Nucleophilic Functionalization of Activated P in [CpFe(CO)-(η-P)][Al(OR)] with Alcohols R-OH.

The bonding situation in [Fp-P][Al(OR)] (1) (Fp = (CO)CpFe, R = C(CF)) gives rise to an Umpolung of the P fragment, which should make it accessible for nucleophiles. To investigate this projected reactivity, the complex was combined with a series of hydroxy-nucleophiles - that all do not react with free P - leading to a variety of P building blocks. With excess of R-OH (R = Me, Et, Ph), the thermodynamically more stable complex salts [Fp-P(H)(OR))][Al(OR)] (x=2,1,0) (2b-2d) are formed and show that the phosphonium type pathway is accessible.

Carbodiphosphorane-Activated Distibene and Dibismuthene Dications.

Low-valent antimony and bismuth have emerged as novel platforms for achieving reversible small-molecule activation at main-group metals. Although various examples of oxidative addition reactions at monomeric Sb(I) and Bi(I) have been reported, the chemistry of the heavy group 15 Sb(I)═Sb(I)/Bi(I)═Bi(I) double bonds toward small molecules remains largely unexplored. In this study, we present a straightforward synthesis of distibene and dibismuthene dications coordinated with a neutral carbodiphosphorane (CDP) ligand.

Activation of the Ga Cation for Bond Activation: from Oxidative Additions into C-Cl and H-P Bonds to Reversible Insertion into P.

Although the discovery of the Ga complex salt [Ga(PhF) ][Al(OR ) ] (R =C(CF ) , PhF=C H F) invoked the preparation of a diverse library of cationic Ga(I) coordination complexes and clusters, studies on small molecule activation with low-valent Ga cations are scarce. Herein, a first experimental study on the reactivity of a monomeric Ga(I) cation activated with a pyridine-diimine pincer ligand (in [Ga(PDI )][Al(OR ) ]) towards small-molecules is reported. First controlled oxidative additions of the Ga cation into C-Cl, H-P and P-P bonds are presented.

Cationic dialanes with fluxional π-bridged cyclopentadienyl ligands.

Unique π-cyclopentadienyl bridged dialanes are synthesized as complex salts with aluminate anions by comproportionation of aluminocenium cations [Al(Cp)(Cp*)]/[AlCp] with [(AlCp*)]. Very short Al-Al bond lengths occur in positively charged Al fragments. Intriguingly, the prepared asymmetric dialane shows a unique fluxional coordination of the cyclopentadienyl ligands.

Low-Valent M Al Cluster Salts with Tetrahedral [SiAl ] and Trigonal-Bipyramidal [M Al ] Cores (M=Si/Ge).

Schnöckel's [(AlCp*) ] and Jutzi's [SiCp*][B(C F ) ] (Cp*=C Me ) are landmarks in modern main-group chemistry with diverse applications in synthesis and catalysis. Despite the isoelectronic relationship between the AlCp* and the [SiCp*] fragments, their mutual reactivity is hitherto unknown. Here, we report on their reaction giving the complex salts [Cp*Si(AlCp*) ][WCA] ([WCA] =[Al(OR ) ] and [F{Al(OR ) } ] ; R =C(CF ) ).

From mixed group 13 cations [M(AlCp*)] (M = Ga/In/Tl) to an Al cluster.

AlCp*-complexes with transition metals have shown to be highly reactive and enable C-H or Si-H bond activation. Yet, complexes of AlCp* with low-valent main-group metals are scarce. Here, we report the syntheses of [M(AlCp*)][Al(OR)] (R = C(CF)) with M = Ga, In, Tl, which include the first covalent Al-In and Al-Tl bonds.

Synthesis of a low-valent Al cluster cation salt.

Low-valent aluminium compounds are very reactive main-group species and have therefore been widely investigated. Since the isolation of a stable molecular Al(I) compound in 1991, [(AlCp*)] (Cp* = [CMe]), a variety of highly reactive neutral or anionic low-valent aluminium complexes have been developed. By contrast, their cationic counterparts have remained difficult to access.

A Highly Lewis Acidic Strontium ansa-Arene Complex for Lewis Acid Catalysis and Isobutylene Polymerization.

The potential of a dicationic strontium ansa-arene complex for Lewis acid catalysis has been explored. The key to its synthesis was a simple salt metathesis from SrI and 2 Ag[Al(OR ) ], giving the base-free strontium-perfluoroalkoxyaluminate Sr[Al(OR ) ] (OR =OC(CF ) ). Addition of an ansa-arene yielded the highly Lewis acidic, dicationic strontium ansa-arene complex.