Reactive carbon-chain molecules: synthesis of 1-diazo-2,4-pentadiyne and spectroscopic characterization of triplet pentadiynylidene (H-C[triple bond]C-:C-C[triple bond]C-H)

Journal of the American Chemical Society
Nathan P BowlingRobert J McMahon

Abstract

1-Diazo-2,4-pentadiyne (6a), along with both monodeuterio isotopomers 6b and 6c, has been synthesized via a route that proceeds through diacetylene, 2,4-pentadiynal, and 2,4-pentadiynal tosylhydrazone. Photolysis of diazo compounds 6a-c (lambda > 444 nm; Ar or N2, 10 K) generates triplet carbenes HC5H (1) and HC5D (1-d), which have been characterized by IR, EPR, and UV/vis spectroscopy. Although many resonance structures contribute to the resonance hybrid for this highly unsaturated carbon-chain molecule, experiment and theory reveal that the structure is best depicted in terms of the dominant resonance contributor of penta-1,4-diyn-3-ylidene (diethynylcarbene, H-C[triple bond]C-:C-C[triple bond]C-H). Theory predicts an axially symmetric (D(infinity h)) structure and a triplet electronic ground state for 1 (CCSD(T)/ANO). Experimental IR frequencies and isotope shifts are in good agreement with computed values. The triplet EPR spectrum of 1 (absolute value(D/hc) = 0.6157 cm(-1), absolute value(E/hc) = 0.0006 cm(-1)) is consistent with an axially symmetric structure, and the Curie law behavior confirms that the triplet state is the ground state. The electronic absorption spectrum of 1 exhibits a weak transition near 400 nm with e...Continue Reading

Citations

Jun 27, 2013·Chemical Reviews·Robert S Sheridan
Jul 17, 2010·The Journal of Chemical Physics·Jan FularaJohn P Maier
Jun 17, 2010·The Journal of Chemical Physics·Daniel J GoebbertAndrei Sanov
Dec 2, 2011·The Journal of Chemical Physics·Kristen M VogelhuberW Carl Lineberger
Dec 3, 2008·The Journal of Chemical Physics·Fangtong ZhangRalf I Kaiser
Apr 17, 2015·The Journal of Chemical Physics·Bernadette M BroderickGary E Douberly
Jul 3, 2015·The Journal of Chemical Physics·Mathias SteglichJohn P Maier
Sep 20, 2016·Journal of the American Chemical Society·Stephanie N KnezzRobert J McMahon
Oct 19, 2007·Organic & Biomolecular Chemistry·Daesung Lee, Mansuk Kim
Jul 10, 2008·Angewandte Chemie·José BarluengaAngel L Suárez-Sobrino
Sep 26, 2008·Angewandte Chemie·Bernhard SchäferSascha Ott
Feb 29, 2020·Physical Chemistry Chemical Physics : PCCP·Krishnan ThirumoorthyVenkatesan S Thimmakondu
Nov 18, 2020·Proceedings of the National Academy of Sciences of the United States of America·Chao HeRalf I Kaiser
May 23, 2009·Journal of the American Chemical Society·Phillip S ThomasRobert J McMahon
Jun 18, 2009·Journal of the American Chemical Society·Randal A SeburgRobert J McMahon
Sep 25, 2009·Journal of the American Chemical Society·Sergey E BoganovOleg M Nefedov
Nov 17, 2009·The Journal of Organic Chemistry·Elisabet ObergSascha Ott
Feb 24, 2011·Journal of the American Chemical Society·Scott GronertRory A More O'Ferrall
Sep 21, 2013·The Journal of Physical Chemistry. a·Dmitry KhuseynovAndrei Sanov
Jan 5, 2018·The Journal of Physical Chemistry. a·Tamás VörösGyörgy Tarczay
Jul 4, 2019·The Journal of Physical Chemistry. a·Venkatesan S ThimmakonduAmir Karton
Jan 7, 2020·The Journal of Physical Chemistry. a·Nisha JobVenkatesan S Thimmakondu
Feb 19, 2019·The Journal of Physical Chemistry. a·Engelbert ReuschPatrick Hemberger
Jul 20, 2006·Journal of the American Chemical Society·Kouichi OheKoji Miki
Feb 7, 2007·Journal of the American Chemical Society·Jeffrey T DePintoRobert J McMahon

❮ Previous
Next ❯

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.