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The triangular clusters [Zn3Cp*3]+ and [Zn2CuCp*3] were obtained by addition of the in situ generated, electrophilic, and isolobal species [ZnCp*]+ and [CuCp*] to Carmona's compound, [Cp*ZnZnCp*], without splitting the ZnZn bond. The choice of non-coordinating fluoroaromatic solvents was crucial. The bonding situations of the all-hydrocarbon-ligand-protected clusters were investigated by quantum chemical calculations revealing a high degree of σ-aromaticity similar to the triatomic hydrogen ion [H3]+. The new species serve as molecular building units of Cu nZn m nanobrass clusters as indicated by LIFDI mass spectrometry. [ABSTRACT FROM AUTHOR]

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The first example of ligand protected Cu--Zn clusters is described. Reaction of [CpCu(CNt Bu)] with [Zn2Cp*2] yields [(CuCNtBu)4(ZnCp*)4] (1a) and [(CuCNt Bu)4(ZnCp*)3(ZnCp)] (1b). According to DFT calculations, the [Cu4Zn4] unit fulfils the unified superatom model for cluster valence shell closing. [ABSTRACT FROM AUTHOR]

A combined synchrotron X-ray and density functional theory (DFT) study on the structure of a Jäger-type N2O2 chelate complex was carried out. The ethoxy-substituted bis(3-oxo-enaminato)cobalt(II) complex ( 1) was an original sample from the laboratory of the late Professor Ernst-G. Jäger (University of Jena, Germany). Single-crystal X-ray analysis revealed essentially flat molecules of 1, which are unsolvated and coordinatively unsaturated. The DFT calculations on the isolated molecule predict a planar structure for the non-hydrogen atoms, which is a local minimum on the energy surface. The crystal packing is achieved through off-set stacking (staircase arrangement), resulting in a herringbone pattern in the space group P212121. The structure of 1 is compared to known structures of related bis(3-oxo-enaminato)cobalt(II) complexes ( 2- 4). Original bulk material of 1 was investigated by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), melting point determination, and infrared (IR) spectroscopy. [ABSTRACT FROM AUTHOR]

Defined molecular models for the surface chemistry of Hume-Rothery nanophases related to catalysis are very rare. The Al-Cu intermetalloid cluster [(Cp*AlCu)6H4] was selectively obtained from the clean reaction of [(Cp*Al)4] and [(Ph3PCuH)6]. The stronger affinity of Cp*Al towards Cu sweeps the phosphine ligands from the copper hydride precursor and furnishes an octahedral Al6 cage to encapsulate the Cu6 core. The resulting hydrido cluster M12H4 reacts with benzonitrile to give the stoichiometric hydrometalation product [(Cp*AlCu)6H3(N=CHPh)]. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Treatment of tetrakis(diethylamido)zirconium(IV); [Zr(NEt2)4] with a series of β-ketoimines ({[RHN]C- (CH3)vC(H)C(CH3)vO} where R is a functionalized side-chain; 4-(2-methoxyethylamino)pent-3-en-2-one, Hmeap; 4-(3-methoxypropylamino)pent-3-en-2-one, Hmpap; 4-(2-(dimethylamino)ethylamino)pent- 3-en-2-one, Hdeap; 4-(3-(dimethylamino)propylamino)pent-3-en-2-one, Hdpap) leads to an amine substitution reaction that yielded novel monomeric heteroleptic mixed amido-ketoiminato complexes of the type bis(4-(2-methoxyethylamino)pent-3-en-2-onato)bis(diethylamido)zirconium(IV) (1), bis(4-(3-methoxypropylamino) pent-3-en-2-onato)bis(diethylamido)zirconium(IV) (2), and bis(4-(3-(dimethylamino)propylamino) pent-3-en-2-onato)bis(diethylamido)zirconium(IV) (3), and eight-coordinated homoleptic complexes tetrakis(4-(2-methoxyethylamino)pent-3-en-2-onato)zirconium(IV) (4) and tetrakis(4-(2-(dimethylamino) ethylamino)pent-3-en-2-onato)zirconium(IV) (5), depending on the ratio of the ligand to zirconium. Adopting a similar strategy with zirconium alkoxide, namely [Zr(OiPr)4.iPrOH], with β-ketoimine Hmeap, leads to the formation of a dimer, bis(μ2-isopropoxo)bis(4-(2-methoxyethylamino)pent-3- en-2-onato)tetrakis(isopropoxo)dizirconium(IV) (6). The newly synthesised complexes were characterized by NMR spectroscopy, mass spectrometry, single crystal X-ray diffraction, elemental analysis and thermal analysis. The low decomposition temperature facilitated by the stepwise elimination of the ketominate ligand from the complex and the stability of the complexes obtained in air as well as in solution makes them highly suitable for solution based processing of ZrO2 thin films, which is demonstrated using compound 5 on Si(100) substrates. High quality ZrO2 films were obtained and were investigated for their structure, morphology, composition and optical properties. Low temperature crystallisation of ZrO2 is achieved by a simple chemical deposition process using the new class of Zr precursors and the films exhibit an optical transmittance above 90%. [ABSTRACT FROM AUTHOR]

