Search results for "lek"

Kvantu automātu un meklēšanas algoritmu iespējas un ierobežojumi

2013

ANOTĀCIJA Kvantu skaitļošana ir nozare, kas pēta uz kvantu mehānikas likumiem balstīto skaitļošanas modeļu īpašības. Disertācija ir veltīta kvantu skaitļošanas algoritmiskiem aspektiem. Piedāvāti rezultāti trijos virzienos: Kvantu galīgi automāti Analizēta stāvokļu efektivitāte kvantu vienvirziena galīgam automātam. Uzlabota labāka zināmā eksponenciālā atšķirība [AF98] starp kvantu un klasiskajiem galīgajiem automātiem. Grovera algoritma analīze Pētīta Grovera algoritma noturība pret kļūdām. Vispārināts [RS08] loģisko kļūdu modelis un piedāvāti vairāki jauni rezultāti. Kvantu klejošana Pētīta meklēšana 2D režģī izmantojot kvantu klejošanu. Paātrināts [AKR05] kvantu klejošanas meklēšanas alg…

Kvantu skaitļošanas konstrukcijas

2011

Elektroniskā versija nesatur pielikumus

Anders Wilhelm Ingman – kiistanalainen raamatunkääntäjä

2022

The Difficult Marriage of Triarylcorroles with Zinc and Nickel Ions.

2022

The coordination chemistry of corrole has witnessed a great improvement in the past few years and its Periodic Table has been widened to be so large that it is compared with that of porphyrins. However, Ni and Zn ions, commonly used with porphyrins for both synthetic and theoretical purposes, are sparsely reported in the case of corroles. Here, we report synthetic protocols for preparing Ni and Zn triarylcorrole complexes. In the case of Zn, the preliminary oxidation of the free base corrole in DMSO to the neutral corrole radical is a necessary step to obtain the coordination of the metal ion, because the direct reaction led to the formation of an open-chain tetrapyrrole. The Ni complex cou…

Synthesis, X-ray Structure of Two Hexa-Coordinated Ni(II) Complexes with s-Triazine Hydrazine Schiff Base Ligand

2023

The hydrazine s-triazine ligand (E)-4,4’-(6-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)-1,3,5-triazine-2,4-diyl)dimorpholine (DMPT) was used to synthesize two new Ni(II) complexes via a self-assembly technique. The two complexes were synthesized by a one-pot synthesis strategy and characterized by elemental analysis, FTIR and single-crystal X-ray diffraction analysis to be [Ni(DMPT)(H2O)3](NO3)2.3H2O (1) and [Ni(DMPT)(H2O)3](NO3)2.H2O (2). The structures of both complexes were very similar regarding the coordination sphere and counter anions, but differ only in the number of the crystal water molecules. In the case of complex 1, there are three water molecules instead of one H2O molecu…

Intra- vs Intermolecular Aurophilic Contacts in Dinuclear Gold(I) Compounds: Impact on the Population of the Triplet Excited State.

2022

Two series of dinuclear gold(I) complexes that contain two Au–chromophore units (chromophore = dibenzofurane or dimethylfluorene) connected through a diphosphane bridge that differs in the flexibility and length (diphosphane = dppb for 1,4-bis(diphenylphosphino)butane, DPEphos for bis[(2-diphenylphosphino)phenyl]ether, xanthphos for 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, and BiPheP for 2,2′-bis(diphenylphosphino)-1,1′-biphenyl) have been synthesized and structurally characterized. Their photophysical properties have been carefully investigated, paying attention to the role of the presence, or absence, of aurophilic contacts and their nature (intra- or intermolecular character). Th…

Binding of ion pairs and neutral guests by aryl-extended meso‑p-hydroxyphenyl calix[4]pyrrole : The interplay between three binding sites

2023

An aryl-extended calix[4]pyrrole with four meso‑p-hydroxyphenyl substituents was investigated as a host for chloride, acetate, and benzoate anions. Crystal structures of pyridinium and imidazolium chloride complexes were obtained in which chloride ions are hydrogen bonded exo-cavity to the upper rim hydroxyl groups, and the aromatic cations are bound to the shallow cavity of the host. Furthermore, the calix[4]pyrrole formed a hydrogen bonded dimeric capsule templated by inclusion of adiponitrile guest in the endo-cavity binding site. NMR titrations revealed the preference of the OH groups of the host to bind anionic guests in solution. Benzoate anion had the highest binding constant (4 700 …

Ruthenium‐assisted tellurium abstraction in bis(thiophen‐2‐yl) ditelluride

2023

The reaction of [RuCl2(CO)3]2 and Te2Tpn2 (Tpn = thiophen-2-yl, C4H3S) in the absence of light resulted in the formation of cct-[RuCl2(CO)2(TeTpn2)2] (1) [cis(Cl)-cis(CO)-trans(TeTpn2)] and TeTpn2 (2) together with the precipitation of tellurium. The complex 1 and the monotelluride 2 were characterized by NMR spectroscopy and single-crystal X-ray diffraction. The decomposition of Te2Tpn2 to TeTpn2 has been monitored by 125Te NMR spectroscopy and seemed to be faster than the ligand substitution in [RuCl2(CO)3]2 by TeTpn2. A catalytic cycle is proposed for the decomposition of Te2Tpn2 to TeTpn2 based on the PBE0-D3/def2-TZVP calculations. peerReviewed

Utility of Three-Coordinate Silver Complexes Toward the Formation of Iodonium Ions

2021

The work herein describes the synthesis of five three-coordinate silver(I) complexes comprising a bidentate ligand L1, either bpy (2,2′-bipyridyl) or bpyMe2 (4,4′-dimethyl-2,2′-dipyridyl), and a monodentate ligand L2, either mtz (1-methyl-1H-1,2,3-triazole), 4-Etpy (4-ethylpyridine), or 4-DMAP (N,N-dimethylpyridin-4-amine). Upon reaction of the three-coordinate silver(I) complexes with 0.5 equiv of I2, the reactions quantitatively produce a 1:1 pair of complexes of a four-coordinate silver(I) complex [Ag(L1)2]PF6 and a two-coordinate iodonium complex [I(L2)2]PF6. The combination of [Ag(bpyMe2)2]PF6 and [I(4-DMAP)2]PF6 gave rise to an I+···Ag+ interaction where the I+ acts as a nucleophile, …

Copper(I) Complexes of Bis(2-(diphenylphosphino)phenyl) Ether:  Synthesis, Reactivity, and Theoretical Calculations

2007

The tricoordinated cationic Cu-I complex [Cu(kappa(2)-P,P'-DPEphos)(kappa(1)-P-DPEphos)][BF4] (1) (DPEphos = bis(2-(diphenylphosphino)phenyl) ether) containing a dangling phosphorus center was synthesized from the reaction of [Cu(CH3CN)(4)][BF4] with DPEphos in a 1:2 molar ratio in dichloromethane. When complex 1 is treated with MnO2, elemental sulfur, or selenium, the uncoordinated phosphorus atom undergoes oxidation to form a PE bond resulting in the formation of complexes of the type [Cu(kappa(2)-P,P'-DPEphos)(kappa(2)-P,E-DPEphos-E)][BF4] (2, E = O; 3, E = S; 4, E = Se) containing a Cu-E bond. The zigzag polymeric Cu-I complex [Cu(kappa(2)-P,P'-DPEphos)(mu-4,4'-bpy)](n)[BF4](n) (5) was …