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Two bismuth(III) coordination polymers, namely [Bi2X6(µ-dtpo)3]n [X = Cl (1), Br (2); dtpo = 2,2′-dithiobis(pyridine N-oxide)], were prepared using a crystal engineering strategy and structurally characterized by X-ray crystallography. In the isostructural compounds 1 and 2 (trigonal system, space group P-3c1), fac-configured BiX3 units as nodes are joined by the C2-symmetrical dtpo bridging ligand as spacers to generate 2D honeycomb layers with (6,3) topology. The 2D sheets stack along the [001] direction, resulting in virtually hexagonal channels parallel to this direction, which are occupied by disordered methanol and water molecules. The potential solvent area per unit cell volume is 42.2% for 1 and 44.0% for 2. Two isostructural 2D honeycomb bismuth(III) coordination, synthesized from 2,2′-dithiobis(pyridine N-oxide) and bismuth(III) halides are described. [ABSTRACT FROM AUTHOR]

Reactions of 2,2'-dithiobis(pyridine N-oxide) with various ZnII metal precursors and HgII halides are investigated and the products structurally characterized by X-ray crystallography. The crystal structures of the heteroleptic dinuclear complexes [HgX2(pyrithionate)2] (X = Br, I) are reported for the first time and that of the widely used antifungal and antifouling agent, the homoleptic dinuclear complex [Zn2(pyrithionate)4] (zinc pyrithione), is redetermined at low temperature, thereby improving the previous room temperature study in terms of precision. The encountered anionic chelate ligand pyrithionate results from reductive cleavage of the disulfide bond of 2,2'-dithiobis(pyridine N-oxide). [ABSTRACT FROM AUTHOR]

The oxidative formation of N−N bonds from primary amides has been recently reported and then retracted in the journal Nature Communications by Kathiravan, Nicholls, and co‐authors, utilizing a hypervalent iodane reagent. Unfortunately, the authors failed to recognize the Curtius reaction taking place under the described reaction conditions. Thus, the claimed N−N coupling products were not formed. Instead, the Curtius rearrangement urea coupling products were obtained. We demonstrate this herein by means of NMR and x‐ray analysis, as well as with the support of an alternative synthetic route. [ABSTRACT FROM AUTHOR]

The title compound, [HgI2(C10H8N2O2S2)]n, a one-dimensional coordination polymer with HgI2 units and 2,2′-di­thio­bis­(pyridine N-oxide) spacer ligands in an alternating fashion, forms helical chains running along the b axis in the crystal. Within a single coordination polymer strand, the axially chiral 2,2′-di­thio­bis­(pyridine N-oxide) ligands are homochiral, but the enanti­omeric conformation is present in adjacent strands. Within a coordination polymer strand, the iodido ligands point towards the centroids of the aromatic rings of the pyridine N-oxide moieties in the coordination sphere of HgII. Moreover, intra-strand C—HO and C—HI inter­actions, and inter-strand short SI and SO contacts are observed. [ABSTRACT FROM AUTHOR]

A three-part experiment that leads to the synthesis of palladium(II) complex starting from a C3-symmetric triaminoguanidinium-based ligand is presented. In the first part, the preparation of tris-benzylidenetriaminoguanidinium chloride ([H6Br3L]C1) by an acidic catalyzed 3-fold imine formation reaction of 5-bromo-2-hydroxybenzaldehyde and triaminoguanidinium chloride is described. Starting from the second part, the reaction procedures are performed under inert gas atmosphere. The conversion of PdC12 with acetonitrile to give [Pd(MeCN)4]C12 as a precursor is performed at 80 °C. The third part of the experiment is a three-step procedure that begins with deprotonation of [H6jBr3L]Cl, followed by transfer of [Pd(MeCN)4]C12 to the reaction flask, where the chelation of Pd(II)-precursor leads to the in situ species [Pd(MeCN)H3Br3L], Addition of PPh3 as the final reaction step yields [Pd(PPh3)H3Br3L]. This sequence of experiments provides an excellent example of ligand and transition metal preparation and its subsequent complexation to form an oxidant-sensitive organometallic species. Undergraduate students get the opportunity to learn Schlenk techniques and to investigate 1H NMR spectra of organic and organometallic compounds starting from relatively simple to more advanced spectra. The distinct result of the chemical shift of the 4J P-H-affected doublet mirrors the preparative success of the student and demonstrates the utility of 1H NMR experiments. [ABSTRACT FROM AUTHOR]

