New charge tranfer salts containing BEDT-TTF and structurally related transition metal complexes

The two-dimensional behaviour of BEDT-TTF salts is normally explained with the typical geometry of this donor and its arrangement in the crystal lattice. In order to extend the range of physical properties produced by BEDT-TIF like compounds, we synthesized sulfur containing transition metal complexes with a molecular structure very similar to BEDT-TTF. The bis(5,6-dihydro-1,4-dithiin-2,3-dithiolate)metallates of the nickel triad can be prepared in different oxidation states as anions and in a fully oxidized neutral form

Electrochemically generated peryleniumyl-hexafluorophosphate and hexafluoroarsenate : new one-dimensional metals

Compounds of stoichiometry (pe)2(PF6)1.1x times 0.8CH2Cl2(1) (pe = perylene), (pe)2(AsF6)1.1 timesx 0.7 CH2Cl2 (2), (pe)2(PF6)1.4 times 0.6 THF (3), (pe)2(AsF6)1.5x times 0.5 THF (4) and (pe)3(SbF6)2 times 0.75 CH2Cl2 (5) have been obtained as crystalline samples by electrochemical deposition from CH2Cl2 [(1), (2) and (5)] or from THF [(3) and (4)] solutions of perylene, containing the appropriate counterion. The three compounds (1)-(3) crystallize in isomorphous orthorhombic lattices. (1) forms black needles: space group Pnmn with a = 4.285 Aring, b = 12.915 Aring and c = 14.033 Aring, z = 1. (2) gives black needles, orthorhombic space group Pnmn with a = 4.294 Aring, b = 13.077 Aring, and c = 14.132 Aring, z = 1. The structures of (1) and (2) were solved by direct methods and refined by least squares to final R = 0.148 and R = 0.088 based on 476 and 322 observed reflections. The perylene forms segregated stacks in direction of the a-axis with interplanar distances of 3.40 Aring and an angle of 37.7° between the bc-plane and the perylene. The channels between the segregated stacks are filled by anions and solvent molecules. The d.c. conductivities (four probe measurements) of (1)-(4) fall in the range of 70-1200Ω-1. cm-1 at room temperature. The conductivities show a metallic regime down to about 200°K and drop off below that temperature

TCNQ salts of planar metal complex cations: novel molecular conductors and semiconductors

The facile variation of positive charge of oxamide oxime metal complexes, caused by acid-base equilibrium, allows the growth of single crystals of their TCNQ salts. 1:1 salts consist of reqular segregated stacks of the components, with metallic room temperature behaviour of the Ni compound, the Pt compound being a semiconductor. Room temperature conductivities are of the order of 10 Siemens per cm. A 2:3 Pt complex TCNQ salt contains segregated acceptor stacks with half a negative charge per molecule. These stacks run perpendicular to mixed stacks -D-D-A-D-D-A-, with integral charges on donors D and acceptors A

A novel molecular metal: (oxamide oximato)(oxamide oxime)nickel(II) tetracyanoquinodimethanide, [Ni(oaoH)(oaoH2)]tcnq, and physical properties of its semiconducting Pt analogue

(C4H11N8NiO4)+(C12H4N4)-, Mr = 498.09 is triclinic, p1, a -=3.7718(6), b = 7.436(2), c =17.511(4) A, a=88.67(2), β=86.93(2), γ=85.05(2), γ= 488.51 A 3, Z = 1, d c=1.69 gcm -3, final R w= 0.035 for 1454 observed independent reflections. The crystals consist of segregated regular parallel stacks of planar metal complex cations and tcnq - counterions with intermolecular H bonds stabilizing the structure. The compound is metallic at room temperature. A metal to semiconductor transition around 230 K shows up in thermopower data, in the microwave conductivity and epr around 170 K. It is not visible in the static magnetic susceptibility

Electrochemical synthesis of new one-dimensional metals: radical salts of perylene

The electrochemical synthesis of four highly conducting peryleniumyl salts is reported. The temperature dependence of the conductivity has been measured and exhibits a metallic regime between 200-300 K. The crystal structures of two of the compounds have been solved

The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package

The Astropy project supports and fosters the development of open-source and openly-developed Python packages that provide commonly-needed functionality to the astronomical community. A key element of the Astropy project is the core package Astropy, which serves as the foundation for more specialized projects and packages. In this article, we provide an overview of the organization of the Astropy project and summarize key features in the core package as of the recent major release, version 2.0. We then describe the project infrastructure designed to facilitate and support development for a broader ecosystem of inter-operable packages. We conclude with a future outlook of planned new features and directions for the broader Astropy project

The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package*

Abstract The Astropy Project supports and fosters the development of open-source and openly developed Python packages that provide commonly needed functionality to the astronomical community. A key element of the Astropy Project is the core package astropy, which serves as the foundation for more specialized projects and packages. In this article, we summarize key features in the core package as of the recent major release, version 5.0, and provide major updates on the Project. We then discuss supporting a broader ecosystem of interoperable packages, including connections with several astronomical observatories and missions. We also revisit the future outlook of the Astropy Project and the current status of Learn Astropy. We conclude by raising and discussing the current and future challenges facing the Project.</jats:p