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Terminal oxo compounds of high-valent late transition metals attracted attention because of their peculiar metal–oxygen bond in which the oxo ligand exhibits an electrophilic and distinct radical oxyl (O˙−) rather than the commonly expected nucleophilic (O2−) character. These properties confer the late transition metal oxo compounds their promising high reactivity in oxidation reactions, as well as H-atom transfer (HAT) and O-atom transfer (OAT) reactions. On the other hand, because of their highly reactive nature, direct spectroscopic evidence especially for high-valent nickel oxo compounds is rare. In this work, we report on linear oxo monofluorides OMF (C∞v) and difluorides OMF2 (C2v) of the group 10 metal atoms M = Ni, Pd and Pt, as well as on the hypofluorite FOPdF (Cs) and the oxo trifluoride OPtF3 (C2v). These molecules were prepared by the reaction of the metal atoms with gaseous OF2 and isolated in solid Ne and Ar matrices. They have been investigated by a joint analysis of IR matrix isolation spectroscopy and electronic structure calculations at the DFT, CCSD(T), as well as CASPT2 and MRCI levels of theory. The linear OMF molecules have 4Σ− ground states and bear a terminal oxyl radical ligand. The oxo difluorides have planar T-shaped structures in the 3A2 electronic states. The terminal oxo ligand in these difluorides also carries large spin densities of ≥1.0. A contradiction about the electronic ground state for the recently reported ONiF2 [Wei et al., Inorg. Chem., 2019, 58, 9796–9810] could be solved experimentally by the observation of a more complete vibrational spectrum. The relationship between the electron and spin population on the oxo ligand in the group 10 transition metal oxofluorides and related compounds will be discussed. Remarkable differences were found for the metal–oxygen bonds in ONiF2 and OCuF2. The continuous transition from a predominantly ionic to an inverted ligand field is shown by comparing the linear oxo monofluorides of group 10 (O[10]F), with the difluorides of group 9 (F[9]F) and the isoelectronic dioxides of group 11 (O[11]O).

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

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., The fluoronitrenoid metal complexes FNCoF2 and FNRhF2 as well as the first ternary RhVI and IrVI complexes NIrF3 and NRhF3 are reported. They were obtained by the reaction of excited Group‐9 metal atoms with NF3 and their IR spectra, isolated in solid rare gases, were recorded.

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 phaseurn x wiley 14337851 media anie202207688 anie202207688 math 0001 n 1 4 , we identify urn x wiley 14337851 media anie202207688 anie202207688 math 0002 as the urn x wiley 14337851 media anie202207688 anie202207688 math 0003 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

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 H2 AnX2 molecules (An=U, Th, X=Cl, Br) formed by the exothermic reaction of a second HX molecule with the above primary products.

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 C 3v 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., In different states: Molecular hexavalent group 8 nitrido fluorides feature different electronic ground‐state d2 configurations in solid Ne matrices. While NFeF3 adopts a high symmetry structure, the heavier homologues are subject to symmetry lowering and spin‐crossover caused by a pseudo Jahn−Teller effect “hidden” in the excited states. For NOsF3 two coexisting high‐ and low‐spin structures show triplet–singlet spin crossover and magnetic bistability. A weakened covalent N−Fe bond in NFeVIF3 indicates the non‐innocent character of the nitrido ligand.

The reaction of laser‐ablated iridium atoms with dinitrogen molecules and nitrogen atoms yield several neutral and ionic iridium dinitrogen complexes such as Ir(N2), Ir(N2)+, Ir(N2)2, Ir(N2)2 −, IrNNIr, as well as the nitrido complexes IrN, Ir(N)2 and IrIrN. These reaction products were deposited in solid neon, argon and nitrogen matrices and characterized by their infrared spectra. Assignments of vibrational bands are supported by ab initio and first principle calculations as well as 14/15N isotope substitution experiments. The structural and electronic properties of the new dinitrogen and nitrido iridium complexes are discussed. While the formation of the elusive dinitrido complex Ir(N)2 was observed in a subsequent reaction of IrN with N atoms within the cryogenic solid matrices, the threefold coordinated iridium trinitride Ir(N)3 could not be observed so far., Iridium and nitrogen: This work presents the last missing homoleptic dinitrogen and nitrido complexes of the platinum‐group metals and helps understanding the interaction of nitrogen with metals to facilitate nitrogen fixation. Dinitrogen activation, oxidation states and bond orders are discussed and give insight to the reactivity and electronic structure of these intriguing compounds.

