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para-diethynylbenzene dianion; The gaseous state of all three anions are of theoretical interest. They have been generated by decarboxylation of benzene dipropynoic acids, using the technique of mass spectrometry. [1] [2] The three isomers of the dianion are the three strongest known superbases ever, with the ortho isomer being the strongest ...
The higher the proton affinity, the stronger the base and the weaker the conjugate acid in the gas phase.The (reportedly) strongest known base is the ortho-diethynylbenzene dianion (E pa = 1843 kJ/mol), [3] followed by the methanide anion (E pa = 1743 kJ/mol) and the hydride ion (E pa = 1675 kJ/mol), [4] making methane the weakest proton acid [5] in the gas phase, followed by dihydrogen.
It was the strongest known base until 2008, when the isomeric diethynylbenzene dianions were determined to have a higher proton affinity. The methanide ion CH − 3 was the strongest known base before lithium monoxide anion was discovered. [2] LiO − has a proton affinity of ~1782 kJ/mol. [3]
Ortho-diethynylbenzene dianion (C 6 H 4 (C 2) 2) 2− (the strongest superbase ever synthesized) Meta-diethynylbenzene dianion (C 6 H 4 (C 2) 2) 2− (second strongest superbase) Para-diethynylbenzene dianion (C 6 H 4 (C 2) 2) 2− (third strongest superbase) Lithium monoxide anion (LiO −) was considered the strongest superbase before ...
Ortho effect is an organic chemistry phenomenon where the presence of a chemical group at the at ortho position or the 1 and 2 position of a phenyl ring, relative to the carboxylic compound changes the chemical properties of the compound.
By Paul Mohai, Byoung-Suk Kweon, Sangyun Lee, and Kerry Ard Air Pollution Around Schools Is Linked To Poorer Student Health And Academic Performance
The ratio between numbers of ortho and para molecules is about 3:1 at standard temperature where many rotational energy levels are populated, favoring the ortho form as a result of thermal energy. However, at low temperatures only the J = 0 level is appreciably populated, so that the para form dominates at low temperatures (approximately 99.8% ...
Chinese exports of low-value packages soared to $66 billion in 2023, up from $5.3 billion in 2018, according to report released last week by the Congressional Research Service. In the U.S., Temu ...