Pre-reactive intermediates in mixtures of hydrocarbons with chlorine monofluoride: characterisation of ethyne ? ClF and ethene ? ClF by rotational spectroscopy

Abstract

Pre-reactive complexes B-CIF, where B is ethyne or ethene, of CZv symmetry have been isolated in mixtures of B and CIF by using a fast-mixing nozzle in a pulsed-nozzle, Fourier-transform microwave spectrometer and characterised by their rotational spectra.

Are Various σ‐Hole Bonds Steered by the Same Mechanisms?

“…A T‐shaped C 2 v structure was also observed here for the FCl⋅⋅⋅C 2 H 2 complex calculated at the MP2/aug‐cc‐pVTZ level. The calculated length of 2.730 Å for the Cl⋅⋅⋅center contact (midpoint of the C≡C bond; see Table ) is, however, much shorter than the value of 2.869(2) Å determined experimentally . However, here too a few assumptions were applied to determine the spectroscopic complex geometry, and again the other theoretical results are in agreement with the value presented in this study (Table ).…”

“…The same experimental approach as that appliedf or the FCl···NH 3 complex [44] was also used to analyze complexes of FCl with ethenea nd ethyne, and T-shaped C 2v -symmetric structures were detected for both complexes. [57] AT -shaped C 2v structurew as also observedh ere for the FCl···C 2 H 2 complexc alculated at the MP2/aug-cc-pVTZ level. The calculated length of 2.730 for the Cl···centerc ontact (midpoint of the CCb ond; see Ta ble 1) is, however,m uch shorter than the value of 2.869(2) determined experimentally.…”

“…The same experimental approach as that applied for the FCl⋅⋅⋅NH 3 complex was also used to analyze complexes of FCl with ethene and ethyne, and T‐shaped C 2 v ‐symmetric structures were detected for both complexes . A T‐shaped C 2 v structure was also observed here for the FCl⋅⋅⋅C 2 H 2 complex calculated at the MP2/aug‐cc‐pVTZ level.…”

“…It is important that few systems were analyzed experimentally; for example, complexes of FCl with ammonia and acetylene are characterized by geometries similar to those presented here and as a result of MP2/aug‐cc‐pVTZ calculations. The FCl⋅⋅⋅NH 3 complex was previously analyzed experimentally and was observed by using a fast‐mixing nozzle/FT microwave spectrometer combination; C 3 v symmetry was detected for this complex and a N⋅⋅⋅Cl length of 2.376(3) Å was determined.…”

“…Some of the complexes presented herein (Table 1) have been analyzed in previous studies. These are the FCl···NH 3 , [44][45][46][47][48][49][50][51][52] FBr···NH 3 , [52] SeFH···NH 3 , [53,54] PFH 2 ···NH 3 , [55] SFH···C 2 H 2 , [56] FCl···C 2 H 2 , [46][47][48][57][58][59] PFH 2 ···C 2 H 2 , [60] and Si/GeFH 3 ···NH 3 [61,62] complexes. However,c alculations were performed at different levels and these studies concerned rather narrow types of interaction;h erein the same high level of calculation was applied for the varioust ypes of s-hole bond.…”