Group 13 metal(i) and (ii) guanidinate complexes: effect of ligand backbone on metal oxidation state and coordination sphere

Abstract

Reactions of lithium salts of the bulky guanidinate and phosphaguanidinate ligands, [ArNC(ER 2 )NAr] À (ER 2 = NPr i 2 (Priso À ), cis-NC 5 H 8 Me 2 -2,6 (Pipiso À ) or P(C 6 H 11 ) 2 (PGiso À ); Ar = C 6 H 3 Pr i 2 -2,6), with group 13 metal(I) halides have been carried out. All reactions with TlBr led to monomeric thallium(I) complexes, [Tl{ArNC(ER 2 )NAr}], in which the ligand chelates the metal in an N,arene-fashion. The reactions with InCl led to mixed results and the isolation of the dimeric indium(II) complexes, [{InCl(Priso)} 2 ] and [{InCl(Pipiso)} 2 ], and the monomeric indium(I) species, [In(Pipiso)] and [In(PGiso)]. The ligands of the latter two complexes exhibit differing coordination modes in the solid state, namely N,N 0 -chelating and N,arene-chelating, respectively. The reactions with ''GaI'' were less successful and gave only low yields of the poorly characterised gallium(II) complexes, [{GaI(Priso)} 2 ] and [{GaI(Pipiso)} 2 ]. This study has shown that the related ligand, [ArNC{N(C 6 H 11 ) 2 }NAr] À (Giso À ) is superior for the stabilisation of group 13 metal(I) complexes. The oxidative additions of I 2 or SiMe 3 I to one such complex, [Ga(Giso)], yielded the gallium(III) compounds, [GaI 2 (Giso)] and [GaI(SiMe 3 )(Giso)].

Heavier Group 13 Metal(I) Heterocycles Stabilized by Sterically Demanding Diiminophosphinates: A Structurally Characterized Monomer–Dimer Pair For Gallium

“…In 4 , a central gallium atom (Ga2) is bonded to three {( Mes L)Ga}‐fragments and I2 in a distorted tetrahedral fashion. The geometry around the Ga2‐Ga1 bonded (2.45 Å) unit to the {( Mes L)Ga I }‐fragment is a common structural motif found for gallium(II) complexes of the type LGa(X)‐Ga(X)L, in which L is a sterically demanding N , N′ ‐chelating ligand . Two further {( Mes L)Ga}‐fragments (Ga3, Ga3′) bind to Ga2 in an almost linear fashion (P⋅⋅⋅Ga3‐Ga2: 164°) and a remaining iodide ligand (I3) bridges both {( Mes L)Ga} centers at an almost right angle (Ga2‐Ga3‐I3: 92°).…”

Oxidative Addition Reactions of Element–Hydrogen Bonds with Different Polarities to a Gallium(I) Compound

“…[14] In matrix studies, it was demonstrated that GaH can be hydrogenated to GaH 3 by photolytic activation. [15][16][17] Only recently, several oxidative addition reactions of element-halogen bonds to 1, [18,19] the gallium(I) guanidinate, [20] and the anionic derivative [21] mentioned above were reported. Gallium(I) compounds with bulky aryl substituents even added hydrogen and ammonia at ambient temperature, thereby forming a dihydride [GaA C H T U N G T R E N N U N G (aryl)H 2 ] 2 and [GaA C H T U N G T R E N N U N G (aryl')(H)NH 2 ] 2 , respectively [22] (aryl = 2,6-(2,6-iPr 2 C 6 H 3 ) 2 C 6 H 3 ; aryl' = 2,6-(2,6-iPr 2 C 6 H 3 ) 2 -4-(Me 3 Si)C 6 H 2 ).…”

En Route to Bis‐Carbene Analogues of the Heavier Group 13 Elements: Consideration of Bridging Group and Metal(I) Source

“…The last decades have seen rapid development of the chemistry of low oxidation state group 13 species, and numerous compounds have been synthesized since the seminal work on group 13 diyls in the last century . Although the first example of a stable group 13 element analogue of carbenes was not isolated until 1999, today examples are known for aluminium, gallium, indium,, and thallium,, and they have found numerous applications as ligands in transition metal complexes, for the stabilization of unusual molecules, and as reagents for the activation of small molecules and strong bonds . The corresponding neutral boron compound, that is, a borylene stabilized by one Lewis base, remains undiscovered to date .…”