Essence of others works

Essence of others works:

1.       Source [ C:\Users\Andy\hzhang\Projects\Vanadium\literature\05302013 ]

Energetics of the Ligated Vanadium Dictions VO²⁺, VOH²⁺, and [V, O, H2]²⁺

Point1: Experiment: Charge-stripping mass spectrometry

Point2: Abstract: According to the theoretical results, [V (OH₂)] ²⁺ is also a thermochemically stable dication, whereas [HVOH] ²⁺ is suggested to be metastable.

Point3: [M (OH₂)] ²⁺, for larger values of n, these species can easily be generated from solution by means of electrospray ionization. A key aspect of these isolated dications on the dilute gas phase concerns their stability with respect to the relevant dissociation and charge-separation asymptotes.   

Point4: for [M (OH₂)] ²⁺, three types of fragmentation can occur, similar schemes apply for metal dications with other open- or closed- shell ligands.

Ligand Evaporation: [M (OH₂) _n] ²⁺ à [M (OH₂) _n-1 ] ²⁺ + H₂O

Electron Transfer: [M (OH₂) _n] ²⁺ à [M (OH₂) _n-1 ] ²⁺ + H₂O^+.

Proton Transfer: [M (OH₂) _n] ²⁺ à [M (OH)(OH₂) _n-2 ] ²⁺ + H₃O⁺

Rules: For large n, the evaporation of water predominates. The smaller the number of ligands n, and the larger the ionization energy, IE(M⁺), [large ionization energy means it needs more energy to release one electron from M⁺ to form M²⁺ ], the more likely become the competing electron- and proton-transfer reactions.

Point5: experiment

The monocationic precursors were generated via two independent routes: a) fast-atom bombardment of an aqueous slurry of V₂O₅; and b) electron ionization of trimethoxy vanadate, OV(OCH₃)₃

Armentrout，1994，JCP，98，7538-7544

Point 1: These ideas show that if the metal 4s orbital (and to a lesser extent the 3dσ) is occupied, the interaction of the metal ion with water will be repulsive at short range because the 4s (3dσ) orbital correlates to an anti-bonding orbital of the intermediate.  Oxidative addition of O-D to a metal center can be achieved by donation of electrons in σ bonding orbitals into empty 4s and 3dσ orbitals on the metal and molecular fragments and back-donation of metal 3dπ electron into σ* anti-bonding orbitals. This increases the electron density between the metal and molecular fragments and also lengthens the O-D bond.