The chain structure of [Ni(C4H2O4)(C12H8N2)(H2O)]n with different types of fumarate bridging

Using modified solvothermal conditions (longer cooling time), beside previously characterized dark-green crystals of [Ni(C4H2O4)(C12H8N2)] (main product), a few light-green crystals of the polymeric title compound, catena-poly[[aqua­(1,10-phenanthroline-κ2 N,N′)nickel(II)]-μ-fumarato-κ2 O:O′-[aqua­(1,10-phenanthroline-κ2 N,N′)nickel(II)]-μ-fumarato-κ4 O,O′:O′′,O′′′], [Ni(C4H2O4)(C12H8N2)(H2O)]n were isolated. Its crystal structure is made up from zigzag chains, propagating in [001], in which the Ni2+ ions are linked alternatively by μ2-fumarato and bis-chelating fumarato bridging ligands. The Ni2+ ion is coordinated in a deformed octa­hedral geometry by one chelating 1,10-phenanthroline ligand, one aqua ligand in a cis position with regard to both N-donor atoms and by two different fumarato ligands, each residing with its central C=C bond on an inversion centre, occupying the remaining coordination sites in a fac fashion. The chains thus formed are linked by O—H⋯O hydrogen bonds and π–π inter­actions between the aromatic rings of the phenanthroline ligands with a shortest ring centroid separation of 3.4787 (10) Å

Tris(propane-1,2-diamine-κ2 N,N′)nickel(II) tetra­cyanidonickelate(II)

The title compound, [Ni(C3H10N2)3][Ni(CN)4], is built up of [Ni(pn)3]2+ cations (pn is 1,2-diamino­propane) and [Ni(CN)4]2− anions. Both NiII atoms in the cation and the anion lie on a mirror plane. The respective ions inter­act through Coulombic forces and through a complex network of hydrogen bonds. Extended disorder associated with the cation has been resolved. The occupancies of the respective disordered positions are 0.4:0.4:0.2

Tris(1,2-diamino­ethane)­nickel(II) hexa­fluoridosilicate

The ionic title complex, [Ni(C2H8N2)3](SiF6), is built up of [Ni(en)3]2+ complex cations (en = 1,2-diamino­ethane) and hexa­fluoridosilicate anions. Single crystals of the title complex were isolated from an aqueous–ethano­lic Ni2+–en–SiF6 2− system. The Ni(II) and Si atoms are each located on a special position with site symmetry 3.2. The Ni(II) atom coordination sphere is octa­hedrally deformed, being coordinated by three chelating diamine ligands with an Ni—N distance of 2.1233 (18) Å. The crystal packing of the respective ions corresponds to the structure type of the hexa­gonal form of BN. Beside ionic forces, the packing is governed by N—H⋯F hydrogen bonds, which lead to the formation of hydro­phobic channels running along the 63 screw axis. The structure was refined as an inversion twin [0.49 (3): 0.51 (3)]

Di-μ-hydroxido-bis­[hemiaqua­(N,N,N′,N′-tetra­methyl­ethane-1,2-diamine)­copper(II)] bis­(tetra­fluoridoborate)

The title compound, [Cu2(OH)2(C6H16N2)2(H2O)](BF4)2, consists of dinuclear centrosymmetric [Cu2(OH)2(tmen)2(H2O)]2+ complex cations (tmen = N,N,N′,N′-tetra­methyl­ethane-1,2-diamine) and tetra­fluoridoborate anions. In the cation, the CuII atom shows a slightly distorted square-pyramidal coordination geometry provided by a pair of μ-OH− anions and by the N atoms of a chelate tmen ligand in the basal plane. The apical position is statistically occupied by the O atom of a half-occupancy water mol­ecule. The F atoms of the anion are disordered over three sets of sites with occupancies of 0.598 (9):0.269 (6):0.134 (8). The crystal packing is governed by ionic forces as well as by O—H⋯F hydrogen bonds

catena-Poly[[[diaqua­(di-2-pyridylamine-κ2 N,N′)nickel(II)]-μ-fumarato-κ2 O 1:O 4] tetra­hydrate]

In the crystal structure of the title compound, {[Ni(C4H2O4)(C10H9N3)(H2O)2]·4H2O}n, zigzag chains are built up from cis-[Ni(dpya)(H2O)2]2+ cations (dpya is di-2-pyridylamine) linked by bis-monodentate coordinated bridging fumarate ligands. The NiII atom is coordinated by one chelating dpya ligand, two aqua ligands in trans positions and two monodentate fumarate ligands in cis positions in the form of a deformed octa­hedron. The water mol­ecules, O atoms of the fumarate carboxyl­ate groups and the amine group of the dpya ligand are involved in an extended network of intra- and inter­molecular O—H⋯O hydrogen bonds. Moreover, π–π inter­actions between the pyridine rings of the dpya ligand contribute to the stability of the structure. Two of the five uncoordinated water molecules are half-occupied

