

One-pot reactions between Ni(ii), Pd(ii) or Pt(ii) salts and 3,6-dichloro-1,2-benzenedithiol (HSC6H2Cl2SH) in KOH medium under argon lead to a series of bis-dithiolene coordination polymers. X-ray analysis shows the presence of a common square planar complex [M(SC6H2Cl2S)2]2- linked to potassium cations forming either a two-dimensional coordination polymer network for {[K2(μ-H2O)2(μ-thf)(thf)2][M(SC6H2Cl2S)2]}n [M = Ni (1) and Pd (2)] or a one-dimensional coordination polymer for {[K2(μ-H2O)2(thf)6][Pt(SC6H2Cl2S)2]}n (3). In 3 the coordination environment of the potassium ions may slightly change leading to the two-dimensional coordination polymer {[K2(μ-H2O)(μ-thf)2][Pt(SC6H2Cl2S)2]}n (4) that crystallizes together with 3. The physical characterization of compounds 1-3 show similar trends, they are diamagnetic and behave as semiconductorsWe thank financial support from MICINN (MAT2013-46753-C2-1-P, CTQ2014-52758-P and MAT2014-56143-R) and Generalitat Valenciana (PrometeoII/2014/076

Structural study of the compounds formed in the reactions of FeCl3·6H2O with Ni(OH)2 in the presence of dithiolenes HSRSH (R = C6H2Cl2 or C6H4)

In our attempts to prepare coordination polymers by reaction of FeCl3·6H2O and Ni(OH)2 in the presence of dithiolenes HSC6H2X2SH (X = Cl or H), several ion pairs of compounds containing the anionic entity [Ni(SC6H2X2S)2]⁻ were obtained instead. It was also found that other species without dithiolene ligands were formed in these reactions, giving rise to different ion pairs and a tetrametallic cluster. The careful isolation of the different types of crystalline solids allowed the characterization of all of the resulting compounds by single crystal X-ray diffraction (SCXRD). In order to establish the amount of nickel and iron present in the crystals, complementary total reflection X-ray fluorescence (TXRF) analyses were performed. The eight different structural types that were obtained are described and compared with related ones found in the literaturaThis research was funded by the Spanish Ministerio de Economía y Competitividad, grand number (MAT2016-77608-C3-1-P) and Ministerio de Ciencia, Innovación y Universidades (PGC2018-094644-B-C21

Stability and electronic structure of M-DNA: Role of metal position

We investigate, by first-principles density-functional calculations, fragments and periodic helices of CG- and AT-DNA, modified by incorporation of Zn2+ cations. We study the relative stability of different binding sites for the metal ions as well as different methods of charge neutralization. We find that binding the Zn cation to the N(7) atom of guanine or adenine leads always to lower energies than substitution of an imino proton between two H-bonded bases. Also, neutralizing with OH- groups bonded to Zn2 + is more stable than removing protons from the phosphate groups. Contrarily to common wisdom, we find that planarity of the base pairs is not an essential factor of stability, and that nonplanar base pairs can also be stacked effectively. Finally, we find that the most stable CG and AT helices, with Zn2+ bonded to N(7) atoms and neutralized by OH- ions, have wide band gaps of more than 2 eV, and we conclude that they are poor candidates for electronic conductionThis work has been supported by Brazilian agencies: Fapemig, CNPq, and Ministerio da Ciencia e Tecnologia; by Grants FIS2009-12712, MAT2010-20843-C02-01, and CSD2007-00050 of the Spanish Ministry of Science and Innovation; and by European Grant EU(FP6-029192

