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Although the highest possible oxidation states of all transition elements are rare, they are not only of fundamental interest but also relevant as potentially strong oxidizing agents. In general, the highest oxidation states are found in the electron‐rich late transition elements of groups 7–9 of the periodic table. Rhodium is the first element of the 4d transition metal series for which the highest known oxidation state does not equal its group number of 9, but reaches only a significantly lower value of +6 in exceptional cases. Higher oxidation states of rhodium have remained elusive so far. In a combined mass spectrometry, X‐ray absorption spectroscopy, and quantum‐chemical study of gas‐phaseRhOn+ (n=1–4), we identify RhO3+ as the 1A1' trioxidorhodium(VII) cation, the first chemical species to contain rhodium in the +7 oxidation state, which is the third‐highest oxidation state experimentally verified among all elements in the periodic table. [ABSTRACT FROM AUTHOR]

Obwohl selten, sind die höchsten Oxidationsstufen im Periodensystem nicht nur von grundlegendem Interesse, sondern auch als starke Oxidationsmittel relevant. Die höchsten Oxidationsstufen finden sich für die elektronenreichen späten Übergangsmetalle der Gruppen 7–9 des Periodensystems. Rhodium ist das erste Element aus der Reihe der 4d Übergangsmetalle, für das die höchste bekannte Oxidationsstufe nicht mehr mit seiner Gruppennummer von 9 übereinstimmt, sondern nur den deutlich niedrigeren Wert von +6 annimmt, und auch dies nur in Ausnahmefällen. Höhere Oxidationsstufen des Rhodiums blieben bisher verborgen. Mittels Kombination von massenspektrometrischen, röntgenabsorptionsspektroskopischen und quantenchemischen Untersuchungen von Gasphasenionen der Art RhOn+ , (n=1–4), identifizieren wir RhO3+ als 1A1' Trioxidorhodium(VII)‐Kation, welches das erste Beispiel von Rhodium in seiner höchsten Oxidationstufe +7, und gleichzeitig in der dritthöchsten experimentell bestätigten Oxidationsstufe des Periodensystems, darstellt. [ABSTRACT FROM AUTHOR]

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Although the highest possible oxidation states of all transition elements are rare, they are not only of fundamental interest but also relevant as potentially strong oxidizing agents. In general, the highest oxidation states are found in the electron‐rich late transition elements of groups 7–9 of the periodic table. Rhodium is the first element of the 4d transition metal series for which the highest known oxidation state does not equal its group number of 9, but reaches only a significantly lower value of +6 in exceptional cases. Higher oxidation states of rhodium have remained elusive so far. In a combined mass spectrometry, X‐ray absorption spectroscopy, and quantum‐chemical study of gas‐phaseRhOn+ (n=1–4), we identify RhO3+ as the 1A1' trioxidorhodium(VII) cation, the first chemical species to contain rhodium in the +7 oxidation state, which is the third‐highest oxidation state experimentally verified among all elements in the periodic table. [ABSTRACT FROM AUTHOR]

Pseudo‐tetrahedral nitrido trifluorides N≡MF3 (M=Fe, Ru, Os) and square pyramidal nitrido tetrafluorides N≡MF4 (M=Ru, Os) were formed by free‐metal‐atom reactions with NF3 and subsequently isolated in solid neon at 5 K. Their IR spectra were recorded and analyzed aided by quantum‐chemical calculations. For a d2 electron configuration of the N≡MF3 compounds in C3v symmetry, Hund's rule predict a high‐spin 3A2 ground state with two parallel spin electrons and two degenerate metal d(δ)‐orbitals. The corresponding high‐spin 3A2 ground state was, however, only found for N≡FeF3, the first experimentally verified neutral nitrido FeVI species. The valence‐isoelectronic N≡RuF3 and N≡OsF3 adopt different angular distorted singlet structures. For N≡RuF3, the triplet 3A2 state is only 5 kJ mol−1 higher in energy than the singlet 1A′ ground state, and the magnetically bistable molecular N≡OsF3 with two distorted near degenerate 1A′ and 3A" electronic states were experimentally detected at 5 K in solid neon. [ABSTRACT FROM AUTHOR]