Interior decorating: A post‐synthetic method allows porous organic cage compounds to be prepared with functionalized interior cavities. The approach produces modified cage compounds in quantitative yield and opens the possibility of preparing organic alloys with different functionality. The solution‐based technique shows the advantage of solubility, an inherent property of porous materials derived from discrete organic molecules. [ABSTRACT FROM AUTHOR]

Ein indirekter Weg wurde erstmals eingeschlagen, um poröse organische Käfigverbindungen mit funktionalisierten Hohlräumen zu synthetisieren. Die Methode liefert quantitativ modifizierte Käfige und könnte die Möglichkeit eröffnen, poröse organische Legierungen mit verschiedenen Funktionalitäten herzustellen. [ABSTRACT FROM AUTHOR]

Golden beauty: For the first time a ligand‐stabilized Au14 cluster has been examined. The structure of this superatom complex bears several impressive and unique features, which will further support the understanding of certain guiding principles for molecular‐precision synthesis and functionalization of ultrasmall nanoparticles. [ABSTRACT FROM AUTHOR]

Schönheit des Goldes: Erstmalig konnte ein ligandenstabilisierter Au14 ‐ Cluster untersucht werden. Die Struktur dieses Superatomkomplexes beinhaltet eindrucksvolle und einzigartige Merkmale, die Impulse für das Verständnis der Wirkmechanismen bei der molekular präzisen Synthese und Funktionalisierung ultrakleiner Nanopartikel liefern könnten. [ABSTRACT FROM AUTHOR]

3,6-Substituted tetrazines 2 (a: R² = 2-pyridyl or b: CO2Me) react with 2,3,9,10-(R¹)4-dihydro-6,13-ethenopentacene 3 in solution at elevated temperature to the corresponding pentacene 1 (a: R¹ = H, b: OBn, c: F). [ABSTRACT FROM AUTHOR]

The reaction of 2,2′-dilithiobiphenyl, generated from 2,2′-dibromobiphenyl and n-BuLi, with BCl3 using n-hexane as solvent provides a high-yielding, simple preparative route to 9-chloro-9-borafluorene 1a. This in turn can be reacted with trimethylsilyl azide to yield 9-azido-9-borafluorene 2. Compound 2 exists as a cyclic trimer in the solid state, but in dichloromethane solution the monomer can coexist with the trimer. Azide 2 is rather unstable both in the solid state and in solution, and it transforms with trace amounts of water and oxygen to the 1,3,5-tris(2-biphenylyl)cyclotriboroxane that was characterized by X-ray diffraction analysis. Addition of pyridine and t-butyl pyridine to azide 2 afford the corresponding pyridine adducts. Compound 1a as well as the Lewis base adducts of 2 have been characterized by multinuclear NMR spectroscopy, and the structures were confirmed by X-ray diffraction analysis. The structural features of azide 2 and the strong Lewis acidity of its boron center have also been investigated by computational chemistry techniques at the MP2 level of theory. [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 presents a scientific report on the three-dimensional structure of the compound, catena-Poly[[[aqua(ethylenediamine-κ²N,N')(nitrato-κO)copper(II)]-µ-4,4'-dithiodipyridine-κ²N:N'] nitrate monohydrate]. The entry notes that the blue and violet crystals of the compound were obtained through evaporation at ambient temperature following dissolution in methanol of the polymeric chains and the bridging ligand.

The reaction of C3‐symmetric tris‐(2‐pyridinylene‐N‐oxide)triaminoguanidinium salts ([H3L]X) and zinc(II) in presence of thiocyanate and different carboxylate ions as co‐ligands yields in a series of different coordination compounds. Supramolecular metallocycles and carboxylate‐bridged dimers are defined by two fundamentally different binding motifs. By adjusting the co‐ligands' stoichiometry, metallocycles and carboxylate‐bridged compounds can be synthesized selectively. Furthermore, the occupation of the metallocycles with co‐ligands can also be controlled that way. Directed synthesis of these metallocycles is essential for further application in host‐guest chemistry due to their cavities and porosity in the solid state. [ABSTRACT FROM AUTHOR]

