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Full process of preparation of single crystals; powder patterns; IR spectra; molecular structures; hydrogen bonding system; and geometric parameters.

Penta-coordinated complexes of Ni(II) (S = 1) represent promising magnetically active materials. The synthetic strategy leading to penta-coordination may be based on using a combination of two- and three-donor voluminous ligands, e.g. N,N-donor chelating neoc (2,9-dimethyl-1,10-phenantroline), and O,N,O-donor pyridine-2,6-dicarboxylato(2-) (pdca) ligands. We have experimentally studied the aqueous-ethanolic systems formed of various Ni(II) salts, H2pdca and L being neoc, phen (1,10-phenantroline), bpy (2,2ˈ-bipyridine) and dtbpy (4,4ˈ-di-tert-butyl-2,2ˈ-bipyridine). We have isolated and characterized five different Ni(II) complexes, four of them being molecular and one ionic. All molecular complexes are built up of complex molecules with the general formula [Ni(pdca)(L)(H2O)]; however, all these complexes contain hexacoordinated Ni(II) atoms. In addition, the crystal structures of these four complexes comprise various solvate molecules. The fifth ionic complex also contains hexacoordinated Ni(II) atoms and is built up of [Ni(phen)2(H2O)2]2+ complex cations and [Ni(pdca)2]2- complex anions and solvate water molecules.

From methanolic solutions of Ni(NO3)2, 5,5ˈ-dimethyl-2,2ˈ-bipyridine and LiTCNQ (TCNQ = 7,7,8,8-tetracyanidoquinodimethane), complex [Ni(5,5ˈ-dmbpy)3](TCNQ)2 was isolated and its thermal properties were studied. The complex is stable in air atmosphere up to 208 ºC. The thermal decomposition consists in 3 consecutive steps in the temperature ranges 208-274 ºC (weight loss of 10.0 %), 274-401 ºC (17.5 %) and 401-495 ºC (64.2 %). The weight of the solid residue (8.3 %) corresponds to formation of NiO (calc. 7.3 %).KTCNQ was prepared reacting boiling acetonitrile solutions of TCNQ and KI. It is thermally stable up to 300 ºC. Its crystal structure at 200 ºC was determined. KTCNQ consists of one crystallographically independent TCNQ- anion and one potassium cation K+. Each K+ cation is octa-coordinated by eight nitrogen atoms from cyanide groups of TCNQ- anions. This crystal structure corresponds to the high-temperature phase of KTCNQ. As expected, the cell volume is by 1.5 % larger than the reported value measured at 140 ºC.

Commentary is given on a paper [Butler et al. (2022). IUCrJ, 9, 364–369] reporting the crystallization of two room-temperature liquids, water and 2,2,6,6-tetra­methyl­piperidine, to form a crystalline solid with a water-lined channel potentially capable of proton transport.

Isolable crystals of the cesium salt of an anionic Jahn-Teller-active Cu complex, initially formed by reaction in solution, are spontaneously consumed in a solvent-mediated crystal-to-crystal transformation that produces a final product with a four-coordinate Cu center. Depending on the size of the crystals of the intermediate and the evaporation rate of the solvent, the transformation from intermediate to final product occurs in a two-week time frame. The crystalline Jahn-Teller Cu intermediate presents a noteworthy difference in stability compared to its non-Jahn-Teller Ni-centered isomorph. It is proposed that a Jahn-Teller intermediate may precede the formation of other four-coordinate Cu complexes.

This educational review postulates the importance of maintaining an adequate level of crystallographic education among structure-dependent scientists whose interests are not primarily in crystallography, at a time when automation and validation have made it possible to obtain high-quality structure analyses in many cases with a minimum of crystallographic background. The topics addressed are intended to form a second round of crystallographic education for a novice user whose first round involved hands-on experience with structure solution and an introduction to elementary concepts. The specific topics, chosen for their relevance as basic knowledge and their lack of emphasis in many formal treatments, are (1) crystallographic reference frames and the utility of the reciprocal cell in geometrical calculations; (2) the relationship between the two concepts that constitute our model of the crystal, namely the unit cell and the lattice; (3) the manner in which an atom is represented in concept and in practice; (4) the importance of interleaved symmetry elements required by the presence of additional symmetry on a lattice; (5) the harnessing of the natural properties of the crystalline state for the potential manipulation of properties of synthetic crystals; and (6) useful terminology for navigating a crystal structure.

