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Search results for: CRYSTAL STRUCTURES
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Modulated crystal structures - periodicity in more than three dimensions
PublicationThe initial definition of a crystal was that it is an object with flat faces. When diffraction studies were developed it turned out that crystal consists of a highly ordered particles and it is possible to isolate a small unique part of their structure - a unit cell - and the definition has been changed to rely on this fact. Nowadays by a crystal we mean any solid having an essentially discrete diffraction diagram. It is because...
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Crystal structures of the DsbG disulfide isomerase reveal an unstable disulfide
PublicationDsb proteins control the formation and rearrangement of disulfide bonds during the folding of secreted and membrane proteins in bacteria. DsbG, a member of this family, has disulfide bond isomerase and chaperone activity. Here, we present two crystal structures of DsbG at 1.7- and 2.0-Angstrom resolution that are meant to represent the reduced and oxidized forms, respectively. The oxidized structure, however, reveals a mixture...
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Pyrrole azocrown ethers - synthesis, crystal structures, and fluorescence properties
PublicationZsyntezowano nowe związki makrocykliczne zawierające w makropierścieniu pierścień pirolowy, grupy azowe oraz reszty chromoforowe i fluorescencyjne. Scharakteryzowano strukturę krystaliczną dwóch spośród otrzymanych makrocykli metodą rentgenografii strukturalnej. Stwierdzono, że zaprezentowane pirolowe azokorony to związki czułe i selektywne na jony ołowiu(II) oraz, że mogą być użyte jako chemosensory zarówno w spektroskopii UV-Vis,...
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ZEITSCHRIFT FUR KRISTALLOGRAPHIE-NEW CRYSTAL STRUCTURES
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The Syntheses and Crystal Structures of the First Disiloxane-1,3-dithiol and Its Cadmium Complex.
PublicationThe new silicon–sulfur compound: disiloxane-1,3-dithiol was obtained from silicon disulfide and 2,6-diisopropylphenol in a reaction catalyzed by imidazole or 4-(dimethylamino)pyridine (DMAP). Crystal structure of disiloxane–1,3-dithiol reveals a close-to-linear Si–O–Si angle and a mutual trans position of the two hydrosulfido groups. The compound forms a chelating mononuclear complex with cadmium ions.
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Crystal structures of the Bacillus subtilis prophage lytic cassette proteins XepA and YomS
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Silver complexes stabilized by large silanethiolate ligands – crystal structures and luminescence properties
PublicationBulky silanethiolate and disiladithiolate ligands were applied to synthesize one mononuclear and three trinuclear silver complexes including two cyclic “microclusters” and a linear tri-nuclear silanethiolate complex. All obtained compounds are characterized by X-ray diffraction and FT-IR. NMR and emission spectroscopies were used where possible. The first trinuclear anionic silver thiolate is structurally characterized. The influence...
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Crystal structures of aminotransferases Aro8 and Aro9 from Candida albicans and structural insights into their properties
PublicationAminotransferases catalyze reversibly the transamination reaction by a ping-pong bi-bi mechanism with pyridoxal 5′-phosphate (PLP) as a cofactor. Various aminotransferases acting on a range of substrates have been reported. Aromatic transaminases are able to catalyze the transamination reaction with both aromatic and acidic substrates. Two aminotransferases from C. albicans, Aro8p and Aro9p, have been identified recently, exhibiting...
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Crystal structures of eight- and ten-membered cyclic bisanisylphosphonothioyl disulfanes and comparison with their P-ferrocenyl analogues
PublicationTwo new crystal structures of eight- and ten-membered cyclic bisanisylphosphonothioyl disulfanes, namely 2,5-bis(4-methoxyphenyl)-1,6,3,4,25,55- dioxadithiadiphosphocane-2,5-dithione, C16H18O4P2S4, and 2,5-bis(4-methoxyphenyl)-1,6,3,4,25,55-dioxadithiadiphosphecane-2,5-dithione, C18H22O4P2S4, have been determined and compared to structures of the ferrocenyl analogues. The eight-membered rings have similar conformations (TBC) but...