Es wird über die Synthesen der neuartigen siliciumverbrückten tris‐tetraorganozinnverbindungen MeSi(CH2SnPh2R)3 (2, R=Ph; 5, R=Me3SiCH2) und ihrer halogensubstituierten Derivative MeSi(CH2SnPh(3−n) In)3 (3, n=1; 4, n=2) und MeSi(CH2SnI2R)3 (6, R=Me3SiCH2) berichtet. Die Reaktion von Verbindung 4 mit Di‐tert‐butylzinnoxid, (t‐Bu2SnO)3 liefert das oktokaideka‐nukleare (18‐nuklear) molekulare Diorganozinnoxid [MeSi(CH2SnPhO)3]6 (7), während aus der Umsetzung von 6 mit Natriumhydroxid, NaOH, das trikonta‐nukleare (30‐nuklear) molekulare Diorganozinnoxid [MeSi(CH2SnRO)3]10 (8, R=Me3SiCH2) erhalten wurde. Sowohl 7 und 8 zeigen gürtelartige Leiter‐Typ makrocyclische Strukturen und sind die bei weitem größten bekannten molekularen Diorganozinnoxide. Die Verbindungen wurden mittels Elementaranalysen, Elektrospray‐Massenspektrometrie (ESI‐MS), NMR‐Spektroskopie, 1H‐DOSY‐ NMR‐Spektroskopie (7), IR‐Spektroskopie (7, 8) und Einkristallröntgenstrahlbeugungsanalyse (2, 7, 8) charakterisiert. [ABSTRACT FROM AUTHOR]

The syntheses of the novel silicon‐bridged tris(tetraorganotin) compounds MeSi(CH2SnPh2R)3 (2, R=Ph; 5, R=Me3SiCH2) and their halogen‐substituted derivatives MeSi(CH2SnPh(3−n)In)3 (3, n=1; 4, n=2) and MeSi(CH2SnI2R)3 (6, R=Me3SiCH2) are reported. The reaction of compound 4 with di‐t‐butyltin oxide (t‐Bu2SnO)3 gives the oktokaideka‐nuclear (18‐nuclear) molecular diorganotin oxide [MeSi(CH2SnPhO)3]6 (7) while the reaction of 6 with sodium hydroxide, NaOH, provides the trikonta‐nuclear (30‐nuclear) molecular diorganotin oxide [MeSi(CH2SnRO)3]10 (8, R=Me3SiCH2). Both 7 and 8 show belt‐like ladder‐type macrocyclic structures and are by far the biggest molecular diorganotin oxides reported to date. The compounds have been characterized by elemental analyses, electrospray mass spectrometry (ESI‐MS), NMR spectroscopy, 1H DOSY NMR spectroscopy (7), IR spectroscopy (7, 8), and single‐crystal X‐ray diffraction analysis (2, 7, 8). [ABSTRACT FROM AUTHOR]

Hierarchical helicates based on ketone‐substituted titanium(IV)triscatecholates show different monomer‐dimer behavior depending on different solvents. The dimerization constants of a whole series of differently alkyl‐substituted complexes is analyzed to show that the solvent has a very strong influence on the dimerization. Hereby, effects like solvophobicity/philicity, sterics, electronics of the substituents and weak side‐chain—side‐chain interactions seem to act in concert. [ABSTRACT FROM AUTHOR]

The crystal structures of the methanol nitrobenzene sesquisolvate hemihydrate ( 1) and the 3.75-dimethyl sulfoxide solvate monohydrate ( 2) of 5,10,15,20-tetra(4-hydroxyphenyl)porphyrinatocopper(II) (CuTOHPP) are reported. Both 1 and 2 crystallise in the triclinic system with two molecules of the metalloporphyrin in the asymmetric unit (Z′ = 2). Compound 1 exhibits an extended two-dimensional hydrogen-bonded network in the crystal, whereas discrete hydrogen-bonded assemblies of CuTOHPP and solvent molecules are found in 2. Face-to-face stacking of the metalloporphyrin units and O-H⋯O hydrogen bonding interactions are identified as the most important solid-state organisational features in both 1 and 2. Saddle distortion of the metalloporphyrin units is encountered in both new solvates and there are no Cu⋯O interactions, despite four hydroxy groups on each porphyrin ligand and the presence of oxygen donor solvent molecules. Graphical Abstract: The methanol nitrobenzene sesquisolvate hemihydrate and the 3.75-dimethyl sulfoxide solvate monohydrate of 5,10,15,20-tetra(4-hydroxyphenyl)porphyrinatocopper(II) both crystallise in the triclinic system with two molecules in the asymmetric unit (Z′ = 2), featuring face-to-face stacking of the saddle-distorted metalloporphyrin units. [ABSTRACT FROM AUTHOR]

Phosphinate and phosphane substituted hierarchical helicates have been prepared, and the phosphinate derivatives could be characterized in the crystal. The helicate with phosphane substituents was submitted to an orientating study on catalysis, showing its potential to act as chelating ligand for the generation of active rhodium‐based hydrogenation catalysts. [ABSTRACT FROM AUTHOR]

