89939-85-5Relevant academic research and scientific papers
Bistabilities in 1,3,2-dithiazolyl radicals
Brusso, Jaclyn L.,Clements, Owen P.,Haddon, Robert C.,Itkis, Mikhail E.,Leitch, Alicea A.,Oakley, Richard T.,Reed, Robert W.,Richardson, John F.
, p. 8256 - 8265 (2004)
New synthetic methods for heterocyclic 1,3,2-dithiazolyl (DTA) radicals have been developed, and trends in the molecular spin distributions and electrochemical properties of a series of DTA radicals are reported. The crystal structures of [1,2,5]thiadiazolo[3,4-f[1,3,2]benzodithiazol-2-yl (TBDTA) and [1,3,2]-pyrazinodithiazol-2-yl (PDTA) have been determined. The structure of TBDTA (at 293 and 95 K) contains two molecules in the asymmetric unit, each of which generates π-stacked arrays, one consisting of antiparallel chains of centrosymmetrically associated dimers, the other comprising parallel chains of unassociated radicals. The structure of PDTA (at 293 and 95 K) is simpler, consisting of slipped stacks of π-dimers. Variable-temperature magnetic susceptibility (χP) measurements on TBDTA indicate essentially paramagnetic behavior for the unassociated radical π-stacks over the range 5-400 K. By contrast PDTA is diamagnetic at all temperatures below 300 K, but between 300 and 350 K the value of χP follows a sharp and well-defined hysteresis loop, with Tc↓ = 297 K and Tc↑ = 343 K. These features are symptomatic of a regime of bistability involving the observed low temperature π-dimer structure and a putative high-temperature radical π-stack. A mechanism for the interconversion of the two phases of PDTA and related structures is proposed in which hysteretic behavior arises from cooperative effects associated with the breaking and making of a lattice-wide network of intermolecular S- - -N′ and/or S- - -S′ interactions.
Proton and Electron Transfer in the Formation of a Copper Dithiolene-Based Coordination Polymer
Henfling, Stefan,Kultaeva, Anastasia,P?ppl, Andreas,Klose, Jennifer,Kersting, Berthold,Domasevitch, Kostiantyn V.,Krautscheid, Harald
, p. 9008 - 9018 (2021)
Metal bis(dithiolene) complexes are promising building blocks for electrically conductive coordination polymers. N-Heterocyclic dithiolene complexes allow their cross-linking via the coordination of N-donor atoms to additional transition metal ions. In this study, we present the formal copper(II) and copper(III) 6,7-quinoxalinedithiolene complexes [Cu(qdt)2]- and [Cu(qdt)2]2- (qdt2-: 6,7-quinoxalinedithiolate), as well as the 2D coordination polymer Cu[Cu(Hqdt)(qdt)] (3). The dithiolene complexes were isolated as (Bu4N)2[Cu(qdt)2] (1), Na[Cu(qdt)2]·4H2O (2a), [Na(acetone)4][Cu(qdt)2] (2b), and [Ni(MeOH)6][Cu(qdt)2]2·2H2O (2c). Their crystal structures reveal nearly planar complexes with a high tendency of π-stacking. For a better understanding of their coordination behavior, the electronic properties are investigated by UV-vis-NIR spectroscopy, cyclic voltammetry, and DFT simulations. The synthesis of the 2D coordination polymer 3 involves the reduction and protonation of the monoanionic copper(III) complex. A combination of powder X-ray diffraction, magnetic susceptibility measurements, as well as IR and EPR spectroscopy confirm that formal [CuII(Hqdt)(qdt)]- units link trigonal planar copper(I) atoms to a dense 2D coordination polymer. The electrical conductivity of 3 at room temperature is 2 × 10-7 S/cm. Temperature dependent conductivity measurements confirm the semiconducting behavior of 3 with an Arrhenius derived activation energy of 0.33 eV. The strong absorption of 3 in the visible and NIR regions of the spectrum is caused by the small optical band gap of Eg,opt = 0.65 eV, determined by diffuse reflectance spectroscopy. This study sheds light on the coordination chemistry of N-heterocyclic dithiolene complexes and may serve as a reference for the future design and synthesis of dithiolene-based coordination polymers with interesting electrical and magnetic properties.
Fluoride-selective optical sensor based on the dipyrrolyl- tetrathiafulvalene chromophore
Rivadehi, Shadi,Reid, Ellen F.,Hogan, Conor F.,Bhosale, Sheshanath V.,Langford, Steven J.
supporting information; experimental part, p. 705 - 709 (2012/02/03)
A chemosensor bearing dipyrrolyl motifs as recognition sites and a tetrathiafulvalene redox tag has been evaluated as an optical and redox sensor for a series of anions (F-, Cl-, Br-, HSO 4-, CH3COO-, and H 2PO4-) in DCM solution. The receptor shows specific optical signaling for fluoride but little electrochemical effect in solution. The solid-state performance of the sensor leads to measurable changes in water. Design implications towards better systems based on these results and other examples are discussed.
Synthesis, crystal structure and electrocatalysis of 1,2-ene dithiolate bridged diiron carbonyl complexes in relevance to the active site of [FeFe]-hydrogenases
Durgaprasad, Gummadi,Bolligarla, Ramababu,Das, Samar K.
scheme or table, p. 37 - 45 (2012/06/29)
A series of binuclear FeIFeI complexes have been prepared by the treatment of N-heterocyclic 1,2-dithiols, such as, quinoxaline-6,7-dithiol (H26,7-qdt), 2,3-diphenyl-6,7-quinoxaline dithiol (H2diph-6,7-qdt) and
