Structures and dynamic properties of aluminium-group 16 derivatives

An investigation of catalyst/cocatalyst/support interactions in silica-supported olefin polymerization catalysts based on Cp*TiMe3*

“…In the molecular complexes [R 2 Al(OR¢)] n containing bridging alkoxide [48,54] or siloxide [55][56][57] ligands, the heteroatoms are invariably found in bridging positions [58,59]. We therefore suggest that the two Al centers are held together by a strong bridging siloxide interaction.…”

“…The proposed mononuclear, three-coordinate Al structures shown in Scheme 2 are highly unusual in organoaluminum chemistry, which strongly favors tetracoordination and oligomeric structures, except in the presence of particularly bulky ligands or extreme reaction conditions [48]. Although silica may inhibit the oligomerization of organometallic fragments on its surface, it is not clear how electron-deficient Al is prevented from associating with nearby surface oxygens.…”

Synthesis and crystal structures of organometallic compounds containing the ligands C(SiMe3)2(SiMe2H) and C(SiMe2Ph)2(SiMe2H)

“…Most compounds containing four-membered Al 2 O 2 rings crystallize with the anti configuration [37,44], presumably because it is the less crowded. However, there are reports in the literature that indicate that the difference in energy between the syn and anti forms may be small [41]. In some cases both isomers are present in the equilibrium mixture in solution and either may constitute the least soluble species and thus crystallize preferentially.…”

“…In both 8 and 9 the bonds from aluminium to the central carbon of the C(SiMe 2 Ph) 2 (SiMe 2 H) group are significantly longer than the Al-Me bonds, as is commonly found in compounds that contain bulky groups. The Al-C, Al-Cl and Al-O bond lengths are all in the usual range [41][42][43].…”

Crystal Structure of Methyl[4-(2-iminophenolate)-pentan-2-onato]gallium

“…The chemistry of organogallium complexes which contain either group 15 or group 16 elements has been under investigation for the last few decades due to their rich structural chemistry and possible applications as precursors of semiconductor materials 1 and as emitting materials in OEL display. 2 We recently synthesized the title compound 1 by using trimethylgallium reacting with 4-(2-hydroxylphenylimine)-pentan-2-one at room temperature.…”