Photodissociation of Free Metalloporphyrin Dimer Multianions.

We have used action photofragmentation spectroscopy in the visible spectral range (410 to 650 nm) to investigate the optical properties of different monomeric and dimeric M-meso-tetra-(4-sulfonatophenyl)-porphyrin (with M = Pd(II), Cu(II), Zn(II)) multianions isolated in the gas phase without solvent. In particular, we report the position of the Q-bands (S → S transitions) as a function of charge state, counterions, oligomerization, and dimer structure type. The results for the monomers (charge states = 4- and 3-, sodiated and protonated) are in good agreement with TDDFT calculations and condensed-phase spectra.

Quaternionic formulation of the two-component Kohn-Sham equations and efficient exploitation of point group symmetry.

The quaternionic formulation of the time-reversal invariant quasirelativistic Kohn-Sham equations with exact Hartree-Fock exchange leads to hypercomplex one-component equations with half of the dimension compared to the original two-component problem. The combination of the quaternionic equations with point group symmetry exploitation for D and its subgroups by construction of corepresentations leads to quaternionic, complex, or real algorithms depending on the structure of the point group. In this work, the quaternionic approach with point group symmetry exploitation of the relativistic four-component Dirac-Hartree-Fock theory by Saue and Jensen [J.

Metal Complexes of a Redox-Active [1]Phosphaferrocenophane: Structures, Electrochemistry and Redox-Induced Catalysis.

The synthesis and characterisation of several metal complexes of a redox-active, mesityl(Mes)-substituted [1]phosphaferrocenophane, FcPMes (1), are reported. Cyclic voltammetry studies on the bimetallic complexes [M(κ P-1)(cod)Cl] (M=Rh: 2; M=Ir: 4), [Rh(κ P-1) (CO)Cl] (3) and [AuCl(κ P-1)] (5), in conjunction with DFT calculations, provided indications for a good electronic communication between the metal atoms. To confirm that the ferrocenophane unit might be able to electrochemically influence the reactivity of the coordinated transition metal, the rhodium complex 2 was employed as stimuli-responsive catalyst in the hydrosilylation of terminal alkynes.

Q and Soret Band Photoexcitation of Isolated Palladium Porphyrin Tetraanions Leads to Delayed Emission of Nonthermal Electrons over Microsecond Time Scales.

We have used both action and photoelectron spectroscopy to study the response of isolated Pd(II) meso-tetra(4-sulfonatophenyl)porphyrin tetraanions ([PdTPPS](4-)) to electronic excitation over the 2.22-2.98 eV photon energy range.

Tris(3,5-dimethylpyrazolyl)methane-based heterobimetallic complexes that contain Zn - and Cd - transition-metal bonds: synthesis, structures, and quantum chemical calculations.

Reactions of the tris(3,5-dimethylpyrazolyl)methanide amido complexes [M'{C(3,5-Me2 pz)3 }{N(SiMe3 )2 }] (M'=Mg (1 a), Zn (1 b), Cd (1 c); 3,5-Me2 pz=3,5-dimethylpyrazolyl) with two equivalents of the acidic Group 6 cyclopentadienyl (Cp) tricarbonyl hydrides [MCp(CO)3 H] (M=Cr (2 a), Mo (2 b)) gave different types of heterobimetallic complex. In each case, two reactions took place, namely the conversion of the tris(3,5-dimethylpyrazolyl)methanide ligand (Tpmd*) into the -methane derivative (Tpm*) and the reaction of the acidic hydride M = H bond with the M' = N(SiMe3 )2 moiety. The latter produces HN(SiMe3 )2 as a byproduct.

Cu(II)- and Mn(III)-porphyrin-derived oligomeric multianions: structures and photoelectron spectra.

We present structures and photoelectron spectra of Mn(III) and Cu(II) meso-tetra(4-sulfonatophenyl)porphyrin (TPPS) multianions, as well as of homomolecular dimers and trimers thereof. The structural assignments are based on a combination of mass spectrometry, ion mobility measurements, and semiempirical as well as density functional theory (DFT) calculations. Depending on the type of central metal atom, two completely different dimer structural motifs are found.

Self-consistent treatment of spin-orbit interactions with efficient Hartree-Fock and density functional methods.

Efficient self-consistent field (SCF) schemes including both scalar relativistic effects and spin-orbit (SO) interactions at Hartree-Fock (HF) and density functional (DFT) levels are presented. SO interactions require the extension of standard procedures to two-component formalisms. Efficiency is achieved by using effective core potentials (ECPs) and by employing the resolution-of-the-identity approximation for the Coulomb part (RI-J) in pure DFT calculations as well as also for the HF-exchange part (RI-JK) in the case of HF or hybrid-DFT treatments.

Basis-set extensions for two-component spin-orbit treatments of heavy elements.

The accuracy of standard basis sets of quadruple-zeta and lower quality for the use in two-component self-consistent field procedures including spin-orbit coupling is investigated for the elements In-I and Au-At. Spin-orbit coupling leads to energetic and spatial splittings of inner shells, which are not described accurately with standard basis sets optimized for scalar relativistic calculations. This results in large errors in total atomic energies and significant errors in atomization energies of compounds containing these atoms.