Review: 150 refs. [ABSTRACT FROM AUTHOR]

Cations of the dinuclear title compound, [Ir2(C10H15)2(C5H10NS2)2](ClO4)2, contain two half-sandwich (η5-C5Me5)IrIII fragments and two tridentate diethyldithiocarbamate ligands, whose S atoms coordinate individual IrIII atoms in a κ2 S, S′-fashion to afford four-membered chelate rings. The IrIII atoms are linked by the thiocarbamate ligands in a μ-S bridging manner in a central (IrS)2 ring. The (η5-C5Me5)IrIII fragments adopt a cis arrangement relative to this ring and exhibit Ir—C distances in the range 2.167 (5)–2.206 (5) Å. Ir—S bond lengths to the bridging S atoms lie between 2.3897 (11) and 2.4098 (12) Å, and are slightly longer than those of 2.3842 (12) and 2.3832 (12) Å observed for the monodentate S atoms. The ions are linked by C—H...O hydrogen bonds. [ABSTRACT FROM AUTHOR]

Group 12 halides and 2,2′-dithiobis(pyridine N-oxide) (dtpo) form the crystalline the 1D coordination polymers [Zn X2(μ-dtpo-κ2 O: O′)] n [ X = Cl ( 1), Br ( 2), I ( 3)], [Cd3(μ-Cl)4Cl2(μ-dtpo-κ2 O: O′)2(CH3OH)2] n ( 4), [(CdBr2)2(μ3-dtpo-κ3 O, O: O′)2(H2O)2] n ( 5), and [(CdI2)2(μ-dtpo-κ2 O: O′)3] n ( 6) in methanol. The compounds were structurally characterized by single-crystal X-ray analysis. Compounds 1- 3 represent an isomorphous series of single-stranded coordination polymers, whereas the CdII derivatives are structurally diverse. The metal nodes in 4 and 5 are trinuclear and dinuclear cadmium clusters, respectively. In 4 and 5, the metal nodes are linked into double-stranded 1D coordination polymers by two dtpo bridging ligands. Compound 6 contains mononuclear CdI2 units as nodes and can be viewed as an alternating copolymer of CdI2(μ-dtpo-κ2 O: O′)2 and CdI2(μ-dtpo-κ2 O: O′) entities. Owing to the disulfide moiety, the dtpo bridging ligand inevitably exhibits an axially chiral angular structure. The dtpo ligand adopts various coordination modes through the pyridine N-oxide oxygen atoms. [ABSTRACT FROM AUTHOR]

The crystal structures of 5,10,15,20-tetra(4-hydroxyphenyl)-21,23H-porphyrin nitrobenzene hexasolvate (1), 5,10,15,20-tetra(4-hydroxyphenyl)porphyrinatonickel(II) nitrobenzene hexasolvate (2) and 5,10,15,20- tetra(4-hydroxyphenyl)porphyrinatocopper(II) nitrobenzene hexasolvate (3) are described. Compounds 1-3 crystallise isomorphously in the non-centrosymmetric tetragonal space group P4cc with Z = 8. There are three crystallographically distinct porphyrin molecules, two of which contain fourfold axes perpendicular to the porphyrin plane. The remaining one contains a twofold axis perpendicular to the porphyrin ring system. The porphyrin building blocks are joined into a three-dimensional network through self-complementary O-H...O hydrogen bonding interactions between 4-hydroxyphenyl groups of adjacent molecules. The space occupied by the nitrobenzene solvent molecules is remarkably large at ca. 61.5% of the unit cell volume in 1-3. [ABSTRACT FROM AUTHOR]

The [ 18 F]fluoroethyl moiety has been widely utilized in the synthesis of 18 F-labelled compounds. The aim of this work was the reliable synthesis of [ 18 F]FEtOTf with a novel strategy to increase the reactivity of the commonly used [ 18 F]FEB and [ 18 F]FEtOTos. [ 18 F]FEtOTf and the intermediate [ 18 F]FEtOH were synthesized in high RCY (78% and 85%, respectively) and purified by SPE. The high potency of [ 18 F]FEtOTf was shown by the efficient alkylation of the deactivated nucleophile aniline under mild conditions, as well as by the synthesis of [ 18 F]FEC. [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]

