Synthesis, characterization, and modeling of naphthyl-terminated sp carbon chains: dinaphthylpolyynes.
We report a combined study on the synthesis, spectroscopic characterization, and theoretical modeling of a series of α,ω-dinaphthylpolyynes. We synthesized this family of naphthyl-terminated sp carbon chains by reacting diiodoacetylene and 1-ethynylnaphthalene under the Cadiot-Chodkiewicz reaction conditions. By means of liquid chromatography (HPLC), we separated the products and recorded their electronic absorption spectra, which enabled us to identify the complete series of dinaphthylpolyynes Ar-C(2n)-Ar (with Ar = naphthyl group and n = number of acetilenic units) with n ranging from 2 to 6. The longest wavelength transition (LWT) in the electronic spectra of the dinaphthylpolyynes red shifts linearly with n away from the LWT of the bare termination. This result is also supported by DFT-LDA simulations. Finally, we probed the stability of the dinaphthylpolyynes in a solid-state precipitate by Fourier-transform infrared spectroscopy and by differential scanning calorimetry (DSC).
Actinium Chemical Research, Via Casilina 1626/A, I-00133 Rome, Italy. franco.cataldo@fastwebnet.it
Franco
F
Cataldo
Luca
L
Ravagnan
Eugenio
E
Cinquanta
Ivano Eligio
IE
Castelli
Nicola
N
Manini
Giovanni
G
Onida
Paolo
P
Milani