Magnetically induced current density susceptibilities and ring-current strengths have been calculated for neutral and doubly charged persubstituted benzenes CX and CX with X = F, Cl, Br, I, At, SeH, SeMe, TeH, TeMe, and SbH. The current densities have been calculated using the gauge-including magnetically induced current (GIMIC) method, which has been interfaced to the Gaussian electronic structure code rendering current density calculations using effective core potentials (ECP) feasible. Relativistic effects on the ring-current strengths have been assessed by employing ECP calculations of the current densities. Comparison of the ring-current strengths obtained in calculations on CAt and CAt using relativistic and non-relativistic ECPs show that scalar relativistic effects have only a small influence on the ring-current strengths. Comparisons of the ring-current strengths and ring-current profiles show that the CI, CAt, C(SeH), C(SeMe), C(TeH), C(TeMe), and C(SbH) dications are doubly aromatic sustaining spatially separated ring currents in the carbon ring and in the exterior of the molecule. The CI radical cation is also found to be doubly aromatic with a weaker ring current than obtained for the dication.

Concentric bond approach has been employed to rationalize the electronic structure of endohedral clusters.

Nuclear magnetic shieldings have been calculated at the density functional theory (DFT) level for stacks of benzene, hexadehydro[12]annulene, dodecadehydro[18]annulene, and hexabenzocoronene. The magnetic shieldings due to the ring currents in the adjacent molecules have been estimated by calculating nucleus independent molecular shieldings for the monomer in the atomic positions of neighbor molecules. The calculations show that the independent shielding model works reasonably well for the H NMR shieldings of benzene and hexadehydro[12]annulene, whereas for the larger molecules and for theC NMR shieldings the interaction between the molecules leads to shielding effects that are at least of the same size as the ring current contributions from the adjacent molecules. A better agreement is obtained when the nearest neighbors are also considered at full quantum mechanical (QM) level. The calculations suggest that the nearest solvent molecules must be included in the quantum mechanical system, at least when estimating solvent shifts at the molecular mechanics (MM) level. Current density calculations show that the stacking does not significantly affect the ring current strengths of the individual molecules, whereas the shape of the ring current for a single molecule differs from that of the stacked molecules.

A spherical and cavernous carbocage molecule exhibiting faces with larger ring sizes than regular fullerenes is a suitable species for investigating how molecular magnetic properties depend on the structure of the molecular framework. The studied all-carbon gaudiene (C72) is a highly symmetrical molecule with three- and four-fold faces formed by twelve membered rings. Here, we attempt to unravel the magnetic response properties of C72 by performing magnetic shielding and current density calculations with the external magnetic field applied in different directions. The obtained results indicate that the induced current density flows mainly along the chemical bonds that are largely perpendicular to the magnetic field direction. However, the overall current strength for different directions of the magnetic field is nearly isotropic differing by only 10% indicating that C72 can to some extent be considered to be a spherical aromatic molecule, whose current density and magnetic shielding are ideally completely isotropic. The induced magnetic field is found to exhibit long-range shielding cones in the field direction with a small deshielding region located perpendicularly to the field outside the molecule. The magnetic shielding is isotropic inside the molecular framework of C72, whereas an orientation-dependent magnetic response appears mainly at the exterior of the molecular cage.

/ 1d transitions. The gold nanoclusters studied here can serve as model compounds for assessing the metallic core size effects on the absorption energies and the influence of the surface structure of the gold core on the cluster properties. The present study suggests that it is also plausible that even larger hollow structures derived from Au 42 , Au 72 , and Au 92 golden fullerenes can exist.

Rational design of artificial water-splitting catalysts is central for developing new sustainable energy technology.

† Footnotes relating to the title and/or authors should appear here. Electronic Supplementary Information (ESI) available: Optimized coordinates for [trans-Cu(μ-OH)(μ-dmpz)]6. See [trans-Cu(μ-OH)(μ-dmpz)]6 (1), exhibits six Cu(II) centers effectively coupled through an ligand mediated mechanism leading to a diamagnetic ground state for a wide temperature interval. Here we investigate further magneto-structural correlations standing on the possible free electron precession along such a copper-based ring-like nanocoil mediated by the bridging ligands. We find that in 1, the mediated antiferromagnetic coupling leads to the characteristic that reminisce the aromatic ring behavior through evaluation of both induced currents and shielding cones from relativistic density functional theory level. According to our calculations of gauge including magnetically induced current densities and the induced magnetic field, a sizable ring current strength susceptibility is obtained for the cyclic Cu-N-N-Cu and Cu-O-Cu pathways allowing a magnetic exchange between the copper centers. Our study suggests that [Cu6(dmPz)6(OH)6] consisting of an aromatic ring structure displays aromaticity and superexchange along the Cu-O-Cu and Cu-N-N-Cu backbones, which accounts for the 80 % and 20% of the overall ring current strength susceptibility, respectively. This unravels the presence of particular aromatic rings characteristics in coordination compounds without a direct metal-metal bond, where several formally paramagnetic centers are antiferromagnetically-coupled through supporting ligands. We envisage that our findings can be extended to other examples depicting ligand-mediated interaction between metal centers. This journal is

The magnetically induced current density of an intriguing naphthalene-fused heteroporphyrin have been studied, using the quantum-chemical, gauge-including magnetically induced currents (GIMIC) method. The ring-current strengths and current-density pathways for the...