Reaction of Zn(NO)·6HO with the bent bridging ligand 4,4′-dithiodipyridine (dtdp), showing axial chirality, in the presence of the chelating 1,10-phenanthroline (phen) ligand in ethanol yielded [{Zn( μ-dtdp)(HO)}(NO)·2CHOH·2HO] ( 1). In 1, Zn ions are linked by two dtdp ligands of opposite chirality into a one-dimensional coordination polymer of the repeated-rhomboid type; the phen co-ligand was not encountered in the crystal. Pseudo-symmetry of the lattice is discussed for 1. Reaction of Zn(NO)·6HO and dtdp in an ethanol/water mixture in absence of phen led to the known repeated-rhomboid coordination polymer [{Zn(NO)( μ-dtdp)(HO)}NO·4HO] ( 2), the crystal structure of which was redetermined at 110 K. At low temperature, the nitrato-κ O ligand in one axial position of Zn was found to be non-disordered as distinct from the room temperature structure (Horikoshi and Mikuriya, Cryst Growth Des 5:223-230, ). The Zn ions in 2 are joined by two dtdp ligands of the same chirality. [ABSTRACT FROM AUTHOR]

Abstract: Racemic forms of 1,1′-bi-(2-naphthol) (BINOL) monopivalate (rac-1) and its 6-nitro substitute (rac-2) were structurally characterized by X-ray crystallography. Molecules of opposite chirality form dimers in the crystalline state of rac-1 through OO hydrogen-bonds between the free hydroxy and the pivalate carbonyl group. In contrast, polymeric hydrogen-bonded homo chiral chains were encountered for rac-2. In both rac-1 and rac-2, the dihedral angle between the naphthyl systems shows a significant deviation compared to the approximate 90° angle of BINOL. As expected, compound rac-1 exhibits an increased angle (108.80(4)° and 102.09(4)°) as one of the hydroxy groups in BINOL is replaced by the sterically demanding pivaloyl ester. In contrast, the angle is decreased to 72.0(2)° in the nitro derivative rac-2. [ABSTRACT FROM AUTHOR]

The reinvestigation of the synthesis of the fascinating cage compound 2 reveals an incorrect structure of photodimer 2, as well as of the putatively isolated intermediate 9. These products have to be reassigned as monomeric pyramidalized alkene 3 and spirocyclic dichloride 10, respectively. [ABSTRACT FROM AUTHOR]

A bisnaphthyl-substituted acenaphthylene is synthesized via two independent two-step procedures, Pd-catalyzed and classically with Grignard reagents. The subsequent dehydrocyclization stops after the first carbon-carbon bond formation, leading to an octacyclic π-system as the main product. [ABSTRACT FROM AUTHOR]

Novel cobalt(II) containing compounds of tris‐(2‐pyridinylene‐N‐oxide)triaminoguanidine ligands L2− are presented: the supramolecular metallocycle [Co6(OOCMe)3(NCS)3L3]4 and the one‐dimensional coordination polymer {[Co3(μ‐OOCMe)3L]NO3}n. Analog zinc(II) complexes show similar to identical structures that are slightly influenced by different preferences regarding the coordination number. In the polymers, the coordination number is five, which is less common for zinc(II) and rare for cobalt(II). The compounds are characterized by single‐crystal as well as powder X‐ray diffraction, IR spectroscopy, and ESI mass spectrometry. Magnetic measurements revealed predominantly antiferromagnetic exchange interaction between the cobalt(II) centers linked by the triaminoguanidine backbone. [ABSTRACT FROM AUTHOR]

Mono‐ or biscatechol esters with ether‐type substituents or spacers form either triple lithium bridged dimeric helicates or triple stranded helicates with the ability to bind three lithium cations in their interior. Hierarchical helicates with ether or thioether substituents show in solution a monomer‐dimer equilibrium which is independent of the heteroatom in the ester substituent. However, dimerization constants are significantly lower than for corresponding alkyl derivatives. Dinuclear helicates with oligoether spacers are well obtained in the presence of lithium cations. Upon removal of the cations the helicates expand and successive addition of LiCl results in compression again. [ABSTRACT FROM AUTHOR]

The thioester moiety is introduced as a lithium binding unit for the hierarchical formation of titanium(IV) catecholate‐based lithium‐bridged helicates. In solution, the coordination compounds show a monomer–dimer equilibrium which —in comparison to the oxo esters— is significantly shifted towards the monomers. In addition, the influence of the thioester side chain on the dimerization behavior is investigated and an expansible/compressible molecular switch is synthesized. In the latter case expansion and compression are performed reversibly in methanol, whereas in DMSO spontaneous expansion occurs. [ABSTRACT FROM AUTHOR]

