Gold(I) and silver(I) complexes of 1-methyl-5-thio-tetrazole (1) have been prepared and the coordination chemistry of this ligand toward metal-phosphine frameworks has been explored. As indicated by IR and Raman data, ligand 1 is deprotonated and the resulted anion acts as a bidentate (S,N)-tetrazole-5-thiolato unit in the new gold(I) complexes, [Au(SCN(4)Me)(PPh(3))] (2), [{Au(SCN(4)Me)}(2)(μ-dppm)] (3), and [{Au(SCN(4)Me)}(2)(μ-dppe)] (4), while it is coordinated only through the sulfur atom as its neutral tetrazole-5-thione form in the silver(I) derivative, [Ag(HSCN(4)Me)(PPh(3))](2)(OTf)(2) (5). Further characterization of the new compounds was performed using multinuclear ((1)H, (13)C, (31)P, (19)F) NMR spectroscopy, mass spectrometry, and DSC measurements. Single-crystal X-ray diffraction studies revealed basically linear P-M-S arrangements in complexes 3-5. The bidentate (S,N) coordination pattern results in a T-shaped (S,N)PAu core in 3 and 4, whereas, in 5, a similar coordination geometry is achieved in the dimer association based on S-bridging ligand 1. Herein, weak (C)H···Au and (C)H···Ag agostic interactions were observed. An intramolecular Au···Au contact occurs in 3, while in 4 intermolecular aurophilic bonds lead to formation of a chain polymer. An intermolecular Ag···Ag contact is also present in the dimer unit of 5. Low-temperature (31)P NMR data for 5 evidenced the presence of monomer and dimer units in solution. Theoretical calculations on model of the complexes 2 and 4 are consistent with the geometries found by X-ray diffraction studies.

The homogeneous mixture of anhydrous hydrogen fluoride aHF and antimony pentafluoride AsF5 is known as a superacidic system. The high acidity is derived from the formation of [H2F](+) [AsF6](-). No experimental evidence exists for the existence of the free acid molecule HAsF6. The reaction of trimethylsilyl N,N-dimethylcarbamate in the binary system aHF/AsF5 led to decomposition of trimethylsilyl N,N-dimethylcarbamate at -50 °C to dimethylammonium hexafluoridoarsenate and cocrystallization of HAsF6. The single-crystal X-ray structure displays an HAsF6 molecule involved in an asymmetric hydrogen bridge to the hexafluoridoarsenate anion. As a result of the incalculable situation in the crystal lattice, the molecular structure of HAsF6 is calculated by quantum chemical structure optimization of the extreme cases of [FHF-AsF5](-) (strong hydrogen bond) and HAsF6 (no hydrogen bond) at the PBE1PBE/6-311G(3df,3pd) level of theory.

Dimethyl sulfoxide (DMSO) reacts with the superacidic solutions of XF/MF5 and XF/GeF4 (X=H, D; M=As, Sb) under formation of the corresponding salts [(CX3)2SOX+]MF6− and [(CH3)2SOH+]4Ge3F164−, respectively. The salts are characterized by vibrational and NMR spectroscopy, and in the case of [(CH3)2SOH+]4Ge3F164− also by single‐crystal X‐ray analysis. The salt [(CH3)2SOH+]4Ge3F164− crystallizes in the monoclinic space group P21/c with two formula units in the unit cell. The crystal structure possesses an unusual anion consisting of a chain of three slightly distorted fluorine‐bridged GeF6 octahedra. The vibrational spectra are compared to the quantum chemically calculated free [(CX3)2SOX+] cations. The described salts are isolated examples of completely protonated DMSO molecules in the condensed phase.

The solid states of bromofluoromethane (BFM) and fluoroiodomethane (FIM) are characterized by X-ray diffraction analysis and by Raman spectroscopy. The single crystals were obtained by crystallization in situ at low temperature. BFM and FIM crystallize in the space group I2/a and Abm2, respectively. The Raman spectra of both compounds were re-

Acetamide and thioacetamide react with the superacid solutions HF/MF 5 (M = As, Sb) under formation of the corresponding salts [H 3 CC(OH)NH 2 ] + MF 6 and [H 3 CC(SH)NH 2 ] + MF 6 -(M = As, Sb), respectively. The reaction of DF/AsF 5 with acetamide and thioacetamide lead to the corresponding deuterated salts [H 3 CC(OD)ND 2 ] + AsF 6 and [H 3 CC(SD)ND 2 ] + AsF 6 -, respectively . The salts are characterized by vibrational and NMR spectroscopy, and in the case of [H 3 CC(OH)NH 2 ] + AsF 6 and [H 3 CC(SH)NH 2 ] + AsF 6 also by singlecrystal X-ray analyses. The [H 3 CC(OH)NH 2 ] + AsF 6 -(1) salt crys-* Prof. Dr. A. Kornath