64725-65-1Relevant academic research and scientific papers
IONIC HYDROGEN BOND. 2. INTRAMOLECULAR AND PARTIAL BONDS. PROTONATION OF POLYETHERS, CROWN ETHERS, AND DIKETONES.
Meot-Ner
, p. 4906 - 4911 (1983)
The relation between molecular structure and intramolecular hydrogen bonding was observed in polyfunctional oxonium ions in terms of the enthalpy and entropy of the internal bond; the thermal stability of the bond as reflected by the bond opening temperature, the bond weakening factor, and the entropy of 'cyclization' per single C-C, C-O, or C-N bond incorporated into the ring. It was found that in the smallest compounds the 'cyclic' structure may amount only to a stabilized cis conformation, while in the largest compounds the hydrogen bond approaches its full intermolecular strength. Together with previous results, the present data show that intramolecular bonding is prevalent in complex organic ions.
Solutions of Carbonyl Compounds in Dibromodifluoromethane in the Presence of Hydrogen Bromide: Protonation of Ketones and Formation of 1-Bromo-alcohols from Aldehydes
Emsley, John,Gold, Viktor,Jais, M. Jamil B.,Zdunek, Leszek Z.
, p. 881 - 884 (1982)
HBr in CBr2F2 is capable of protonating a variety of ketones, and at low temperatures separate 1H n.m.r. signals can be seen for the acid and protonated base.Line shape analysis of the signals enables rates of protonation to be calculated.Aldehydes in HBr-CBr2F2 give n.m.r. spectra that are consistent with the formation of 1-bromo-alcohols.
RING SIZE EFFECTS ON THE GAS PHASE PROTONATION OF CYCLIC KETONES
Bouchoux, G.,Houriet, R.
, p. 5755 - 5758 (2007/10/02)
Experimental proton affinities of cyclic ketones are determined showing evidence for a larger strain energy in protonated vs. neutral cyclic ketones.
Oxonium Ions. Solvation by Single Acetonitrile Molecules in the Gas Phase and by Bulk Solvents
Bromilow, J.,Abboud, J. L. M.,Lebrilla, C. B.,Taft, R. W.,Scorrano, G.,Lucchini V.
, p. 5448 - 5453 (2007/10/02)
The standard free energy of formation of gaseous complexes between monoprotonic oxonium ions and acetonitrile have been obtained by using the ion cyclotron resonance equilibrium constant method for exchange of acetonitrile between the ions.The results show that the "solvation" by a single molecule of acetonitrile in the gas phase reproduces the important diverse effects of molecular structure on oxonium ion solvation by bulk water.It is estimated from the present results that the effects of solvation by bulk water are only about three times as great as the corresponding effects of "solvation" by a single water molecule in the gas phase.Internal charge delocalization from the protonic site of the oxonium ions may be reversed by differential solvation, both with single H-bonding molecules in the gas phase and with bulk solvent.Further evidence for the site of preffered protonation of esters and amides is provided.