The title compound, [Zn(SiF6)(C12H8N2)2]·CH3OH, contains a neutral heteroleptic tris-chelate ZnII complex, viz. [Zn(SiF6)(phen)2] (phen is 1,10-phenanthroline), exhibiting approximate molecular C2 point-group symmetry. The ZnII cation adopts a severely distorted octahedral coordination. As far as can be ascertained, the title complex represents the first structurally characterized example of a ZnII complex bearing a bidentate-bound hexafluorosilicate ligand. A density functional theory study of the isolated [Zn(SiF6)(phen)2] complex was undertaken to reveal the influence of crystal packing on the molecular structure of the complex. In the crystal structure, the methanol solvent molecule forms a hydrogen bond to one F atom of the hexafluorosilicate ligand. The hydrogen-bonded assemblies so formed are tightly packed in the crystal, as indicated by a high packing coefficient (74.1%). [ABSTRACT FROM AUTHOR]

The title compound, [K(C14H23)(C4H8O)] n, comprises zigzag chains of alternating bridging 2,3,4,5-tetramethyl-1- n-pentylcyclopentadienyl ligands and potassium ions, with an ancillary tetrahydrofuran ligand in the coordination environment of potassium. The coordination polymer strands so formed extend by 21 screw symmetry in the b-axis direction. The chemically modified cyclopentadienyl ligand, with a tethered n-pentyl group, was synthesized from 2,3,4,5-tetramethylcyclopent-2-enone by a Grignard reaction. [ABSTRACT FROM AUTHOR]

4,4'-Dithiodipyridine (dtdp), also termed 4,4'-dipyridyldisulfide, is a bridging ligand of the 4,4'-bipyridine type. The introduction of the disulfide moiety inevitably leads to a relatively rigid angular structure, which exhibits axial chirality. More than 90 metal complexes containing the dtdp ligand have been crystallographically characterised until now. This review focuses on the preparation and structural diversity of discrete and polymeric metallosupramolecular assemblies constructed from dtdp as bridging ligands. These encompass metallamacrocycles with M2L2 topology and coordination polymers with periodicity in one or two dimensions. One-dimensional coordination polymers represent the vast majority of the metallosupramolecular structures obtained from dtdp. These include repeated rhomboids, zigzag, helical and arched chains among other types. In this contribution, we make an attempt to provide a comprehensive account of the structural data that are currently available for metallosupramolecular assemblies based on the bent bridging ligand dtdp [ABSTRACT FROM AUTHOR]

The photochemistry of 2,4,6-triazido-3,5-difluoropyridine 21 was investigated by matrix infrared and electron paramagnetic resonance spectroscopies. Ultraviolet irradiation (>260 nm) of 21 results in the formation of 3,5-difluoropyridyl-2,4,6-trinitrene 26 in yields high enough for characterization by infrared spectroscopy. The experimental infrared spectrum is in good agreement with density functional theory calculations. Under similar conditions, a very strong electron paramagnetic resonance spectrum of septet trinitrene 26 was obtained. Shorter irradiation times resulted in more complex product mixtures containing, in addition, mononitrenes and dinitrenes. Surprisingly, azirines and keteneimines, the typical photoproducts of arylnitrenes, were not observed. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A series of malonate complexes of dysprosium were synthesized as potential metalorganic precursors for Dy containing oxide thin films using chemical vapor deposition (CVD) related techniques. The steric bulkiness of the dialkylmalonato ligand employed was systematically varied and its influence on the resulting structural and physico–chemical properties that is relevant for MOCVD was studied. Single crystal X-ray diffraction analysis revealed that the five homoleptic tris-malonato Dy complexes (1–5) are dimers with distorted square-face bicapped trigonal-prismatic geometry and a coordination number of eight. In an attempt to decrease the nuclearity and increase the solubility of the complexes in various solvents, the focus was to react these dimeric complexes with Lewis bases such as 2,2′-biypridyl and pyridine (6–9). This resulted in monomeric tris-malonato monoLewis base adduct complexes with improved thermal properties. Finally considering the ease of synthesis, the monomeric nature and promising thermal characteristics, the silymalonate adduct complex [Dy(dsml)3bipy] (8) was selected as single source precursor for growing DySixOythin films by liquid injection metalorganic chemical vapor deposition (LI-MOCVD) process. The as-deposited films were analyzed for their morphology and composition by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, Rutherford backscattering (RBS) analysis and X-ray photoelectron spectroscopy. [ABSTRACT FROM AUTHOR]

