Univalent Gallium and Indium Phosphane Complexes: From Pyramidal M(PPh₃)₃⁺ to Carbene‐Analogous Bent M(PtBu₃)₂⁺ (M=Ga, In) Complexes

Abstract

In a new oxidative route, Ag(+)[Al(OR(F))(4)](-) (R(F)=C(CF(3))(3)) and metallic indium were sonicated in aromatic solvents, such as fluorobenzene (PhF), to give a precipitate of silver metal and highly soluble [In(PhF)(n)](+) salts (n=2, 3) with the weakly coordinating [Al(OR(F))(4)](-) anion in quantitative yield. The In(+) salt and the known analogous Ga(+)[Al(OR(F))(4)](-) were used to synthesize a series of homoleptic PR(3) phosphane complexes [M(PR(3))(n)](+), that is, the weakly PPh(3)-bridged [(Ph(3)P)(3)In-(PPh(3))-In(PPh(3))(3)](2+) that essentially contains two independent [In(PPh(3))(3)](+) cations or, with increasing bulk of the phosphane, the carbene-analogous [M(PtBu(3))(2)](+) (M=Ga, In) cations. The M(I)-P distances are 27 to 29 pm longer for indium, and thus considerably longer than the difference between their tabulated radii (18 pm). The structure, formation, and frontier orbitals of these complexes were investigated by calculations at the BP86/SV(P), B3LYP/def2-TZVPP, MP2/def2-TZVPP, and SCS-MP2/def2-TZVPP levels.

Taming the Cationic Beast: Novel Developments in the Synthesis and Application of Weakly Coordinating Anions

“…Unlike the parent CB 11 Me 12 C,the line widths in the EPR spectra could be determined and analyzed. [322,323] Thes ame silver(I) salt can also be used to oxidize the nickel(0) complex Ni(cod) 2 (cod = 1,5-cyclooctadiene) to give the paramagnetic nickel(I) salt [Ni(cod) 2 ][Al(OR F ) 4 ], which serves as aprecursor for the formation of further substituted nickel(I) complexes. [101] Although an umber of radical species formally derived from CB 11 Me 12 C have been characterized in solution, the parent CB 11 Me 12 C remains the only radical species from this group to be characterized in the solid state and used for the further oxidation of substrates.…”

“…[322,323] Figure 9. Oxidationo felementalg allium and indium by Ag[Al(OR F ) 4 ] for the formation of univalent gallium and indium salts.…”

“…[277] Very recently,t he preparation and structure of the unsubstituted [CpSn] + cation as both [Al-(OR F ) 4 ] À and [( F RO) 3 Al(m-F)Al(OR F ) 3 ] À salts has been reported. [322,323] Figure 11. [362] Subvalent 4 ]c omplexes readily bind s-donor ligands (e.g.…”

Phosphine complexes of lone pair bearing Lewis acceptors

“…Another example is furnished by the phosphine coordination chemistry of M(I), where M = In or Ga. 31 The tris-phosphine complexes [M(PPh 3 ) 3 ] 1+ have pyramidal geometries, as expected for AX 3 E compounds, with P-M-P angles around 95°, consistent with occupation of the three p-orbitals by the ligands and a residual lone pair on the metal (Fig. 5).…”

“…1), but remain rare as few examples are known for most elements. A limited number of elements adopt bis-phosphine complexes and tris-phosphine complexes have only been reported for gallium, 31 indium, 31 thallium 10 and antimony. 11 Phosphine complexes of boron(I) or aluminium(I) are not known even though complexes of these centres with carbene or diketiminate ligands have been reported as stable compounds or trapped intermediates.…”