Experimental and Theoretical Studies on Photophysical Properties: Tuning Redox-Active Amido-Tetrathiafulvalene Derivatives in Paramagnetic Coordination Complexes

Synthesis, properties and surface self-assembly of a pentanuclear cluster based on the new π-conjugated TTF-triazole ligand

The new π-extended redox-active ligand with both TTF and triazole units, 6-(4,5-bis(propylthio)-1,3-dithiol-2-ylidene)-1H-[1,3]dithiolo[4′,5′:4,5]benzo [1,2-d] [1–3]triazole, has been successfully prepared. Based on the versatile ligand and Cu(tta)₂ precursors (tta⁻ = 4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione), a TTF-based pentanuclear Cu^II cluster (Cu₅(tta)₄(TTFN₃)₆) is synthesized and structurally characterized. Their absorption and electrochemical properties are investigated. Antiferromagnetic couplings are operative between metal ion centers bridged by triazoles in the complex. The self-assembled structure of the cluster complex on a highly oriented pyrolytic graphite (HOPG) surface was observed using scanning tunneling microscopy and density functional theory (DFT) calculations have been performed to provide insight into the formation mechanism. The introduction of the redox-active TTF unit into the cluster complexes with interesting magnetic properties renders them promising candidates for new multifunctional materials.

Covalent non-fused tetrathiafulvalene–acceptor systems

The main families of non-fused TTF–acceptors are discussed with a special focus on their characteristics and properties.

Bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)tetrakis(μ4-1,1,1,5,5,5-hexafluoropentane-2,2,4,4-tetraolato)copper(II)octatin(II): a prospective precursor for Cu-doped SnO2 films

The crystal structure of a tin-rich heterometallic supramolecular product, [CuSn8(C5HF6O2)2(C5H2F6O4)4] or [Sn4(hfpt)2-Cu(hfac)2-Sn4(hfpt)2], (I), is reported (hfpt is the tetraanion of 1,1,1,5,5,5-hexafluoropentane-2,2,4,4-tetraol and hfac is the anion of 1,1,1,5,5,5-hexafluoropentane-2,4-dione). Reaction between tin(II) tetraolate, [Sn4(hfpt)2], and copper(II) β-diketonate, [Cu(hfac)2], was utilized for the preparation of (I). The asymmetric unit consists of the whole [Sn4(hfpt)2] unit and half of a [Cu(hfac)2] unit, with the Cu atom lying on an inversion center. Intermolecular Cu···O interactions from the axial positions of copper in [Cu(hfac)2] and O atoms of the hfpt ligand in [Sn4(hfpt)2] mediate the formation of a sandwich-type structure for (I). Additional intermolecular Sn···O interactions between neighbouring [Sn4(hfpt)2] units complete a two-dimensional network.