32870-98-7Relevant articles and documents
Polycyclic aromatic hydrocarbon-substituted push-pull chromophores: An investigation of optoelectronic and nonlinear optical properties using experimental and theoretical approaches
Dengiz, ?a?atay
, p. 1375 - 1390 (2021/10/26)
A series of new push-pull chromophores were synthesized in moderate to very high yields (65%-97%) by treating TCNE and TCNQ with alkynes substituted by electron-rich diethylaniline and polycyclic aromatic hydrocarbons. Some of the chromophores exhibit strong intramolecular charge-transfer bands in the near-IR region with λmax values between 695 and 749 nm. With the help of experimental and theoretical analysis, it is concluded that the trend in λmax values is affected by PAH substituents sterically, not electronically. Steric constraints led to the increased dihedral angles, reducing conjugation efficiencies. The absorption properties of push-pull compounds have been investigated in solvents possessing different polarities. All chromophores exhibited positive solvatochromism. As an additional proof of efficient charge-transfer in push-pull chromophores, quinoid character (dr) values were predicted using calculated bond lengths. Remarkably, substantial dr values (0.045-0.049) were predicted for donor diethylaniline rings in all compounds. The effects of various polycyclic aromatic hydrocarbons on optical and nonlinear optical properties were also studied by computational methods. Several parameters, such as band gaps, Mulliken electronegativity, chemical hardness and softness, dipole moments, average polarizability, first hyperpolarizability, were predicted for chromophores at the B3LYP/6-31++G(d,p) level of theory. The predicted first hyperpolarizability β(tot) values vary between 198 to 538 × 10-30 esu for the reported push-pull chromophores in this study. The highest predicted β(tot) value in this study is 537.842 × 10-30 esu, 8150 times larger than the predicted β(tot) value of benchmark NLO material urea, suggests possible utilization of these chromophores in NLO devices. The charge-transfer character of the synthesized structures was further confirmed by HOMO-LUMO depictions and electrostatic potential maps.
Direct Exploitation of the Ethynyl Moiety in Calcium Carbide Through Sealed Ball Milling
Hosseini, Abolfazl,Schreiner, Peter R.
, p. 4339 - 4346 (2020/07/04)
Ball milling of calcium carbide (CaC2) enables the reaction of its ethynyl moiety with organic electrophiles. This was realized simply by co-milling CaC2 with organic substrates in a sealed jar without the need for an additive or a catalyst. Various ketones including those bearing α-hydrogens were ethynylated in good yields at short reaction times. Aryl halides are also amenable substrates for this protocol as they furnish aryl ethynes through a benzyne intermediate. This method offers a practical and cheap alternative to the established procedures for introducing ethynyl functionalities.
Ruthenium-Catalyzed Cycloisomerization of 2,2′-Diethynyl- biphenyls Involving Cleavage of a Carbon-Carbon Triple Bond
Matsuda, Takanori,Kato, Kotaro,Goya, Tsuyoshi,Shimada, Shingo,Murakami, Masahiro
, p. 1941 - 1943 (2016/02/14)
A ruthenium complex catalyzes a new cycloisomerization reaction of 2,2′-diethynylbiphenyls to form 9-ethynylphenanthrenes, thereby cleaving the carbon-carbon triple bond of the original ethynyl group. A metal-vinylidene complex is generated from one of th
