VIBRATIONAL SPECTRA AND STRUCTURES OF METAL (Ti, Ni, Pd) MONONITROSYL COMPLEXES. AN IR MATRIX ISOLATION AND DFT STUDY
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Date
2001
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Ohio State University
Abstract
The infrared spectra of nickel, palladium and titanium mononitrosyl isolated in solid argon at low temperature have been reinvestigated. Two kinds of mechanisms of reactions metal-NO have been observed: In the $Ni + NO$ and $Pd + NO$ experiments, concentration and photochemical studies demonstrate the existence of two isomeric forms of NiNO and only one isomeric form of PdNO with a bent structure. In the NiNO complex case, analyses of the $^{58}Ni/^{60}Ni$, $^{14}N/^{15}N$ and $^{16}O/^{18}O$ isotopic effects indicate that a first form has an end-on bent configuration (as with palladium), and a second form has a cyclic structure, in which the NO ligand is significantly more perturbed. Reversible conversion is achieved by photo selective UV-Visible excitation. In the $Ti + NO$ experiments, no side-bonded TiNO form has been observed and insertion reaction doesn't need any appreciable activation energy. All three modes of the $N-Ti-O$ insertion product are detected. Comparisons between the $Ni+NO$, $Pd+NO$ and $Ti+NO$ systems are presented. Density Functional calculations of the geometrical, electronic and vibrational properties of these isomers are also presented and compared to the experimental values. Isomerization energies have been estimated.
Description
Author Institution: UMR7075 CNRS-P6, Universit\'e Pierre et Marie Curie; LAPDIR/Spectroschimie Mol\'eculaire, UMR7075 CNRS-P6, Universit\'e Pierre et Marie Curie