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Novel 1,2,3-Triazole Derivatives as Mimics of Steroidal System—Synthesis, Crystal Structures Determination, Hirshfeld Surfaces Analysis and Molecular Docking
PublicationHerein, we present the synthesis and crystal structures determination of five 4-(1-phenyl-1H-1,2,3-triazol-4-yl)phenol derivatives containing halogen atoms, 6a–e, which may be used as an excellent mimic of steroids in the drug development process. Good quality crystals obtained for all of the synthesized compounds allowed the analysis of their molecular structures. Subsequently, the determined crystal structures were used to calculate...
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Effect of Aromatic System Expansion on Crystal Structures of 1,2,5-Thia- and 1,2,5-Selenadiazoles and Their Quaternary Salts: Synthesis, Structure, and Spectroscopic Properties
PublicationRational manipulation of secondary bonding interactions is a crucial factor in the construction of new chalcogenadiazole-based materials. This article reports detailed experimental studies on phenanthro[9,10-c][1,2,5]chalcogenadiazolium and 2,1,3-benzochalcogenadiazolium salts and their precursors. The compounds were synthesized, characterized employing NMR and UV-Vis spectroscopy. TD-DFT calculations were also performed. The influence...
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Cooperativity of Halogen- and Chalcogen-Bonding Interactions in the Self-Assembly of 4‑Iodoethynyl- and 4,7-Bis(iodoethynyl)benzo-2,1,3-chalcogenadiazoles: Crystal Structures, Hirshfeld Surface Analyses, and Crystal Lattice Energy Calculations
PublicationSeveral new 4-iodoethynyl- and 4,7-bis- (iodoethynyl)benzo-2,1,3-chalcogenadiazoles were prepared, and a comprehensive analysis of the most prominent secondary bonding interactions responsible for the crystal self-assembly was performed using X-ray diffraction. The presence of both the iodoethynyl and chalcogenadiazole moieties allows an evaluation of the preference of these molecules to aggregate through either chalcogen- or halogen-bonding...
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Crystal and electronic structures of Ni(II) silanethiolates containing flexible diamine ligands
PublicationFive nickel(II) complexes containing aliphatic diamines and tri-tert-butoxysilanethiolate ligand have been synthesized for the purpose of studying their structural, spectral (IR, UV–Vis, HF EPR) and thermal properties. Complexes (1)–(5) have been prepared in high yield by reactions of [Ni{SSi(OtBu)3}2(NH3)(H2O)] with 1.3-propanediamine (L1), 1,6-hexanediamine (L2), or 1,7-heptanediamine (L3). The X-ray structures were determined...
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Crystal structures of (E)-3-(4-hydroxybenzylidene)chroman-4-one and (E)-3-(3-hydroxybenzylidene)-2-phenylchroman-4-one
PublicationThe synthesis and crystal structures of (E)-3-(4-hydroxybenzylidene)chroman-4-one, C16H12O3,I, and (E)-3-(3-hydroxybenzylidene)-2-phenylchroman-4-one,C22H16O3,II, are reported. These compounds are of interest with respect to biological activity. Both structures display intermolecular C—H---O and O—H---O hydrogen bonding, forming layers in the crystal lattice. The crystal structure of compound I is consolidated...
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Solvent influence on the crystal structures of new cadmium tri-tert -butoxysilanethiolate complexes with 1,4-bis(3-aminopropyl)piperazine: luminescence and antifungal activity
PublicationMonocrystals of dinuclear -1,4-bis(3-aminopropyl)piperazine-4N1,N10:N4,N40-bis[bis(tri-tert-butoxysilanethiolato-S)cadmium(II)], [Cd2(C12H27O3SSi)4(C10-H24N4)] or [Cd2{SSi(OtBu)3}4(-BAPP)], 1, and polynuclear catena-poly[[bis-(tri-tert-butoxysilanethiolato-S)cadmium(II)]--1,4-bis(3-aminopropyl)piperazine-2N10:N40], [Cd(C12H27O3SSi)2(C10H24N4)]n or [Cd{SSi(OtBu)3}2(-BAPP)]n,2, with 1,4-bis(3-aminopropyl)piperazine (BAPP)...
