Tris(2,6-diisopropylphenolato)titanium(IV) Dihydridodiorganylborates: Synthesis and Structures

• Published in: European Journal of Inorganic Chemistry 2011-04, Vol.2011 (12), p.1888-1900
• Main Authors: Knizek, Jörg, Nöth, Heinrich
• Format: Article
• Language: English
• Subjects: Agostic interactions; Borates; Boron; Structure elucidation; Titanium
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201001108

The reactions of tris(2,6‐diisopropylphenolato)titanium(IV) chloride with alkali‐metal dihydridodiorganylborates M(H2BR2) (M = Li, K; R = Me, C6H11, CMe3; BR2 = BC5H10, BC8H14) led to the corresponding titanium dihydridodiorganylborates. However, in almost all cases byproducts such as (2,6‐diisopropylphenolato)diorganylboranes, triorganylboranes, diorganylboranes, diborane and tetrakis(2,6‐diisopropylphenolato)titanium(IV) were also generated. (2,6‐iPr2C6H3O)3Ti(H2BR2) compounds also resulted from the interaction of methyltris(2,6‐diisopropylphenolato)titanium, for example, with catecholborane. In addition to the formation of tris(2,6‐diisopropylphenolato)catecholboratotitanium(IV), B‐methylcatecholborane was also formed The reaction of potassium dihydro‐9‐cyclooctylborate with 2,6‐bis(2,2‐di‐tert‐butyl‐2‐hydroxyethyl)pyridinetitanium dichloride (LTiCl2) led to the complex LTi(H2BC8H14)2. This compound showed no agostic C–H···Ti interaction in contrast to (2,6‐iPr2C6H3O)3TiH2BC8H14 and the corresponding titanium dihydridobis(cyclohexyl)borate. The reaction of (2,6‐iPr2C6H3O)3TiCl with M(H2BR2) borates not only yielded the hitherto unknown phenolatotitanium dihydridodiorganylborates but also a number of byproducts such as 2,6‐iPr2C6H3OBR2, BR3 and H3BTHF and more importantly the ester Ti(OC6H3iPr2)4. The compounds with dicyclohexyldihydrido‐9‐borato­cyclo­nonane substituents showed C‐agostic interactions.