Summary The influence caused by the position of the chlorine atom on end groups of two non-fullerene acceptors ( ITIC-2Cl-δ and ITIC-2Cl-γ ) was intensely investigated. The single-crystal structures show that ITIC-2Cl-γ has a better molecular planarity and closer π-π interaction distance. More importantly, a 3D rectangle-like interpenetrating network is formed in ITIC-2Cl-γ and is beneficial to rapid charge transfer along multiple directions, whereas only a linear stacked structure could be observed in ITIC-2Cl-δ . The two acceptor-based solar cells show power conversion efficiencies (PCEs) over 11%, higher than that of the ITIC-2Cl- m -based device (10.85%). An excellent PCE of 13.03% is obtained by the ITIC-2Cl-γ -based device. In addition, the ITIC-2Cl-γ -based device also shows the best device stability. This study indicates that chlorine positioning has a great impact on the acceptors; more importantly, the 3D network structure may be a promising strategy for non-fullerene acceptors to improve the PCE and stability of organic solar cells.

Supramolecular copolymers constitute a fundamental new class of functional materials attracting burgeoning interest, but examples that display phosphorescence and long-lived excited states are rare. Herein, we describe the synthesis of sequential phosphorescent multi-block supramolecular copolymers in one and multiple dimensions using pincer Pt II and Pd II complexes as building blocks by manipulating out-of-equilibrium self-assemblies via the living supramolecular polymerization approach. Doping a small amount of Pt II complexes (2 mol %) into the Pd II assemblies significantly boosted the emission efficiency and radiative decay rate constant (F em = 3.7%, k r = 1.8 3 10 4 s À1 in Pd II assemblies; F em = 76.2%, k r = 58.6 3 10 4 s À1 in Pt II -Pd II co-assemblies), which is ascribed to an external heavy-atom spin-orbital coupling effect arising from the doped Pt II complex with a delocalized 3 [ds*/p*] excited state. The findings on Pt II and Pd II supramolecular copolymers with controlled sequences and greatly enhanced phosphorescence efficiencies open the door to new photofunctional and responsive luminescent metal-organic supramolecular materials.

High performance orange (EQE up to 15.64%) and white (EQE up to 6.88%) solution processed OLEDs fabricated solely with emitters of non-platinum group metals were reported. The white device has CIE coordinates of (0.42, 0.44) and CRI of 81.

Metal-catalyzed intramolecular C-H amination of alkyl azides constitutes an appealing approach to alicyclic amines; challenges remain in broadening substrate scope, enhancing regioselectivity, and applying the method to natural product synthesis. Herein we report an iron(III) porphyrin bearing axial N-heterocyclic carbene ligands which catalyzes the intramolecular C(sp )-H amination of a wide variety of alkyl azides under microwave-assisted and thermal conditions, resulting in selective amination of tertiary, benzylic, allylic, secondary, and primary C-H bonds with up to 95 % yield. 14 out of 17 substrates were cyclized selectively at C4 to give pyrrolidines. The regioselectivity at C4 or C5 could be tuned by modifying the reactivity of the C5-H bond. Mechanistic studies revealed a concerted or a fast re-bound mechanism for the amination reaction. The reaction has been applied to the syntheses of tropane, nicotine, cis-octahydroindole, and leelamine derivatives.

Extended intercationic PdPd contacts of 3.30 Å in the crystal structure and distinct MMLCT transitions absorbing at 528 nm and emitting beyond 600 nm in solutions have been revealed with cyclometalated Pd(ii) N-heterocyclic allenylidene complexes. The Pd(ii)-based MMLCT excited states are responsive to concentrations, temperatures, mechanical force and organic vapors.

A total of 35 [Au(NHC) ][MX ] (NHC=N-heterocyclic carbene; M=Au or Cu; X=halide, cyanide or arylacetylide) complex salts were synthesized by co-precipitation of [Au(NHC) ] cations and [MX ] anions. These salts contain crystallographically determined polymeric Au⋅⋅⋅Au or Au⋅⋅⋅Cu interactions and are highly phosphorescent with quantum yields up to unity and emission color tunable in the entire visible regions. The nature of the emissive excited states is generally assigned to ligand (anion)-to-ligand (cation) charge-transfer transitions assisted by d ⋅⋅⋅d metallophilicity. The emission properties can be further tuned by controlled triple-component co-crystallization or by epitaxial growth. Correct recipes for white light-emitting phosphors with quantum yields higher than 70 % have been achieved by screening the combinatorial pool.

The platinum(ii) photo-catalyzed difluoroalkylation of cinnamic acids and alkynes for selective construction of E-,Z-difluoroalkyl alkenes and difluoroalkyl alkenyl iodides, respectively, were achieved under mild conditions. The high efficiency, good substrate scope and high selectivity altogether highlight the prospect of Pt(ii) photocatalysts in visible-light-driven organic transformation reactions.

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