Search

As a rather inert gas, sulfur hexafluoride is still used as a dielectric in high-voltage power applications despite its high global warming potential. Its activation at transition metal complexes has been reported, but the fate of the sulfur-containing products is often unknown. The activation of SF6 at [Rh(H){tBuxanPOP}] (tBuxanPOP = 9,9-dimethyl-4,5-bis(ditert-butylphosphino)xanthene) at room temperature leads to the generation of the bifluorido complex [Rh(FHF){tBuxanPOP}]. A subsequent regeneration of [Rh(H){tBuxanPOP}] completes a cyclic process for the degradation of SF6. Furthermore, the SF6 activation at [Rh(H){tBuxanPOP}] in the presence of triethylsilane as a hydrogen source is described, which leads to the formation of the fluorido complex [Rh(F)2(H){tBuxanPOP}] as well as [Rh(SH){tBuxanPOP}] and S(SiEt3)2 as sulfur-containing products.

The compound BiCl(o-PPh2-C6H4)2, PBiP-Cl, which in previous work had been shown to form complexes with pronounced M→Bi character, when metal(I) ions of group 11 or PtII and PdII ions were coordinated, behave differently in contact with late metal atoms in low oxidation states, known to easily undergo oxidative additions: Treatment of PBiP-Cl with M(PPh3)4, with M = Pt, Pd, led to the formal insertion of M into the Bi–Cl bond to yield complexes [MCl(PBiP)]. Analogues PBiP-X with X = Br, I that could be accessed behaved similarly, producing [MX(PBiP)]. Both types of complexation reactions—coordination of PBiP-Cl as an ambiphilic ligand and oxidative addition—were observed to occur when [Ir(acac)(cod)] was chosen as the precursor compound. NMR investigations clearly indicated the presence of [IrI(acac)(PBiP-Cl)] and [IrIII(acac)Cl(PBiP)] beside each other in solution, from which, however, only [IrIII(acac)Cl(PBiP)] could be crystallized. DFT results showed that both products differ only slightly in energy. R...

Treatment of the rhodium(I) boryl complex [Rh(Bpin)(PEt3)3] (1, pin = pinacolato = O2C2Me4) with pentafluorobenzene, 1,3,5-trifluorobenzene, 1,3-difluorobenzene, or 3,5-difluoropyridine led to C–H activation reactions to give the aryl complexes [Rh(C6F5)(PEt3)3] (4), [Rh(2,4,6-C6F3H2)(PEt3)3] (5), [Rh(2,6-C6F2H3)(PEt3)3] (6), and [Rh{4-(3,5-C5NF2H2)}(PEt3)3] (8). For 5, 6, and 8 consecutive reactions with in situ generated HBpin occurred to yield [Rh(H)(PEt3)3] (7) and boronic esters. The boryl complex 1 gave with hexafluorobenzene or perfluorotoluene the C–F activation products [Rh(C6F5)(PEt3)3] (4) and [Rh(4-C6F4CF3)(PEt3)3] (9), respectively. The complexes 5, 6, and 9 react with B2pin2 to yield 1 and boronic ester derivatives. On the basis of these stoichiometric reactions catalytic C–H and C–F borylation reactions using 1 or 7 were developed to generate 2-Bpin-1,3,5-C6F3H2, 2-Bpin-1,3-C6F2H3, and 4-Bpin-C6F4CF3 from 1,3,5-trifluorobenzene, 1,3-difluorobenzene, or perfluorotoluene and B2pin2. On treatm...

The synthesis of neutral and cationic zinc cyclopentadienyl (Cp) complexes with amino and thio donor groups that are attached to the Cp ring via a side chain is reported. The amino-functionalized zincocene [ZnCp3N2] (3; Cp3N = C5Me4(CH2)3NMe2) was prepared in a salt metathesis reaction from KCp3N and ZnCl2. In the solid-state structure of 3, which was determined by single-crystal X-ray diffraction, one of the Cp3N ligands is coordinated as a chelating ligand through a ring carbon atom and through the amino group, whereas the other Cp3N ligand is bound in a monodentate mode through the Cp ring only. A reaction of 3 with ZnEt2, [ZnCp*2] (Cp* = C5Me5), and [ZnCp2N2] (2; Cp2N = C5Me4(CH2)2NMe2) gave the heteroleptic complexes [ZnEtCp3N] (4), [ZnCp*Cp3N] (5), and [ZnCp3NCp2N] (6), respectively. The incorporation of a second amino group in the same side chain led to the formation of the mononuclear zinc chlorido complex [ZnClCptmeda] (7; Cptmeda = C5Me4(CH2)2NMe(CH2)2NMe2), in which the Cptmeda ligand is bound ...

The amino-functionalized zincocene [ZnCpN2] (4; CpN = C5Me4(CH2)2NMe2), which is the first mononuclear zincocene with two donor-functionalized cyclopentadienyl ligands, was prepared through treatment of KCpN with ZnCl2 in a 2/1 ratio. X-ray crystallography reveals the chelating binding mode of each CpN ligand via an η1-coordinated Cp ring and the amino group. The structural dynamics of 4 in solution were examined by variable-temperature 1H NMR spectroscopy, and decoalescence of the NMR signals was found at low temperatures. Reacting 4 with [ZnR2] (R = Et, Cp*) yields the monocyclopentadienyl and mixed-ring donor-functionalized complexes [ZnEtCpN] (5) and [ZnCp*CpN] (6). In contrast to the reaction of KCpN with ZnCl2 in a 2/1 ratio, which yields the zincocene 4, the reaction in a 1/1 ratio results exclusively in the formation of the chlorido-bridged dimer [Zn(μ-Cl)CpN]2 (7). This compound is comparable to [Zn(μ-Cl)Cp*(THF)]2 (8), which crystallizes from a THF solution of equimolar amounts of [ZnCp*2] (1) a...