Search results for "DFT"

Theoretical and computational studies of magnetic anisotropy and exchange coupling in molecular systems

2018

The field of molecular magnetism studies the magnetic properties of molecular systems as opposed to conventional metal-based magnets. The high chemical modifiability of the constituting molecules makes such materials highly versatile, and the small size of the building blocks leads to the rise of various quantum mechanical phenomena, such as tunneling and entanglement. These phenomena can then be further utilized in the construction of nanoscale quantum devices. This dissertation describes computational and theoretical studies in the field of molecular magnetism using state-of-the-art quantum chemical methods based on ab initio multireference approaches and broken symmetry density functional t…

Reaction of LiArMe6 (ArMe6ArMe6 = C6H3-2,6-(C6H2-2,4,6-Me3)2) with indium(I)chloride yields three m-terphenyl stabilized mixed-valent organoindium su…

2016

Indium(I)chloride reacts with LiArMe6 (ArMe6 = C6H3-2,6-(C6H2-2,4,6-Me3)2) in THF to give three new mixed-valent organoindium subhalides. While the 1:1 reaction of InCl with LiArMe6 yields the known metal-rich cluster In8(ArMe6)4 (1), the use of freshly prepared LiArMe6 led to incorporation of iodide, derived from the synthesis of LiArMe6, into the structures, to afford In4(ArMe6)4I2 (2) along with minor amounts of In3(ArMe6)3I2 (3). When the same reaction was performed in 4:3 stoichiometry, the mixed-halide compound In3(ArMe6)3ClI (4) was obtained. Further increasing the chloride:aryl ligand ratio resulted in the formation of the known mixed-halide species In4(ArMe6)4Cl2I2 that can also be…

Structure ofD-ribonic acid-dimethyltin(IV) in coordinating solvents: an experimental and DFT119Sn NMR study

2006

We have investigated a newly synthesized complex of D-ribonic acid with dimethyltin(IV). The structure of the complex in solution has been characterized by means of 1 H, 13 C, and 119 Sn NMR and by DFT calculations. The comparison of experimental and computational results allowed the determination of the stable conformation in solution as well as the detection of a dimerization process. Moreover, evidence is given of active coordination of the metal by the solvent.

Reactions of m-Terphenyl-Stabilized Germylene and Stannylene with Water and Methanol: Oxidative Addition versus Arene Elimination and Different React…

2015

Reactions of the divalent germylene Ge(ArMe6)2 (ArMe6 = C6H3-2,6-{C6H2-2,4,6-(CH3)3}2) with water or methanol gave the Ge(IV) insertion product (ArMe6)2Ge(H)OH (1) or (ArMe6)2Ge(H)OMe (2), respectively. In contrast, its stannylene congener Sn(ArMe6)2 reacted with water or methanol to produce the Sn(II) species {ArMe6Sn(μ-OH)}2 (3) or {ArMe6Sn(μ-OMe)}2 (4), respectively, with elimination of ArMe6H. Compounds 1–4 were characterized by IR and NMR spectroscopy as well as by X-ray crystallography. Density functional theory calculations yielded mechanistic insight into the formation of (ArMe6)2Ge(H)OH and {ArMe6Sn(μ-OH)}2. The insertion of an m-terphenyl-stabilized germylene into the O–H bond was…

Oxygen Vacancy Formation and Migration within the Antiphase Boundaries in Lanthanum Scandate-Based Oxides: Computational Study.

2022

The study was performed with the financial support from the Latvian Council of Science under the grant agreement LZP-2020/2-0009. Calculations were performed at the HLRS, University of Stuttgart, within the project 12939 DEFTD. The Institute of Solid State Physics, University of Latvia (Latvia), as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Frame-work Programme H2020-WIDESPREAD-01-2016-2017-Teaming Phase2 under grant agreement No. 739508, project CAMART2.

Density Functional Theory study of the TTC> TTT Isomerization of a Photochromic Spyropiran Merocyanine

2008

Synthesis, characterization, and cellular investigations of porphyrin– and chlorin–indomethacin conjugates for photodynamic therapy of cancer

2021

Indomethacin is a potent non-steroidal anti-inflammatory drug (NSAID) with a strong selective inhibitor activity towards cyclooxygenase-2 (COX-2), an enzyme that is highly overexpressed in various tumour cells, being involved in tumourigenesis. Concomitantly, porphyrins have gained much attention as promising photosensitizers (PSs) for the non-invasive photodynamic therapy (PDT) of cancer. Herein, we report the design, and determine the singlet oxygen generation capacity and in vitro cellular toxicity of porphyrin- and chlorin-indomethacin conjugates (P2-Ind and C2-Ind). Both the conjugates were obtained in high yields and were characterized by 1H, 19F and 13C NMR as well as by high resolut…

Formiaattimolekyylin dissosiaation määritys platina- ja rhodiumpinnoilla laskennallisesti

2017

Tutkielmassa käydään lyhyesti läpi laskennallisen kemian historiaa ja kuinka se on muodostanut suuren roolin tutkimuksissa. Lyhyt katsaus katalyysien historiaan tarjoaa lukijalle mahdollisuuden tarkastella kuinka nykypäivän teknologiaan on päästy, ja mistä kaikki alkoivat. Ilman katalyysiä ihmiskunta olisi edelleen hevosten päällä maaseudulla, joten on olennaista tietää millaisilla menetelmillä ja kuinka ihmiskunta on kehittynyt nykypäivän teknologiaan pohjautuvaan yhteiskuntaan. Historiallisen katsauksen ohella tutkielmassa perehdytään heterogeeniseen katalyysireaktioon, joista vesikaasun siirtoreaktio (WGS) on tarkastelun kohteena. WGS-reaktiota sovelletaan hyvin laajasti teollisissa pros…

Understanding selective reduction reactions with heterogeneous Pd and Pt : climbing out of the black box

2016

A New Pt(II) Complex with Anionic s-Triazine Based NNO-Donor Ligand: Synthesis, X-ray Structure, Hirshfeld Analysis and DFT Studies

2022

The reaction of PtCl2 with s-triazine-type ligand (HTriaz) (1:1) in acetone under heating afforded a new [Pt(Triaz)Cl] complex. Single-crystal X-ray diffraction analysis showed that the ligand (HTriaz) is an NNO tridentate chelate via two N-atoms from the s-triazine and hydrazone moieties and one oxygen from the deprotonated phenolic OH. The coordination environment of the Pt(II) is completed by one Cl−1 ion trans to the Pt-N(hydrazone). Hirshfeld surface analysis showed that the most dominant interactions are the H···H, H···C and O···H intermolecular contacts. These interactions contributed by 60.9, 11.2 and 8.3% from the…