[EN[ The present work is focused on the study of single-molecule magnets based on selected transition metals and lanthanides using a selected Schiff base ligand. The first part deals with the theoretical interpretation of the magnetic phenomenon of SMM as well as the coordination and magnetic properties of complexes containing central atoms Ni(II), Co(II)/(III), Ce(III), Gd(III) and Dy(III). In the experimental part, the method of preparation of the required complexes was determined in the first place - the so-called "self-assembly" method. According to the synthetic procedures thus determined, 21 compounds were prepared, which were physically and chemically characterized and their crystal structure was determined by X-ray structure analysis. One chapter is focused on the crystallographic study of polymorphism, where FIM methods and analysis of Hirshfeld surfaces were used for a more detailed examination of two polymorphs [CoIII 2(o-van-en)3]·4CH3CN. The work also includes a crystallographic study of a topotactic reaction of the SC-SC (Single Crystal-to-Single Crystal) type in which the complex [Ni(o-van-en)DyCl3(H2O)] dehydrates at a higher temperature and subsequently dimerizes to form a new complex [Ni2(o-van-en)2Dy2Cl6]. From the prepared substances, 4 complexes were selected and subjected to magnetic examination with respect to SMM properties. For all four substances, the slow relaxation of magnetization, typical for single-molecule magnets, was confirmed. The most significant result was the observation of slow magnetic relaxation in a Ni-Gd sample, where the Ni(II) central atom is diamagnetic and Gd(III) is generally magnetically isotropic. The geometry and the electron density of the coordination sites has been proved to exert a very important influence on the SMM behaviour of lanthanide ions which has contributed to the theoretical knowledge of SMMs., [SL] Predkladaná práca je zameraná na štúdium jednomolekulových magnetov na báze vybraných prechodných kovov a lantanoidov s použitím vybraného ligandu Schiffovej zásady. Prvá časť práce sa venuje teoretickému opisu jednomolekulového magnetizmu ako aj koordinačnej chémii a magnetickým vlastnostiam komplexov obsahujúcich centrálne atómy Ni(II), Co(II)/(III), Ce(III), Gd(III) a Dy(III). V rámci experimentálnej časti bola najprv vypracovaná metóda prípravy požadovaných komplexov – tzv. „self-assembly“ metóda. Podľa takto určených syntetických postupov bolo pripravených 21 látok, ktoré boli fyzikálne a chemicky charakterizované a pomocou rtg. štruktúrnej analýzy bola stanovená ich kryštálová štruktúra. Jedna kapitola práce je zameraná na kryštalografickú štúdiu polymorfie, kde sa použili metódy FIM a analýza Hirshfeldových povrchov na detailnejšie preskúmanie dvoch polymorfov [CoIII 2(o-van-en)3]·4CH3CN. Práca zahŕňa aj kryštalografické štúdium topotaktickej reakcie typu SC-SC (Single Crystal-to-Single Crystal), pri ktorej sa komplex [Ni(o-vanen)DyCl3(H2O)] pri vyššej teplote dehydratuje a v jej dôsledku dimerizuje za vzniku nového komplexu [Ni2(o-van-en)2Dy2Cl6]. Spomedzi pripravených látok boli vybrané 4 komplexy, u ktorých sa študovali ich magnetické vlastnosti s ohľadom na ich SMM charakter. U všetkých štyroch látkach bola potvrdená pomalá relaxácia magnetizácie, ktorá je typická pre jednomolekulové magnety. Najvýznamnejším výsledkom bolo pozorovanie pomalej magnetickej relaxácie v Ni-Gd vzorke, kde centrálny atóm Ni(II) je diamagnetický a Gd(III) je vo všeobecnosti magneticky izotropný. Ukázalo sa, že geometria a elektrónová hustota koordinačných miest majú veľmi dôležitý vplyv na SMM správanie lantanoidových iónov, čo porispelo k doplneniu teoretických poznatkov o SMMs., [ES] El presente trabajo se centra en el estudio de imanes monomoleculares (SMM) basados en metales de transición y lantánidos seleccionados utilizando un ligando base de Schiff seleccionado. La primera parte aborda la interpretación teórica del fenómeno magnético de SMMs, así como las propiedades de coordinación y magnetismo de los complejos que tienen como átomos centrales Ni(II), Co(II)/(III), Ce(III), Gd(III) y Dy(III). En la parte experimental, el método de preparación de los complejos se estableció en primer lugar, el llamado método de "autoensamblaje". De acuerdo con los procedimientos sintéticos así determinados, se prepararon 21 compuestos, que fueron caracterizados físicamente y químicamente mediante las técnicas habituales, mientras se analizaron sus estructuras cristalinas mediante la difracción de rayos X en monocristal. Un capítulo se centra en el estudio cristalográfico del polimorfismo, donde se utilizaron los métodos FIM (full interaction mapping) y el análisis de las superficies de Hirshfeld para una exploración detallada de dos polimorfos de [CoIII 2(o-van-en)3]·4CH3CN. El trabajo también incluye el estudio cristalográfico de una reacción topotáctica del tipo SC-SC (Single Crystal-to-Single Crystal) en el que el complejo [Ni(o-van-en)DyCl3(H2O)] se deshidrata a una temperatura elevada con dimerización concomitante para formar un nuevo complejo [Ni2(o-van-en)2Dy2Cl6]. Cuatro de los compuestos preparados sometidos a estudios magnéticos dirigidos a sus posibles propiedades de SMMs. Para todos los cuatro complejos, se confirmó la relajación lenta de la magnetización, típica de los SMMs. El resultado más significativo fue la observación de la relajación magnética lenta en una muestra de Ni-Gd, donde el átomo central de Ni(II) es diamagnético y Gd(III) es generalmente magnéticamente isotrópico. Se ha demostrado que la geometría y la densidad electrónica del entorno de coordinación ejercen una influencia muy importante en el comportamiento SMM de los ion

