BSSE-corrected consistent Gaussian basis sets of triple-zeta valence quality of the lanthanides La-Lu for solid-state calculations.

Consistent basis sets of triple-zeta valence quality for the elements La-Lu were derived for periodic quantum-chemical solid-state calculations. They are an extension of the pob-TZVP-rev2 [D. Vilela Oliveira, et al., J. Comput. Chem. 2019, 40(27), 2364-2376], [J. Laun and T. Bredow, J. Comput. Chem. 2021, 42(15), 1064-1072], [J. Laun and T. Bredow, J. Comput. Chem. 2022, 43(12), 839-846] basis sets and are based on the fully relativistic effective core potentials of the Stuttgart/Cologne group and on the def2-TZVP valence basis of the Ahlrichs group. The basis sets are constructed to minimize the basis set superposition error in crystalline systems. The contraction scheme, orbital exponents, and contraction coefficients were optimized in order to ensure robust and stable self-consistent-field convergence for a set of compounds and metals. For the applied PW1PW hybrid functional, the average deviations of the calculated lattice constants from experimental references are smaller with pob-TZV-rev2 than with standard basis sets available from the CRYSTAL basis set database. After augmentation with single diffuse s- and p-functions, reference plane-wave band structures of metals can be accurately reproduced.

BSSE-corrected consistent Gaussian basis sets of triple-zeta valence with polarization quality of the fifth period for solid-state calculations.

Revised versions of our published pob-TZVP basis sets [Laun, J.; Vilela Oliveira, D. and Bredow, T., J. Comput. Chem., 2018, 39 (19), 1285-1290] have been derived for periodic quantum-chemical solid-state calculations. They complete our pob-TZVP-rev2 series [Vilela Oliveira, D.; Laun, J.; Peintinger, M. F. and Bredow, T., J. Comput. Chem., 2019, 40 (27), 2364-2376 and Laun, J. and Bredow, J. Comput. Chem. 2021; 42 (15), 1064-1072] for the elements of the fifth period and are based on the fully relativistic effective core potentials (ECPs) of the Stuttgart/Cologne group and the def2-TZVP valence basis of the Ahlrichs group. The pob-TZVP-rev2 basis sets are developed to minimize the basis set superposition error (BSSE) in crystalline systems. For the applied PW1PW hybrid functional, the overall performance, transferability, and SCF stability of the resulting pob-TZVP-rev2 basis sets are significantly improved compared to the original pob-TZVP basis sets. After augmentation with single diffuse s- and p-functions, reference plane-wave band structures of metals can be accurately reproduced.

BSSE-corrected consistent Gaussian basis sets of triple-zeta valence with polarization quality of the sixth period for solid-state calculations.

Consistent basis sets of triple-zeta valence with polarization quality for the elements Cs-Po were derived for periodic quantum-chemical solid-state calculations. They are an extension of the pob-TZVP-rev2 [Vilela Oliveira, D.; Laun, J.; Peintinger, M. F. and Bredow, T., J. Comput. Chem., 2019, 40 (27), 2364-2376] basis sets and are based on the fully relativistic effective core potentials (ECPs) of the Stuttgart/Cologne group and on the def2-TZVP valence basis of the Ahlrichs group. The basis sets are constructed to minimize the basis set superposition error (BSSE) in crystalline systems. The contraction scheme, the orbital exponents, and contraction coefficients were optimized in order to ensure robust and stable self-consistent-field (SCF) convergence for a set of compounds and metals. For the applied PW1PW hybrid functional, the average deviations of the calculated lattice constants from experimental references are smaller with pob-TZVP-rev2 than with standard basis sets available from the CRYSTAL basis set database.

Bridging experiment and theory: enhancing the electrical conductivities of soft-templated niobium-doped mesoporous titania films.

Theoretical calculations suggest a strong dependence of electrical conductivity and doping concentration in transition-metal doped titania. Herein, we present a combined theoretical and experimental approach for the prediction of relative phase stability and electrical conductivity in niobium-doped titania as model system. Our method paves the way towards the development of materials with improved electrical properties.

BSSE-correction scheme for consistent gaussian basis sets of double- and triple-zeta valence with polarization quality for solid-state calculations.

Revised versions of our published pob-TZVP [Peintinger, M. F.; Oliveira, D. V. and Bredow, T., J. Comput. Chem., 2013, 34 (6), 451-459.] and unpublished pob-DZVP basis sets, denoted as pob-TZVP-rev2 and pob-DZVP-rev2, have been derived for the elements HBr. It was observed that the pob basis sets suffer from the basis set superposition error (BSSE). In order to reduce this effect, we took into account the counterpoise energy of hydride dimers as an additional parameter in the basis set optimization. The overall performance, portability, and SCF stability of the resulting rev2 basis sets are significantly improved compared to the original pob basis sets. © 2019 Wiley Periodicals, Inc.