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Solvent influence on the crystal structures of new cadmium tri-tert -butoxysilanethiolate complexes with 1,4-bis(3-aminopropyl)piperazine: luminescence and antifungal activity
PublicationMonocrystals of dinuclear 1,4-bis(3-aminopropyl)piperazine-�4N1,N10:N4,N40-bis[bis(tri-tert-butoxysilanethiolato-�S)cadmium(II)], [Cd2(C12H27O3SSi)4(C10-H24N4)] or [Cd2{SSi(OtBu)3}4(�-BAPP)], 1, and polynuclear catena-poly[[bis- (tri-tert-butoxysilanethiolato-�S)cadmium(II)]-�-1,4-bis(3-aminopropyl)piperazine-�2N10:N40], [Cd(C12H27O3SSi)2(C10H24N4)]n or [Cd{SSi(OtBu)3}2(�-BAPP)]n, 2, with 1,4-bis(3-aminopropyl)piperazine (BAPP)...
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Coordination complexes of Mn(II), Co(II), Ni(II), Zn(II) and Cd(II) with histaminol – Crystal structures and formation constants in aqueous solution
PublicationStability constants were determined for a series of coordination complexes of Mn(II), Co(II), Ni(II), Zn(II) and Cd(II) with histaminol in aqueous solution. The tendency of histaminol to form chelate complexes has been confirmed by the isolation of several complex species in the monocrystalline form and determination of their molecular structures.
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Syntheses and crystal structures of lithium derivatives of diphosphanes R2P-P(SiMe3)Li·3L, R = Ph, iPr and iPr2N, L = THF or DME
PublicationW wyniku reakcji R2P-P(SiMe3)2 z BuLi w THF lub DME powstają pochodne litowe difosfanów R2P-P(SiMe3)Li·3L. Dla R = iPr oraz iPr2N powstają sole R2P-P(SiMe3)Li·3THF, w których atom litu jest czterokrotnie koordynowany a dla R = Ph powstaje sól [Li·3DME]+[Ph2P-PSiMe3]-, która posiada budowę jonową. W reakcji BuLi z Ph2P-P(SiMe3)2 powstają znaczne ilości produktów ubocznych: Ph2P-PPh2 i LiP(SiMe3)2.
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Distortions in structures of the twist bend nematic phase of a bent-core liquid crystal by the electric field
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Formation, crystal and molecular structures of heteroleptic zinc(II) tri-tert-butoxysilanethiolates with ZnNO2S2 and ZnN2S2 coordination pattern.
PublicationZsyntetyzowano pięć tri-tert-butoksysilanotiolanów cynku zawierających jako dodatkowe ligandy heterocykliczne, zasady azotowe. Wzór ogólny tych kompleksów to Zn(SSi(OBut)3)2L, gdzie L=alfa-pikolina, 2,4-lutydyna, N-metyloimidazol lub Zn(SSiOBut)3)2L2, gdzie L=N-metyloimidazol lub pirydyna. Określono strukturę krystaliczną otrzymanych związków oraz zmierzono widma IR i NMR.
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Synthesis and reactivity of 2,2,4,4-Tetrakis(tri-tertbutoxysilane-thiolato)-1,3,2,4-dithiadistannetane - crystal and molecular structures of two polymorphic forms
PublicationTytułowy związek [Sn(μ-S){SSi(OtBu)3}2]2 (1), zawierający dwa, 4-koordynacyjne atomy cyny, krystalizuje w dwóch odmianach polimorficznych. Forma ortorombowa-1a, została otrzymana w reakcji (tBuO)3SiSH i Et3N z SnCl2, podczas gdy forma trójskośna-1b, w reakcji z SnCl4 jako substratem. Struktura krystaliczna i cząsteczkowa obydwu odmian polimorficznych została wyznaczona przez badania metodą Rentgenowskiej Analizy Strukturalnej,...
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Lower rim substituted tert-butylcalix[4]arenes (II). Complexing ability of5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis-O-(piperidinylcarbonyl)me- thylenecalix[4]arene. The crystal structures of the ligand and its sodium complex
PublicationSyntezowano kompleksy wymienionego w tytule liganda z chlorkiem sodu i azotanami itru(III), lantanu(III), samaru(III) i gadolinu(III) w reakcji liganda i odpowiedniej soli, które charakteryzowano za pomocą widm IR, UV-vis,1H NMR, FAB-MS, a także za pomocą analizy elementarnej. W reakcji wymiany z kompleksu z sodem otrzymywano kompleksy z lantanowcami. Określono strukturę krystaliczną wolnego liganda i jego kompleksu z sodem za...
