Vibrational (Infrared and Raman) Spectra of Minerals and Related Compounds

This chapter contains IR spectra of mineral species and varieties, most of which was not included in the preceding reference book (Chukanov in Infrared spectra of mineral species. Springer, Dordrecht 2014a). Along with spectra obtained by us, we provide the most reliable data on the infrared spectra of minerals published elsewhere during the last 60 years. Each spectrum is accompanied with analytical data on the reference sample, its occurrence and general appearance, associated minerals, as well as kind of sample preparation and/or method of registration of the spectrum. In addition, we provide IR spectra of some synthetic compounds which are chemically or structurally related to any known minerals or may be hypothetically considered as synthetic analogs of potentially new mineral species.

IR Spectra of Minerals and Related Compounds, and Reference Samples’ Data

Synthesis and properties of Fischer carbene complexes of N,N-dimethylaniline and anisole π-coordinated to chromium tricarbonyl

New examples of the very rare class of iridium(I) Fischer carbene complexes (FCCs) are reported from the facile transmetalation from group 6 FCCs. Postcomplexation modification of either the carbene ligand or the ancillary coligands results in a tunable IrI metal center, for unprecedented application as a (pre)catalyst in a benchmark transfer hydrogenation reaction. The introduction of an aminocarbene ligand with a pendant N-donor moiety capable of hemilabile coordination yielded the best catalytic results with turnover frequencies reaching 445 h-1 and requiring 0.1 mol % catalyst and 0.5 mol % base loading, respectively.

Fischer Carbene Complexes of Iridium(I) for Application in Catalytic Transfer Hydrogenation

Synthesis and Catalytic Applications of [N,N]‐Pyrrole Ligands for the Regioselective Synthesis of Styrene Derivatives

o-Lithiated reagents,o-LiC6H4XMe (X=O, S, or NMe), react with [Cr(CO)6] to yield, after alkylation with [Et3O][BF4], the pentacarbonyl carbene complexes [Cr{C(OEt)C6H4XR}(CO)5] and tetracarbonyl metallocyclic carbene complexes
 . An analogous five-membered chelate
 is obtainable from the lithiated vinylsulphide PhSCHCH2. The x-ray structure of
 was determined by single crystal x-ray diffraction. It crystallizes in the monoclinic space groupP21/n witha=7.054(3),b=11.746(1),c=19.443(3) A,β = 95.35(2)c and Z = 4. The final R-factors were R = 0.099 and Rw=0.044. Bond distances of 1.990(7) A for Cr−C(carbene) and 2.240(6) A for Cr−N were found.

Metallocyclic carbene complexes of chromium(0). The crystal and molecular structure of a chronium(0) complex with an aminoarylcarbene chelating ligand

The polarized Raman spectra of single crystals of KSbF6-I of P42m-D symmetry are reported. The predicted LO-TO splittings of the B2 and E modes were not observed and the vibrational spectra do not indicate a non-centrosymmetric structure. The calculated relative intensities of the Raman bands in the single-crystal spectra agree very well with the observed values. It is shown that the anions execute fourfold reorientational motions around the S4 axis of the crystals and an activation energy of 3.2 kcal mol−1 (13.4 kJ mol−1) is calculated from the variation of the linewidths of Raman bands with temperature. The barrier is penetrated by the anions and because of the jumping motions of the anions in KSbF6-I the small distortions from a centrosymmetric structure are averaged out and the Raman and infrared spectra appear to be mutually exclusive.

Magda M. van den Berg

Papers

Metallocyclic carbene complexes of chromium(0). The crystal and molecular structure of a chronium(0) complex with an aminoarylcarbene chelating ligand

KSbF6 revisited. I—A Raman and infrared study of the tetragonal phase I