Pseudo‐tetrahedral nitrido trifluorides N≡MF3 (M=Fe, Ru, Os) and square pyramidal nitrido tetrafluorides N≡MF4 (M=Ru, Os) were formed by free‐metal‐atom reactions with NF3 and subsequently isolated in solid neon at 5 K. Their IR spectra were recorded and analyzed aided by quantum‐chemical calculations. For a d2 electron configuration of the N≡MF3 compounds in C3v symmetry, Hund's rule predict a high‐spin 3A2 ground state with two parallel spin electrons and two degenerate metal d(δ)‐orbitals. The corresponding high‐spin 3A2 ground state was, however, only found for N≡FeF3, the first experimentally verified neutral nitrido FeVI species. The valence‐isoelectronic N≡RuF3 and N≡OsF3 adopt different angular distorted singlet structures. For N≡RuF3, the triplet 3A2 state is only 5 kJ mol−1 higher in energy than the singlet 1A′ ground state, and the magnetically bistable molecular N≡OsF3 with two distorted near degenerate 1A′ and 3A" electronic states were experimentally detected at 5 K in solid neon. [ABSTRACT FROM AUTHOR]

The fluoronitrenoid metal complexes FNCoF2 and FNRhF2 as well as the first ternary RhVI and IrVI complexes NIrF3 and NRhF3 are described. They were obtained by the reaction of excited Group‐9 metal atoms with NF3 and their IR spectra, isolated in solid rare gases (neon and argon), were recorded. Aided by the observed 14/15N isotope shifts and quantum‐chemical predictions, all four stretching fundamentals of the novel complexes were safely assigned. The F−N stretching frequencies of the fluoronitrenoid complexes FNCoF2 (1056.8 cm−1) and FNRhF2 (872.6 cm−1) are very different and their N−M bonds vary greatly. In FNCoF2, the FN ligand is singly bonded to Co and bears considerable iminyl/nitrene radical character, while the N−Rh bond in FNRhF2 is a strong double bond with comparatively strong σ‐ and π‐bonds. The anticipated rearrangement of FNCoF2 to the nitrido CoVI complex is predicted to be endothermic and was not observed. [ABSTRACT FROM AUTHOR]

The fluoronitrenoid metal complexes FNCoF2 and FNRhF2 as well as the first ternary RhVI and IrVI complexes NIrF3 and NRhF3 are described. They were obtained by the reaction of excited Group‐9 metal atoms with NF3 and their IR spectra, isolated in solid rare gases (neon and argon), were recorded. Aided by the observed 14/15N isotope shifts and quantum‐chemical predictions, all four stretching fundamentals of the novel complexes were safely assigned. The F−N stretching frequencies of the fluoronitrenoid complexes FNCoF2 (1056.8 cm−1) and FNRhF2 (872.6 cm−1) are very different and their N−M bonds vary greatly. In FNCoF2, the FN ligand is singly bonded to Co and bears considerable iminyl/nitrene radical character, while the N−Rh bond in FNRhF2 is a strong double bond with comparatively strong σ‐ and π‐bonds. The anticipated rearrangement of FNCoF2 to the nitrido CoVI complex is predicted to be endothermic and was not observed. [ABSTRACT FROM AUTHOR]

