Structural diversity in bishydroxylamine complexes of gallium.
Reactions of bishydroxylamines of the type HON(R)CH2CH2N(R)OH (R=Me, tBu) with trimethyl- and triisopropylgallium gave bicyclic metalla cages of the formula R'2GaO(R)NCH2CH2N(R)OGaR'2 [R'=Me, R=Me (), tBu (); R'=iPr, R=Me (), tBu ()] with six-membered Ga2O2N2-rings. While the complexes show the same core constitution in the solid state, NMR spectra reveal the steric influence of the isopropyl substituent of the compounds / on its behaviour in solution. The reaction of the sterically more demanding substituted tri-tert-butylgallium with HON(Me)CH2CH2N(Me)OH yielded a heterodimeric complex O'-[HON(Me)CH2CH2NH(Me)O(tBu2Ga)]-cyclo-(tBu2Ga)-O,N'-[ON(Me)CH2CH2N(Me)O] () with two gallium atoms of different surrounding and two different bishydroxylamine ligands, one doubly deprotonated and one protonated, but at one end in its tautomeric aminoxide form. Further condensation of was observed to give a tricyclic compound cyclo-[(tBuGa)ON(Me)CH2CH2N(Me)O]2 () with a central Ga2O2N2 ring resulting from two Ga-N donor-acceptor bonds.
Bösing
Patrick
P
Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstr. 30, 48149, Münster, Germany.
Willner
Alexander
A
Pape
Tania
T
Hepp
Alexander
A
Mitzel
Norbert W
NW