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Structural motifs in the Cu(II), Mn(II) and Zn(II) complexes based on N,N,N-donor dipodal or N,N,N,N-donor tripodal ligands obtained in situ: Synthesis, crystal structures and xanthine oxidase inhibition properties
PublicationA series of four novel transition metal complexes, [Cu(NCS)2L1] (1), [Mn(NCS)2L1] (2) where L1 = bis(1-(3,5-dimethylpyrazolyl)methyl)amine, [Mn(NCS)2L2] (3) and [Zn(NCS)L2]2[Zn(NCS)4] (4) where L2 = tris(1-(3,5-dimethylpyrazolyl)methyl)amine, has been obtained in situ by a one-step, one-pot synthetic path starting from 1-hydroxymethyl-3,5-dimethylpyrazole (L). The isolated complexes were fully characterised by elemental analysis,...
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Cobalt(II) tri-tert-butoxysialanethiolates.Synthesis, properties, crystal and molecular structures of [Co{SSi(OtBu)3}2(L)] and[Co{SSi(OtBu)3}2(L)2] type complexes with monodentate nitrogen ligands.
PublicationThe title heteroleptic neutral cobalt(II) tri-tert-butoxysilanethiolate complexes with monodentate nitrogen bases (L) as additional ligands have been prepared by the reactions of [Co{μ-SSi(OtBu)3}{SSi(OtBu)3}(NH3)]2 (1) with respective bases. For pyridine both types have been prepared...
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Potassium Tri-tert-butoxysilanethiolates: Synthesis, Properties, and Crystal and Molecular Structures of [(tBuO)3SiSK]6[THF]2·2THF, {[(tBuO)3SiS]2K2}n, and [(tBuO)3SiSK]4[H2O]4·C6H6
PublicationW reakcji tri-tert-butoksysilanotiolu z potasem otrzymano trzy nowe związki:[(tBuO)3SiSK]6[THF]2·2THF, {[(tBuO)3SiS]2K2}n, i[(tBuO)3SiSK]4[H2O]4·C6H6. Stanowią one dogodne substraty w syntezach kompleksów silanotiolanowych metali przejściowych. Charakteryzują się one również różnorodnością tworzonych układów. Rentgenowska analiza strukturalna wykazała, iż tworzą one trzy typy makrocząsteczkowych układów, w których...
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The crystal structures of (<i>O</i>-silyl)thiobenzoates (<sup><i>t</i></sup>BuO)<sub>3</sub>SiOC(S)Ph, Ph<sub>3</sub>SiOC(S)Ph, (2,6-XyO)<sub>3</sub>SiOC(S)Ph, and PhC(O)SSSC(O)Ph
PublicationChlorek benzylu reaguje z silanotiolanami sodu R3SiSNa dając wyłącznie pochodne sililowe kwasu monotiobenzoesowego R3SiOC(S)Ph, R=t-Bu, Ph lub 2,6-XyO w postaci pomarańczowych kryształów. Wymienione produkty zostały poddane rentgenowskiej analizie strukturalnej. Badania NMR roztworów tych substancji wskazują, że te same izomery są obecne w roztworze i w ciele stałym.
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Cobalt(II) and Cobalt(III) Tri‐tert‐butoxysilanethiolates. Synthesis, Properties, Crystal and Molecular Structures of [Co{μ‐SSi(OBut)3}{SSi(OBut)3}(NH3)]2 and [Co{SSi(OBut)3}2(NH3)4][SSi(OBut)3] Complexes
PublicationThe heteroleptic neutral tri‐tert‐butoxysilanethiolate of cobalt(II) incorporating ammonia as additional ligand (1) has been prepared by the reaction of a cobalt(II) ammine complex with tri‐tert‐butoxysilanethiol in water. Complex 1, dissolved in hexane, undergoes oxidation in an ammonia saturated atmosphere to the ionic cobalt(III) compound 2. Molecular and...
