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Remote control in an eight‐component network commanded both the synthesis and shuttling of a [2]rotaxane via metal‐ion translocation, the latter being easily monitored by distinct colorimetric and fluorimetric signals. Addition of zinc(II) ions to the red colored copper‐ion relay station rapidly liberated copper(I) ions and afforded the corresponding zinc complex that was visualized by a bright sky blue fluorescence at 460 nm. In a mixture of all eight components of the network, the liberated copper(I) ions were translocated to a macrocycle that catalyzed formation of a rotaxane by a double‐click reaction of acetylenic and diazide compounds. The shuttling frequency in the copper‐loaded [2]rotaxane was determined to k298=30 kHz (ΔH≠=62.3±0.6 kJ mol−1, ΔS≠=50.1±5.1 J mol−1 K−1, ΔG≠298=47.4 kJ mol−1). Removal of zinc(II) ions from the mixture reversed the system back generating the metal‐free rotaxane. Further alternate addition and removal of Zn2+ reversibly controlled the shuttling mode of the rotaxane in this eight‐component network where the ion translocation status was monitored by the naked eye. Set the control for the heart of the shuttles: Similar to radio‐controlled devices in the real world, triggering a dimeric remote control unit starts the action in the molecular world by transmitting precise ionic commands through solution: With the first push of the button, a rotaxane is built from its constituents via click reaction, with the following ones a defined shuttling process is turned on and off.

A multicatenane is described in which two belts consisting of four annelated rings attached to the wide rims of two calix[4]arenes are interwoven in such a way that each ring of one belt penetrates two adjacent rings of the other belt and vice versa. The key step of the synthesis of this [8]catenane is the exclusive formation of preorganized heterodimers between a multimacrocyclic tetraurea calix[4]arene and an \"open-chain\" tetraurea calix[4]arene containing eight ω-alkenyl groups. When a tetraurea calix[4]arene containing four alkenyl groups is used, a bis-[3]catenane is formed analogously.

This work reports on synthesis and extensive experimental and theoretical investigations on photophysical, structural and thermal properties of the NiII and CuII discrete mononuclear homoleptic complexes [Ni(LI,II)2] and [Cu(LI,II)2] fabricated from the Schiff base dyes o-HOC6H4—CH=N—cyclo-C6H11 (HLI) and o-HOC10H6—CH=N—cyclo-C6H11 (HLII), containing the sterically crowding cyclo­hexyl units. The six-membered metallocycles adopt a clearly defined envelope conformation in [Ni(LII)2], while they are much more planar in the structures of [Ni(LI)2] and [Cu(LI,II)2]. It has been demonstrated by in-depth bonding analyses based on the ETS-NOCV and Interacting Quantum Atoms energy-decomposition schemes that application of the bulky substituents, containing several C—H groups, has led to the formation of a set of classical and unintuitive intra- and inter-molecular interactions. All together they are responsible for the high stability of [Ni(LI,II)2] and [Cu(LI,II)2]. More specifically, London dispersion dominated intramolecular C—H⋯O, C—H⋯N and C—H⋯H—C hydrogen bonds are recognized and, importantly, the attractive, chiefly the Coulomb driven, preagostic (not repulsive anagostic) C—H⋯Ni/Cu interactions have been discovered despite their relatively long distances (∼2.8–3.1 Å). All the complexes are further stabilized by the extremely efficient intermolecular C—H⋯π(benzene) and C—H⋯π(chelate) interactions, where both the charge-delocalization and London dispersion constituents appear to be crucial for the crystal packing of the obtained complexes. All the complexes were found to be photoluminescent in CH2Cl2, with [Cu(LII)2] exhibiting the most pronounced emission – the time-dependent density-functional-theory computations revealed that it is mostly caused by metal-to-ligand charge-transfer transitions.

The title co-crystal, 1,3,5,7-tetraazatricyclo[3.3.1.13,7]decane (HMTA, 1)–4-fluorophenol (4-FP) (1/1), C6H12N4·C6H5FO, shows an unusual asymmetric unit that comprises eight independent molecules (Z′′ = 8), four for each component, with four formula units per asymmetric unit (Z′ = 4). In the molecular packing, each HMTA molecule bridges one 4-FP molecule via an O−H···N hydrogen bond to form a two-molecule aggregate. Differences can be observed between the bond lengths and angles of the independent HMTA and 4-FP molecules and those of the molecules in the aggregate. The C−N bonds exhibit different bond lengths in the tetrahedral cage-like structure of the HMTA molecules, but the largest differences between the molecular aggregates are in the bond lengths in the 4-fluorophenol ring. In the crystal, the HMTA and 4-FP molecules form two hydrogen-bonded (O−H···N, C−H···F and C−H···O) dimers of HMTA and 4-FP molecules, A···D and B···C inversion dimers, which generate enlarged R88(34) ring motifs in both supramolecular structures. In both structures, the crystal packing also features additional C−H···F and C−H···O interactions. The A···D and B···C dimers are linked by additional C−H···F and C−H···O hydrogen bonds, forming columns along the a and b axes, respectively. The importance of the C−H···F interaction to the structure and crystal packing has been demonstrated.

Starting from ( S )-β-phenylalanine, easily accessible by lipase-catalyzed kinetic resolution, a chiral triamine was assembled by a reductive amination and finally cyclized to form the title compound 10 . In the crystals of the guanidinium benzoate salt the six membered rings of 10 adopt conformations close to an envelope with the phenyl substituents in pseudo-axial positions. The unprotonated guanidine 10 catalyzes Diels–Alder reactions of anthrones and maleimides (25–30% ee). It also promotes as a strong Brønsted base the retro-aldol reaction of some cycloadducts with kinetic resolution of the enantiomers. In three cases, the retro-aldol products (48–83% ee) could be recrystallized to high enantiopurity (≥95% ee). The absolute configuration of several compounds is supported by anomalous X-ray diffraction and by chemical correlation.