Layered copper-metallated covalent organic frameworks for huisgen reactions

Covalent organic frameworks (COFs) are porous materials formed through condensation reactions of organic molecules via the formation of dynamic covalent bonds. Among COFs, those based on imine and β-ketoenamine linkages offer an excellent platform for binding metallic species such as copper to design efficient heterogeneous catalysts. In this work, imine- and β-ketoenamine-based COF materials were modified with catalytic copper sites following a metallation method, which favored the formation of binding amine defects. The obtained copper-metallated COF materials were tested as heterogeneous catalysts for 1,3-dipolar cycloaddition reactions, resulting in high yields and recyclabilityThis work was supported by PID2019-106268GB-C32 and RTI2018-096138-A-I00 funded by MCIN/AEI/10.13039/ 501100011033 and EUR2020-112294 funded by MCIN/ AEI/10.13039/501100011033 and by the European Union “NextGenerationEU”/PRTR. A.E.P.-P. and F.Z. acknowledge the financial support from the Spanish Ministry of Science and Innovation, through the “María de Maeztu” Programme for Units of Excellence in R&D (CEX2018-000805-M). A.E.P.-P. acknowledges the Spanish Ministry of Science and Innovation for a Ramón y Cajal fellowship (RYC2018-024328-I). The authors acknowledge beamline P02.1 at DESY (proposal I 20190208 EC), a member of the Helmholtz Association (HGF). They thank Dr. Michael Wharmby for his assistance during the experiment at P02.1. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. I.R.-M. acknowledges an FPI-UAM 2019 fellowship from Universidad Autónoma de Madrid. P.A. acknowledges the financial support from “Ayudas para Contratos Predoctorales para la Formación de Doctores” Program of MINECO (Grant BES-2017-070838

Fast and efficient direct formation of size-controlled nanostructures of coordination polymers based on copper(i)-iodine bearing functional pyridine terminal ligands

We report on the direct formation of 1D nanostructures of two coordination polymers based on copper(i)-iodine double chains decorated with ethyl isonicotinate or 2-amino-5-nitropyridine as terminal ligands. The use of different reaction conditions, e.g. energy of the formation process, solvents, and/or concentration of reactants, has allowed the control of the size of the fibres and ribbons directly formed in this process going from micron- to submicron- up to nano-size. We show experiments that direct the formation of materials kinetically versus thermodynamically controlled, adjusting simple experimental parameters. Finally, a morphological study on the Cu(i)-iodine bearing 2-amino-5-nitropyridine nanofibres has confirmed their reversible molecular recognition ability towards acetic acid vapoursWe are grateful for financial support from the Spanish Ministerio de Economía y Competitividad (MAT2013-46502-C2-2P, MAT2016-75883-C2-2-P, BES-2015-071534) and also to the scientific computing center (CCC) of the Autónoma University of Madrid for their tim

Synthesis and structural characterization of transition metal dithiolene derivatives containing divalent metals as counter-cations

Direct reactions between HSC 6 H 2 Cl 2 SH, FeCl 3 ·6H 2 O and divalent metal bases lead to the formation of the cation-anion metal-dithiolene complexes [Ca(H 2 O) 3 (OCMe 2 ) 4 ][Fe 2 (SC 6 H 2 Cl 2 S) 4 ]·3OCMe 2 and [Zn(DMF) 6 ][Fe 2 (SC 6 H 2 Cl 2 S) 4 ], as well as the molecular compound [Ba(OCMe 2 ) 6 ][Fe 2 (SC 6 H 2 Cl 2 S) 4 ], instead of metal-dithiolene coordination polymers as compared with results previously obtained when alkali metals, under similar conditions, were used. An alternative synthetic route based on the reactions between K 2 [Fe 2 (SC 6 H 2 Cl 2 S) 4 ] and ZnCl 2 ·6H 2 O or NiCl 2 ·6H 2 O was also evaluated, giving rise to the ion-pair compounds [Fe(H 2 O) 2 (THF) 4 ][Ni(SC 6 H 2 Cl 2 S) 2 ] 2 ·4THF and [Fe(H 2 O) 4 (THF) 2 ][Fe 2 (SC 6 H 2 Cl 2 S) 4 ]·4THF and the coordination polymer {[K 2 (THF) 8 ][Zn 6 (μ-Cl) 2 (SC 6 H 2 Cl 2 S) 4 (μ-κO:κO-SC 6 H 2 Cl(ClO 2 )S) 2 ]} n . It is interesting to remark that in the last compound the oxidation of one Cl substituent of a dithiolene ligand resulted in the formation of a Cl(O) 2 groupThis work was supported in part by MICINN (grant MAT2016-77608-C3-1-P