Search results for "guest"

Synergetic effect of host-guest chemistry and spin crossover in 3D Hofmann-like metal-organic frameworks [Fe(bpac)M(CN)4] (M=Pt, Pd, Ni).

2012

The synthesis and characterization of a series of three-dimensional (3D) Hofmann-like clathrate porous metal-organic framework (MOF) materials [Fe(bpac)M(CN) 4] (M=Pt, Pd, and Ni; bpac=bis(4-pyridyl)acetylene) that exhibit spin-crossover behavior is reported. The rigid bpac ligand is longer than the previously used azopyridine and pyrazine and has been selected with the aim to improve both the spin-crossover properties and the porosity of the corresponding porous coordination polymers (PCPs). The 3D network is composed of successive {Fe[M(CN) 4]} n planar layers bridged by the bis-monodentate bpac ligand linked in the apical positions of the iron center. The large void between the layers, w…

Positive Allosteric Control of Guests Encapsulation by Metal Binding to Covalent Porphyrin Cages

2018

The allosteric control of the receptor properties of two flexible covalent cages is reported. These receptors consist of two zinc(II) porphyrins connected by four linkers of two different sizes, each incorporating two 1,2,3‐triazolyl ligands. Silver(I) ions act as effectors, responsible for an on/off encapsulation mechanism of neutral guest molecules. Binding silver(I) ions to the triazoles opens the cages and triggers the coordination of pyrazine or the encapsulation of N,N′‐dibutyl‐1,4,5,8‐naphthalene diimide. The X‐ray structure of the silver(I)‐complexed receptor with short connectors is reported, revealing the hollow structure with a cavity well‐defined by two eclipsed porphyrins. Rath…

X-Ray and NMR Studies on Host-Guest Inclusion Complex Formation between Crown Ethers and Pyridinium Compounds

1998

Aromatic–aromatic, π–π, and cation–π interactions can be exploited in the preparation of molecular complexes between benzene-substituted crown ethers and pyridium cations. These complexes have been studied in the gas phase, in solution, and in the solid state; the structure of one of the complexes is depicted on the right.

Structure and Dynamics of the Host-Guest Complex of a Molecular Tweezer: Coupling Synthesis, Solid-State NMR, and Quantum-Chemical Calculations

2001

Directional Shuttling of a Stimuli-Responsive Cone-Like Macrocycle on a Single-State Symmetric Dumbbell Axle

2018

Rotaxane-based molecular shuttles are often operated using low-symmetry axles and changing the states of the binding stations. A molecular shuttle capable of directional shuttling of an acid-responsive cone-like macrocycle on a single-state symmetric dumbbell axle is now presented. The axle contains three binding stations: one symmetric di(quaternary ammonium) station and two nonsymmetric phenyl triazole stations arranged in opposite orientations. Upon addition of an acid, the protonated macrocycle shuttles from the di(quaternary ammonium) station to the phenyl triazole binding station closer to its butyl groups. This directional shuttling presumably originates from charge repulsion and an …

L’amministrazione giudiziaria ex art. 104 bis disp. att. c.p.p. Un istituto sospeso tra chiarimenti e nuove incertezze

2019

Il contributo affronta le principali problematiche riguardanti l'istituto dell'amministrazione giudiziaria ex art. 104 bis disp. att. c.p.p. Si sofferma sulle numerose questioni emerse anche a causa della continua evoluzione normativa: soprattutto sul giudice competente, sulla scelta ed il ruolo dell'amministratore, nonché sulla tutela dei "terzi". The essay addresses the main problems concerning the judicial administration ex art. 104 bis disp. att. c.p.p. It focuses on several issues that arised because of the continuous regulatory evolution: especially on the competent judge, on the choice and role of the administrator, as well as on the rights of "third parties".

Polarimetry as a useful tool for the study of binding equilibria between cyclodextrins and some suitably sized and structured organic molecules

Polarimetric study of binding equilibria between cyclodextrins and some suitable organic guests

Binding properties of polyaminocyclodextrin materials towards polyanions and p-nitroaniline derivatives

MANGANELLI SCONCLUSIONATO. UN CONVEGNO A PALERMO

2022

Il contributo illustra il carattere scientifico del convegno organizzato a Palermo il 19-20 maggio 2022 e passa in rassegna i singoli saggi dei relatori ospiti del convegno, inquadrandoli nelle varie linee di poetica dello scrittore e valorizzandone gli aspetti di originalità nel contesto degli studi su Manganelli