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ortho-Fluorobenzanilides and ortho-fluorothiobenzanilides: Molecular conformations and crystal packing
PublicationSeries of 2-fluoro and 2,6-difluorobenzanilides and their thiobenzanilide analogs have been synthesized to investigate the influence of the fluorine atom on their crystal structures and self-assembly in the crystal lattice. The X-ray analysis of the single crystal revealed that the synthesized molecules adopt a geometry being deflected from planarity. The deflection was investigated by analysis of dihedral angles between mean planes...
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Ultrasonic spectroscopy of silicon single crystal
PublicationSpecimens of Si single crystals with different crystal orientation [100] and [110] were studied by the electro-ultrasonic spectroscopy (EUS) and Resonant Ultrasonic Spectroscopy (RUS). A silicon single crystal is an anisotropic crystal, so its properties are different in different directions in the material relative to the crystal orientation. EUS is based on interaction of two signals: electric AC signal and ultrasonic signal,...
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Three-dimensional Weyl topology in one-dimensional photonic structures
PublicationTopological features, in particular distinct band intersections known as nodal rings, usually requiring three-dimensional structures, have now been demonstrated experimentally in an elegantly simple one-dimensional photonic crystal.
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TaRh 2 B 2 and NbRh 2 B 2 : Superconductors with a chiral noncentrosymmetric crystal structure
PublicationIt is a fundamental truth in solid compounds that the physical properties follow the symmetry of the crystal structure. Nowhere is the effect of symmetry more pronounced than in the electronic and magnetic properties of materials—even the projection of the bulk crystal symmetry onto different crystal faces is known to have a substantial impact on the surface electronic states. The effect of bulk crystal symmetry on the properties...
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Crystal Facet Engineering of TiO2 from Theory to Application
PublicationRecently, the surface structure effect on photocatalytic activity has gathered increasing attention due to its reported influence on the charge carrier trapping and separation. Detailed control over the surface structure can be achieved by exposing the specific crystal facets. As a result, the photogenerated electrons and holes can be effectively separated between the different facets of semiconductor crystals. TiO2 is the most...
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Crystal structure and physical properties of AePd1-xP1+x (Ae = Ca, Sr)
PublicationWe report the discovery of two new compounds AePd1-xP1+x (Ae = Ca, Sr) crystallized in different hexagonal structures. Single crystals of AePd1-xP1+x (Ae = Ca, Sr) are obtained using the Bi-flux method. Crystallographic analysis by both powder and single crystal X-ray diffraction shows that CaPd1-xP1+x crystallizes in a non-centrosymmetric hexagonal structure with the space group P-6m2 (No.187) and lattice parameters a = b = 4.0391(9)...
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Coordination polymers and molecular structures among complexes of mercury(II) halides with selected 1-benzoylthioureas
PublicationSix new 1-benzoyl-3-phenylthiourea and 1-benzoyl-3-(2-methylphenyl)thiourea complexes of mercury( II) were obtained in the reactions of the ligands with HgX2 in methanol (X = Cl, Br, I). Their structures, determined by single-crystal X-ray diffraction analysis, exhibit different stoichiometries and molecular organization. Coordination centers adopt more or less distorted tetrahedral geometry (five structures) or distorted trigonal...
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Syntheses and structures of the first terminal phosphanylphosphido complexes of molybdenum(IV)
PublicationThe reactions of R2P-P(SiMe3)Li (R = tBu, iPr2N) with [Cp2MoCl2] yield terminal phosphanylphosphido complexes formally via the insertion of the phosphinidene P-atom into the C - H bond of a cyclopentadienyl ring and the migration of the hydrogen atom or SiMe3 moiety to the molybdenum centre. Solid state structures of [Cp(C5H4P-PtBu2)MoH], [Cp(C5H4P-PtBu2)Mo(SiMe3)] and [Cp{C5H4P-P(NiPr2)2}Mo(SiMe3)] were established by single crystal...
