Naslov
Neighboring Effect in Fragmentation Pathways of Cage 2 Guanylhydrazones in the Gas Phase

Autori
Šekutor, Marina ; Glasovac, Zoran ; Mlinarić-Majerski, Kata

Izvornik
Journal of physical chemistry. A (1089-5639) 117 (2013), 10; 2242-2252

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
polycyclic guanylhydrazones; neighboring effect;; electrospray ionization; mass spectrometry; density functional theory

Sažetak
ESI-MS/MS investigation of the mono- and bisguanylhydrazone derivatives 1-5 based on adamantane and pentacycloundecane (PCU) skeleton was described. Elimination of neutral guanidine is the most abundant reaction channel in the case of 2, 4-adamantyl and PCU derivatives 4 and 5, while the elimination of CH2N2 fragment is preferred for other compounds. This was attributed to the cage opening of adamantane or PCU skeletons in the former case leading to the formation of the cyclohexyl- or cyclopropylcarbinyl carbocation stabilized by the conjugation with the guanylhydrazone subunit. The main fragmentation pathways observed experimentally were analyzed by using DFT calculations. All investigated bisguanylhydrazones formed dications and their abundances were found to be proportional to the interguanidine distance in the considered ions. Calculation of the first and the second proton affinities supported qualitative interpretation of the dication abundance. Close contact of two guanidine subunits is thus confirmed to be crucial in determining preferential fragmentation pathway and to suppress formation of the dication.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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