Triangulo -{ErIII^{III}$_{3}} complex showing field supported slow magnetic relaxation

The triangulo-{Er$_{3}$} complex [Er$_{3}$Cl(o-van)$_{3}$(OH)$_{2}$(H$_{2}$O)$_{5}$]Cl$_{3}$·nH$_{2}$O (n = 9.4; H(o-van) = o-vanillin) (1) was generated by an in situ method. The isolated Er(III) complex 1 was characterized by elemental analysis and molecular spectroscopy. The results of single crystal X-ray diffraction studies have shown that 1 is built up of trinuclear [Er$_{3}$Cl(o-van)$_{3}$(OH)$_{2}$(H$_{2}$O)$_{5}$]$^{3+}$ complex cations, chloride anions and water solvate molecules. Within the complex cation the three Er(III) central atoms are placed at the apexes of a triangle which are bridged by three (o-van)$^{–}$ ligands with additional chelating functions and two μ$_{3}$-OH$^{–}$ ligands. Additionally five aqua and one chlorido ligands complete the octa-coordination of the three Er(III) atoms. AC susceptibility measurements reveal that the compound exhibits slow magnetic relaxation with two relaxation modes

Bis(2,2′-bipyridine-κ2 N,N′)(maleato-κ2 O 1,O 1′)nickel(II) 7.34-hydrate

The title compound, [Ni(C4H2O4)(C10H8N2)2]·7.34H2O, was obtained by crystallization from an aqueous ethano­lic reaction mixture containing nickel(II) acetate, maleic acid, bipyridine, sodium hydroxide and ammonia. The asymmetric unit contains one independent complex mol­ecule and 7.34 water mol­ecules occupying eight crystallographically independent positions. Two of these water molecules are disordered. The nickel(II) atom is coordinated in a distorted octa­hedral geometry by two O atoms from one carboxyl­ate group of the maleato ligand and by four N atoms from two 2,2′-bipyridine (bipy) ligands. The water mol­ecules, along with the O atoms of the uncoordinated carboxyl­ate group, form an extended hydro­philic three-dimensional hydrogen-bonded system with large cavities in which the hydro­phobic bipy ligands are located. One H atom of the maleate ligand is involved in a weak hydrogen bond of the C—H⋯O type. Stacking inter­actions between the pyridyl rings of the bipy ligands [centroid–centroid distance = 3.549 (15) Å] lead to the formation of pairs of complex mol­ecules

Redetermination of aqua­(dihydrogen ethyl­enediamine­tetra­acetato-κ5 O,O′,N,N′,O′′)nickel(II)

The crystal structure of the title compound, [Ni(C10H14N2O8)(H2O)] or [Ni(H2edta)(H2O)] (H4edta is ethyl­ene­diamine­tetra­acetic acid), originally determined by Smith & Hoard [J. Am. Chem. Soc. (1959), 81, 556–561] has been redetermined to a significantly higher precision. The NiII atom is coordinated in a distorted octa­hedral geometry by two N atoms and three O atoms from three carboxyl­ate groups of the H2edta2− ligand and by an O atom of a water mol­ecule. The complex mol­ecules are linked by inter­molecular O—H⋯O hydrogen bonds into layers perpendicular to [100]

The Role of Scientometric Criteria in the Formation of Budget and Qualification Growth at Pavol Jozef Šafárik University in Košice, the Slovak Republic

Pavol Jozef Šafárik University in Košice, according to the number of its students (approx. 8,700), belongs to the group of smaller-size public universities in Slovakia. The major part of its budget income (approx. two thirds) comes from a direct state subsidy. The subsidy amount is defined by the Methodology of the Ministry of Education, Science, Research and Sport of the Slovak Republic that is modified yearly. This Methodology uses various input data that are related to research activities of a university, the results of the last complex evaluation, the amount of financial resources obtained from home grant agencies and from abroad, as well as the publications of lecturers, research staff and students of a university, etc. The amount of publications as a scientometric criterion was for the first time used in 2005 and since then its proportional representation has risen substantially and it represents a strong motivational aspect for universities in Slovakia. The number of publications also plays important role in the qualification growth of P. J. Šafárik University lecturers and research staff. The specific requirements as to the categories and numbers of publications to be met by a candidate for the habilitation (associate professor status) and inauguration (full professor status) are defined by several legislative documents and are further specified by the documents approved by the Scientific Board of the University. The qualification growth of lecturers is also important for the University as it has its influence on the amount of the direct state subsidy. The presentation will focus on the importance of the publication activities as one of the scientific criterion relevant to the research and scientific activities of the University and the methods of publication registration by the Ministry and the University, their strengths and weaknesses will be discussed