High-valent manganese(IV or V)-oxo porphyrins are considered as reactive intermediates in the oxidation of organic substrates by manganese porphyrin catalysts. We have generated Mn(V)- and Mn(IV)-oxo porphyrins in basic aqueous solution and investigated their reactivities in C-H bond activation of hydrocarbons. We now report that Mn(V)- and Mn(IV)-oxo porphyrins are capable of activating C-H bo...

according to the bronsted definition, any compound which has a hydrogen atom is an acid, since itmay be lost as a proton. a thermodynamical cycle is proposed to calculate absolute pka values forbronsted acids in aqueous solution. the equilibrium of dissociation of a bronsted acid depends onthe interaction of the acid and its conjugate base with solvent molecules. there fore the pka valuedepends...

A.) Neutral Acylglycerols and Free Fatty Acids by ESI/MS/MS ....................................... 7 A.1.) Structural characterization of triacylglycerols as lithiated adducts by electrospray ionization mass spectrometry using low-energy collisionally activated dissociation on a triple stage quadrupole instrument. ...................................................................................

Classical trajectory calculations have been carried out to simulate the unimolecular decomposition of formaldehyde in the ground electronic state (Se). Global potential-energy surfaces were constructed using the empirical valence-bond (EVB) approach. Two sets of ab initio input were used to characterize two different EVB potential-energy surfaces, and trajectory calculations using one of these ...

Abstract The dynamics of photodissociation for vibrationally pre-excited deuterated pyrrole molecules is simulated using ab initio multiple cloning (AIMC) approach. Total kinetic energy release (TKER) spectra and dissociation times are calculated. results with without vibrational pre-excitation compared. Calculations show that, as expected, the additional fragments lower in mostly located upper...

Fast atom bombardment promotes condensation between trimethyl tetradecyl ammonium cations and the glycerol matrix. Bond formation at both the head and tail of the surfactant is demonstrated by low energy collision-induced dissociation (ClD) of deuterium-labeled precursors, with a preponderance of the reaction apparently occurring at the tail. Two distinct ClD pathways are identified for each ki...

The negative ion chemistry of five azine molecules has been investigated using the combined experimental techniques of negative ion photoelectron spectroscopy to obtain electron affinities (EA) and tandem flowing afterglow-selected ion tube (FA-SIFT) mass spectrometry to obtain deprotonation enthalpies (Δ(acid)H(298)). The measured Δ(acid)H(298) for the most acidic site of each azine species is...

A new MALDI-TOF/TOF system with monoisotopic precursor selection was applied to the analysis of triacylglycerols in an olive oil sample. Monoisotopic precursor selection made it possible to obtain product-ion mass spectra without interference from species that differed by a single double bond. Complete structure determination of all triacylglycerols, including structural isomers, was made possi...

Following core excitation in an isolated molecule, ultrafast dissociation of one particular chemical bond can occur, where "ultrafast" is defined as taking place during the lifetime of the core hole, of the order of few femtoseconds. The signature of such phenomenon can be observed in resonant Auger spectra following core excitation. We present here an investigation of ultrafast dissociation fo...