Bis(μ-3,5-difluorobenzoato)bis[(3,5-di­fluorobenzoato)dimethyltin(IV)]

In the dinuclear title complex, [Sn2(CH3)4(C7H3F2O2)4], the SnIV atom is chelated by two 3,5-difluoro­benzoate (dfb) anions and coordinated by two methyl groups while an O atom from the adjacent dfb anion bridges the Sb atom with a longer Sb—O bond distance of 2.793 (4) Å. The complex mol­ecule has 2 symmetry and the SnIV atom is in a distorted penta­gonal–bipyramidal coordination geometry. In the crystal, mol­ecules are connected by C—H⋯O and C—H⋯F hydrogen bonds

What do we visually focus on in a World Heritage Site? A case study in the Historic Centre of Prague

Since socio-economic development is associated with artificial construction, heritage environments must be protected and renewed while adapting to such development. Many World Heritage Sites’ visual integrity is endangered by new construction. The paper aims to explore people’s visual focus patterns concerning the integrity of heritage to ensure that traditional culture is not endangered by the construction and development of modern life, and to protect Outstanding Universal Values. In this study, visual heatmaps are generated to investigate people’s visual integrity in the Historic Centre of Prague from micro to macro viewpoints using an eye tracker. We found that humans’ perspectives are unobstructed or concentrated, and the view of main attractions is generally maintained by a buffer zone. However, newly constructed high-rise buildings can result in major visual concerns. Therefore, new buildings with large heights and strong contrasting colours should be restricted to World Heritage Sites. Moreover, complex artistic effects (facade midline, domes, mural painting, faces of sculptures) will likely attract people’s attention. In contrast, visual focus is not concentrated on greenery, roofs and floors. Accordingly, greenery could become a flexible space to serve as a background for buildings and landscape nodes. Furthermore, visual focal factors are associated with two significant aspects: people and the environment. Since people and transportation could pose visual concerns, tourism managers should optimise for characteristics such as controlling the density of pedestrian flow and planning parking spaces. The visual patterns identified could be useful for the design, conservation, and management of visual integrity in cultural heritage sites to avoid the spread of artificial constructions within the boundaries of heritage sites, which may lead to their being endangered or delisted

Tetra­kis(μ-naphthalene-1-acetato-1:2κ2 O:O′)bis­(naphthalene-1-acetato)-1κ2 O,O′;2κ2 O,O′-bis­(1,10-phenanthroline)-1κ2 N,N′;2κ2 N,N′-europium(III)samarium(III)

In the title compound, [EuSm(C12H9O2)6(C12H8N2)2], the metal site is statistically occupied (50:50) by Eu and Sm atoms, forming a centrosymmetric complex. The metal site is nine-coordinate, in a distorted monocapped square-anti­prismatic coordination geometry. Mol­ecules are linked into three chains by C—H⋯π interactions and C—H⋯O hydrogen bonds. The combination of these chains generates a three-dimensional framework structure. One of the bridging naphthalene-1-ace­tate ligands was found to be disordered over two sites; the site occupancies for the naphthylmethyl group refined to 0.628 (14) and 0.372 (14)

2006-2007 Master Class - Qi Liu (Piano)

https://spiral.lynn.edu/conservatory_masterclasses/1138/thumbnail.jp

N,N′-Disalicyloylhydrazine

The approximately planar mol­ecule of the title compound, C14H12N2O4, is centrosymmetric and has an E configuration with respect to the N—N bond. This compound adopts the ketoamine form with C=O and C—N distances of 1.233 (3) and 1.331 (4) Å, respectively. Adjacent mol­ecules are assembled into a two-dimensional supra­molecular structure parallel to the (101) plane via inter­molecular O—H⋯O hydrogen bonds

Poly[[diaqua­(μ4-l-tartrato)(μ2-l-tartrato)dizinc(II)] tetra­hydrate]

In the title compound, {[Zn(C4H4O6)(H2O)]·2H2O}n, the l-tartrate ligands adopt μ4- and μ2-coordination modes. The ZnII atom adopts an octa­hedral geometry and is chelated by two kinds of l-tartrate ligands through the hydr­oxy and carboxyl­ate groups and coordinated by one unchelating carboxyl­ate O atom and one water mol­ecule. In the crystal, the l-tartrate ligands link the ZnII atoms, forming a two-dimensional coordination layer; these layers are futher linked into a three-dimensional supra­molecular network by O—H⋯O hydrogen bonds between the two-dimensional coordin­ation layers and the uncoordinated water mol­ecules. The latter are equally disordered over two positions

4-Methyl-2-oxo-2,3-dihydro-1-benzopyran-7-yl benzene­sulfonate

The title compound, C16H12O5S, is a derivative of coumarin. The dihedral angle between the coumarin ring system and the phenyl ring is 65.9 (1)°. In the crystal structure, mol­ecules are linked by weak C—H⋯O hydrogen bonding to form molecular ribbons

Diaqua­bis(N,N′-dibenzyl­ethane-1,2-diamine-κ2 N,N′)nickel(II) dichloride N,N-dimethyl­formamide solvate

The asymmetric unit of the title complex, [Ni(C16H20N2)2(H2O)2]Cl2·C3H7NO, consists of two NiII atoms, each lying on an inversion center, two Cl anions, two N,N′-dibenzyl­ethane-1,2-diamine ligands, two coordinated water mol­ecules and one N,N-dimethyl­formamide solvent mol­ecule. Each NiII atom is six-coordinated in a distorted octa­hedral coordination geometry, with the equatorial plane formed by four N atoms and the axial positions occupied by two water mol­ecules. The complex mol­ecules are linked into a chain along [001] by N—H⋯Cl, N—H⋯O and O—H⋯Cl hydrogen bonds. The C atoms and H atoms of the solvent mol­ecule are disordered over two sites in a ratio of 0.52 (2):0.48 (2)