Plugging a Bipyridinium Axle into Multichromophoric Calix[6]arene Wheels Bearing Naphthyl Units at Different Rims.
Tris-(N-phenylureido)-calix[6]arene derivatives are heteroditopic non-symmetric molecular hosts that can form pseudorotaxane complexes with 4,4'-bipyridinium-type guests. Owing to the unique structural features and recognition properties of the calix[6]arene wheel, these systems are of interest for the design and synthesis of novel molecular devices and machines. We envisaged that the incorporation of photoactive units in the calixarene skeleton could lead to the development of systems the working modes of which can be governed and monitored by means of light-activated processes. Here, we report on the synthesis, structural characterization, and spectroscopic, photophysical, and electrochemical investigation of two calix[6]arene wheels decorated with three naphthyl groups anchored to either the upper or lower rim of the phenylureido calixarene platform. We found that the naphthyl units interact mutually and with the calixarene skeleton in a different fashion in the two compounds, which thus exhibit a markedly distinct photophysical behavior. For both hosts, the inclusion of a 4,4'-bipyridinium guest activates energy- and/or electron-transfer processes that lead to non-trivial luminescence changes.
Dipartimento di Chimica Università degli Studi di Parma Parco Area delle Scienze 17A 43124 Parma Italy.
Guido
0000-0003-1937-3758
G
Orlandini
Dipartimento di Chimica "G. Ciamician" and Interuniversity Center for the Chemical Conversion of Solar Energy Bologna Unit Università di Bologna Via Selmi 2 40126 Bologna Italy.
Giulio
0000-0002-7183-2985
G
Ragazzon
Dipartimento di Chimica Università degli Studi di Parma Parco Area delle Scienze 17A 43124 Parma Italy.
Valeria
0000-0003-2642-1578
V
Zanichelli
Dipartimento di Chimica "G. Ciamician" and Interuniversity Center for the Chemical Conversion of Solar Energy Bologna Unit Università di Bologna Via Selmi 2 40126 Bologna Italy.
Lorenzo
L
Degli Esposti
Dipartimento di Chimica "G. Ciamician" and Interuniversity Center for the Chemical Conversion of Solar Energy Bologna Unit Università di Bologna Via Selmi 2 40126 Bologna Italy.
Massimo
0000-0002-8112-8916
M
Baroncini
Dipartimento di Chimica "G. Ciamician" and Interuniversity Center for the Chemical Conversion of Solar Energy Bologna Unit Università di Bologna Via Selmi 2 40126 Bologna Italy.
Serena
0000-0001-9273-4148
S
Silvi
Dipartimento di Chimica "G. Ciamician" and Interuniversity Center for the Chemical Conversion of Solar Energy Bologna Unit Università di Bologna Via Selmi 2 40126 Bologna Italy.
Margherita
0000-0002-8753-0973
M
Venturi
Dipartimento di Scienze e Tecnologie Agro-alimentari Università di Bologna viale Fanin 50 40127 Bologna Italy.
Alberto
0000-0003-2546-9801
A
Credi
Dipartimento di Chimica Università degli Studi di Parma Parco Area delle Scienze 17A 43124 Parma Italy.
Andrea
0000-0003-4045-961X
A
Secchi
Dipartimento di Chimica Università degli Studi di Parma Parco Area delle Scienze 17A 43124 Parma Italy.
Arturo
0000-0003-2774-0095
A
Arduini
calixarenes; fluorescence spectroscopy; naphthyl ureas; pseudorotaxanes; viologens