Design of a modular and versatile interlock system for ultrahigh vacuum machines: A crossed molecular beam setup as a case study

Guo, Ying; Gu, Xia; Kawamura, Ed; Kaiser, Ralf I.

doi:10.1063/1.2173074

Cited by 61 publications

(80 citation statements)

References 101 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The crossed molecular beam reaction of the silylidyne radical (SiH; X 2 Π) with acetylene (C 2 H 2 ; X 1 Σ g + ) was carried out under single collision conditions exploiting a crossed molecular beams machine [22][23][24][25]. Briefly, disilane (Si 2 H 6 ) seeded in helium at a fraction of 0.5 % was fed into a piezoelectric valve (Physik Instrumente) operating at 120 Hz, -300 V peak voltage, and 2 atm backing pressure; the supersonic beam was intercepted by the 193 nm ArF output of an excimer laser (Coherent, Inc.) which was focused to a 1 mm × 4 mm spot with a pulse energy of 30 mJ at a repetition rate of 60 Hz.…”

Section: Methodsmentioning

confidence: 99%

Untangling the reaction dynamics of the silylidyne radical (SiH; X2Π) with acetylene (C2H2; X1Σg+)

Yang

Dangi

Thomas

2016

Chemical Physics Letters

Self Cite

View full text Add to dashboard Cite

Chemical reaction dynamics of silylidyne (SiH; X 2 Π) with acetylene (C 2 H 2 ; X 1 Σ g +) were studied exploiting the crossed molecular beam approach, and compared with previous studies on D1silylidyne with acetylene. The reaction is initiated by a barrierless addition of silylidyne to one or both carbons of acetylene leading to 1-sila-1-propene-1,3-diylidene and/or the cyclic 1silacyclopropenyl with the former isomerizing to the latter. 1-Silacyclopropenyl eventually loses atomic hydrogen yielding silacyclopropenylidene (c-SiC 2 H 2) in an overall exoergic reaction (experiment:-14.7 ± 8.5 kJ mol-1 ; theory:-13 ± 3 kJ mol-1). The enthalpy of formation for silacyclopropenylidene is determined to be 421.4 ± 9.3 kJ mol-1 .

show abstract

Section: Methodsmentioning

confidence: 99%

Untangling the reaction dynamics of the silylidyne radical (SiH; X2Π) with acetylene (C2H2; X1Σg+)

Yang

Dangi

Thomas

2016

Chemical Physics Letters

Self Cite

View full text Add to dashboard Cite

show abstract

“…[33][34][35][36][37] Briefly, a helium (99.9999%; Gaspro) seeded supersonic beam of meta-tolyl radicals (C 7 H 7 ) at fractions of about 0.2% was generated via single photon dissociation of meta-chlorotoluene (C 7 H 7 Cl, 98%, Aldrich) in the primary source chamber. [33][34][35][36][37] Briefly, a helium (99.9999%; Gaspro) seeded supersonic beam of meta-tolyl radicals (C 7 H 7 ) at fractions of about 0.2% was generated via single photon dissociation of meta-chlorotoluene (C 7 H 7 Cl, 98%, Aldrich) in the primary source chamber.…”

Section: Experimental Methods and Analysismentioning

confidence: 99%

A crossed molecular beam and ab initio study on the formation of 5- and 6-methyl-1,4-dihydronaphthalene (C₁₁H₁₂) via the reaction of meta-tolyl (C₇H₇) with 1,3-butadiene (C₄H₆)

Muzangwa

Yang

Parker

et al. 2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

The crossed molecular beam reactions of the meta-tolyl radical with 1,3-butadiene and D6-1,3-butadiene were conducted at collision energies of 48.5 kJ mol(-1) and 51.7 kJ mol(-1). The reaction dynamics propose a complex-forming reaction mechanism via addition of the meta-tolyl radical with its radical center either to the C1 or C2 carbon atom of the 1,3-butadiene reactant forming two distinct intermediates, which are connected via migration of the meta-tolyl group. Considering addition to C1 proceeds by formation of a van-der-Waals complex below the energy of the separated reactants, we propose that in cold molecular clouds holding temperatures as low as 10 K, the reaction of the meta-tolyl radical with 1,3-butadiene is de-facto barrier less. At elevated temperatures such as in combustion processes, the reaction can also proceed via addition to C2 by overcoming the entrance barrier to addition (11 kJ mol(-1)). Eventually, the resonantly stabilized free radical intermediate C11H13 undergoes isomerization to a cis form, followed by rearrangement through two distinct ring closures at the para- and ortho-position of tolyl radical to yield cyclic intermediates. These intermediates then emit a hydrogen atom forming 6- and 5-methyl-1,4-dihydronaphthalene via tight exit transition states. The steady state branching ratio, 70.0% and 29.2%, at the collision energy of 51.7 kJ mol(-1), of 6- and 5-methyl-1,4-dihydronaphthalene, respectively, is determined mainly by the rates of reverse ring opening of cyclic intermediates. The formation of the thermodynamically less stable 1-meta-tolyl-trans-1,3-butadiene was found to be a less important pathway (0.8%). The reaction of the meta-tolyl radical with 1,3-butadiene leads without entrance barrier to two methyl substituted PAH derivatives holding 1,4-dihydronapthalene cores: 5- and 6-methyl-1,4-dihydronaphthalene thus providing a barrierless route to odd-numbered PAH derivatives under single collision conditions.

