Tetraazidodiammincobaltate(III): Cis-[Co(N3)4(NH3)2]− und [Co(N3)4en]−

Tetra-azidodiamminecobaltates(III): cis-[Co(N₃)₄(NH₃)₂]^? and [Co(N₃)₄en]^? The preparation and the properties of complexes containing the anions cis-[Co(N₃)₄(NH₃)₂]^? and [Co(N₃)₄en]^? are described. The compounds [Co(NH₃)₆][Co(N₃)₄(NH₃)₂ · H₂O], [Co(N₃)₂(NH₃)₄][Co(N₃)₄(NH₃)₂], [As(C₆H₅)₄][Co(N₃)₄en], cis- and trans-[Co(N₃)₂en₂][Co(N₃)₄en] have been isolated.     

Salts of HCN‐Cyanide Aggregates: [CN(HCN)2]− and [CN(HCN)3]−

Although pure hydrogen cyanide can spontaneously polymerize or even explode, when initiated by small amounts of bases (e.g. CN^?), the reaction of liquid HCN with [WCC]CN (WCC=weakly coordinating cation=Ph₄P, Ph₃PNPPh₃=PNP) was investigated. Depending on the cation, it was possible to extract salts containing the formal dihydrogen tricyanide [CN(HCN)₂]^? and trihydrogen tetracyanide ions [CN(HCN)₃]^? from liquid HCN when a fast crystallization was carried out at low temperatures. X‐ray structure elucidation revealed hydrogen‐bridged linear [CN(HCN)₂]^? and Y‐shaped [CN(HCN)₃]^? molecular ions in the crystal. Both anions can be considered members of highly labile cyanide‐HCN solvates of the type [CN(HCN)_n]^? (n=1, 2, 3 …) as well as formal polypseudohalide ions.     

Über die Darstellung der Dimercapto(methyl)sulfonium-Salze[CH3S(SH)2]+AsF−6 und [CH3S(SH)2]+SbCl−6 und der Bis(chlorthio)Methylsulfonium-Salze [CH3S(SCI)2]+ AsF6−und [CH3S(SCL)2]+SbCl−6

On the Preparation of Dimercapto(methyl)Sulfonium Salts [CH₃S(SH)₂]⁺ AsF₆^? and [CH₃S(SH)₂]⁺SbCl₆^? and the Bis(chlorothio)methylsulfonium Salts [CH₃S(SCI)₂]⁺ AsF₆^? and [CH₃S(SCI)₂]⁺ SbCl₆^? The preparation of the dimercapto(methyl)sulfonium salts [CH₃S(SH)₂]⁺ AsF₆^? and [CH₃S(SH)₂]⁺SbCl₆^? from [CH₃SCl₂]⁺ salts and H₂S at 195 K is reported. The salts are stable below 210 K. They are characterized by additional Raman spektroscopic measurements of the isotopic labelled cations [CH₃S(SD)₂]⁺, [CH₃S(³⁴SH)₂]⁺ and [CH₃S(₃₄SD)₂]⁺. The dimercapto(methyl)sulfonium salts are transfered into bis(chlorthio)methylsulfonium salts by reaction with Cl₂ at 195 K.     

Effect of External Pressure on the Excitation Energy Transfer from [Cr(ox)3]3− to [Cr(bpy)3]3+ in [Rh1−xCrx(bpy)3][NaM1−yCry(ox)3]ClO4

Resonant excitation energy transfer from [Cr(ox)₃]^3? to [Cr(bpy)₃]³⁺ in the doped 3D oxalate networks [Rh_1?xCr_x(bpy)₃][NaM^III_1?yCr_y(ox)₃]ClO₄ (ox=C₂O₄^?, bpy=2,2′‐bipyridine, M=Al, Rh) is due to two types of interaction, namely super exchange coupling and electric dipole–dipole interaction. The energy transfer probability for both mechanisms is proportional to the spectral overlap of the ²E→⁴A₂ emission of the [Cr(ox)₃]^3? donor and the ⁴A₂→²T₁ absorption of the [Cr(bpy)₃]³⁺ acceptor. The spin‐flip transitions of (pseudo‐)octahedral Cr³⁺ are known to shift to lower energy with increasing pressure. Because the shift rates of the two transitions in question differ, the spectral overlap between the donor emission and the acceptor absorption is a function of applied pressure. For [Rh_1?xCr_x(bpy)₃][NaM_1?yCr_y(ox)₃]ClO₄ the spectral overlap is thus substantially reduced on increasing pressure from 0 to 2.5 GPa. As a result, the energy transfer probability decreases with increasing pressure as evidenced by a decrease in the relative emission intensity from the [Cr(bpy)₃]³⁺ acceptor.     

Studies on the Reactivity of [Ge9]4− towards [Fe(cot)(CO)3]: Synthesis and Characterization of [Ge8Fe(CO)3]3− and of the Anionic Organometallic Species [Fe(cot)(CO)3]−

Reaction of cyclooctatetraene (COT) iron(II) tricarbonyl, [Fe(cot)(CO)₃], with one equivalent of K₄Ge₉ in ethylenediamine (en) yielded the cluster anion [Ge₈Fe(CO)₃]^3? which was crystallographically‐characterized as a [K(2,2,2‐crypt)]⁺ salt in [K(2,2,2‐crypt)]₃[Ge₈Fe(CO)₃]. The chemically‐reduced organometallic species [Fe(η³‐C₈H₈)(CO)₃]^? was also isolated as a side‐product from this reaction as [K(2,2,2‐crypt)][Fe(η³‐C₈H₈)(CO)₃]. Both species were further characterized by EPR and IR spectroscopy and electrospray mass spectrometry. The [Ge₈Fe(CO)₃]^3? cluster anion represents an unprecedented functionalized germanium Zintl anion in which the nine‐atom precursor cluster has lost a vertex, which has been replaced by a transition‐metal moiety.     

Binary Pnictogen Azides—An Experimental and Theoretical Study: [As(N3)4]−, [Sb(N3)4]−, and [Bi(N3)5(dmso)]2−

[PPh₄][EI₄] (E=As, Sb, Bi) salts were reacted with four and five equivalents of AgN₃ to form tetraazidopnictates and pentaazidopnictates of the type [PPh₄][E(N₃)₄] and [PPh₄]₂[E(N₃)₅], respectively. The synthesis of [PPh₄][P(N₃)₄] was also attempted from the reaction of P(N₃)₃ with [PPh₄]N₃, but it yielded only the starting materials. Herein, we report the synthesis and structure elucidation of [PPh₄][E(N₃)]₄ (E=As, Sb) and pentaazidobismuthate, stabilized as the dimethyl sulfoxide (DMSO) anion adduct, [PPh₄]₂[Bi(N₃)₅(dmso)]. Successive anion formation along the series E(N₃)₃+nN₃^? (n=1–3) and E(N₃)₅+N₃^? was studied by density functional theory.