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Comparison of hydrogen bonds and diverse weak interactions of the nitro group in 2-methyl-4-nitroanilinium nitrate, bisulfate and two hexafluoridosilicates: elementary graph-set approach
PublicationCrystal structures of (H2m4na)NO3 (1), (H2m4na)HSO4 (2), (H2m4na)2SiF6 (3) and (H2m4na)2SiF6*2H2O (4), where 2m4na = 2-methyl-4-nitroaniline, are presented. Two layers of interactions occur in the structures, N—H...O/F hydrogen bonds and interactions with the nitro group. Although diverse, hydrogen-bonding patterns are compared with each other by means of interrelations among elementary graph-set descriptors and descriptors of hydrogen-bonding...
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New uranium(vi) and isothiouronium complexes: synthesis, crystal structure, spectroscopic characterization and a DFT study
PublicationThe crystal structures of S,S′-2,5-dimethylbenzene-1,4-diylbis(methylisothiouronium) diacetate (1_ac), S,S′-2,5-dimethylbenzene-1,4-diylbis(methylisothiouronium) dichloride (1_Cl), 1_U complex, S,S′-naphthalene-1,4-diylbis(methylisothiouronium) dichloride (2_Cl), and 2_U complex were determined for the first time. The supramolecular structures of the compounds obtained are mainly based on hydrogen bonding and ionic interactions...
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Mononuclear sodium(I) and copper(I) silanethiolates
PublicationStericallyencumberedligand(ArO) 3 SiS − , where Ar = 2,6-diisopropylphenyl, was employed for the synthesisof a dicoordinate copper(I) complex. The ligand creates a very hydrophobic environment around the metal center as indicated by the crystal structures and FT-IR spectroscopy.
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Intermolecular Hydrogen Bonding Directed by Aryl–Perfluoroaryl π–π Stacking Interactions
PublicationThe crystal structures of five compounds capable of forming self-complementary hydrogen bonds but crystallizing as catemers or creating more complex crystal structures were compared with their complexes prepared by cocrystallization with perfluoroaryl compounds. The results of X-ray diffraction revealed that in all the cases the π–π stacking interactions caused reorganization of hydrogen bonds and induced creation of the expected...
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Wykorzystanie wiązań niekowalencyjnych do otrzymywania jedno- i dwuskładnikowych struktur supramolekularnych
PublicationPrzedstawiona rozprawa doktorska dotyczy badań nad wykorzystaniem oddziaływań międzycząsteczkowych do projektowania i syntezy uporządkowanych struktur krystalicznych, ze szczególnym uwzględnieniem wiązań halogenowych i chalkogenowych jako stosunkowo nowych i bardzo atrakcyjnych z punktu widzenia inżynierii kryształu. Praca podzielona jest na kilka części. Pierwsza z nich stanowi wstęp teoretyczny obejmujący opis, założenia oraz...
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New lanthanide–CB[6] coordination compounds: relationships between the crystal structure and luminescent properties
PublicationThe reaction between cucurbit[6]uril (CB[6]) and lanthanide chlorides (Eu, Sm, Tb and Tm) in acidic aqueous media led to four new structures. The compounds obtained are isostructural with general formula [Ln2(H2O)12(H2O@CB[6])]Cl6(H2O)4 (Ln = Eu3+ (1), Sm3+ (2), Tb3+ (3) and Tm3+ (4)) and crystallize in the P21/c space group. For the complexes with Eu3+, Sm3+ and Tb3+, the luminescent properties in the solid state and aqueous media...
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Syntheses, Structures and Reactivity of Terminal Phosphido Complexes of Iron(II) Supported by a β-Diketiminato Ligand
PublicationWe report the synthesis of the first series of terminal phosphido iron complexes supported by a β‐diketiminato ligand (Dippnacnac) and their catalytic activity in dehydrocoupling of secondary phosphines. Anionic and neutral mono‐ or diphosphido complexes were obtained from the reaction of [(Dippnacnac)FeCl2Li(dme)2] with the R2PLi (R = iPr, tBu, Cy, Ph) phosphides by tuning the stoichiometric ratio, polarity of the solvent, and...