The fluoronitrenoid metal complexes FNCoF2 and FNRhF2 as well as the first ternary RhVI and IrVI complexes NIrF3 and NRhF3 are described. They were obtained by the reaction of excited Group‐9 metal atoms with NF3 and their IR spectra, isolated in solid rare gases (neon and argon), were recorded. Aided by the observed 14/15N isotope shifts and quantum‐chemical predictions, all four stretching fundamentals of the novel complexes were safely assigned. The F−N stretching frequencies of the fluoronitrenoid complexes FNCoF2 (1056.8 cm−1) and FNRhF2 (872.6 cm−1) are very different and their N−M bonds vary greatly. In FNCoF2, the FN ligand is singly bonded to Co and bears considerable iminyl/nitrene radical character, while the N−Rh bond in FNRhF2 is a strong double bond with comparatively strong σ‐ and π‐bonds. The anticipated rearrangement of FNCoF2 to the nitrido CoVI complex is predicted to be endothermic and was not observed. [ABSTRACT FROM AUTHOR]

The fluoronitrenoid metal complexes FNCoF2 and FNRhF2 as well as the first ternary RhVI and IrVI complexes NIrF3 and NRhF3 are described. They were obtained by the reaction of excited Group‐9 metal atoms with NF3 and their IR spectra, isolated in solid rare gases (neon and argon), were recorded. Aided by the observed 14/15N isotope shifts and quantum‐chemical predictions, all four stretching fundamentals of the novel complexes were safely assigned. The F−N stretching frequencies of the fluoronitrenoid complexes FNCoF2 (1056.8 cm−1) and FNRhF2 (872.6 cm−1) are very different and their N−M bonds vary greatly. In FNCoF2, the FN ligand is singly bonded to Co and bears considerable iminyl/nitrene radical character, while the N−Rh bond in FNRhF2 is a strong double bond with comparatively strong σ‐ and π‐bonds. The anticipated rearrangement of FNCoF2 to the nitrido CoVI complex is predicted to be endothermic and was not observed. [ABSTRACT FROM AUTHOR]

Uranium and thorium hydrides are known as functional groups for ligand stabilized complexes and as isolated molecules under matrix isolation conditions. Here, the new molecular products of the reactions of laser‐ablated U and Th atoms with HCl and with HBr, namely HUCl, HUBr and HThCl, HThBr, based on their mid and far infrared spectra in solid argon, are reported. The assignment of these species is based on the close agreement between observed and calculated vibrational frequencies. The H−U and U−35Cl stretching modes of HUCl were observed at 1404.6 and 323.8 cm−1, respectively. Using DCl instead to form DUCl gives absorption bands at 1003.1 and 314.7 cm−1. The corresponding bands of HThCl are 1483.8 (H−Th) and 1058.0 (D−Th), as well as 340.3 and 335.8 cm−1 (Th−35Cl), respectively. HUBr is observed at 1410.6 cm−1 and the BP86 computed shift from HUCl is 6.2 cm−1 in excellent agreement. The U−H stretching frequency increases from 1383.1 (HUF), 1404.6 (HUCl), 1410.6 (HUBr) to 1423.6 cm−1 (UH) as less electronic charge is removed from the U−H bond by the less electronegative substituent. These U−H stretching frequencies follow the Mayer bond orders calculated for the three HUX molecules. A similar trend is found for the Th counterparts. Additional absorptions are assigned to the H2AnX2 molecules (An=U, Th, X=Cl, Br) formed by the exothermic reaction of a second HX molecule with the above primary products. Uranium and thorium hydrides are known as functional groups for ligand stabilized complexes and as isolated molecules under matrix isolation conditions. Here, the new molecular products of the reactions of laser‐ablated U and Th atoms with HCl and with HBr, namely HUCl, HUBr and HThCl, HThBr, based on their mid and far infrared spectra in solid argon, is reported. [ABSTRACT FROM AUTHOR]

Transition metal complexes bearing terminal oxido ligands are quite common, yet group 11 terminal oxo complexes remain elusive. Here we show that excited coinage metal atoms M (M = Au, Ag, Cu) react with OF2 to form hypofluorites FOMF and group 11 oxygen metal fluorides OMF2, OAuF and OAgF. These compounds have been characterized by IR matrixisolation spectroscopy in conjunction with state-of-the-art quantum-chemical calculations. The oxygen fluorides are formed by photolysis of the initially prepared hypofluorites. The linear molecules OAgF and OAuF have a ³Σ -- ground state with a biradical character. Two unpaired electrons are located mainly at the oxygen ligand in antibonding O--M π* orbitals. For the ²B2 ground state of the OMIIIF2 compounds only an O--M single bond arises and a significant spin-density contribution was found at the oxygen atom as well. [ABSTRACT FROM AUTHOR]

