Spectroscopic properties of hybrid systems carbazole@hydroxypropyl-b-cyclodextrin@silver nanoparticles.

IULIANA MIHALACHE; MATIAS CARRANZA; NATALIA L. PACIONI; ANTONIO RADOI; MIHAELA KUSKO; ALICIA VEGLIA

Carlos Paz, Córdoba

Conferencia; 13th Latin American Conference on Physical Organic Chemistry; 2015

Universidad Nacional de Córdoba

Physical chemistry of nanomaterials afterimproving the synthetic procedures to obtain them has become a growing researcharea in the last decades, in order to understand their unique properties beyondthe surface Plasmon phenomena. On the other hand, supramolecular chemistry aimsto interpret and design new chemical systems further than the covalent bond, buildingon supramolecular structures with specific new properties in molecularrecognition, catalysis, separations and sensors, among others. It is known metal nanoparticles (NP) like gold (AuNP) and silver  (AgNP) have a characteristic extinction in theUV-visible region called Surface Plasmon Resonance Band (SPB) that is sensitiveto several factors such as size, shape, coverage and interparticle distance.Moreover, this SPR has been proposed to produce interesting light-inducedphenomena on molecules in the vicinity of the metal surface.1 However,understanding well what are the supramolecular chemistry characteristics behindthese phenomena is still unanswered.  Ourultimate aim is to reveal what factors (and how) have a relevant role in thephysical chemistry properties of hybrid systems comprising supramolecularcomplexes and NP. Previous results obtained in the Argentineangroup showed that Carbazole (CZL) interacts with hydroxypropyl-b-cyclodextrin (HPCD; KA = 1200 M-1) and as aresult of this interaction the CZL fluorescence is enhanced around 1.5 timesrespect to the free guest in water and buffer pH 7 media.2 In this work, we will present the effect ofsilver (AgNP) nanoparticles stabilized by different ligands on thespectroscopic properties (UV-visible, fluorescence and circular dichroism) ofthe CZL@HPCD complex. For example, addition of 50 nm AgNP quenched both, CZLand CZL@HPCD but the effect was more marked on the complex. In addition,induced circular dichroism signals were modified in the presence of AgNPindicating the their interaction with the CZL@HPCD system. We will discussthese results on the basis of the supramolecular chemistry principles. [1] Anger, P et al. Phys. Rev. Lett. 2006, 94,4; Pacioni, N.L. et al, J. Am. Chem. Soc. 2010, 132, 6298; Stamplecoskie, K.G. et al J. Am.Chem. Soc. 2011, 133, 9160; Stamplecoskie, K.G. et al, J. Phys. Chem. C, 2011,115, 1403.[2]Carranza, M.E.; PhD Thesis, February 2015.