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Leszek Ziemczonek dr
PeopleUniversity education 1973-1978 – Nicolaus Copernicus University in Toruń, University of Gdańsk in Gdańsk, Mathematical Physics, M. Sc. 1979 – Diploma of Postgraduate Studies, Pedagogics 1989 – Institute of Physics, Polish Academy of Sciences in Warsaw, Theoretical Physics, Ph. D. 2010-2012 – Diploma of Postgraduate Studies, Mathematics Training: · 09.1983 – Trieste (Italy) – International Centre for Theoretical Physics...
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In Situ Random Microseeding and Streak Seeding Used for Growth of Crystals of Cold-Adapted beta-D-Galactosidases: Crystal Structure of betaDG from Arthrobacter sp. 32cB
PublicationThere is an increasing demand for cold-adapted enzymes in a wide range of industrial branches. Nevertheless, structural information about them is still scarce. The knowledge of crystal structures is important to understand their mode of action and to design genetically engineered enzymes with enhanced activity. The most difficult task and the limiting step in structural studies of cold-adapted enzymes is their crystallization,...
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The accretion of the new ice layer on the surface of hexagonal ice crystal and the influence of the local electric field on this process
PublicationThe process of creation of a new layer of ice on the basal plane and on the prism plane of a hexagonal ice crystal is analyzed. It is demonstrated that the ordering of water molecules in the already existing crystal affects the freezing. On the basal plane, when the orientations of water molecules in the ice block are random, the arrangement of the new layer in a cubic manner is observed more frequently — approximately 1.7 times...
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LattE- first-principles lattice energy calculations
PublicationCrystal engineering is currently attracting much interest. Its aim is to create materials of predefined properties fulfilling the requirements imposed by the applications. There are several parameters describing crystal structures, but the most important one is probably the energy of a crystal lattice. It is the energy released by the system when crystalline solid is formed out of molecules or ions in gaseous phase. Approximate...
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Proton transfer and hydrogen bonds in supramolecular, self-assembled structures of imidazolium silanethiolates. X-ray, spectroscopic and theoretical studies
PublicationThe reaction of 1-methylimidazole, 2-ethyl-4-methylimidazole and 2-ethylimidazole with tris(2,6- diisopropylphenoxy)silanethiol (TDST) leads to the formation of three new salts, which have been characterized by elemental analyses, thermogravimetric analyses, FTIR spectroscopy, and their structures were determined by single-crystal X-ray diffraction. Structural analyses indicate that in all three compounds a proton transfer has...
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Synthesis, crystal structure and spectroscopic characterization of new anionic iridium(III) complexes and their interaction with biological targets
PublicationThe synthesis and characterisation of new anionic iridium(II) complexes (NH4)2[IrCl4(κ2N,N’-H2biim)]2 · 5H2O (1) and ((CH3)2NH2)[IrCl4(κ2N,N’-PyBIm)] · H2O (2) are presented in this article. Spectroscopic methods (1H, 13C and 15N NMR, FTIR, UV-Vis) were used to characterize these new complexes. Solid-state structural analysis (SC-XRD) of complexes 1 and 2 shows a slightly distorted octahedral geometry of Ir(III) ions, which is...
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New heterometallic Co/Zn, Ag/Co, and Ag/Zn imidazolates: structural characterization and catalytic activity in the oxidation of organic compounds
PublicationNanocrystalline powders of monometallic and bimetallic imidazolates of Co, Zn, and Ag were produced by a reaction carried out in water. The powders were characterized by powder X-ray diffraction and the crystal structures of new compounds Ag2ZnIm4 and Ag2CoIm4 (Im = imidazolate) were solved. Heterometallic Co/Zn imidazolates showed the standard ZIF-8 crystal structure while Ag/Zn and Ag/Co systems were isostructural with the copper...
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Novel complexes possessing Hg–(Cl, Br, I)⋯O=C halogen bonding and unusual Hg₂S₂(Br/I)₄ kernel. The usefulness of τ₄′ structural parameter
PublicationOne mononuclear and two binuclear Hg(II) complexes have been synthesized and characterized by X-ray diffraction, ATR IR and Hirshfeld surface analysis. Single-crystal X-ray diffraction showed that binuclear compounds are centrosymmetric and isostructural. All complexes form bifurcated intermolecular N–H···O hydrogen bonds that contribute to a formation of the centrosymmetric dimers. In binuclear complexes, sulfur atoms of thiourea...