Abstract
Tri-t-butylgallium has been reacted with the macrocycle 1,12-diaza-3,4:9,10-dibenzo-5,8-dioxocyclopentadecane which could be a potential ligand for gallium(III). A reaction product was analyzed and single crystal X-ray diffraction experiments showed that it consisted of the cyclic dimer of di-t-butylgallium-hydroxide hydrogen bonded to the macrocycle. Without a co-crystallized organic molecule di-t-butylgallium hydroxide crystallizes as a trimer. Density functional calculations have been used to predict the structures and the total energies for the monomer, dimer, trimer, and tetramer of dimethylgallium hydroxide in order to provide a basis for the understanding of oligomer population for the dimethylgallium hydroxides. Force field calculations are shown to be able to produce a similar strain energy difference for dimer, trimer, and tetramer forms of (CH3)2Ga(OH) and this method can economically be used for larger alkyl groups. The force field computations show that the trimeric di-t-butyl gallium(III) hydroxide is much more stable than the dimeric form which therefore must owe its existence to the association with the hydrogen-bonded macrocycle.
Highlights
There is a great interest in the chemistry of group 13 organometallic compounds [1,2,3,4,5,6]
In the present communication we describe a hydrogen bonded reaction product composed by OenNtn (I), and the cyclic dimer [(t-Bu)2Ga(μ-OH)]2 (II) (Scheme1)
The dimer of di-t-butylgalliumhydroxide is found in the crystal formed by co-crystallizing di-tbutylgalliumhydroxide with the macrocyclic compound, 1,12-diaza-3,4:9,10-dibenzo-5,8-dioxocyclo-pentadecane, I
Summary
There is a great interest in the chemistry of group 13 organometallic compounds [1,2,3,4,5,6]. The reactions of tri-alkyl aluminum and gallium are of interest in the study of alumoxanes and galloxanes of the general formula (R-M-O)n (M = Al, Ga). This group of compounds has in recent years been a target of several investigations into the formation of methylalumoxane (MAO). In an earlier paper one of us reported on the unexpected reaction products from the reaction between Me3Ga and the macrocycles 1,12,15-triaza-3,4:9,10-dibenzo-5,8-dioxacycloheptadecane and 1,12-diaza-3,4:9,10-dibenzo-5,8dioxacyclopenta-decane (OenNtn) [23] These compounds represented the first examples of hydrogen bonded cyclic tetrameric and trimeric gallium hydroxide compounds with N/O mixed-donor macrocyclic ethers. The factors that determine the degree of association of μ-hydroxodialkylgallium compounds are explored by theoretical calculations based on density functional and molecular mechanical methods
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call