Balance Is Key.

We look back at our tenth anniversary celebrations and other developments at ChemPlusChem, including the #ChemLifeBalance social media campaign. We also introduce our new Editorial Board Co-Chair and bring the latest news from Chemistry Europe.

Celebrating Ten Years of ChemPlusChem.

Double figures: ChemPlusChem celebrates its tenth anniversary in 2022. Editor-in-Chief Jonathan Faiz looks back at the last ten years, and our board members present their views on how the multidisciplinary research landscape has evolved and will continue to develop in the next decade.

Staying Connected.

2020 Vision: This year has seen the first Early-Career Board, a virtual symposium, the launch of Chemistry Europe, the next Early-Career Award winner, and some exciting special collections containing a great selection of top multidisciplinary research. Editor in Chief Jonathan Faiz outlines the news from ChemPlusChem in 2020, and introduces some of the latest developments for the coming year.

Photoinduced energy transfer across non-covalent bonds in the nanoscale: cyclodextrin hosts with enhanced luminescent properties for guest communication.

Two photoactive cyclodextrin hosts have been prepared and studied in participation on photophysical processes, one with a ruthenium tris(bipyridyl) core which forms a trimeric host and the other with an appended anthracene unit. An acetylide functionalized bipyridyl cyclodextrin, , was prepared by palladium coupling of mono-6-propargyl permethylated beta-CD and 4-bromo-2,2'-bipyridine. The ruthenium complex, [Ru(3)]Cl(2), shows luminescence from the (3)MLCT centered at 650 nm with a quantum yield of 0.044 and a lifetime at room temperature of 1.1 micros in aerated aqueous solution. The enhanced luminescence properties have been attributed to extra delocalisation afforded by the three propargyl units appended to the complex and the stabilization of the MLCT state. An anthracene functionalised cyclodextrin was prepared from mono-6-O-p-toluenesulfonyl permethylated beta-cyclodextrin and 9-anthracene methanol. It shows fluorescence at room temperature with a maximum at 400 nm with a lifetime of 7 ns. Transient absorption spectroscopy has been used to elucidate the excited state properties of [Ru(3)]Cl(2) and hosts. A broad band centered around 600 nm in the [Ru(3)]Cl(2) transient spectrum corresponds to the absorption of the pi-radical anion of the ethynyl fragment of ligand and in a signal at 595 nm was observed, corresponding to the absorption of the anthracene excited singlet state. We used a bisadamantyl guest to assemble the two hosts and studied the energy transfer from the ruthenium core to the anthracene unit by steady state emission spectroscopy. The photoinduced energy transfer process in assemblies of host with ruthenium or osmium metalloguests, [Ru(biptpy)(tpy)](NO(3))(2) and [Os(biptpy)(tpy)](NO(3))(2), was studied by femtosecond transient spectroscopy and steady state emission spectroscopy. The singlet state of the anthracene pendant unit acted as a donor to the MLCT of the Ru(II) or Os(II) metalloguests. An energy transfer rate from the singlet anthracene excited state to the (1)MLCT of the ruthenium centre of 4.8 x 10(8) s(-1) was estimated in the case of the ruthenium guest. The photoinduced triplet energy transfer ( approximately 6 x 10(6) s(-1)) from a longer lived luminescent guest Rubph to the anthracene unit was studied by transient absorption spectroscopy.

Design and synthesis of porphyrin-containing catenanes and rotaxanes.

Catenanes and rotaxanes containing porphyrin subunits have become popular synthetic targets because of the large variety of available synthetic strategies including the coordination chemistry of metallated porphyrins, coupled with the many attractive physical properties of porphyrins. This tutorial review outlines various synthetic approaches and templating strategies that have been used to prepare a range of mechanically interlocked architectures that incorporate porphyrins as fundamental subunits either grafted onto macrocycles or as stoppers. These species are of interest in relation to recreating natural processes such as the photosynthetic apparatus or enzyme binding sites.

Far-red luminescent ruthenium pyridylimine complexes; building blocks for multinuclear arrays.

Ruthenium(II) pyridylimine complexes are explored for their potential as units that might be incorporated into electronic or photonic arrays. The complexes [Ru(bipy)2(L)][PF6]2 (1) and [Ru(tpy)(L)Cl][BF4] (2) with L = phenylpyridin-2-ylmethylene-amine are synthesized and fully characterised using X-ray diffraction analysis and (2D) NMR spectroscopy. 1 displays emission in the far-red area of the spectrum at room temperature. The emission is significantly shifted to longer wavelength with respect to [Ru(bpy)3]2+ indicating that the lowest MLCT state is localised on the pyridylimine ligand. 2 is non-emissive at room temperature and at 77 K.

A unidirectional energy transfer cascade process in a ruthenium junction self-assembled by alpha- and beta-cyclodextrins.

A Ru(II) complex, Ru(alpha2beta), with a trisbipyridyl core and two different receptor sites, alpha- and beta-cyclodextrins, acts as a junction to recognize photoactive guests based on anthracene, Anth, and Os(II), Os-ada, in aqueous solution. Upon light excitation of the self-assembled system Anth.Ru(alpha2beta).Os-ada, an energy cascade process takes place from the Anth guest to the Ru(alpha2beta) core, and subsequently, the energy is funneled to the Os-ada guest. The rates of the two photoinduced processes are determined by time-resolved emission and transient absorption spectroscopic techniques. The system introduces a directed self-assembly approach to unidirectional wires that can lead to nanosized arrays by judicious selection of the individual components.

Acetylenic cyclodextrins for multireceptor architectures: cups with sticky ends for the formation of extension wires and junctions.

A mono-6-O-propargyl permethylated beta-cyclodextrin, 3, has been prepared by two synthetic routes as a versatile building block for the construction of cyclodextrin dimers and trimers with a core junction which is potentially electron conducting. Glaser-Hay coupling of 3 gave beta-cyclodextrin dimer 6, and Pd(0)-catalysed coupling allowed the preparation of a cyclodextrin dimer with a 1,4-phenylene bridge, 7, and a cyclodextrin trimer based on a 1,3,5-trisubstituted benzene, 8. All compounds have been fully characterised, and in particular, detailed analysis by 2D NMR spectroscopic techniques has provided useful insight into the identities of the compounds. The detailed full characterisation of mono-3,6-anhydro-heptakis(2,3-O-methyl)-hexakis(6-O-methyl)-beta-cyclodextrin, 5, is also described. Product 5 is formed during the methylation of compound 3, and its formation was found to be sensitive to the reaction conditions. The absorption and fluorescence spectra of the phenylene-bridged dimer 7 and trimer 8 are also reported. They show different properties of the excited state based on the different electronic coupling imposed by the phenylene core.