The UV photofragmentation spectroscopy of the metal dication complex [Mn(pyridine)₄]²⁺

[MLn]2+ doubly charged systems: modeling, bonding, life times and unimolecular reactivity

“…50 A similar competition between coulomb explosion processes and the loss of neutral fragments has also been reported for the reactions between Y 2+ and small alkanes. 42 For ethane both the dehydrogenation process (reaction (15)) and the hydride-transfer (reaction (16) Doubly charged species are also readily formed by direct ionization of neutral molecules or clusters of neutral molecules, either by photoionization techniques 193,194 or by collision with fast highly charged ions. [195][196][197][198] The latter techniques are actually a promising therapy for the treatment of malignant tumors through the induction of DNA damage.…”

Gas Phase UV Spectrum of a Cu(II)–Bis(benzene) Sandwich Complex: Experiment and Theory

“…However, if valid comparisons are to be made with their condensed phase analogues, then it is important to develop experimental methods that are capable of preparing metal–benzene complexes where the metal occupies a more common charge state [i.e., Fe(II), Cu(II), Ni(II), etc.]. In recent years suitable techniques have appeared, and a wide range of complexes containing first row transition metals in charge states commonly observed in condensed phase chemistry have been prepared and these include Mn(II), , Co(II), Fe(II), , and Cu(II). − These experiments are frequently done in association with ligands that occupy pivotal positions in traditional transition metal chemistry, such as H 2 O, NH 3 , pyridine, and bipyridine.…”

Ultraviolet Photofragmentation Spectroscopy of Alkaline Earth Dication Complexes with Pyridine and 4-Picoline (4-Methyl pyridine)

“…12 A similar combined theoretical and experimental study of [Mn(pyridine) 4 ] 2þ was far less conclusive in the assignment of spectroscopic transitions. 17 Although there was evidence of intraligand π* r π and π * r σ transitions, a quantitative assignment of metal-based transitions was not possible. 17 In part, the high density of transitions prevented their individual assignment by TDDFT theory, but there are also inherent problems in modeling electronic transitions in a d 5 complex with a singleexcitation theory.…”

“…17 Although there was evidence of intraligand π* r π and π * r σ transitions, a quantitative assignment of metal-based transitions was not possible. 17 In part, the high density of transitions prevented their individual assignment by TDDFT theory, but there are also inherent problems in modeling electronic transitions in a d 5 complex with a singleexcitation theory. 21 However, there were spectroscopic features that were common to both Mn 2þ and Zn 2þ complexes, and these helped toward a partial identification of electronic transitions.…”

“…In contrast, gas-phase spectroscopy has the advantage of allowing the study of isolated species independent of both solvent and counterion, and indeed for singly charged metal complexes a large catalogue of studies now exists at both infrared and UV/visible wavelengths. − When sufficient number densities can be generated, metal complexes can be studied via photodissociation/photodepletion methods using either infrared multiphoton excitation to generate vibrational spectra or single photon visible/UV excitation to give electronic spectra. However, the overwhelming majority of these gas-phase studies have focused on singly charged ions; − in contrast, dication metal complexes, while not without examples − have received far less attention. This observation differs markedly from the circumstances that prevail in nature, where +2 is the most common charge state found for metal ions…”