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 matrix-isolation 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., While transition metal complexes bearing terminal oxido ligands are common, those of group 11 elements have yet to be experimentally observed. Here, Riedel and colleagues synthesise molecular oxygen fluorides of copper, silver and gold, and show that the oxo ligands possess radical character.

Losungen von Azidomethylidenmalononitril wurden bei tiefer Temperatur photolysiert, um das entsprechende 2H-Azirin und Tricyanmethan zu bilden, was durch Tieftemperatur-NMR-Spektroskopie analysiert wurde. Das letztgenannte Produkt wurde auch nach kurzer Thermolyse einer Losung der Azid-Vorstufe beobachtet, wahrend die Bestrahlung des in einer Argonmatrix isolierten Azids nicht zum Tricyanmethan, sondern erstmals zum zweifelsfreien Nachweis des tautomeren Ketenimins durch IR-Spektroskopie fuhrte. Wenn die lange bekannte, grunliche “aquoethereal” Phase, die aus Kaliumtricyanmethanid, verdunnter Schwefelsaure und Diethylether entsteht, rasch eingedampft und sublimiert wurde, resultierte statt des fruher proklamierten Ketenimin-Tautomers eine Mischung aus Hydroniumtricyanmethanid und Tricyanmethan. Unter speziellen Bedingungen ergab die Sublimation Einkristalle des Tricyanmethans, was die Analyse der Molekulstruktur mithilfe der Rontgenbeugung ermoglichte.

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.

We report on the solid-state structures of bis(nonafluoro-tert-butyl) peroxide [(F3 C)3 CO]2 and bis(undecafluoro-2-methyl-2-butyl) peroxide [(C2 F5 )(F3 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 (X2 ). Ferrocene is oxidized by [(F3 C)3 CO]2 to [FeIII Cp2 ][OC(CF3 )3 ].

Laser-ablated group IV transition metal atoms have been co-deposited with hydrogen selenide at 5 K in excess of argon. The metal atoms were observed to insert into the Se H bond of hydrogen selenide to form the novel molecules HMSeH, H2MSe, H2M(SeH)2 and HMSe (M = Ti, Zr, Hf). These species were identified by argon matrix-isolation IR spectroscopy, and their assignment is supported by 1H/2D substitution as well as quantum-chemical calculations. In Particular, the molecules H2MSe and HMSe are of interest as they are rare examples of multiple bonding between a heavier main group element and a group IV transition metal.

The synthesis and characterization of the new perfluorinated hypochlorite, undecafluoro-tert-pentyl hypochlorite, (C2F5)(F3C)2COCl, is reported. Its gas-phase infrared, UV/Vis and NMR spectra have been recorded and its spectroscopic properties are discussed and compared with quantum-chemical predictions and those of other known perfluorinated hypochlorites such as RFOCl [RF = F3C, (F3C)3C, (C2F5)(F3C)2C]. A synthetic route to otherwise difficult to access perfluorinated dialkyl peroxides, RFOORF, is also provided by low-temperature photolysis of the corresponding hypochlorite.

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

Optical properties of modified diamondoids have been studied theoretically using vibrationally resolved electronic absorption, emission and resonance Raman spectra. A time-dependent correlation function approach has been used for electronic two-state models, comprising a ground state (g) and a bright, excited state (e), the latter determined from linear-response, time-dependent density functional theory (TD-DFT). The harmonic and Condon approximations were adopted. In most cases origin shifts, frequency alteration and Duschinsky rotation in excited states were considered. For other cases where no excited state geometry optimization and normal mode analysis were possible or desired, a short-time approximation was used. The optical properties and spectra have been computed for (i) a set of recently synthesized sp(2)/sp(3) hybrid species with C[double bond, length as m-dash]C double-bond connected saturated diamondoid subunits, (ii) functionalized (mostly by thiol or thione groups) diamondoids and (iii) urotropine and other C-substituted diamondoids. The ultimate goal is to tailor optical and electronic features of diamondoids by electronic blending, functionalization and substitution, based on a molecular-level understanding of the ongoing photophysics.

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 3 A2 ground state with two parallel spin electrons and two degenerate metal d(δ)-orbitals. The corresponding high-spin 3 A2 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 3 A2 state is only 5 kJ mol-1 higher in energy than the singlet 1 A' ground state, and the magnetically bistable molecular N≡OsF3 with two distorted near degenerate 1 A' and 3 A" electronic states were experimentally detected at 5 K in solid neon.