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Published By Walter De Gruyter Gmbh

1865-7117, 0932-0776

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Peter Luger ◽  
Birger Dittrich

Abstract The electron density distribution (EDD) of a tetrasaccharide composed of four benzoylated fructopyranosyl units was obtained by refinement with scattering factors from the invariom library. X-ray diffraction data was downloaded from the Cambridge Structural Database (CSD). Bond topological and atomic properties were obtained by application of Bader’s QTAIM formalism. From a large number of 105 C–C bonds in the molecule average bond orders for 33 single and 72 aromatic bonds were calculated yielding values of 1.33 and 1.61. Molecular Hirshfeld and electrostatic potential (ESP) surfaces show that only weak non-covalent interactions exist. The phenyl rings of the benzoyl fragments in the outer regions of the molecule generate a positive ESP shell with repulsive properties between adjacent molecules. Weak surface interactions result in a rather unusual low density around 1.3 g cm−3, which is understandable when compared to other carbohydrates where strong O–H⋯O hydrogen bonds allow a 20% more dense packing with densities >1.5 g cm−3 as determined by single crystal X-ray diffraction.


2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Adrienne Ndiolene ◽  
Tidiane Diop ◽  
Ndiak Ndiaye ◽  
Mouhamadou Sembene Boye ◽  
François Michaud ◽  
...  

Abstract Two novel zinc(II) complexes containing 4-methoxybenzylidene moieties namely, Zn(L)Cl2 (L = N, N′-bis(4-methoxybenzylidene)ethane-1, 2-diamine (1) or N-(4-methoxybenzylidene)-ethane-1, 2-diamine (2)) have been synthesized and characterized by infrared spectroscopy and single-crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic space group P21/c with a = 9.2315(4); b = 12.0449(4); c = 18.2164(7) Å; β = 98.472(4)°, V = 1278.9(4) Å3 and Z = 4. Complex 2 crystallizes in the monoclinic space group P21/n with a = 6.5733 (2), b = 13.6595(5), c = 15.1615(5) Å; β = 101.846(4)°, V = 1332.33(8) Å3 and Z = 4. The environment of each Zn(II) atom is distorted tetrahedral with coordination of two terminal Cl atoms and two N atoms of the N,N′ – bis(4-methoxybenzylidene)ethane-1,2-diamine (1) or N-(4-methoxybenzylidene)ethane-1,2-diamine (2) ligand. The stability of the crystalline structure is ensured by the existence of intra- and intermolecular hydrogen bonds of the type C–H…Cl (1) and N–H…Cl (2) leading to supramolecular topologies.


2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Christoph Ludwig Teske ◽  
Huayna Terraschke ◽  
Sebastian Mangelsen ◽  
Wolfgang Bensch

Abstract The title compounds were prepared by precipitation from acidic solutions of the reactants in acetone/water. Bi(S2CNH2)2Cl (1) crystallizes in the non-centrosymmetric trigonal space group P32 with a = 8.6121(3) and c = 11.1554(4) Å, Z = 3; Bi(S2NH2)2SCN (2) in P21/c (monoclinic) with a = 5.5600(2), b = 14.3679(5), c = 12.8665(4) Å, and β = 90.37(3)°. In the crystal structure of 1 Bi3+ is in a sevenfold coordination of two bidentate and one monodentate S2CHNH2 − anions with an asymmetric coordination pattern of five Bi–S and two Bi–Cl− bonds. The linkage of these polyhedra via common Cl–S edges leads to a 1D polymeric structure with undulated chains propagating in the direction [001]. These chains are linked by strong and medium strong hydrogen bonds forming the 3D crystal structure. In the crystal structure of 2 the Bi3+ cation is in an eightfold coordination. The polyhedron can be described as a significantly distorted tetragonal anti-prism, capped by an additional S atom. Two of these prisms share a common quadrilateral face to form a “prism-double” (Bi2S10N2). These building units are linked by common edges, and the resulting 1D infinite angulated chains propagate along [100]. By contrast to organo-dithiocarbamate compounds, where C–H···X bridges are dominant, the interchain connections in the crystal structures of 1 and 2 are formed exclusively via N–H···S, N–H···Cl, and N–H···N interactions, generating the 3D networks. A significant eccentricity of the Bi3+ cation in the crystal structures of both complexes is observed. Both compounds emit light in the orange range of the electromagnetic spectrum.