The synthesis of a new triaminoguanidinium‐based ligand with three tris‐chelating [NNO]‐binding pockets and C3 symmetry is described. The reaction of tris‐(2‐pyridinylene‐N‐oxide)triaminoguanidinium salts with zinc(II) formate leads to the formation of cyclic supramolecular coordination compounds which in solution bind fullerenes in their spherical cavities. The rapid encapsulation of C60 can be observed by NMR spectroscopy and single‐crystal X‐ray diffraction and is verified using computation. [ABSTRACT FROM AUTHOR]

The dissociation of hierarchically formed dimeric triple lithium bridged triscatecholate titanium(IV) helicates with hydrocarbyl esters as side groups is systematically investigated in DMSO. Primary alkyl, alkenyl, alkynyl as well as benzyl esters are studied in order to minimize steric effects close to the helicate core. The 1H NMR dimerization constants for the monomer–dimer equilibrium show some solvent dependent influence of the side chains on the dimer stability. In the dimer, the ability of the hydrocarbyl ester groups to aggregate minimizes their contacts with the solvent molecules. Due to this, most solvophobic alkyl groups show the highest dimerization tendency followed by alkenyls, alkynyls and finally benzyls. Furthermore, trends within the different groups of compounds can be observed. For example, the dimer is destabilized by internal double or triple bonds due to π–π repulsion. A strong indication for solvent supported London dispersion interaction between the ester side groups is found by observation of an even/odd alternation of dimerization constants within the series of n‐alkyls, n‐Ω‐alkenyls or n‐Ω‐alkynyls. This corresponds to the interaction of the parent hydrocarbons, as documented by an even/odd melting point alternation. [ABSTRACT FROM AUTHOR]

Zwei Biscatecholesterliganden mit Oligoether‐Verbrückung wurden eingesetzt, um zweikernige Triscatecholattitan(IV)‐basierte Helicate herzustellen. Im Fall von Li4[(1/2)3Ti2] wurden "klassische" Helicate mit drei intern gebundenen Li+ und einer syn‐Orientierung der Liganden in den Komplexen (fac/fac‐Isomer) erhalten. Im Fall des Natriumsalzes Na4[(2)3Ti2] wird ein andersartiges homochirales zweikerniges, dreisträngiges Helicat mit zwei internen Nariumionen gebildet. Die Komplexeinheiten sind hier anti‐konfiguriert, wobei zwei der verbrückenden Einheiten innere Positionen der Liganden im Helicat mit äußeren verknüpfen (mer/mer‐Isomer). Entfernen der Natriumkationen und Zugabe von Lithiumionen führt zum Schalten von der einen topologischen Form zur Anderen, wobei ein gestrecktes Helicat [(2)3Ti2]4− als Zwischenstufe entsteht. Das Zurückschalten zu dem "nicht‐klassischen" Helicat ist nicht möglich, da hierbei zu große strukturelle Änderungen nötig sind. [ABSTRACT FROM AUTHOR]

Two biscatecholester ligands with oligoether spacers were used to prepare dinuclear titanium(IV) triscatecholate based helicates. In the case of Li4[(1/2)3Ti2], "classical" helicates with three internally bound Li+ ions and syn‐oriented ligands in the complex units (fac/fac isomer) were obtained. In the case of the sodium salt Na4[(2)3Ti2], a different homochiral dinuclear triple‐stranded helicate with two internally bound Na+ ions was formed. The complex units are anti‐configured, and two of the ligand spacers are connecting internal with external positions of the helicate (mer/mer isomer). Removal of the sodium ions and addition of lithium ions leads to the switching from one topology to the other with an expanded helicate [(2)3Ti2]4− as an intermediate. Switching back to the "non‐classical" helicate cannot be observed because severe structural rearrangements would be required. [ABSTRACT FROM AUTHOR]

Abstract: Die Kontrolle von Strukturveränderungen, die durch externe Signale gesteuert werden, ist von enormer Wichtigkeit für die Entwicklung neuer funktionaler Einheiten. In der vorliegenden Studie wird gezeigt, dass Helicate synthetisiert werden können, die auf die Anwesenheit unterschiedlicher Gegenionen strukturell reagieren und entweder eine gestauchte oder gestreckte Geometrie einnehmen. Reversibles Schalten ist nicht nur zwischen diesen beiden Zuständen möglich, vielmehr kann die Verdrillung der helikalen Gebilde ebenfalls kontrolliert werden. Drei von vier möglichen Zuständen des Helicats (gestreckt/linksgängig, gestreckt/rechtgängig, gestaucht/linksgängig) können im Fall eines chiralen Biscatecholesterliganden erreicht werden, indem Kationen eingeführt, ausgetauscht oder entfernt werden. Dies wird genutzt, um zwischen den drei Zuständen zu schalten oder sie gezielt zu adressieren. [ABSTRACT FROM AUTHOR]

