Hydrogen and halogen bonding drive the orthogonal self-assembly of an organic framework possessing 2D channels

Orthogonal self-assembly of an open organic framework showing 2D channels has been obtained by combining hydrogen and halogen bonding. The framework is able to host various guest molecules with a diverse set of steric demands and substitution patterns, and survives single-crystal-to-single-crystal guest exchanges from liquid and gas phases

Tuning electrical properties of hierarchically assembled Al-doped ZnO nanoforests by room temperature Pulsed Laser Deposition

Large surface area, 3D structured transparent electrodes with effective light management capability may represent a key component in the development of new generation optoelectronic and energy harvesting devices. We present an approach to obtain forest-like nanoporous/hierarchical Al-doped ZnO conducting layers with tunable transparency and light scattering properties, by means of room temperature Pulsed Laser Deposition in a mixed Ar:O2 atmosphere. The composition of the background atmosphere during deposition can be varied to modify stoichiometry-related defects, and therefore achieve control of electrical and optical properties, while the total background pressure controls the material morphology at the nano- and mesoscale and thus the light scattering properties. This approach allows to tune electrical resistivity over a very wide range (10^-1 - 10^6 Ohm*cm), both in the in-plane and cross-plane directions. Optical transparency and haze can also be tuned by varying the stoichiometry and thickness of the nano-forests

An Iodine-Vapor-Induced Cyclization in a Crystalline Molecular Flask

A vapor‐induced cyclization has been observed in the host environment of a crystalline molecular flask (CMF), within which 1,8‐bis(2‐phenylethynyl)naphthalene (bpen), a diarenynyl system primed for cyclization, was exposed to iodine vapor to yield the corresponding indeno[2,1‐α]phenalene species. The cyclization process, unique in its vapor‐induced, solvent‐free nature, was followed spectroscopically, and found to occur concurrently with the displacement of lattice solvent for molecular iodine in CMF⋅0.75 bpen⋅2.25 CHCl3⋅H2O. The cyclization occurred under mild conditions and without the need to suspend the crystals in solvent. The ability of CMFs to host purely gas‐induced reactions is further highlighted by the subsequent sequential oxidation reaction of cyclized 7‐iodo‐12‐phenylindeno[2,1‐α]phenalene (ipp) with molecular oxygen derived from air, yielding 12‐hydroxy‐7‐iodo‐2‐phenylindeno[2,1‐α]phenalen‐1(12H)‐one (hipp)

A robust binary supramolecular organic framework (SOF) with high CO2 adsorption and selectivity

A robust binary hydrogen-bonded supramolecular organic framework (SOF-7) has been synthesized by solvothermal reaction of 1,4-bis-(4-(3,5-dicyano-2,6 dipyridyl)dihydropyridyl)benzene (1) and 5,5’-bis-(azanediyl)-oxalyl-diisophthalic acid (2). Single crystal X-ray diffraction analysis shows that SOF-7 comprises 2 and 1,4-bis-(4-(3,5-dicyano-2,6-dipyridyl)pyridyl)benzene (3), the latter formed in situ from the oxidative dehydrogenation of 1. SOF-7 shows a three-dimensional four-fold interpenetrat-ed structure with complementary O−H···N hydrogen bonds to form channels that are decorated with cyano- and amide-groups. SOF-7 exhibits excellent thermal stability and sol-vent and moisture durability, as well as permanent porosity. The activated desolvated material SOF-7a shows high CO2 sorption capacity and selectivity compared with other po-rous organic materials assembled solely through hydrogen bonding

Tetrahedral oxyanions in halogen-bonded coordination networks

The deliberate construction of (6,3) networks via halogen bond-driven self-assembly of tetra-n-butylammonium perchlorate, periodate, and perrhenate with 1,4-diiodotetrafluorobenzene is reported. The mononegative oxyanions sit at network nodes and work as tridentate halogen bond (XB) acceptors, the diiodobenzene derivative spaces the nodes and function as a bidentate XB donor, while the ammonium cations occupy the space encircled by the supramolecular (6,3) frames. Mixed crystals wherein two different oxyanions statistically occupy the network nodes have also been obtained and show geometrical parameters intermediate to the corresponding pure crystals containing only one of the two oxyanions. Mononegative tetrahedral oxyanions are thus demonstrated to behave as general and effective tectons in anion coordination and anion-templated assembly driven by halogen bonding. © 2011 American Chemical Society

Solution and Solid State Synthesis of the Discrete Polyiodide I73–under Modular Cation Templation

Discrete I 7 3- polyiodide is obtained in pure form through solution and solid-state processes thanks to templation by a triammonium cation which elicits the selective formation of the size matching supramolecular anion. © 2012 American Chemical Society