The copper(I)-catalyzed Huisgen [3 þ 2] cycloaddition is a general reaction encompassing wide ranges of organoazide and primarily terminal alkyne reacting partners. Strained internal alkynes can also undergo cycloaddition with azides. We report here that tetrakis(acetonitrile)copper(I) hexafluorophosphate catalyzes the [3 þ 2] cycloaddition of (phosphine)-and (N-heterocyclic carbene)gold(I) alkynyls with benzyl azide. Isolated yields of up to 96% result. The reaction protocol broadly tolerates functionalities on the alkynyl reagent. Gold(I) triazolate products form with complete 1,4-regioselectivity. Some 15 new gold(I) triazolates are reported along with crystal structures of nine. Triazolate complexes bearing polycyclic aromatic substituents show dual singlet-and triplet-state luminescence from excited states localized on the aromatic fragment. Time-resolved emission experiments find long lifetimes consistent with triplet emission parentage. Absorption and emission transitions are analyzed with time-dependent density-functional theory calculations.

A series of phosphane‐ and (N‐heterocyclic carbene)gold(I) complexes were prepared by deprotonation of terminal alkyne precursors and reaction with the corresponding gold(I) chlorides. Some ten new compounds are reported; these are characterized by multinuclear NMR, optical spectroscopy, and elemental analysis. Crystallographic characterization is reported for five complexes. Organogold species bearing conjugated aryl substituents on the alkynyl ligand are luminescent. Density‐functional theory calculations on a model complex suggest that emission and the first several absorption transitions result from excited states dominated by the arylacetylide ligand. Excited‐state geometry optimization finds that the lowest‐energy triplet state bears linear, two‐coordinate gold(I) with a miniscule lengthening of the alkynyl carbon–carbon bond. An unusual triplet excited state having a bent geometry at gold lies at higher energy in arylacetylide complexes. For the model terminal acetylideMe3PAuC≡CH, the calculations find this bent state to be the lowest‐energy triplet.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Rhenium(I) complexes of azadipyrromethene ligands are reported; three have been characterized crystallographically. The free ligands and their metallo-complexes undergo reductive electrochemistry. Red-light absorption results from optically allowed transitions to a ligand-localized LUMO.

The syntheses of benzoxaphospholes and new benzobisoxaphospholes that display blue fluorescence are presented. The latter compounds were accessed by the use of a new precursor, 2,5-diphosphinohydroquinone. The new compounds were fully characterized, including a structural study of 2,6-tert-butylbenzo[1,2-d;4,5-d']bisoxaphosphole. Quantum yields for photoluminescence were determined for a series of compounds. These materials feature bona fide P horizontal lineC p-p pi bonds suitable for conjugated materials having phosphorus as a participatory atom and can thus "photocopy" the properties of other conjugated organic molecules.