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Herein, we report the synthesis of a new family of extremely efficient TADF three-coordinated gold(I) emitters based on the chelating and bridging abilities of the 1,2,4,5-tetrakis(diphenylphosphino)benzene (tpbz) ligand and the neutral gold(I) [AuR] fragments (R = C6F5 (1), C6Cl2F3 (2), C6Cl5 (3)). Their emission energies appear in the orange range of the spectrum. The quantum yields of the emissions are directly related to the electronegativity of the perhalophenyl groups bonded to the metal center, even when they are not directly involved in the orbitals responsible for the luminescence. DFT and TD-DFT calculations suggest that the symmetry of the solid-state structures facilitates the coupling of the transition dipole moments, which leads to a drastic increase in their quantum yields as the electronic accepting abilities of the perhalophenyl groups decreases. [ABSTRACT FROM AUTHOR]

The reactivity of the heterometallic polynuclear complexes [{Au(R)2}2Cu2(MeCN)2]n (R=C6F5, C6Cl5) with the thioether crowns 1,4,7‐trithiacyclononane (L1, [12]aneS3), 1,4,8,11‐tetrathiacyclododecane (L2, [14]aneS4), 1,4,7,10,13,16,19,22‐octathiacyclotetracosane (L3, [24]aneS8), and the quinoline functionalized pendant arm derivatives of the 12‐membered mixed‐donor macrocycles 1‐aza‐,4,7,10‐trithiacyclododecane ([12]aneNS3) and 1,7‐diaza‐4,10‐dithiacyclododecane ([12]aneN2S2), L4 and L5, respectively, was investigated in THF solution. While with L4 and L5 only ionic compounds of general formulation [Cu(L)][Au(R)2] were isolated and structurally characterized (none of them featuring Au⋅⋅⋅Cu interactions), with L1‐L3, beside similar ionic compounds, some heteronuclear complexes of general formulation [{Au(R)2}{Cu(L)}] and featuring Au⋅⋅⋅Cu interactions were also obtained. All of them display rather unusual non‐classical C−H⋅⋅⋅Au hydrogen interactions. The complexes display in the solid state different optical properties related to their structures, which have been studied experimentally and theoretically via TD‐DFT calculations. In particular, all compounds of the type [{Au(R)2}{Cu(L)}] featuring Au⋅⋅⋅Cu metallophilic interactions display luminescence in the solid state both at room temperature (RT) and at 77 K. On the contrary, ionic compounds of general formulation [Cu(L)][Au(R)2], except [Cu(L4)][Au(C6F5)2], are not luminescent. [ABSTRACT FROM AUTHOR]

The reaction among [Au2Ag2(C6F5)4(OEt2)2]n, PbCl2 and terpyridine leads to the polymeric complex [{Au(C6F5)2}2{Pb(terpy)}]n (1). Its crystal structure reveals potential voids close to the lead centres large enough to hold different molecules. The availability of these free sites allows complex 1 to act as a VOC sensor. Thus, when 1 is exposed to different solvent vapours such as acetonitrile, toluene or THF, variations in its solid appearance and its photophysical properties are observed as a consequence of the formation of the new polymorphs [{Au(C6F5)2}2{Pb(terpy)(CH3CN)2}]n (2), [{Au(C6F5)2}2{Pb(terpy)}]n·Tol (3) and [{Au(C6F5)2}2{Pb(terpy)(THF)}]n·THF (4). Each polymorph displays a different emission energy depending on its structure and the presence of metallophilic interactions. In addition, the reversible solvent molecule exchange allows the tuning of the luminescence emissions in the greenish yellow–red range. DFT and TD-DFT calculations were performed to explain the origin of the luminescence of all these complexes. [ABSTRACT FROM AUTHOR]