2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Savita A. Kundaikar ◽  
Sudesh M. Morajkar ◽  
Wolfgang Bensch ◽  
Bikshandarkoil R. Srinivasan

Abstract The reaction of Na2MoO4·2H2O with 2-amino-2-(hydroxymethyl)propane-1,3-diol (LH) in water at room temperature results in the formation of the heterometallic coordination polymer [Mo2O6L2(Na2(H2O)4)]·2H2O 1 (L = 2-amino-3-hydroxy-2-(hydroxymethyl)propan-1-olato). The structure of 1 consists of a neutral (Mo2O6) unit located on an inversion center. The Mo atoms exhibit hexa-coordination and are bonded to two terminal and two bridging oxido ligands, an alkoxide oxygen and the amine N atoms of an anionic ligand L– resulting in the formation of an edge-sharing {Mo2O8N2} bioctahedron. The Na+ cations of a centrosymmetric bis(μ2-aqua)-bridged (Na2(H2O)4)2+ unit are penta-coordinated and bonded to two symmetry related L– ligands via the oxygen atoms of their OH groups. The µ3-bridging tetradentate binding mode of L– results in the formation of a two-dimensional heterometallic coordination polymer. The constituents of 1 viz. (Mo2O6), (L)–, (Na2(H2O)4)2+ and lattice water molecules are interlinked with the aid of three varieties of hydrogen bonding interactions. The corresponding tungstate reported recently has been obtained through a similar synthetic protocol and is isostructural.


2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Hong-Yan Lin ◽  
Qian-Qian Liu ◽  
Yuan Tian ◽  
Ling Zeng

Abstract Two new metal-organic compounds (MOCs) [Cu(L)0.5(3-nba)2] (1) and [Cu(L)(2,5-tdc)] (2) have been hydrothermally synthesized by employing the ligand N,N′-di(3-pyridyl)adipoamide (L) and two carboxylic acids (3-Hnba = 3-nitrobenzoic acid, 2,5-H2tdc = 2,5-thiophenedicarboxylic acid) as ligands. Compound 1 displays a metal-organic chain-like structure formed by the {Cu2(3-nba)4} double-paddle wheel units and the µ 2-bridging L ligands. The adjacent polymeric chains form a supramolecular layered structure through hydrogen bonding. Compound 2 shows a 3D metal-organic polymeric framework derived from Cu-L layers and µ 2-bridging 2,5-tdc ligands, which presents a 3,5-connected {4.62}{4.66.83} topology. The electrochemical and electrocatalytic behavior of the two compounds has been studied in detail. Carbon paste working electrodes modified with compounds 1 and 2 can be used as highly selective sensors for detecting traces Cr(VI). Both electrodes show also electrocatalytic performance in oxygen evolution reactions (OERs).


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Natalie Eichstaedt ◽  
Kasper P. van der Zwan ◽  
Lina Mayr ◽  
Renée Siegel ◽  
Jürgen Senker ◽  
...  

Abstract Potassium 15-crown-5 phenanthrenide and potassium 18-crown-6 phenanthrenide were synthesized and characterized by powder X-ray diffraction and 39K solid state NMR spectroscopy. While the radical carbanion is very reactive in solution, the crystals are stable and storable under inert atmosphere. For 15-crown-5, a sandwich-like complex of potassium is formed with two molecules of crown ether per potassium resulting in a coordination number of 10. For the larger 18-crown-6 ligand, a 1:1 complex is obtained and a coordination number of 6 for the potassium cation. In neither crystal structure solvent molecules are incorporated. The 15-crown-5 compound crystallizes faster and is less soluble in THF as compared to the 18-crown-6 compound. Both compounds form solid phenanthrenide that is easy to handle and can be applied for reduction reactions.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jens Rudlof ◽  
Beate Neumann ◽  
Hans-Georg Stammler ◽  
Norbert W. Mitzel

Abstract Based on the previously described bifunctional Lewis acid with a functional distance of the boron functions of 4.918(2) Å, the development of a further bifunctional, boron-containing Lewis acid with a wider functional distance is demonstrated. Again, a stannylated precursor was used and the Lewis-acidic boron functions were introduced by means of tin-boron exchange. The general suitability of this class of compounds for the formation of host-guest-complexes is demonstrated by NMR experiments and by solid-state structures using pyridine and TMPD (N 1,N 1,N 4,N 4-tetramethylbenzene-1,4-diamine) as Lewis basic guests. The influence of traces of moisture on the boron-containing, bifunctional Lewis acids was investigated by the structure elucidation of a decomposition product.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kai-Long Zhong ◽  
Jing Quan ◽  
Xian-Xiao Pan ◽  
Wei Song ◽  
Bing-Feng Li

Abstract A new cadmium(II)-based coordination polymer [Cd3(FcCOO)6(4,4′-bipy)(H2O)2] n (FcCOO = ferrocenecarboxylato and 4,4′-bipy = 4,4′-bipyridine) has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The results of a crystal structural analysis has revealed that the title compound consists of two crystallographically unique CdII centers, one in a general position with a five-coordinated and one on an inversion center with a six-coordinated environment. The CdII centers are connected by FcCOO− units to form a metal carboxylate oxygen chain extending parallel to the [100] direction while the 4,4′-bipy ligands further act as bridging linkers of the CdII centers resulting in a layered polymer. In addition, an X-ray powder diffraction and thermal gravimetric analysis and a cyclo-voltammetric characterization of the complex have also been carried out.


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