show abstract

“…The signal from the PMT was then filtered by a discriminator (Advanced Research Instruments, Model F-100TD, level: 1.6 mV) prior to feeding into a Stanford Research System SR430 multichannel scaler to record TOF spectra. [54,55] TOF spectra were recorded at 2.58 intervals over the angular distribution with 2.6 10 5 TOF spectra recorded at each angle. The TOF spectra recorded at each angle and the product angular distribution in the laboratory frame (LAB) were fit with Legendre polynomials by using a forward-convolution routine.…”

Section: Methodsmentioning

confidence: 99%

Indene Formation under Single‐Collision Conditions from the Reaction of Phenyl Radicals with Allene and Methylacetylene—A Crossed Molecular Beam and Ab Initio Study

Parker

Zhang

Kaiser

et al. 2011

Chemistry An Asian Journal

View full text Add to dashboard Cite

Polycyclic aromatic hydrocarbons (PAHs) are regarded as key intermediates in the molecular growth process that forms soot from incomplete fossil fuel combustion. Although heavily researched, the reaction mechanisms for PAH formation have only been investigated through bulk experiments; therefore, current models remain conjectural. We report the first observation of a directed synthesis of a PAH under single-collision conditions. By using a crossed-molecular-beam apparatus, phenyl radicals react with C(3)H(4) isomers, methylacetylene and allene, to form indene at collision energies of 45 kJ mol(-1). The reaction dynamics supported by theoretical calculations show that both isomers decay through the same collision complex, are indirect, have long lifetimes, and form indene in high yields. Through the use of deuterium-substituted reactants, we were able to identify the reaction pathway to indene.

show abstract

Design of a modular and versatile interlock system for ultrahigh vacuum machines: A crossed molecular beam setup as a case study

Cited by 61 publications

References 101 publications

Untangling the reaction dynamics of the silylidyne radical (SiH; X2Π) with acetylene (C2H2; X1Σg+)

Untangling the reaction dynamics of the silylidyne radical (SiH; X2Π) with acetylene (C2H2; X1Σg+)

A crossed molecular beam and ab initio study on the formation of 5- and 6-methyl-1,4-dihydronaphthalene (C₁₁H₁₂) via the reaction of meta-tolyl (C₇H₇) with 1,3-butadiene (C₄H₆)

Indene Formation under Single‐Collision Conditions from the Reaction of Phenyl Radicals with Allene and Methylacetylene—A Crossed Molecular Beam and Ab Initio Study

Contact Info

Product

Resources

About

Design of a modular and versatile interlock system for ultrahigh vacuum machines: A crossed molecular beam setup as a case study

Cited by 61 publications

References 101 publications

Untangling the reaction dynamics of the silylidyne radical (SiH; X2Π) with acetylene (C2H2; X1Σg+)

Untangling the reaction dynamics of the silylidyne radical (SiH; X2Π) with acetylene (C2H2; X1Σg+)

A crossed molecular beam and ab initio study on the formation of 5- and 6-methyl-1,4-dihydronaphthalene (C11H12) via the reaction of meta-tolyl (C7H7) with 1,3-butadiene (C4H6)

Indene Formation under Single‐Collision Conditions from the Reaction of Phenyl Radicals with Allene and Methylacetylene—A Crossed Molecular Beam and Ab Initio Study

Contact Info

Product

Resources

About

A crossed molecular beam and ab initio study on the formation of 5- and 6-methyl-1,4-dihydronaphthalene (C₁₁H₁₂) via the reaction of meta-tolyl (C₇H₇) with 1,3-butadiene (C₄H₆)