Abstract: The control of structural transformations triggered by external signals is important for the development of novel functional devices. In the present study, it is demonstrated that helicates can be designed to structurally respond to the presence of different counterions and to adopt either a compressed or an expanded structure. Reversible switching is not only possible between those two states, furthermore, the twist of the aggregate also can be controlled. Thus, three out of four possible states of a helicate (expanded/left‐handed, expanded/right‐handed, compressed/left‐handed) based on an enantiomerically pure ester bridged dicatecholate ligand are specifically addressed by introduction, exchange, or removal of countercations. This approach is used to reversibly switch between the different states or to successively address them. [ABSTRACT FROM AUTHOR]

Porphyrin assemblies display interesting photophysical properties and a relatively high thermal stability. Moreover, meso-functionalized porphyrins with virtually fourfold symmetry can be relatively readily synthesized from pyrrole and the appropriate aldehyde. A number of metallo derivatives of 5,10,15,20-tetrakis(4-cyanophenyl)porphyrin, where the N atom of the linear cyano group can act both as a donor for coordination bonds or as an acceptor for hydrogen bonds, have been structurally characterized by single-crystal X-ray analysis. The supramolecular and structural chemistry of the corresponding 2- and 3-cyanophenyl isomers of the parent porphyrin, however, has remained largely unexplored. The crystal structure of [5,10,15,20-tetrakis(3-cyanophenyl)porphyrinato]copper(II) (CuTCNPP) nitrobenzene trisolvate, [Cu(C48H24N8)]·3C6H5NO2, has been determined at 80 K by synchrotron single-crystal X-ray diffraction. CuTCNPP exhibits a C2 h-symmetric ααββ conformation, despite an unsymmetrical crystal environment, and is situated on a crystallographic centre of symmetry. The CuII ion adopts a genuine square-planar coordination by the four pyrrole N atoms. The 24-membered porphyrin ring system shows no marked deviation from planarity. In the crystal, the CuTCNPP molecules and two nitrobenzene molecules are face-to-face stacked in an alternating fashion, resulting in corrugated layers. The remaining nitrobenzene guest molecule per CuTCNPP resides in the region between four neighbouring columnar stacks of CuTCNPP and sandwiched nitrobenzene molecules, and is disordered over four positions about a centre of symmetry. [ABSTRACT FROM AUTHOR]

All four isoquinolin-1-yl substituents at the upper rim of a resorcinarene adopt the same preferred conformation, with the lone electron pairs of the nitrogen atoms pointing towards the molecular bowl. Thus, an electron-rich narrow cavity is formed, suitable for linear molecules as molecular guests, such as CS 2 and acetonitrile, but also flexible enough to incorporate benzonitrile. [ABSTRACT FROM AUTHOR]

Die dreieckigen Cluster [Zn3Cp*3]+ und [Zn2CuCp*3] wurden durch Addition der in situ generierten, elektrophilen und isolobalen Spezies [ZnCp*]+ und [CuCp*] an das Carmona-Reagens [Cp*ZnZnCp*] synthetisiert, wobei die Zn-Zn-Bindung des Letzteren erhalten blieb. Die Verwendung von nichtkoordinierenden fluorierten aromatischen Lösungsmitteln ist dabei essenziell. Die Bindungssituation der ligandenstabilisierten Cluster wurde mit quantenchemischen Methoden untersucht, wobei sich ein hohes Maß an σ-Aromatizität zeigte, ähnlich der Bindungssituation im Triwasserstoffkation [H3]+. Die neuen Spezies dienen als molekulare Bausteine für Cu nZn m-Cluster (Nanomessing), die auch im LIFDI-Massenspektrum der neuen Verbindungen detektiert werden können. [ABSTRACT FROM AUTHOR]

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]

Discrete interlocked three-dimensional structures are synthetic targets that are sometimes difficult to obtain with 'classical' synthetic approaches, and dynamic covalent chemistry has been shown to be a useful method to form such interlocked structures as thermodynamically stable products. Although interlocked and defined hollow structures are found in nature, for example, in some viruses, similar structures have rarely been synthesized on a molecular level. Shape-persistent interlocked organic cage compounds with dimensions in the nanometer regime are now accessible in high yields during crystallization through the formation of 96 covalent bonds. The interlocked molecules form an unprecedented porous material with intrinsic and extrinsic pores both in the micropore and mesopore regime. [ABSTRACT FROM AUTHOR]