The Thirty-Meter Telescope (TMT) project is a well-advanced effort to construct one of the first of the next generation of extremely large telescopes with primary mirror diametre larger than 25 m. When used with an adaptive optics systems capable of producing diffraction-limited images, the science reach of a 30 m telescope is extraordinary with improvements in sensitivity over existing telescopes by as much as a factor of 80 for some kinds of observations. The TMT design extends that of the twin Keck 10 m telescopes now in operation and uses the same close-packed segmented primary mirror. The partnership that will finish the design, construct and operate the telescope is described.

Structural and vibrational studies have been carried out for the most stable conformer of 3,3′-ethane-1,2-diyl-bis-1,3,5-triazabicyclo[3.2.1]octane (ETABOC) at the DFT/B3LYP/6-31G(dp) level using the Gaussian 03 software. In light of the computed vibrational parameters, the observed IR Bolhmann bands for the C2V, C2, and Ci symmetrical structures of ETABOC have been analyzed. Hyperconjugative interaction was done by Natural Bond Orbital Analysis. Interpretation of hyperconjugative interaction involving the lone pairs on the bridgehead nitrogen atoms with the neighboring C–N and C–C bonds defines the conformational preference of the title compound. The recorded X-ray diffraction bond parameters were compared with theoretical values calculated at B3LYP/6-31G(d,p) and HF/6-31G(d,p) level of theory showed that ETABOC adopts a chair conformation and possesses an inversion center.

The synthesis and single crystal structure of a new cocrystal, which is composed of OHphenolic∙∙∙OHphenolic∙∙∙Naminalic supramolecular heterosynthons assembled from 4-tert-butylphenol and the macrocyclic aminal TATU, is presented. This cocrystal was prepared by solvent-free assisted grinding, which is a commonly used mechanochemical method. Crystal structure, supramolecular assembly through hydrogen bonding interactions as well as the physical and spectroscopic properties of the title cocrystal are presented in this paper.

Molecular species containing multiple bonds to aluminium have long been challenging synthetic targets. Despite recent landmark discoveries in this area, heterodinuclear Al–E multiple bonds (where E is a group-14 element) have remained rare and limited to highly polarized π-interactions (Al=E ↔ +Al–E–). Here we report the isolation of three alumanyl silanide anions that feature an Al–Si core stabilized by bulky substituents and a Si–Na interaction. Single-crystal X-ray diffraction studies, spectroscopic analysis and density functional theory calculations show that the Al–Si interaction possesses partial double bond character. Preliminary reactivity studies support this description of the compounds through two resonance structures: one that displays a predominant nucleophilic character of the sodium-coordinated silicon centre in the Al–Si core, as shown by silanide-like reactivity towards halosilane electrophiles and the CH-insertion of phenylacetylene. Moreover, we report an alumanyl silanide with a sequestered sodium cation. Cleavage of the Si–Na bond by [2.2.2]cryptand increases the double bond character of the Al–Si core to produce an anion with high aluminata-silene (–Al=Si) character.Aluminium and silicon, two Earth-abundant, well-understood elements, typically form weak Al–Si bonds. Now, complexes featuring an anionic Al–Si core stabilized by bulky substituents and a Si–Na interaction have been isolated. This Al–Si interaction possesses partial double bond character, which can be increased by sequestration of the sodium counterion.

5-(Tert-butyl)-N-(2,4-dichlorophenyl)-1H-1,2,4-triazol-3-amine was synthesized in four steps starting from pivalic acid via thiourea formation followed by heterocyclization with hydrazine hydrate. The structure was established by spectroscopic data, elemental analysis, and substantiated by single-crystal X-ray crystallography. It crystallizes in orthorhombic crystal system with Pbca as space group. In crystal structure, the intermolecular N-H···N hydrogen bonds link the molecules which stabilize the structure. Density functional theory (DFT) calculations have been performed to gain insights into the electronic structure of the compound. The inhibitory activity of the compound against the Jack bean urease revealed significant inhibition IC.sub.50 value 0.21 ± 0.2 [mu]M (~ 100-folds higher than standard). The Hirshfeld surface is an external 3D curve of electrostatic potential in space over a particular molecule in crystalline state. Hirshfeld surface analysis and 2D fingerprint plots were performed. The evaluation of the electrostatic, dispersion, and total energy frameworks indicates that the stabilization is dominated via the electrostatic energy contribution. The molecular docking of compound exhibited hydrogen bonding and C-H-[pi] interaction with docking energy score of - 6.68 and - 6.46 kcal/mol respectively. The compound was also evaluated for antioxidant scavenging activities against DPPH and showed promising antioxidant property with an IC.sub.50 value of 0.45 [mu]g/mL. In addition, the compound was also tested for cytotoxicity using brine shrimp lethality bioassay and LD.sub.50 was found to be 0.5 [mu]g/mL. DNA protection assay was performed with human blood DNA and DNA cleavage was protected by compound at or above 6 [mu]M concentration. Furthermore, DNA titration by UV-visible spectroscopy for compound's interaction with DNA revealed substantial (K.sub.b; 1.605 x 10.sup.3 M.sup.-1) and spontaneous ([DELTA]G; - 19.023 kJmol.sup.-1) interaction via intercalation and the linear rise in DNA viscosity in the presence of compound's concentrations further verified the intercalation binding mode.