The title compound, 3‐[(benzo‐1,3‐dioxol‐5‐yl)amino]‐4‐methoxycyclobut‐3‐ene‐1,2‐dione, C12H9NO5 (3), is a precursor to an antimycobacterial squaramide. Block‐shaped crystals of a monoclinic form (3‐I, space group P21/c, Z = 8, Z′ = 2) and needle‐shaped crystals of a triclinic form (3‐II, space group P‐1, Z = 4, Z′ = 2) were found to crystallize concomitantly. In both crystal forms, R22(10) dimers assemble through N—H...O=C hydrogen bonds. These dimers are formed from crystallographically unique molecules in 3‐I, but exhibit crystallographic Ci symmetry in 3‐II. Twinning by pseudomerohedry was encountered in the crystals of 3‐II. The conformations of 3 in the solid forms 3‐I and 3‐II are different from one another but are similar for the unique molecules in each polymorph. Density functional theory (DFT) calculations on the free molecule of 3 indicate that a nearly planar conformation is preferred. [ABSTRACT FROM AUTHOR]

• The crystal structure of L-serinium hydrogensquarate (CSD refcode: HUQNIT), published in this journal very recently is revised. • Problems are due to assignment of the absolute configuration and placement of disordered hydrogen atoms. • HUQNIT actually represents the CSD entry PAZCUO, published more than 20 years ago. The crystal structure of L-serinium hydrogensquarate (CSD refcode: HUQNIT), published in this journal very recently [Tyagi et al., J. Mol. Struct. 1224 (2021) 129190], is revised. Problems arise from the assignment of the absolute configuration of the serinium cation and the positioning of disordered hydrogen atoms of the hydrogensquarate anion. The correct structure of L-serinium hydrogensquarate was published more than 20 years ago [CSD refcode: PAZCUO; Kolev et al., Z. Kristallogr. NCS 213 (1998) 169-170]. [ABSTRACT FROM AUTHOR]

The article presents a study which explored the structure of the compound [Pd2(C4H13N3)2(C14H16N2)](NO3)4. This compound consists of discrete tetracationic dumbbell-type dinuclear complexmolecules and noncoordinating nitrate anions. Two Pd(dien)2+M moieties (dien is diethylenetriamine) are merged by the rigid linear exo-bidentate bridging 2,2',6,6'-tetramethyl-4,4'-bipyri-dine ligand.

The article analyzes the crystal structure of the organic compound N,N-Diethyl-N'-[(E)-4-pyridylmethylene]benzene-1,4-diamine supported by combined X-ray and density functional theory structure optimization. It determines the presence of neutral molecules of a dipolar Schiff base chromophore in the structure and observes the crystallization of the compound in the noncentrosymmetric space group Pna21. Also observed is the stacking interactions in the crystal structure leading to herring-bone packing motif.

4-(4-nitrophenyl)thiomorpholine, the title compound, has been used as a precursor for the corresponding 4-thiomorpholinoaniline, which is a useful building block in medicinal chemistry. The crystal and molecular structures of the title compound, however, have not been described thus far. We synthesized the title compound by means of a nucleophilic aromatic substitution reaction of 4-fluoronitrobenzene and thiomorpholine and structurally characterized it by X-ray crystallography, DFT calculations, and Hirshfeld surface analysis. In the crystal, the molecule exhibits an approximately CS-symmetric structure, with the nitrogen-bound 4-nitrophenyl group in a quasi axial position on the six-membered thiomorpholine ring in a low-energy chair conformation. The solid-state structure of the title compound is markedly different from that of its morpholine analogue. This can be ascribed to the formation of centrosymmetric dimers through intermolecular C–H···O weak hydrogen bonds involving the methylene groups adjacent to the sulfur atom and face-to-face aromatic stacking. [ABSTRACT FROM AUTHOR]