Discrete interlocked three-dimensional structures are synthetic targets that are sometimes difficult to obtain with 'classical' synthetic approaches, and dynamic covalent chemistry has been shown to be a useful method to form such interlocked structures as thermodynamically stable products. Although interlocked and defined hollow structures are found in nature, for example, in some viruses, similar structures have rarely been synthesized on a molecular level. Shape-persistent interlocked organic cage compounds with dimensions in the nanometer regime are now accessible in high yields during crystallization through the formation of 96 covalent bonds. The interlocked molecules form an unprecedented porous material with intrinsic and extrinsic pores both in the micropore and mesopore regime. [ABSTRACT FROM AUTHOR]

Review: 104 refs. [ABSTRACT FROM AUTHOR]

Recently, porous organic cage crystals have become a real alternative to extended framework materials with high specific surface areas in the desolvated state. Although major progress in this area has been made, the resulting porous compounds are restricted to the microporous regime, owing to the relatively small molecular sizes of the cages, or the collapse of larger structures upon desolvation. Herein, we present the synthesis of a shape-persistent cage compound by the reversible formation of 24 boronic ester units of 12 triptycene tetraol molecules and 8 triboronic acid molecules. The cage compound bears a cavity of a minimum inner diameter of 2.6 nm and a maximum inner diameter of 3.1 nm, as determined by single-crystal X-ray analysis. The porous molecular crystals could be activated for gas sorption by removing enclathrated solvent molecules, resulting in a mesoporous material with a very high specific surface area of 3758 m2 g−1 and a pore diameter of 2.3 nm, as measured by nitrogen gas sorption. [ABSTRACT FROM AUTHOR]

Recently, porous organic cage crystals have become a real alternative to extended framework materials with high specific surface areas in the desolvated state. Although major progress in this area has been made, the resulting porous compounds are restricted to the microporous regime, owing to the relatively small molecular sizes of the cages, or the collapse of larger structures upon desolvation. Herein, we present the synthesis of a shape-persistent cage compound by the reversible formation of 24 boronic ester units of 12 triptycene tetraol molecules and 8 triboronic acid molecules. The cage compound bears a cavity of a minimum inner diameter of 2.6 nm and a maximum inner diameter of 3.1 nm, as determined by single-crystal X-ray analysis. The porous molecular crystals could be activated for gas sorption by removing enclathrated solvent molecules, resulting in a mesoporous material with a very high specific surface area of 3758 m2 g−1 and a pore diameter of 2.3 nm, as measured by nitrogen gas sorption. [ABSTRACT FROM AUTHOR]

C3-symmetric ligands carrying a rigid triaminoguanidinium backbone are important building blocks for the preparation of supramolecular coordination cages as tetrahedra or trigonal bipyramides. Coordination of Eu(iii)- or Gd(iii)-ions leads to 1,2,4-triazole formation, which has been reported only rarely. Using Pd(ii)-complexes as a model system, this triazole formation could be analyzed in more detail. The preparation of Pd(ii)-coordination compounds can be easily done under stoichiometric control. These complexes could be transformed into 1,2,4-triazoles using O2 or H2O2 as an oxidation reagent. The steric demand of the PR3-coligand seems to play a key role in the cyclisation reaction. [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 crystal structure of [ZnBr( μ-dtdp)] ( 1) (dtdp = 4,4'-dithiodipyridine) is described. Compound 1 is a one-dimensional coordination polymer of the arched chain type, composed of ZnBr units as tetrahedral metal nodes joined by the bent bridging ligand dtdp. 1 was found to crystallise in the monoclinic space group C2/ c with the lattice parameters a = 12.713(4) Å, b = 10.108(4) Å, c = 10.835(5) Å, β = 91.21(3)°, V = 1392.0(9) Å. In the crystal, the coordination polymer strands run parallel to the c axis direction with the ZnBr units and disulfide bridges containing crystallographic twofold rotation axes. The structure of 1 belongs to an isomorphous series of [Zn X( μ-dtdp)] ( X = Cl, SCN, CHCOO) coordination polymers, which can be found in the literature. The crystal of 1 studied was found to be a two component non-merohedral twin with the twin operation representing a twofold rotation about the c axis, as for the isostructural chlorido derivative [Seidel RW, Dietz C, Oppel IM (2012) Z Kristallogr NCS 227:305]. Graphical Abstract: The crystal structure of the one-dimensional coordination polymer [ZnBr( μ-dtdp)] (dtdp = 4,4'-dithiodipyridine) has been determined from a non-merohedrally twinned crystal[Figure not available: see fulltext.]. [ABSTRACT FROM AUTHOR]