Research

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Research activities of the Uhl group were directed towards the organoelement chemistry of the heavier Group 13, 14 and 15 elements.

• Compounds with Al-Al, Ga-Ga and In-In single bonds were generated for the first time. They showed a unique chemical reactivity with cleavage versus retainment of their E-E bonds.
• Macromulecules and huge cage compounds with supramolecular entities were obtained based on Ga-Ga bonds and functional carboxylates.

• Homonuclear clusters of the elements Al, Ga and In in unusual low oxidation states close to +I were obtained. They found wide application in Main Group and Transition Metal chemistry.

• Deprotonation of C-H acidic organoaluminium compounds resulted in the formation of interesting heterocyclic molecules.

• Hydroalumination and hydrogallation of alkynes gave chelating Lewis acids and new cage compounds. The mechanism of these fundamental reactions was elucidated. Carbaalanes were synthesized on such a route; they had clusters formed by Al and C atoms.

• Hydrazides of Al, Ga and In showed a wide structural diversity. A completely deprotonated hydrazine, a hydrazinetetraide, was stabilized by six Ga atoms.

• Very unusual peroxides were isolated and characterized, which in a very strange situation had highly reducing E-C bonds (E = Al, Ga, In) beside oxidizing peroxo groups.

• Functionalization of silanes and germanes by Lewis acids resulted in the activation of E-X bonds (E = Si, Ge) and an approach to a cationic character of these elements.

•      Frustrated Lewis pairs based on Al or Ga and P atoms showed a remarkable reactivity with respect to the ambiphilic coordination and activation of molecules and were applied in stoichiometric and catalytic transformations
• Active Lewis pairs based on Al or Ga and N atoms showed a completely different structural chemistry and were applied in numerous reactions including catalytic processes (together with Prof. Würthwein).

• Phosphaallenes were synthesized on a facile route in a multigram scale, which allowed their systematic application in various secondary reactions. 
• Novel strained heterocyclic phosphines with the P atom exclusively bound to C atoms showed a unique reactivity by ring opening, coordination, oxidation or reduction.