Dynamics of acetylene dimers hosted in helium droplets

Abstract

The CH antisymmetric stretch of the CH moieties in acetylene dimers was explored over the range 3270-3290 cm using the helium nanodroplet isolation (HENDI) technique. This work is part of a general investigation which addresses the dynamical consequences of coupling the deformation motions of weakly bound complexes with a finite size quantum liquid (the helium droplet). The acetylene dimer is attractive from this point of view because one of its deformation coordinates promotes a tunneling isomerization process. A numerical simulation of the observed spectrum allows deriving a set of effective spectroscopic constants which help understanding the dynamical role played by the droplet on the rotation and deformation of the dimer.

Penning spectroscopy and structure of acetylene oligomers in He nanodroplets

“…This finding is in line with recent results from an infrared spectroscopic study of acetylene dimers in He nanodroplets. 25 Nonetheless, the unambiguous observation of the oligomer ions leads us to the conclusion that following the Penning ionization, the oligomer ions are strongly bound and escape the droplet facilitated by the energy released into the droplet. The free jet study indicates that the [C 2 H 2 ] 2 + and [C 2 H 2 ] 3 + are covalently bound with substantial binding energies 42 eV.…”

Reaction dynamics within a cluster environment

“…187,188 The (C 2 H 2 ) 2 dimer has also been studied. 189 The experimental work in ref. 187 and 188 was conducted along the well established HENDI technique.…”

“…For comparison, the C 2 H 2 HENDI spectrum recorded in ref. 189 is shown in the top panel of the figure.…”

Construction of Cu(DMF)2Cl Active Sites for Gas–Solid Acetylene Dimerization: Effects of DMF Ligand and Catalytic Mechanism

“…The typical catalyst for the acetylene dimerization is a Nieuwland catalyst (NC), which consists of a highly concentrated aqueous solution of CuCl and KCl/NH 4 Cl. − Most studies on NC-catalyzed gas–liquid acetylene dimerization concentrated on solvent effect, ligand modification, metal additives, catalytic mechanism, and kinetics of the reaction, − while the low conversion, low selectivity, and excessive polymerization were the bottleneck problems. − It is necessary to develop novel acetylene dimerization catalysts to increase the catalytic activity and stability. Based on this, several studies have focused on the gas–solid acetylene dimerization reaction process, which could provide more efficient contact opportunities between the acetylene and the catalytic system compared to the gas–liquid acetylene dimerization reaction and is easier to separate and recycle.…”