Precise Polymer Synthesis by Autonomous Self-Optimizing Flow Reactors.

A novel continuous flow system for automated high-throughput screening, autonomous optimization, and enhanced process control of polymerizations was developed. The computer-controlled platform comprises a flow reactor coupled to size exclusion chromatography (SEC). Molecular weight distributions are measured online and used by a machine-learning algorithm to self-optimize reactions towards a programmed molecular weight by dynamically varying reaction parameters (i.e. residence time, monomer concentration, and control agent/initiator concentration). The autonomous platform allows targeting of molecular weights in a reproducible manner with unprecedented accuracy (<2.5 % deviation from pre-selected goal) for both thermal and light-induced reactions. For the first time, polymers with predefined molecular weights can be custom made under optimal reaction conditions in an automated, high-throughput flow synthesis approach with outstanding reproducibility.

Consistent gaussian basis sets of double- and triple-zeta valence with polarization quality of the fifth period for solid-state calculations.

Consistent basis sets of double- and triple-zeta valence with polarization quality for the fifth period have been derived for periodic quantum-chemical solid-state calculations with the crystalline-orbital program CRYSTAL. They are an extension of the pob-TZVP basis sets, and are based on the full-relativistic effective core potentials (ECPs) of the Stuttgart/Cologne group and on the def2-SVP and def2-TZVP valence basis of the Ahlrichs group. We optimized orbital exponents and contraction coefficients to supply robust and stable self-consistent field (SCF) convergence for a wide range of different compounds. The computed crystal structures are compared to those obtained with standard basis sets available from the CRYSTAL basis set database. For the applied hybrid density functional PW1PW, the average deviations of calculated lattice constants from experimental references are smaller with pob-DZVP and pob-TZVP than with standard basis sets. © 2018 Wiley Periodicals, Inc.

Reversible Surface Engineering via Nitrone-Mediated Radical Coupling.

Efficient and simple polymer conjugation reactions are critical for introducing functionalities on surfaces. For polymer surface grafting, postpolymerization modifications are often required, which can impose a significant synthetic hurdle. Here, we report two strategies that allow for reversible surface engineering via nitrone-mediated radical coupling (NMRC). Macroradicals stemming from the activation of polymers generated by copper-mediated radical polymerization are grafted via radical trapping with a surface-immobilized nitrone or a solution-borne nitrone. Since the product of NMRC coupling features an alkoxyamine linker, the grafting reactions can be reversed or chain insertions can be performed via nitroxide-mediated polymerization (NMP). Poly( n-butyl acrylate) ( Mn = 1570 g·mol-1, D̵ = 1.12) with a bromine terminus was reversibly grafted to planar silicon substrates or silica nanoparticles as successfully evidenced via X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry, and grazing angle attenuated total reflection Fourier-transform infrared spectroscopy (GAATR-FTIR). NMP chain insertions of styrene are evidenced via GAATR-FTIR. On silica nanoparticles, an NMRC grafting density of close to 0.21 chains per nm2 was determined by dynamic light scattering and thermogravimetric analysis. Concomitantly, a simple way to decorate particles with nitroxide radicals with precise control over the radical concentration is introduced. Silica microparticles and zinc oxide, barium titanate, and silicon nanoparticles were successfully functionalized.

2D laser lithography on silicon substrates via photoinduced copper-mediated radical polymerization.

A 2D laser lithography protocol for controlled grafting of polymer brushes in a single-step is presented. A series of polyacrylates were grafted from silicon substrates via laser-induced copper-mediated radical polymerization. Film thicknesses up to 39 nm were reached within 125 µs of exposure to UV laser light (351 nm). Successful block copolymerization underpinned the controlled nature of the grafting methodology. The resolution of a small structure of grafted PHEA reached 270 µm and was limited by the type of laser used in the study. Further, a checkerboard pattern of PtBA and POEGA was produced and imaged via time-of-flight secondary ion mass spectrometry (ToF-SIMS), and X-ray photoelectron spectroscopy (XPS).

Surface Grafting via Photo-Induced Copper-Mediated Radical Polymerization at Extremely Low Catalyst Concentrations.

Surface-initiated photo-induced copper-mediated radical polymerization is employed to graft a wide range of polyacrylate brushes from silicon substrates at extremely low catalyst concentrations. This is the first time that the controlled nature of the reported process is demonstrated via block copolymer formation and re-initiation experiments. In addition to unmatched copper catalyst concentrations in the range of few ppb, film thicknesses up to almost 1 µm are achieved within only 1 h.