Search results for "guest"

Studio polarimetrico degli equilibri di inclusione tra ciclodestrine native ed opportuni guest modello alifatici e aromatici

Supramolecular Chirogenesis in Bis-Porphyrin: Crystallographic Structure and CD Spectra for a Complex with a Chiral Guanidine Derivative

2021

The complexation of (3aR,7aR)-N-(3,5-bis(trifluoromethyl)phenyl)octahydro-2H-benzo[d]imidazol-2-imine (BTI), as a guest, to ethane-bridged bis(zinc octaethylporphyrin), bis(ZnOEP), as a host, has been studied by means of ultraviolet-visible (UV-Vis) and circular dichroism (CD) absorption spectroscopies, single crystal X-ray diffraction, and computational simulation. The formation of 1:2 host-guest complex was established by X-ray diffraction and UV-Vis titration studies. Two guest BTI molecules are located at the opposite sides of two porphyrin subunits of bis(ZnOEP) host, which is resting in the anti-conformation. The complexation of BTI molecules proceed via coordination of the imine nitr…

Thiourea Organocatalysts as Emerging Chiral Pollutants: En Route to Porphyrin-Based (Chir)Optical Sensing

2021

Environmental pollution with chiral organic compounds is an emerging problem requiring innovative sensing methods. Amino-functionalized thioureas, such as 2-(dimethylamino)cyclohexyl-(3,5-bis(trifluoromethyl)phenyl)thiourea (Takemoto’s catalyst), are widely used organocatalysts with virtually unknown environmental safety data. Ecotoxicity studies based on the Vibrio fischeri luminescence inhibition test reveal significant toxicity of Takemoto’s catalyst (EC50 = 7.9 mg/L) and its NH2-substituted analog (EC50 = 7.2–7.4 mg/L). The observed toxic effect was pronounced by the influence of the trifluoromethyl moiety. En route to the porphyrin-based chemosensing of Takemoto-type thioureas, their s…

A conformationally adaptive macrocycle : conformational complexity and host–guest chemistry of zorb[4]arene

2018

Large amplitude conformational change is one of the features of biomolecular recognition and is also the basis for allosteric effects and signal transduction in functional biological systems. However, synthetic receptors with controllable conformational changes are rare. In this article, we present a thorough study on the host–guest chemistry of a conformationally adaptive macrocycle, namely per-O-ethoxyzorb[4]arene (ZB4). Similar to per-O-ethoxyoxatub[4]arene, ZB4 is capable of accommodating a wide range of organic cations. However, ZB4 does not show large amplitude conformational responses to the electronic substituents on the guests. Instead of a linear free-energy relationship, ZB4 foll…

Guest-Host Systems of 1,3,5-Tristyrylbenzenes

2003

(E,E,E)-1,3,5-Tris(3,4,5-trimethoxystyryl)benzene (1a) forms monoclinic crystals of the space group P21/c. Incorporation of three transoid diacetyl guest molecules between the three arms leads to triclinic crystals of the space group P1. The styryl groups, originally present in a nonsymmetrical conformation, are simultaneously transformed to a C3 arrangement. (E,E,E)-1,3,5-Tris- (3,4,5-tripropoxystyryl)benzene (1b) forms monoclinic crystals of the space group P21/c. The C3 arrangement of the styryl groups is present in the first, the unsymmetrical arrangement in the second modification. Incorporation of two acetone guests in the largest and the middle-sized angle space between the styryl ar…

Binding properties of mono-6-amino-beta-cyclodextrin towards p-nitroaniline derivatives: a polarimetric study

Studio teorico dell’interazione host-guest fra un sistema tubolare ciclopeptidico e la cesio azide

2006

Systems Thinking and Sustainability in Organisations

2015

This set of articles arises from a series of conferences (Business Systems Laboratory Symposia, 2013-2015) and in particular from the 2nd Business systems Laboratory International Symposium, Rome 2014 with the theme ‘Systems Thinking for a Sustainable Economy’, concerned with systems thinking and its relations with sustainable management, where the relevance of systems thinking was demonstrated. The current period of our global society is characterised by intense transformations in the competitive logics of organisations, markets, and, generally speaking, society. Social circumstances today are typified by dynamism, connectivity, nonlinearity, and emergent properties — in other words by ‘co…

Tourism sustainability and economic efficiency: a statistical analysis of Italian provinces

2009

Latest technology and communication consistency in hospitality: a comparison between two Mediterranean countries

2016

AbstractThe goal of this research is to examine customers′ perceptions of the latest technology solutions and marketing communications within the hotel context in two Mediterranean countries – Croatia and Italy. In particular, hotel guests of four- and five-star hotels located in these countries participated in the research. Firstly, guest perceptions of advanced Information and Communication Technology (ICT) and communication consistency are analysed and compared in Croatian and Italian hotels. Secondly, the impact of ICT on communication consistency is tested in both studies. The findings show that the level of customer perceptions of communication consistency is relatively high in both c…