605-42-5Relevant articles and documents
On-Surface Synthesis and Collective Spin Excitations of a Triangulene-Based Nanostar
Castro, Silvia,Corso, Martina,Frederiksen, Thomas,Friedrich, Niklas,Hieulle, Jeremy,Lara, Francisco Romero,Pascual, Jose Ignacio,Pe?a, Diego,Rey, Dulce,Sanz, Sofía,Vegliante, Alessio
, p. 25224 - 25229 (2021/10/19)
Triangulene nanographenes are open-shell molecules with predicted high spin state due to the frustration of their conjugated network. Their long-sought synthesis became recently possible over a metal surface. Here, we present a macrocycle formed by six [3]triangulenes, which was obtained by combining the solution synthesis of a dimethylphenyl-anthracene cyclic hexamer and the on-surface cyclodehydrogenation of this precursor over a gold substrate. The resulting triangulene nanostar exhibits a collective spin state generated by the interaction of its 12 unpaired π-electrons along the conjugated lattice, corresponding to the antiferromagnetic ordering of six S=1 sites (one per triangulene unit). Inelastic electron tunneling spectroscopy resolved three spin excitations connecting the singlet ground state with triplet states. The nanostar behaves close to predictions from the Heisenberg model of an S=1 spin ring, representing a unique system to test collective spin modes in cyclic systems.
Light-Induced Charge Separation in Densely Packed Donor-Acceptor Coordination Cages
Frank, Marina,Ahrens, Jennifer,Bejenke, Isabel,Krick, Marcel,Schwarzer, Dirk,Clever, Guido H.
, p. 8279 - 8287 (2016/07/16)
Photon-powered charge separation is achieved in a supramolecular architecture based on the dense packing of functional building blocks. Therefore, self-assembled dimers of interpenetrated coordination cages consisting of redoxactive chromophors were synthesized in a single assembly step starting from easily accessible ligands and Pd(II) cations. Two backbones consisting of electron rich phenothiazine (PTZ) and electron deficient anthraquinone (ANQ) were used to assemble either homo-octameric or mixed-ligand double cages. The electrochemical and spectroscopic properties of the pure cages, mixtures of donor and acceptor cages and the mixed-ligand cages were compared by steady-state UV-vis and transient absorption spectroscopy, supported by cyclic voltammetry and spectroelectrochemistry. Only the mixed-ligand cages, allowing close intra-assembly communication between the donors and acceptors, showed the evolution of characteristic PTZ radical cation and ANQ radical anion features upon excitation in the transient spectra. In contrast, excitation of the mixtures of the homo-octameric donor and acceptor cages in solution did not lead to any signs of electron transfer. Densely packed photo- and redox-functional self-assemblies promise molecular-level control over the morphology of the charge separation layer in future photovoltaic applications.
Triazinyl dyes
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, (2008/06/13)
Vat dyestuffs of the formula EQU1 wherein R represents alkyl with 1 to 4 carbon atoms, R1 and R2 represent hydrogen or alkyl with 1 to 4 carbon atoms and each of A1 and A2 represents a vattable radical with 3 to 7 condensed rings are characterized by improved resistance to alkali and are suitable for dyeing and printing the most diverse materials, in particular fibers made from natural or regenerated cellulose.