We present an accessible implementation of augmented reality projections for the depiction of complex structures and motifs, including atomic orbitals and elemental allotropes. The utilization of a free, crossplatform-compatible, online database of these structures provides the access route for closer examination, either via augmented reality or an online interface. Both will facilitate an enhanced understanding of the complex structures and can be applied in taught courses as well as during the self-study of students.

Herein we describe the first examples of isolable electron‐precise diboranes(4) that bear azide moieties: the acyclic 1,2‐diazido‐1,2‐bis(dimethylamino)diborane(4) and the cyclic 1,4‐diaryl‐2,3‐diazido‐1,4‐diaza‐2,3‐diborinines (aryl=mesityl, 2,6‐xylyl, 4‐tolyl). The reported examples are not only stable enough to be observed and isolated (putative transient diborane(4) azides previously reported by our group spontaneously decompose even below room temperature), but some of them are even robust enough to undergo controlled pyrolysis without explosive decomposition at temperatures well above 100 °C. In two cases, the controlled pyrolysis allows the isolation of complex diazaboretidines, which are the apparent dimerization products of endocyclic boryl‐iminoboranes.

An unprecedented trimeric complex of the composition [{Tc(NO)(PPh 3 )(μ 2 -Cl)} 3 (μ 3 -O)(μ 3 -Cl)] is formed during an attempted reaction of [Tc I (NO)Cl 2 (PPh 3 ) 2 (CH 3 CN)] with PhC�CPh in boiling toluene. No evidence for the intended formation of complexes with a side-on bonded alkyne was found during this reaction or with a variety of other technetium starting materials. Most of such reactions resulted in a recovery of the starting materials and/or in the isolation of unexpected side products. Reactions of the technetium(V) complex [TcNCl 2 (PPh 3 ) 2 ] with lithium acetylides, however, give fivecoordinate products of the composition [TcN(C�CR) 2 (PPh 3 ) 2 ] (R = t Bu, SiMe 3 , Ph(CF 3 ) 2 ). The complexes are stable as solids but undergo a gradual decomposition in solutions. The choice of the solvents used for the synthesis and purification operations is crucial to obtain pure products in satisfactory yields. Similar results were also obtained for the corresponding rhenium complexes [ReN(C�CR) 2 (PPh 3 ) 2 ] with R = SiMe 3 or Ph(CF 3 ) 2 , which have been used to optimize the reaction conditions for the Tc complexes.

Crystallographic tables, bond lengths, angles and ellipsoid plots; spectroscopic data (PDF)Accession Codes CCDC 2151025−2151030 and 2166733 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk

The reaction of [Tc I (NO)(L OMe )(PPh 3 )Cl] ({L OMe } À = η 5cyclopentadienyltris(dimethyl phosphito-P)cobaltate(III)) with Ag(PF 6 ) gives two unexpected products: the dimeric technetium(I) complex [{Tc(NO)(L OMe )(PPh 3 )Cl} 2 Ag](PF 6 ) with a central Ag + ion and the cationic Tc(II) compound [Tc-(NO)(L OMe )(PPh 3 )Cl](PF 6 ). The products have been studied spectroscopically and by X-ray diffraction.