Betaines of squaric acid have gained research interest because of their structural and spectral properties. We elucidated the crystal and molecular structure of the triethylammonium betaine of squaric acid (1) by X-ray crystallography, IR, and NMR spectroscopy augmented by Hirshfeld surface analysis and DFT calculations. The crystal structure determination using Hirshfeld atom refinement reveals that the resonance hybrid structure with partial enolate character of the two lateral squaric acid C=O groups describes 1 best. The solid-state supramolecular structure features weak intermolecular C−H···O hydrogen bonds. The number of C=O bands in the IR spectrum in the solid-state is consistent with local C2v symmetry of the squaric acid residue in 1. The 13C NMR signals of this group in solution were assigned based on 2D NMR experiments and computational prediction using the Gauge-Independent Atom Orbital (GIAO) method. The present study provides the first structural characterization of a betaine of squaric acid containing a four-coordinate nitrogen atom directly attached to the four-membered ring. [ABSTRACT FROM AUTHOR]

Trehalose conjugates of 3-hydroxychromone (3HC) dyes have previously been utilized as fluorescence labels to detect metabolically active mycobacteria with a view to facilitating point-of-care detection of mycobacterial pathogens, especially Mycobacterium tuberculosis. We subjected the 3HC dye 2-(6-(diethylamino)benzofuran-2-yl)-3-hydroxy-4H-chromen-4-one (3HC-2) to a combined X-ray crystallography and density functional theory (DFT) study, and conducted preliminary fluorescence labelling experiments with the model organism Mycobacterium aurum. In the crystal, 3HC-2 exhibits an s-cis conformation of the chromone and the benzofuran moieties about the central C–C bond. According to DFT calculations, the s-cis conformer is about 1.8 kcal mol−1 lower in energy than the s-trans conformer. The solid-state supramolecular structure features hydrogen-bonded dimers and π...π stacking. Fluorescence microscopy revealed fluorescence of M. aurum cells treated with the dye trehalose conjugate 3HC-2-Tre in the GFP channel. It was concluded that s-cis is the preferred conformation of 3HC-2 and that the generally considered non-pathogenic M. aurum can be labelled with the fluorescence probe 3HC-2-Tre for convenient in vitro drug screening of new antimycobacterial agents. [ABSTRACT FROM AUTHOR]

(Z)-1,2-Bis[4-oxo-2-(piperidin-1-yl)-6-(trifluoromethyl)-4H-benzo[e][1,3]thiazin-8-yl]diazene oxide, C28H24F6N6O3S2, was obtained and its structure determined while attempting to crystallize and structurally characterize 8-nitro-2-(piperidin-1-yl)-6-(trifluoromethyl)-4H-benzo[e][1,3]thiazin-4-one, a simplified analogue of the antituberculosis clinical drug candidate BTZ043. X-ray crystallography revealed the structure of the azoxy compound to be comprised of two benzothiazinone moieties linked by a Z-configured azoxy group in an almost coplanar arrangement. In the crystal, the molecules are densely packed, revealing a herringbone pattern. [ABSTRACT FROM AUTHOR]

The crystal structure and in vitro antimycobacterial properties of N-(2-fluoroethyl)-1-[(6-methoxy-5-methylpyrimidin-4-yl)methyl]-1H-benzo[d]imidazole-4-carboxamide (C17H18FN5O2, 1), a previously reported benzimidazoleanalogue of the 1,4-azaindole-based antituberculosis drug candidate TBA-7371, are reported. The structure determination was achieved using Hirshfeld atomrefinement. Compound 1 crystallizes in the triclinic system (space group P1)with two molecules in the asymmetric unit (Z0 = 2). The two crystallographicallydistinct molecules exhibit a similar conformation with the amide groups in a Zconformation, forming an intramolecular Namide--H· · ·Nbenzimidazole hydrogenbond. The most significant supramolecular feature in the solid-state is arelatively short Cbenzimidazole--H· · ·Npyrimidine hydrogen bond. Antimycobacterialtesting confirmed in vitro activity against Mycobacterium smegmatis, but nogrowth inhibtion of Mycobacterium abscessus was found. [ABSTRACT FROM AUTHOR]

Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes with the formula [ZnLn(HL)(µ-OAc)(NO3)2(H2O)x(MeOH)1-x]NO3 · n H2O · n MeOH [Ln = Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO3)2(H2O)] [ZnNd(HL)(OAc)(NO3)2(H2O)](NO3)2 · n H2O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H2L) is formed from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller ZnII ion occupies the inner N2O2 compartment of the ligand, whereas the larger and more oxophilic LnIII ions are found in the outer O2O2' site. Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes (Ln = Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation are reported. [ABSTRACT FROM AUTHOR]