Pt(ii) and Pd(ii) complexes with unprecedented photophysical properties were developed. Encapsulation in nanoparticles boosted their performance while rendering them as self-referenced oxygen sensors.

Oxidative addition: complexes containing an anionic NHC ligand with an unsubstituted nitrogen atom within the heterocycle have been prepared by oxidative addition of 2-chloro-N-methylbenzimidazole to Ni(0) and Pt(0). The "naked" nitrogen atom of the NHC ligand reacts as a strong nucleophile.

In this work, for the first time, the comparative use of P-, As-, and Sb-based ligands in phosphorescent coordination compounds is reported toward new coordination chemical concepts in the design and realization of tailored triplet emitters with nonconventional elements. By means of spectroscopic, X-ray diffractometric, and quantum-chemical methods, we reconstructed the nature of the chemical bonds as well as the influence of the increasingly heavy elements on the photoexcited state properties, which were correlated with the hybridization and polarizability of the pnictogen atoms (Pn). In particular, we elucidated the structural and photophysical properties of a series of homologous Pt­(II) complexes with monodentate ancillary ligands based on group 15 elements, namely P, As, and Sb. Six coordination compounds bearing tridentate dianionic 2,6-bis­(1H-1,2,4-triazol-5-yl)­pyridine luminophoric pincer ligands bearing either CF 3 or t Bu moieties on the triazole rings along with triphenylpnictogens (PnPh 3 ) as monodentate ancillary ligands ([CF 3 /Pn] or [ t Bu/Pn], respectively) have been investigated. The electron donating or withdrawing effect of the peripheral substituent ( t Bu vs. CF 3 , respectively) and its influence on the bonding, crystal packing as well as the excited state energies and lifetimes was assessed in fluid solutions, frozen glassy matrices, amorphous solids, and crystalline phases. A progressively red-shifted phosphorescence was observed with increasing atomic number along with a growing compensation of hybridization defects upon coordination of the Pn atom to the Pt­(II) center. The change of molecular geometry of the PnPh 3 unit upon complexation was extrapolated to predict the structural and excited state characteristics of the Bi-based analogues, which according to DFT calculations should be stable species and are the subject of ongoing synthetic efforts. In general, we envisage the use of these ligands for the relativistic enhancement of radiative deactivation rate processes, especially if Bi-based s-orbitals participate on the bond with the metal center, paving the road toward novel coordination compounds using abundant elements with high spin–orbit coupling for sustainable electroluminescent devices.

Treatment of diphenyl-diethynylsilanes, (H 5 C 6 ) 2 Si(CϵC-RЈ) 2 (RЈ = -C 6 H 5 , -4-Me-C 6 H 4 ), with two equivalents of dialkylaluminium hydrides, R 2 Al-H (R = -CMe 3 , -CH 2 CMe 3 ), afforded the corresponding dialkenylsilanes (3-5) by hydroalumination. The mixed alkenyl-alkynyl compounds resulting from the reduction of only one CϵC triple bond occurred as intermediates. Two of these (1 and 2) were isolated and characterized by crystal structure determinations. They show close interactions of the α-carbon atoms of the ethynyl groups with the coordinatively unsaturated aluminium atoms and a cis arrangement of H and Al atoms across the C=C double bonds. cis/trans Rearrangement took place upon the [a]