Synthesis, characterization, and chemistry of pentacarbonylnitrosylvanadium, V(CO)5NO, a remarkably reactive relative of hexacarbonylchromium

Vanadium Carbonyl Nitrosyl Compounds: The Carbonyl Nitrosyl Chemistry of an Oxophilic Early Transition Metal

“…The calculated ν(CO) frequencies for V(NO)(CO) 5 fall within 40 cm -1 of the experimental values [3] on the high side. However, the calculated ν(NO) frequency for V(NO)(CO) 5 at 1787 cm -1 lies 92 cm -1 above the experimental ν(NO) frequency [3] of 1695 cm -1 . Two structures are predicted for V(NO)(CO) 4 .…”

“…[1] The most extensive such isoelectronic series consists of the tetrahedral molecules Ni(CO) 4 Ǟ Co(NO)(CO) 3 Ǟ Fe(NO) 2 (CO) 2 Ǟ Mn(NO) 3 CO Ǟ Cr(NO) 4 . The extent of this tetrahedral isoelectronic series is particularly surprising because Ni(CO) 4 is by far the least thermally stable of the known homoleptic mononuclear carbonyl compounds of the first-row transition metals.…”

“…What is even more striking is the observation that the only known metal carbonyl nitrosyl isoelectronic with the very stable octahedral Cr(CO) 6 is the vanadium derivative V(NO)(CO) 5 . However, whereas Cr(CO) 6 is the most stable known homoleptic first-row transition metal carbonyl derivative, being stable enough for steam distillation in air, the isoelectronic V(NO)(CO) 5 is reported [3] to decompose at -10°C. Furthermore, V(NO)(CO) 5 is much more reactive towards carbonyl substitution reactions [3] than Cr(CO) 6 .…”

“…However, whereas Cr(CO) 6 is the most stable known homoleptic first-row transition metal carbonyl derivative, being stable enough for steam distillation in air, the isoelectronic V(NO)(CO) 5 is reported [3] to decompose at -10°C. Furthermore, V(NO)(CO) 5 is much more reactive towards carbonyl substitution reactions [3] than Cr(CO) 6 . Thus, V(NO)(CO) 5 reacts with ligands such as phosphanes, trimethylamine, and iodide at temperature in the range -30°t o 0°C to give carbonyl substitution products whereas Cr(CO) 6 generally requires temperatures in excess of 100°C for analogous substitution reactions.…”

Redox Properties of Vanadium Ions in SBA-15-Supported Vanadium Oxide: An FTIR Spectroscopic Study

“…18 The V 5+ sites are not reduced through treating the For applications in partial oxidation catalysis, it is expected that the transfer of oxygen to the substrate is ratelimiting and not the catalyst reoxidation. Indeed, Argyle et al 50 found that the rate constant for reoxidation of VxOy/Al 2 O 3 catalyst during propane oxidative dehydrogenation is 3-5 times larger than that for the C-H bond activation reduction step. In the light of our data, the release of oxygen, which is tightly bound to the vanadium, will pose a significant activation barrier.…”