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Geometrical characterization of basic cable-strut systems
Published in Wang Bin Bing, Free-standing Tension Structures, 2004
A prism (P) is topologically identical to an anti-prism or anti-truncated pyramid. The resulting simplexes can also be formed by short struts from inside and relatively longer edge cables from outside. The principles of forming cable-strut simplexes by truncated pyramids (TPs) are the same. The resulting TP forms can be considered as the variation of P simplexes.
Synergistic lanthanide extraction triggered by self-assembly of heterodinuclear Zn(II)/Ln(III) Schiff base/carboxylic acid complexes
Published in Solvent Extraction and Ion Exchange, 2021
Norman Kelly, Thomas Doert, Felix Hennersdorf, Karsten Gloe
Changing the solvent from ethanol to tetrahydrofuran in the system Zn(II)–Yb(III)–H2L3 results in a further heterodinuclear complex with the composition of [Zn(L3)(µ-CH3COO)Yb(NO3)2]·0.5H2O (Figure 9). Zn1 possesses an almost ideal square-pyramidal geometry (τ5 = 0.05)[105] with an N2O3 donor set. One coordination site is occupied by a bridging acetate ion, making the structure comparable to [Zn(L1)(µ-CH3COO)Yb(NO3)2]. Yb1 has a distorted bicapped square antiprism as a coordination polyhedron (coordination number 9) and a distance to Zn1 of 3.376(1) Å. Intramolecular hydrogen bonds stabilize the orientation of the two nitrate ions. Interestingly, the packing motif of the crystal with a tetragonal space group (I-4) differs strongly from the other dinuclear complexes. Four molecules each form a cyclic unit, which is stabilized by weak interactions (Fig. S8). CH···π interactions dominate linking the individual units to form molecular strands in the direction of the crystallographic c-axis (Fig. S9). The molecular strands are arranged independently of each other resulting in the formation of channel-like structures. Within a molecular strand, water molecules are embedded between the layers. Water molecules are also located within the channel-like structures (Fig. S10).
Investigation of intermolecular interactions between [Ho(H2O)8]4+ based 3D metal-organic supramolecular host and bipyridyl guest through crystal structure and Hirshfeld surface analysis
Published in Journal of Coordination Chemistry, 2021
Maxcimilan Patra, Soumen Kumar Dubey, Soumen Singha, Corrado Rizzoli, Subham Bhattacharjee, Rajat Saha
SCXRD analysis reveals that 1 is a mononuclear complex and crystallizes in the tetragonal space group I4cm. The crystallographic parameters are given in Table 1. The asymmetric unit contains one Ho4+ metal ion with 0.25 occupancy, one-half unit of TBTA moiety and one-half unit of bipy (Figure S1). The metal ion Ho14+ shows an eight coordinated distorted square antiprism geometry. Eight water molecules are coordinated with the metal ion. Ho1-Owater bond distances are 2.33(2) Å (Ho1-O1W) and 2.380(19) Å (Ho1-O2W). The coordination bond angles vary within the range of 72.5°–148.7° (Table S1). For the TBTA anion, the carboxylate groups are almost perpendicular (89.05°) to the phenyl ring. The C-O bond distances are 1.25 Å (C4-O1) and 1.22 Å (C4-O2) for the doubly deprotonated TBTA anion. For the bipyridyl molecule, both the pyridyl groups are in a plane.
Quantum chemical calculation studies of PdnSi12 (n = 1–3) clusters: effects of doping Pd atoms on the structural and electronic properties
Published in Molecular Physics, 2020
Sheng-Jie Lu, Li-Shun Wu, Bao-Hua Yin, Feng Lin, Ming-Yong Chao
As for Si15 cluster, its the lowest-lying isomer is a C3v symmetric tricapped trigonal prism fused with a tricapped trigonal antiprism [86]. When three of fifteen Si atoms substitute by three Pd atoms for and , Si15 prolate structure transforms into a tritruncated trigonal bipyramid, whereas Si15 prolate structure turns into a wheel-shaped configuration when three of fifteen Si atoms are replaced by three Pd atoms for Pd3Si12. After carefully comparing the most stable structures of anions, Pd1–3Si12 neutrals, and cations, we can find that their structural evolution is different, suggesting that the extra charge has important effect on the geometrical transformation and multiple-palladium atoms doped silicon clusters are not just a simple stack of single palladium atom doped silicon clusters, they have more unexpected structures than single palladium atom doped silicon clusters.