Photoluminescent Properties of Tb-UiO-66 Metal-Organic Framework Analogues.

Three new analogues of Tb-UiO-66 with various functional groups (-F, -Br, -NH) on the terephthalic acid linker of the metal-organic framework (MOF) are synthesized and characterized. The photoluminescent properties of these analogues, as well as Tb-UiO-66 and Tb-UiO-66-(OH), are studied and correlated to the calculated energies for the triplet (T) states of each linker. The results show that the addition of electron withdrawing groups, such as -F and -Br, lead to higher T energies, resulting in quantum yields in the range of 6-31%.

Conjugated core-shell bottlebrush polymers that exhibit crystallization-driven self-assembly.

Bottlebrush polymers are complex architectures with densely grafted polymer side chains along polymeric backbones. The dense and conformationally extended chains in bottlebrush polymers give rise to unique properties, including low chain entanglement, low critical aggregation concentrations, and elastomeric properties in the bulk phase. Conjugated polymers have garnered attention as lightweight, processible, and flexible semi-conducting materials.

Diastereoselective Synthesis of Phosphinyl Peptides via Rh-Catalyzed 1,4-Addition in Coparticipation of a -Chiral Moiety and Difluorphos.

The asymmetric Rh-catalyzed 1,4-addition of aryl/heteroaryl moieties to α,β-unsaturated esters was achieved in high diastereoselectivity via the coparticipation of a -chiral phosphinyl moiety at Cβ to the prochiral center and ()- or ()-Difluorphos. This methodology expands the synthetic toolbox available for the preparation of structurally diverse chiral phosphinyl peptides.

From Coordination to π-Hole Chemistry of Transition Metals: Metalloporphyrins as a Case of Study.

Herein we have evidenced the formation of favorable π-hole Br⋅⋅⋅metal noncovalent interactions (NCIs) involving elements from groups 9, 11 and 12. More in detail, M (M=Co, Ni, Cu and Zn) containing porphyrins have been synthesized and their supramolecular assemblies structurally characterized by means of single crystal X-ray diffraction and Hirshfeld surface analyses, revealing the formation of directional Br⋅⋅⋅M contacts in addition to ancillary hydrogen bond and lone pair-π bonds. Computations at the PBE0-D3/def2-TZVP level of theory revealed the π-hole nature of the Br⋅⋅⋅M interaction.

Solvent-Switchable Remote C-H Activation via 1,4-Palladium Migration Enables Site-Selective C-P Bond Formation: A Tool for the Synthesis of -Chiral Phosphinyl Imidazoles.

Solvent-switchable and site-selective phosphorylation of imidazoles at the C2 or C5 position of the imidazole ring was achieved via 1,4-palladium migration. -Chiral -butyl(aryl)phosphine oxides were cross-coupled to 1-(2-bromophenyl)-1-imidazoles with high enantiospecificity, thereby leading to a novel class of chiral imidazole-based phosphine oxides. As proof of concept, reduction of an analogue yielded the corresponding -chiral 2-phosphinyl imidazole ligand, which was shown to induce high enantioselectivity in the formation of axially chiral molecules synthesized via Pd-catalyzed Suzuki-Miyaura cross-coupling.