The group 10 transition metal atoms Pd and Pt react with nitrogen trifluoride (NF 3 ) forming N-coordination M(NF 3 ) complexes in solid neon and argon matrices. The M(NF 3 ) complexes isomerize to more stable fluoronitrenoid FNMF 2 isomers via fluorine migration upon blue LED ( λ = 470 nm) light irradiation. These products are characterized on the basis of infrared absorption spectroscopy with isotopic substitutions and theoretical frequency calculations. The analysis of the electronic structure of nitrogen trifluoride complexes indicates that the bonding between metal and nitrogen trifluoride can be described as σ donation from the HOMO of nitrogen trifluoride to the empty metal d z 2 orbital and π back-donation from the metal d xz / yz orbitals to the LUMO of nitrogen trifluoride, the latter of which stabilized the metal ligand bond and destabilized the ligand N-F bond. In FNMF 2 , the FN ligand doubly bonded to the metal and bear imido character., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Although the highest possible oxidation states of all transition elements are rare, they are not only of fundamental interest but also relevant as potentially strong oxidizing agents. In general, the highest oxidation states are found in the electron-rich late transition elements of groups 7-9 of the periodic table. Rhodium is the first element of the 4d transition metal series for which the highest known oxidation state does not equal its group number of 9, but reaches only a significantly lower value of +6 in exceptional cases. Higher oxidation states of rhodium have remained elusive so far. In a combined mass spectrometry, X-ray absorption spectroscopy, and quantum-chemical study of gas-phase R h O n + (n=1-4), we identify R h O 3 + as the 1 A 1 ' trioxidorhodium(VII) cation, the first chemical species to contain rhodium in the +7 oxidation state, which is the third-highest oxidation state experimentally verified among all elements in the periodic table., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Pseudo-tetrahedral nitrido trifluorides N≡MF 3 (M=Fe, Ru, Os) and square pyramidal nitrido tetrafluorides N≡MF 4 (M=Ru, Os) were formed by free-metal-atom reactions with NF 3 and subsequently isolated in solid neon at 5 K. Their IR spectra were recorded and analyzed aided by quantum-chemical calculations. For a d 2 electron configuration of the N≡MF 3 compounds in C 3v symmetry, Hund's rule predict a high-spin 3 A 2 ground state with two parallel spin electrons and two degenerate metal d(δ)-orbitals. The corresponding high-spin 3 A 2 ground state was, however, only found for N≡FeF 3 , the first experimentally verified neutral nitrido Fe VI species. The valence-isoelectronic N≡RuF 3 and N≡OsF 3 adopt different angular distorted singlet structures. For N≡RuF 3 , the triplet 3 A 2 state is only 5 kJ mol -1 higher in energy than the singlet 1 A' ground state, and the magnetically bistable molecular N≡OsF 3 with two distorted near degenerate 1 A' and 3 A" electronic states were experimentally detected at 5 K in solid neon., (© 2021 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

The fluoronitrenoid metal complexes FNCoF 2 and FNRhF 2 as well as the first ternary Rh VI and Ir VI complexes NIrF 3 and NRhF 3 are described. They were obtained by the reaction of excited Group-9 metal atoms with NF 3 and their IR spectra, isolated in solid rare gases (neon and argon), were recorded. Aided by the observed 14/15 N isotope shifts and quantum-chemical predictions, all four stretching fundamentals of the novel complexes were safely assigned. The F-N stretching frequencies of the fluoronitrenoid complexes FNCoF 2 (1056.8 cm -1 ) and FNRhF 2 (872.6 cm -1 ) are very different and their N-M bonds vary greatly. In FNCoF 2 , the FN ligand is singly bonded to Co and bears considerable iminyl/nitrene radical character, while the N-Rh bond in FNRhF 2 is a strong double bond with comparatively strong σ- and π-bonds. The anticipated rearrangement of FNCoF 2 to the nitrido Co VI complex is predicted to be endothermic and was not observed., (© 2020 The Authors. Published by Wiley-VCH GmbH.)

