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. Keywords: alkynes, synthesis,semiempirical/ci methods, theoretical absorption and emission spectra, experimental absorption spectratron 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. MethodologyAll 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 hydrochloride 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][11][12][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

Tunable Optoelectronic Properties of Triply Bonded Carbon Molecules with Linear and Graphyne Substructures

“…A comparison of the calculated peak positions with the experimental measurements for LU-14, LU-22, and LU-38 is presented in Table , while for LU-30, we could not locate any experimental data. Dale, Suzuki, and Rosseto et al reported the measurements of the optical absorption in diphenylacetylene (chemical analog of LU-14), which are in good agreement with each other. In particular, Suzuki classified the absorption in three bands labeled A, B, and C, located at 4.17, 5.22, and 6.30 eV, respectively.…”

“…Robertson and Woodward, 29 based upon X-ray measurements, reported identical values of the single and the phenyl ring bond lengths to be 1.40 Å and a triple bond length of 1.19 Å, in the crystalline phase of diphenylacetylene. Rosseto et al 30 reported spectroscopic measurements on diphenylacetylene, along with PM3/CI level optimized geometries for the gas phase. Their optimized values of the single and the phenyl ring bond lengths were in the range 1.389−1.415 Å, while that of the triple bond was 1.195 Å. Chernia et al 31 also performed geometry optimization for diphenylacetylene at the PM3/RHF level and reported 1.195 Å for the triple bond length, while the other ones were in the range 1.390−1.415 Å.…”

Functionalization of Disubstituted Polyacetylenes through Polymer Reactions: Syntheses of Functional Poly(1-phenyl-1-alkyne)s

“…Strong absorption peaks are observed at ∼300 nm in the UV spectra of 5-7 due to the electronic transitions of their diarylacetylene chromophores. 12 Upon photoexcitation, 4 emits a blue light (Figure S4), whose λ max is close to that of its precursor 3 (Table 1) and those of its nonfunctionalized poly-(1-phenyl-1-alkyne) parents, 3 indicating that the light emission is from its poly(1-phenyl-1-pentyne) skeleton. The introduction of the phenylethynyl unit does not affect the emission color but enhances the luminescence efficiency.…”

“…The aromatic rings of polymer 4 absorb at ∼240 nm (K band) and ∼280 nm (B band), while its polyene backbone absorbs in the wavelengths longer than 300 nm (Figure S4, Supporting Information). Strong absorption peaks are observed at ∼300 nm in the UV spectra of 5 − 7 due to the electronic transitions of their diarylacetylene chromophores . Upon photoexcitation, 4 emits a blue light (Figure S4), whose λ max is close to that of its precursor 3 (Table ) and those of its nonfunctionalized poly(1-phenyl-1-alkyne) parents, indicating that the light emission is from its poly(1-phenyl-1-pentyne) skeleton.…”