Reactivity of the Indenyl Radical (C₉H₇) with Acetylene (C₂H₂) and Vinylacetylene (C₄H₄)

Abstract

The reactions of the indenyl radicals with acetylene (C2H2) and vinylacetylene (C4H4) is studied in a hot chemical reactor coupled to synchrotron based vacuum ultraviolet ionization mass spectrometry. These experimental results are combined with theory to reveal that the resonantly stabilized and thermodynamically most stable 1‐indenyl radical (C9H7.) is always formed in the pyrolysis of 1‐, 2‐, 6‐, and 7‐bromoindenes at 1500 K. The 1‐indenyl radical reacts with acetylene yielding 1‐ethynylindene plus atomic hydrogen, rather than adding a second acetylene molecule and leading to ring closure and formation of fluorene as observed in other reaction mechanisms such as the hydrogen abstraction acetylene addition or hydrogen abstraction vinylacetylene addition pathways. While this reaction mechanism is analogous to the bimolecular reaction between the phenyl radical (C6H5.) and acetylene forming phenylacetylene (C6H5CCH), the 1‐indenyl+acetylene→1‐ethynylindene+hydrogen reaction is highly endoergic (114 kJ mol−1) and slow, contrary to the exoergic (−38 kJ mol−1) and faster phenyl+acetylene→phenylacetylene+hydrogen reaction. In a similar manner, no ring closure leading to fluorene formation was observed in the reaction of 1‐indenyl radical with vinylacetylene. These experimental results are explained through rate constant calculations based on theoretically derived potential energy surfaces.

Slowly rotating Einstein–Maxwell-dilaton black hole and some aspects of its thermodynamics

“…where L = T (s 2 − s 1 ) is the latent heat of the phase change and here s 1 and s 2 represent corresponding entropies for the first and the second phases respectively. In our case these two phases represent the black holes of different sizes, namely the so called small and large black holes [10,64,66] and the latent heat represents the gain or loss of the mass of the black hole during the phase transition [77]. From the latter equation one can obtain the relation for the latent heat of the phase change:…”

“…where ρ c is the critical ratio given by the relation (47) and h(ν) might be even more general than in the relation (64). In the neighbourhood of the critical point (τ = 1, ν = 1) one can represent τ = 1 + t, ν = (1 + ω) 1/z (67) and it should be noted that z > 0.…”

“…Considerable attention was paid to the investigation of thermodynamic properties of corresponding dilatonic black holes. It should be noted that the standard approach as well as the extended technique were applied for the study of their thermodynamics [47,54,57,59,60,61,62,63,64,65,66,67,68,69].…”

Hierarchical MnCo2O4/NiMn Layered Double Hydroxide Composite Nanosheet Arrays on Nickel Foam for Enhanced Electrochemical Storage in Supercapacitors

“…Recently, LDHs have been investigated as SCs electrodes by virtue of their unique two-dimensional ionic lamellar structures, tunable chemical composition, and relatively high redox activities. [26][27][28][29]…”

Impact of the self-steepening effect on soliton spectral tunneling in PCF with three zero dispersion wavelengths

“…As indicated by Fig. 2, the injected pulse attains its maximum bandwidth after strong temporal compression and then evolves through the perturbations of high-order dispersion and other nonlinear effects, such as stimulated Raman scattering (SRS) and four-wave mixing (FWM), where the high-order soliton begins to split into a series of fundamental solitons with different peak intensities in D2 [24][25][26][27] . In this process, according to the PM condition between the soliton and the DWs, the soliton can respectively radiate B-DW and R-DW to the normal dispersion region on both sides [28][29][30] .…”