Synthesis and Structural Characterization of the Novel Compounds from the Reactions of Trimethylaluminum or Trimethylgallium with N,O-Donor Crown Ethers

The reactions of two N/O mixed-donor crown ethers, 1,12,15-triaza-3,4:9,10-dibenzo-5,8-dioxacycloheptadecane (OenNdienH<sub>4</sub>) and 1,12-diaza-3,4:9,10-dibenzo-5,8-dioxacyclopentadecane (OenNtnH<sub>4</sub>) with MMe<sub>3</sub> (M = Al, Ga) are reported. OenNdienH<sub>4</sub> reacted with 3 equiv of AlMe<sub>3</sub> to form (AlMe)(AlMe<sub>2</sub>)(OenNdienH<sub>4</sub>)(AlMe<sub>3</sub>) (<b>1</b>) which contains three different Me<i><sub>n</sub></i>Al groups:  AlMe, AlMe<sub>2</sub>, AlMe<sub>3</sub>. OenNtnH<sub>4</sub> reacted with 2 equiv of AlMe<sub>3</sub> to afford (AlMe<sub>2</sub>)(OenNtnH<sub>4</sub>)(AlMe<sub>3</sub>) (<b>2</b>) containing two chemically inequivalent aluminum centers. However, the reaction of OenNdienH<sub>4</sub> with GaMe<sub>3</sub> in 1:3 ratio resulted in (OenNdienH<sub>4</sub>)<sub>2</sub>(GaMe<sub>2</sub>OH)<sub>4</sub> (<b>3</b>). The (Me<sub>2</sub>GaOH)<sub>4</sub> component contains an eight-membered Ga−O ring linked <i>via </i>four hydrogen bonds to two molecules of OenNdienH<sub>4</sub> which interacts from opposite sides of the Ga<sub>4</sub>O<sub>4</sub> ring. The reaction of OenNtnH<sub>4</sub> with GaMe<sub>3</sub> in 1:2 ratio produced (OenNtnH<sub>4</sub>)(GaMe<sub>2</sub>OH)<sub>3</sub> (<b>4</b>), a one-dimensional hydrogen bonded system which incorporates one OenNtnH<sub>4</sub> ligand and one nonplanar six-membered ring with alternating Ga and O atoms (GaMe<sub>2</sub>OH)<sub>3</sub>.