Reactivity of transition metal fluorides. Vi. Halogen-exchange reactions of vanadium pentafluoride

Abstract

In an earlier paper in this series, it was indicated that halogen-exchange reactions between vanadium pentafluoride and covalent chlorides are very complex. The present work shows that the results may be rationalized on the basis of an initial halogen-exchange reaction, producing vanadium tetrachloride, chlorine, and the appropriate fluoride. As soon as some vanadium tetrachloride is formed, competitive reactions commence, thus making the exact elucidation of the reaction schemes very difficult. In order to clarify the situation, some reactions of vanadium tetrachloride itself were studied.

The Highest Oxidation State of Rhodium: Rhodium(VII) in [RhO3]+

“…The formal concept of oxidation states is of fundamental importance in chemistry to characterize properties of elements in compounds [1, 2] . The search for compounds with transition metals in their highest oxidation states [1, 3–6] is not only of academic interest, but complexes with metal centers in unusually high oxidation states are of particular relevance in the context of strong oxidants [7–9] or fluorinating agents, [10–13] in catalytic processes, [14–19] and as intermediates in key reactions [20, 21] …”

“…The formal concept of oxidation states is of fundamental importance in chemistry to characterize properties of elements in compounds. [1,2] The search for compounds with transition metals in their highest oxidation states [1,[3][4][5][6] is not only of academic interest, but complexes with metal centers in unusually high oxidation states are of particular relevance in the context of strong oxidants [7][8][9] or fluorinating agents, [10][11][12][13] in catalytic processes, [14][15][16][17][18][19] and as intermediates in key reactions. [20,21] Of the 4d transition elements, ruthenium, in the form of tetraoxido ruthenium(VIII), [22] is the last element for which the highest experimentally verified oxidation state corresponds to its group number.…”

Die höchste Oxidationsstufe von Rhodium: Rhodium(VII) in [RhO3]+

“…Chemie für die Charakterisierung der Eigenschaften der Elemente in Verbindungen von grundlegender Bedeutung. [1,2] Dabei ist die Suche nach Übergangsmetallelementen in ihren höchsten Oxidationsstufen nicht nur von akademischem Interesse, vielmehr sind Komplexe von Metallzentren in ungewöhnlich hohen Oxidationsstufen auch als starke Oxidationsmittel, [7][8][9] Fluoridierungsmittel, [10][11][12][13] in katalytischen Prozessen, [14][15][16][17][18][19] oder als reaktive Zwischenstufen wichtiger Reaktionen von Bedeutung. [20,21] Innerhalb der 4d Übergangselemente stellt Ruthenium, in Form des Tetraoxidoruthenium(VIII), [22] das letzte Element dar, für welches die höchste experimentell bestätigte Oxidationsstufe der Gruppennummer entspricht.…”

“…Das formale Konzept der Oxidationsstufen ist in der Chemie für die Charakterisierung der Eigenschaften der Elemente in Verbindungen von grundlegender Bedeutung [1, 2] . Dabei ist die Suche nach Übergangsmetallelementen in ihren höchsten Oxidationsstufen nicht nur von akademischem Interesse, vielmehr sind Komplexe von Metallzentren in ungewöhnlich hohen Oxidationsstufen auch als starke Oxidationsmittel, [7–9] Fluoridierungsmittel, [10–13] in katalytischen Prozessen, [14–19] oder als reaktive Zwischenstufen wichtiger Reaktionen von Bedeutung [20, 21] …”