Chlorophyll and pheophytin protonated and deprotonated ions: Observation and theory.

Pheophytin a and chlorophyll a have been investigated by electrospray mass spectrometry in the positive and negative modes, in view of the importance of the knowledge of their properties in photosynthesis. Pheophytin and chlorophyll are both observed intensely in the protonated mode, and their main fragmentation route is the loss of their phytyl chain. Pheophytin is observed intact in the negative mode, while under collisions, it is primarily cleaved beyond the phytyl chain and loses the attaching propionate group.

Experimental and theoretical study of resonant core-hole spectroscopies of gas-phase free-base phthalocyanine.

We studied N 1s inner-shell processes of the free base Phthalocyanine molecule, HPc, in the gas-phase. This complex organic molecule contains three different nitrogen sites defined by their covalent bonds. We identify the contribution of each site in ionized, core-shell excited or relaxed electronic states by the use of different theoretical methods.

Excited state dynamics of normal dithienylethene molecules either isolated or deposited on an argon cluster.

Real-time dynamics of the electronically excited open-ring isomer of 1,2-bis(2-methylbenzo[]thiophen-3-yl)perfluorocyclopentene (BTF6) and 1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)perfluorocyclopentene (PTF6) molecules was investigated using a set-up that associates a molecular beam, femtosecond lasers and velocity map imaging. The molecules were either free in the gas phase or bound to an argon cluster. DFT and TDDFT calculations were performed on BTF6.

Consistent characterization of the electronic ground state of iron(II) phthalocyanine from valence and core-shell electron spectroscopy.

We studied the iron(II) phthalocyanine molecule in the gas-phase. It is a complex transition organometallic compound, for which, the characterization of its electronic ground state is still debated more than 50 years after the first published study. Here, we show that to determine its electronic ground state, one needs a large corpus of data sets and a consistent theoretical methodology to simulate them.

Time-Resolved Observation of the Solvation Dynamics of a Rydberg Excited Molecule Deposited on an Argon Cluster. II. DABCO at Long Time Delays.

The real-time dynamics of DABCO-argon clusters is investigated in a femtosecond pump-probe experiment where the pump excites DABCO to the S state within the argon cluster. The probe operates by photoionization and documents the energy and angular distributions of the resulting photoelectrons. The present work complements a previous work from our group [Awali , 2014, 16, 516-526] where this dynamics was probed at short time, up to 4 ps after the pump pulse.