New luminescent heterometallopolymers [(Au‐C6F5)m(AgOSO2CF3)n (PVP)] with different Au:Ag molar ratios were synthesized. The luminescent emissions of these polymers are strongly dependent on the temperature, excitation wavelengths, and the Au(I):Ag(I) molar ratio. The incorporation of a precise amount of Ag(I) atoms in the backbone of [(Au‐C6F5)m(PVP)] metallopolymer allows a controlled tuning of the emission energy in the green‐blue range. [ABSTRACT FROM AUTHOR]

A study was conducted theoretically for the organometallic compound (NBu(sub 4)(sub 2) [Au(3,5-C(sub 6)F(sub 3)Cl(sub 2))(sub 2) Ag(sub 4)(cF(sub 3)CO(sub 2)(sub 5)], whose dianionic part displays a AuAg(sub 4) square pyramidal arrangement based on closed-shell Au(I)...Ag(I) interactions between two monoanionic fragments. The modelsystem [AuPh(sub 2)](super -)...[Ag(sub 4(CO(sub 2)H)(sub 5)](super -) (C1) was choosen from DFT results as an appropriate model for the study of the interactions.

The loosely bound butterfly luminescent clusters [Au(sub 2-)Tl(sub 2)(C(sub 6)Cl(sub 5))(sub 4).L (L = PhMeC=o, acacH) and [Au(sub 2)Tl(sub 2)(C(sub 6)-Cl(sub 5))(sub 4)(bipy)].(acacH) are prepared via the reaction of [AuTl(C(sub 6)Cl(sub 5))(sub 2)](sub n) with ketones. Their luminiscence in solution and their conductivity measurements, are in agreement with the maintenance of the Tl...Tl contact in solution.

The extended, unsupported linear-chain complex {Tl[Au-(C6Cl5)2]}(sub n), reacts in solution with several organic ligands, L, to give extended, unsupported, zigzag-chain complexes of the type {TlL2[Au(C6Cl5)2]}(sub n). The coordination of the ligands (or VOCs) take place at the Tl(I) centers producing different colored products on filter paper.

The features of coexistence of aurophilic interactions and the hydrogen bonds of the type N-H...F in complex M(C6F5){N(H)=CPh2}, where M=Ag or Au, is investigated by ab initio calculation at HR and MP2 level. Results revealed that the Au(l)-Au(l) interaction is stronger than Ag(l)-Ag(l) and that N-H...F hydrogen bonding and Au(l)-Au(l) contacts have similar strength in the same molecule.

Research has been conducted on [NBu (sub)4][AuR (sub)2], where R is C (sub)6 F (sub)5, C (sub)5 Cl (sub)5, complexes. The acid-base reaction between these complexes and thallium(I) hexafluorophosphate carried out in the presence of 4,4'-bipyridine has been investigated and the results of the structural analysis, synthesis and photophysical studies of the reaction are presented.

Crystallographic analysis demonstrates that among the third transition series element gold(III) and its derivatives of 2-(diphenylphosphino)-aniline, the compound gold(III)-N displays unusual reactivity and gold(I)-gold(III) interactions.

Small size AuAg colloidal nanoparticles (AuAg NPs) are prepared through the mild decomposition of the organometallic precursor [Au2Ag2(C6F5)4(OEt2)2]n in THF, using polyvinylpyrrolidone (PVP) as the stabilizing polymer. These nanoparticles are directly deposited on the surface of TiO2 NPs through impregnation in solution at RT or under hydrothermal conditions. AuAg–TiO2–rGO (rGO = reduced graphene oxide) hybrid nanostructures are also prepared under hydrothermal reduction of graphene oxide. The obtained nanomaterials have been characterized through XRD, TEM, HRTEM, solid state UV/vis, Raman and XPS. The use of the nanomaterials as plasmonic photocatalysts under visible white LED light and sunlight is studied and the possible mechanisms of the catalytic degradation of methylene blue (MB) are proposed. The localized surface plasmon resonance (LSPR) displayed by the spherical AuAg nanoparticles enhances their ability of visible light absorption, whereas graphene nanosheets provide a very efficient charge carrier separation, allowing a good performance of the photocatalysts under low-power white LED sources or sunlight. [ABSTRACT FROM AUTHOR]