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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]

Photophysical properties of the three-fold symmetric 2,5,8-tris(phenylthiolato)heptazine molecule (1) are studied from combined experimental and computational viewpoints. The intense blue photoemission of 1 in the solid state and in toluene solution is proposed to have a fluorescent origin on the basis of a relatively short emission lifetime and no detectable triplet decay. Calculations at correlated ab initio levels of theory also show that 1 has a large inverted singlet–triplet (IST) gap, a non-vanishing spin–orbit coupling matrix element between the first excited singlet and triplet states, and a fast intersystem crossing rate constant that leads to singlet population from the higher-lying triplet state. The IST gap implies that the first excited singlet state is the lowest excited one, agreeing with the measured fluorescent behaviour of 1. IST gaps are also obtained for the oxygen-containing (2) and selenium-containing (3) analogues of 1 at the ADC(2) level of theory, but not for the tellurium one (4). Calculations of the magnetically induced current density demonstrate that the heptazine core of 1 is globally non-aromatic due to the alternation of carbon and nitrogen atoms along its external rim. [ABSTRACT FROM AUTHOR]

Polymers can serve as an effective matrix to stabilize gold nanoparticles. These materials offer a continuous light-activated supply of subnanoclusters, which are composed of a few atoms. We report an efficient approach to enhance the catalytic activity of gold subnanoclusters by in situ feeding of these species through the generation of hot carriers via 5d-6s6p interband transitions on PEG-stabilized Au nanoparticles.