Multiple Photochemical Reaction Pathways in a Ni(II) Coordination Compound

Abstract

The gas-phase photofragmentation of the mixed-ligand coordination compound trans-bis(trifluoroacetato)bis(N,N'-dimethylethylenediamine)nickel(II) (Ni(tfa)2(dmen)2) detected via time-of-flight mass spectrometry is reported. In contrast to most gas-phase studies of metal-containing compounds where fragmentation of weak metal-ligand bonds dominates, the data here show that the dmen ligands fragment while still coordinated to nickel. The manner in which these ligands fragment is highly specific, leading to mono- and diimine species that remain coordinated to nickel. Uncoordinated mono- and diimine species and various small dmen fragments are also observed with high intensities in the low mass region of the spectra. NiF+, a fragment that is formed by fluorine abstraction, is always observed, even though no Ni-F bonds exist in the starting material.

Nickel, palladium and platinum

“…The gas-phase photofragmentation of [Ni(tfa) 2 (L 1 ) 2 )] [L 1 = N,N 0 -dimethylethylenediamine] has been used to show that fragmentation of weak metal-ligand bonds dominate leading to mono-and di-imine species that remain coordinated although high intensities of NiF + , a fragment formed by fluorine abstraction from tfa, is always observed. 8 The first nickel-boryl complex [Ni{N(2-P( i Pr) 2 -p-tol) 2 }-(BO 2 C 6 H 4 )] has been structurally characterized with a PNP pincer ligand. 9 The Ni nitrosyl compounds [Ni(L 2 )(NO)] of the tridentate nitrogen and selenium ligands tris (3,5-dimethylpyrazolyl)hydroborate and tris(2-seleno-1-mesitylimidazolyl)hydroborate (L 2 ) complexes have been structurally characterized; theoretical studies indicate that the nitrosyl behaves as a trivalent ligand with multiple Ni-N bond character.…”

“…But this does not diminish their importance in many areas of modern chemistry such as catalysis, clusters and nanoparticles, metal organic frameworks (MOF) and medicinal chemistry, which are discussed elsewhere. Attention is drawn to a review which highlights the theoretical bonding properties of N-heterocyclic carbenes coordinated to electron-rich d 8 metal centres 4 and an article discussing the theory and application of 195 Pt NMR spectroscopy. 5…”

Photofragmentation Pathways and Photodeposition of Nanoparticles from a Gas Phase Copper-Containing Precursor

“…Electrochem photofragmentation patterns. [23][24][25][26][27][28][29][30][31][32] Although the atomic metal species tend to be the dominant products, other metalcontaining photofragments can form as well. The formation of these fragments can be enhanced under certain conditions such as optimal wavelengths and laser power.…”

“…The formation of these fragments can be enhanced under certain conditions such as optimal wavelengths and laser power. 23,24,[27][28][29][30][31] A correlation between the photodeposits and these photofragmentation patterns would prove to be useful. Although many studies have analyzed the photodeposited copper films, research about the photochemical mechanisms leading to the formation of the deposits is scarce.…”

“…Recent studies in gas phase photochemistry of metal-containing chemical vapor deposition (CVD) precursors monitored by mass spectrometry have uncovered unique photofragmentation patterns. − Although the atomic metal species tend to be the dominant products, other metal-containing photofragments can form as well. The formation of these fragments can be enhanced under certain conditions such as optimal wavelengths and laser power. ,,− A correlation between the photodeposits and these photofragmentation patterns would prove to be useful.…”