Modeling of alkynes: synthesis and theoretical properties

Abstract

In this paper we present the synthesis and simulation of alkynes derivatives. Semiempirical calculations were carried out for the ground and first excited states, including the spectroscopic properties of the absorption and emission (fluorescence and phosphorescence) spectra by INDO/S-CI and DNdM-INDO/S-CI methods with geometries fully optimized by PM3/CI. The fact that the theoretical spectra are in accord with the experimental absorption spectra gives us a new possible approach on how structure modifications could affect the non-linear optical properties of alkynes. tron acceptor group (III), electron donor and acceptor group (IV). C 6 H 4 N (pyridil) was used in place of the phenyl rings in alkynes VI and VII, and 1,3-diphenylbutadiyne (VIII) was studied to evaluate the extension of conjugated chain. 2. Methodology All reactions were carried out under dry argon using standard Schlenk techniques. Solvents (diethylamine and triethylamine) were dried and distilled prior to use. Diphenylacetylene, phenylacetylene, 4-iodoaniline, 1-iodo-4-nitrobenzene, 4-iodoanisole, and 4-bromopyridine hydro-chloride were purchased from Aldrich Chemical Co send were used without further purification, and bis(triphenylphosphine)palladium(II) dichloride [PdCl 2 (PPh 3) 2 ] and cuprous iodide (CuI) were purchased from Strem Chemical, Inc. UV-Vis spectra were obtained from CH 2 Cl 2 and hexane solutions , in a 1 cm path length quartz cuvette, on a HP8452 spectrometer. Infrared spectra were recorded using NaCl cell in nujol on a Bomem MB-Series FT-IR spectrometer. All compounds (I-VIII) were prepared and characterized as previously described 10-13 and the following is a typical example: Alkyne II (para-aminodiphenylacetylene). To a mixture of 4-iodoaniline (0.97 g, 5 mmol) and phenylacetylene (0.65 ml, 6 mmol) was added [PdCl 2 (PPh 3) 2 ] (170 mg, 5% mol) and CuI (47 mg, 5% mol) in 30 ml a deaerated solution of triethylamine. The reaction mixture was stirred at room