A close competition between O–H⋯O and O–H⋯π hydrogen bonding: IR spectroscopy of anisole–methanol complex in helium nanodroplets

2020 ◽  
Vol 22 (39) ◽  
pp. 22408-22416
Author(s):  
Tarun Kumar Roy ◽  
Devendra Mani ◽  
Gerhard Schwaab ◽  
Martina Havenith
Keyword(s):  
Hydrogen Bonding ◽  
Ir Spectroscopy ◽  
Helium Nanodroplets

Anisole forms O–H⋯O as well O–H⋯π bound complexes with methanol.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

scholarly journals Vibrational dynamics and solvatochromism of the label SCN in various solvents and hemoglobin by time dependent IR and 2D-IR spectroscopy

2014 ◽  
Vol 16 (36) ◽  
pp. 19643-19653 ◽  
Author(s):  
Luuk J. G. W. van Wilderen ◽  
Daniela Kern-Michler ◽  
Henrike M. Müller-Werkmeister ◽  
Jens Bredenbeck
Keyword(s):  
Hydrogen Bonding ◽  
Ir Spectroscopy ◽  
Structural Dynamics ◽  
Spectral Diffusion ◽  
Time Dependent ◽  
Vibrational Dynamics ◽  
2D Ir

The vibrational label SCN is used to report on local structural dynamics in a protein revealing spectral diffusion on a picosecond scale. The SCN spectra are compared to the response of methylthiocyanate in solvents with different polarity and hydrogen-bonding capabilities.

scholarly journals Influence of the hydrophobic domain on the self-assembly and hydrogen bonding of hydroxy-amphiphiles

2019 ◽  
Vol 21 (21) ◽  
pp. 11242-11258
Author(s):  
Valery Andrushchenko ◽  
Walter Pohle
Keyword(s):  
Hydrogen Bonding ◽  
Ir Spectroscopy ◽  
Self Assembly ◽  
Supramolecular Assemblies ◽  
The Self ◽  
Hydrophobic Domain

IR spectroscopy paired with calculations reveals that structurally similar amphiphiles ODA and DOG form very different supramolecular assemblies.

scholarly journals Acid solvation versus dissociation at “stardust conditions”: Reaction sequence matters

2019 ◽  
Vol 5 (6) ◽  
pp. eaav8179 ◽  
Author(s):  
Devendra Mani ◽  
Ricardo Pérez de Tudela ◽  
Raffael Schwan ◽  
Nitish Pal ◽  
Saskia Körning ◽  
...  
Keyword(s):  
Molecular Evolution ◽  
Ir Spectroscopy ◽  
Theoretical Study ◽  
Water Clusters ◽  
Acid Dissociation ◽  
Reaction Sequence ◽  
Helium Nanodroplets ◽  
Interstellar Clouds ◽  
Ab Initio Simulations ◽  
Reaction Stoichiometry

Chemical reactions at ultralow temperatures are of fundamental importance to primordial molecular evolution as it occurs on icy mantles of dust nanoparticles or on ultracold water clusters in dense interstellar clouds. As we show, studying reactions in a stepwise manner in ultracold helium nanodroplets by mass-selective infrared (IR) spectroscopy provides an avenue to mimic these “stardust conditions” in the laboratory. In our joint experimental/theoretical study, in which we successively add H2O molecules to HCl, we disclose a unique IR fingerprint at 1337 cm−1 that heralds hydronium (H3O+) formation and, thus, acid dissociation generating solvated protons. In stark contrast, no reaction is observed when reversing the sequence by allowing HCl to interact with preformed small embryonic ice-like clusters. Our ab initio simulations demonstrate that not only reaction stoichiometry but also the reaction sequence needs to be explicitly considered to rationalize ultracold chemistry.

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