Gas-phase basicity of 2-furaldehyde

作者：Ricci Andreina^*; Piccolella Simona; Pepi Federico; Patsilinakos Alexandros; Ragno Rino; Garzoli Stefania; Giacomello Pierluigi

来源：Journal of Mass Spectrometry, 2012, 47(11): 1488-1494.

DOI：10.1002/jms.3058

• 2-furaldehyde
• extended kinetic method
• proton affinity
• gas-phase basicity
• mass spectrometry

2-Furaldehyde (2-FA), also known as furfural or 2-furancarboxaldehyde, is an heterocyclic aldehyde that can be obtained from the thermal dehydration of pentose monosaccharides. This molecule can be considered as an important sustainable intermediate for the preparation of a great variety of chemicals, pharmaceuticals and furan-based polymers. Despite the great importance of this molecule, its gas-phase basicity (GB) has never been measured. In this work, the GB of 2-FA was determined by the extended Cooks%26apos;s kinetic method from electrospray ionization triple quadrupole tandem mass spectrometric experiments along with theoretical calculations. As expected, computational results identify the aldehydic oxygen atom of 2-FA as the preferred protonation site. The geometries of O-O-cis and O-O-trans 2-FA and of their six different protomers were calculated at the B3LYP/aug-TZV(d,p) level of theory; proton affinity (PA) values were also calculated at the G3(MP2, CCSD(T)) level of theory. The experimental PA was estimated to be 847.9?+/-?3.8?kJ?mol-1, the protonation entropy 115.1 +/-?5.03?J?mol-1?K-1 and the GB 813.6?+/-?4.08?kJ?mol-1 at 298?K. From the PA value, a Delta H degrees f of 533.0?+/-?12.4?kJ?mol-1 for protonated 2-FA was derived.

• 出版日期2012-11