Invited for the cover of this issue is the group of Sebastian Riedel at Freie Universität Berlin. The image depicts an iridium rainbow reacting with dinitrogen to form iridium-nitrogen compounds. Read the full text of the article at 10.1002/chem.201905514., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We report on the solid-state structures of bis(nonafluoro-tert-butyl) peroxide [(F 3 C) 3 CO] 2 and bis(undecafluoro-2-methyl-2-butyl) peroxide [(C 2 F 5 )(F 3 C) 2 CO] 2 . These peroxides were prepared from the corresponding hypofluorites and fluorinated silver wool. The solid-state structures obtained after in situ crystallisation show unusual COOC dihedral angles of 180°, as well as elongated O-O bonds because of the bulky perfluorinated alkyl groups. The perfluorinated alkyl peroxides are insensitive to both impact (>40 J) and friction (>360 N), and resistant towards mineral acids (HX; X=F, Cl, Br) and elemental halogens (X 2 ). Ferrocene is oxidized by [(F 3 C) 3 CO] 2 to [Fe III Cp 2 ][OC(CF 3 ) 3 ]., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Uranium and thorium hydrides are known as functional groups for ligand stabilized complexes and as isolated molecules under matrix isolation conditions. Here, the new molecular products of the reactions of laser-ablated U and Th atoms with HCl and with HBr, namely HUCl, HUBr and HThCl, HThBr, based on their mid and far infrared spectra in solid argon, are reported. The assignment of these species is based on the close agreement between observed and calculated vibrational frequencies. The H-U and U- 35 Cl stretching modes of HUCl were observed at 1404.6 and 323.8 cm -1 , respectively. Using DCl instead to form DUCl gives absorption bands at 1003.1 and 314.7 cm -1 . The corresponding bands of HThCl are 1483.8 (H-Th) and 1058.0 (D-Th), as well as 340.3 and 335.8 cm -1 (Th- 35 Cl), respectively. HUBr is observed at 1410.6 cm -1 and the BP86 computed shift from HUCl is 6.2 cm -1 in excellent agreement. The U-H stretching frequency increases from 1383.1 (HUF), 1404.6 (HUCl), 1410.6 (HUBr) to 1423.6 cm -1 (UH) as less electronic charge is removed from the U-H bond by the less electronegative substituent. These U-H stretching frequencies follow the Mayer bond orders calculated for the three HUX molecules. A similar trend is found for the Th counterparts. Additional absorptions are assigned to the H 2 AnX 2 molecules (An=U, Th, X=Cl, Br) formed by the exothermic reaction of a second HX molecule with the above primary products., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Solutions of azidomethylidenemalononitrile were photolyzed at low temperatures to produce the corresponding 2H-azirine and tricyanomethane, which were analyzed by low-temperature NMR spectroscopy. The latter product was also observed after short thermolysis of the azide precursor in solution whereas irradiation of the azide isolated in an argon matrix did not lead to tricyanomethane, but to unequivocal detection of the tautomeric ketenimine by IR spectroscopy for the first time. When the long-known "aquoethereal" greenish phase generated from potassium tricyanomethanide, dilute sulfuric acid, and diethyl ether was rapidly evaporated and sublimed, a mixture of hydronium tricyanomethanide and tricyanomethane was formed instead of the previously claimed ketenimine tautomer. Under special conditions of sublimation, single crystals of tricyanomethane could be isolated, which enabled the analysis of the molecular structure by X-ray diffraction., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)