Syntheses and X-ray crystal structures of lithium and chromium(II) complexes of the tri-t-butylmethoxide ligand

Abstract

The syntheses and X-ray crystal structures of Li and Cr" complexes of the tri-t-butylmethoxide ligand are described, these are [{Li (OCBut,) (thf))J and [Cr( OCBut,) .Lie1 (thf) 2] (thf = tetra hydrofuran) ; the latter compound has a rare distorted T-shaped geometry at chromium and when dissolved in n-hexane gives LiCl and a complex that analyses as [Cr(OCBut,),(thf),].

Synthesis and characterization of novel chelated dimethylamino lithium alkoxides: molecular structures of [1‐LiOC(C6H11)2‐2‐NMe2C6H4]2 and [1‐LiOCPh2CH2‐2‐NMe2C6H4]2

“…The pyramidal distortion of the environment of the lithium atoms in 5 and 6 and the outof-plane bending of the nitrogen atoms can be attributed to repulsion between the dimethylamino and cyclohexyl (5) or phenyl (6) groups. 4 The structure of the central core of 5 and 6 is similar to that of (1R, The bond lengths and angles of the organic fragments of 5 and 6 are similar to those observed for the corresponding organic compounds 2 and 3.…”

“…a THF-solvated dimer of lithium tert-butoxide. 4 Internal coordination by oxygen, 5 nitrogen, 6±13 phosphorus, 14,15 sulfur, 16 p-systems, 16±18 and cyclopropyl groups 19 have been identified in lithium alkoxides and show the diversity of the compounds. X-ray, NMR, and other techniques have confirmed a variety of different aggregate sizes of lithium alkoxides.…”

Some highlights from the development and use of bulky monodentate ligands

“…Schematic drawing of [(THF) 2 LiCl AE Cr(OCBu t 3 ) 2 ] illustrating the almost T-shaped coordination of Cr 2+[30].…”

[(Ph)2(NMe2)C(OLi)⋅THF]2: Crystal Structure of the Tetrahedral Intermediate Formed in the Reaction of N,N-Dimethylbenzamide and Phenyllithium

“…[6] In (CH 3 ) 3 CÀOLi a length of 139.2 pm has been determined for [11] a) G. Ashkenasy, C. E. Felder and A. Shanzer unpublished results; minimum-energy conformational studies, using EFF parameters, [11b] have the C À O bond. [7] In amides such as 8 the C O bond measures 123.1 pm, [8] and in aromatic ketones 123.0 pm. [8] The C1ÀN1 bond is 150.0(3) pm long, which corresponds to the value of 149 pm determined for the above-mentioned a-alkoxyamine.…”