Under various experimental conditions seven complexes have been crystallized from the systems Ni(II) – HBz – bpy (HBz = benzoic acid, bpy = 2,2′-bipyridine). The use of freshly prepared Ni(OH)2 as starting reagent leads to isolation of [Ni(bpy)(Bz)2] (1) and [Ni(bpy)3](Bz)2·5H2O (2). On the other hand, the use of nickel(II) nitrate as starting salt yielded 1 and also resulted in the formation of additional complexes in which the nitrate group entered into the final compositions, namely [Ni(bpy)2(Bz)](NO3)·2HBz (3), [Ni(bpy)2(Bz)](NO3)·1.25H2O (4), [Ni(bpy)2(H2O)(NO3)](NO3)·0.5HBz (5), [Ni(bpy)2(NO3)](NO3) (6) and [Ni(bpy)3](NO3)2·nH2O (n = 4.25) (7). The newly prepared complexes were characterized chemically and spectroscopically. The results of X-ray structure analyses of 1, 3–6 have shown that in all complexes, the Ni(II) atoms are hexacoordinated. Complex 1 exhibits a mononuclear molecular structure, while the ionic structures of 3–6 are built up of mononuclear complex cations with a heteroleptic coordination sphere around the Ni(II) atoms and by nitrate anions. In addition, the structures of 3–5 contain HBz solvate molecules or water molecules. The magnetic properties of 1 were studied in the temperature range 1.8–300 K showing that 1 is characterized by the presence of single-ion anisotropy of the easy-axis type with a value of D/kB = −6.32 K and a strong rhombic term with E/D = 0.327. Theoretical calculations using the ORCA package also confirm a significant influence of rhombic anisotropy.

The reactions of [Re(N‐N)(CO)3(PMe3)]OTf (N‐N=2,2′‐bipyridine, bipy; 1,10‐phenanthroline, phen) compounds with tBuLi and with LiHBEt3 have been explored. Addition to the N‐N chelate took place with different site‐selectivity depending on both chelate and nucleophile. Thus, with tBuLi, an unprecedented addition to C5 of bipy, a regiochemistry not accessible for free bipy, was obtained, whereas coordinated phen underwent tBuLi addition to C2 and C4. Remarkably, when LiHBEt3 reacted with [Re(bipy)(CO)3(PMe3)]OTf, hydride addition to the 4 and 6 positions of bipy triggered an intermolecular cyclodimerization of two dearomatized pyridyl rings. In contrast, hydride addition to the phen analog resulted in partial reduction of one pyridine ring. The resulting neutral ReI products showed a varied reactivity with HOTf and with MeOTf to yield cationic complexes. These strategies rendered access to ReI complexes containing bipy‐ and phen‐derived chelates with several C(sp3) centers.

The involvement of silver in two-electron AgI/AgIII processes is currently emerging. However, the range of stability of the required and uncommon AgIII species is virtually unknown. Here, the stability of AgIII towards the whole set of halide ligands in the organosilver(III) complex frame [(CF3)3AgX]− (X=F, Cl, Br, I, At) is theoretically analyzed. The results obtained depend on a single factor: the nature of X. Even the softest and least electronegative halides (I and At) are found to form reasonably stable AgIII−X bonds. Our estimates were confirmed by experiment. The whole series of nonradiative halide complexes [PPh4][(CF3)3AgX] (X=F, Cl, Br, I) has been experimentally prepared and all its constituents have been isolated in pure form. The pseudohalides [PPh4][(CF3)3AgCN] and [PPh4][(CF3)3Ag(N3)] have also been isolated, the latter being the first silver(III) azido complex. Except for the iodo compound, all the crystal and molecular structures have been established by single-crystal X-ray diffraction methods. The decomposition paths of the [(CF3)3AgX]− entities at the unimolecular level have been examined in the gas phase by multistage mass spectrometry (MSn). The experimental detection of the two series of mixed complexes [CF3AgX]− and [FAgX]− arising from the corresponding parent species [(CF3)3AgX]− demonstrate that the Ag−X bond is particularly robust. Our experimental observations are rationalized with the aid of theoretical methods. Smooth variation with the electronegativity of X is also observed in the thermolyses of bulk samples. The thermal stability in the solid state gradually decreases from X=F (145 °C, dec.) to X=I (78 °C, dec.) The experimentally established compatibility of AgIII with the heaviest halides is of particular relevance to silver-mediated or silver-catalyzed processes.